* [for-next][PATCH 01/46] tracing: Move hist trigger Documentation to histogram.txt
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
@ 2018-03-21 2:20 ` Steven Rostedt
2018-03-21 2:20 ` [for-next][PATCH 02/46] tracing: Add Documentation for log2 modifier Steven Rostedt
` (44 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:20 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0001-tracing-Move-hist-trigger-Documentation-to-histogram.patch --]
[-- Type: text/plain, Size: 174387 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
The hist trigger Documentation takes up a large part of events.txt -
since it will be getting even larger, move it to a separate file.
Link: http://lkml.kernel.org/r/92761155ea4f529e590821b1e02207fe8619f248.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
Documentation/trace/events.txt | 1548 +-----------------------------------
Documentation/trace/histogram.txt | 1568 +++++++++++++++++++++++++++++++++++++
2 files changed, 1569 insertions(+), 1547 deletions(-)
create mode 100644 Documentation/trace/histogram.txt
diff --git a/Documentation/trace/events.txt b/Documentation/trace/events.txt
index 2cc08d4a326e..e28f7f29f2b3 100644
--- a/Documentation/trace/events.txt
+++ b/Documentation/trace/events.txt
@@ -517,1550 +517,4 @@ The following commands are supported:
totals derived from one or more trace event format fields and/or
event counts (hitcount).
- The format of a hist trigger is as follows:
-
- hist:keys=<field1[,field2,...]>[:values=<field1[,field2,...]>]
- [:sort=<field1[,field2,...]>][:size=#entries][:pause][:continue]
- [:clear][:name=histname1] [if <filter>]
-
- When a matching event is hit, an entry is added to a hash table
- using the key(s) and value(s) named. Keys and values correspond to
- fields in the event's format description. Values must correspond to
- numeric fields - on an event hit, the value(s) will be added to a
- sum kept for that field. The special string 'hitcount' can be used
- in place of an explicit value field - this is simply a count of
- event hits. If 'values' isn't specified, an implicit 'hitcount'
- value will be automatically created and used as the only value.
- Keys can be any field, or the special string 'stacktrace', which
- will use the event's kernel stacktrace as the key. The keywords
- 'keys' or 'key' can be used to specify keys, and the keywords
- 'values', 'vals', or 'val' can be used to specify values. Compound
- keys consisting of up to two fields can be specified by the 'keys'
- keyword. Hashing a compound key produces a unique entry in the
- table for each unique combination of component keys, and can be
- useful for providing more fine-grained summaries of event data.
- Additionally, sort keys consisting of up to two fields can be
- specified by the 'sort' keyword. If more than one field is
- specified, the result will be a 'sort within a sort': the first key
- is taken to be the primary sort key and the second the secondary
- key. If a hist trigger is given a name using the 'name' parameter,
- its histogram data will be shared with other triggers of the same
- name, and trigger hits will update this common data. Only triggers
- with 'compatible' fields can be combined in this way; triggers are
- 'compatible' if the fields named in the trigger share the same
- number and type of fields and those fields also have the same names.
- Note that any two events always share the compatible 'hitcount' and
- 'stacktrace' fields and can therefore be combined using those
- fields, however pointless that may be.
-
- 'hist' triggers add a 'hist' file to each event's subdirectory.
- Reading the 'hist' file for the event will dump the hash table in
- its entirety to stdout. If there are multiple hist triggers
- attached to an event, there will be a table for each trigger in the
- output. The table displayed for a named trigger will be the same as
- any other instance having the same name. Each printed hash table
- entry is a simple list of the keys and values comprising the entry;
- keys are printed first and are delineated by curly braces, and are
- followed by the set of value fields for the entry. By default,
- numeric fields are displayed as base-10 integers. This can be
- modified by appending any of the following modifiers to the field
- name:
-
- .hex display a number as a hex value
- .sym display an address as a symbol
- .sym-offset display an address as a symbol and offset
- .syscall display a syscall id as a system call name
- .execname display a common_pid as a program name
-
- Note that in general the semantics of a given field aren't
- interpreted when applying a modifier to it, but there are some
- restrictions to be aware of in this regard:
-
- - only the 'hex' modifier can be used for values (because values
- are essentially sums, and the other modifiers don't make sense
- in that context).
- - the 'execname' modifier can only be used on a 'common_pid'. The
- reason for this is that the execname is simply the 'comm' value
- saved for the 'current' process when an event was triggered,
- which is the same as the common_pid value saved by the event
- tracing code. Trying to apply that comm value to other pid
- values wouldn't be correct, and typically events that care save
- pid-specific comm fields in the event itself.
-
- A typical usage scenario would be the following to enable a hist
- trigger, read its current contents, and then turn it off:
-
- # echo 'hist:keys=skbaddr.hex:vals=len' > \
- /sys/kernel/debug/tracing/events/net/netif_rx/trigger
-
- # cat /sys/kernel/debug/tracing/events/net/netif_rx/hist
-
- # echo '!hist:keys=skbaddr.hex:vals=len' > \
- /sys/kernel/debug/tracing/events/net/netif_rx/trigger
-
- The trigger file itself can be read to show the details of the
- currently attached hist trigger. This information is also displayed
- at the top of the 'hist' file when read.
-
- By default, the size of the hash table is 2048 entries. The 'size'
- parameter can be used to specify more or fewer than that. The units
- are in terms of hashtable entries - if a run uses more entries than
- specified, the results will show the number of 'drops', the number
- of hits that were ignored. The size should be a power of 2 between
- 128 and 131072 (any non- power-of-2 number specified will be rounded
- up).
-
- The 'sort' parameter can be used to specify a value field to sort
- on. The default if unspecified is 'hitcount' and the default sort
- order is 'ascending'. To sort in the opposite direction, append
- .descending' to the sort key.
-
- The 'pause' parameter can be used to pause an existing hist trigger
- or to start a hist trigger but not log any events until told to do
- so. 'continue' or 'cont' can be used to start or restart a paused
- hist trigger.
-
- The 'clear' parameter will clear the contents of a running hist
- trigger and leave its current paused/active state.
-
- Note that the 'pause', 'cont', and 'clear' parameters should be
- applied using 'append' shell operator ('>>') if applied to an
- existing trigger, rather than via the '>' operator, which will cause
- the trigger to be removed through truncation.
-
-- enable_hist/disable_hist
-
- The enable_hist and disable_hist triggers can be used to have one
- event conditionally start and stop another event's already-attached
- hist trigger. Any number of enable_hist and disable_hist triggers
- can be attached to a given event, allowing that event to kick off
- and stop aggregations on a host of other events.
-
- The format is very similar to the enable/disable_event triggers:
-
- enable_hist:<system>:<event>[:count]
- disable_hist:<system>:<event>[:count]
-
- Instead of enabling or disabling the tracing of the target event
- into the trace buffer as the enable/disable_event triggers do, the
- enable/disable_hist triggers enable or disable the aggregation of
- the target event into a hash table.
-
- A typical usage scenario for the enable_hist/disable_hist triggers
- would be to first set up a paused hist trigger on some event,
- followed by an enable_hist/disable_hist pair that turns the hist
- aggregation on and off when conditions of interest are hit:
-
- # echo 'hist:keys=skbaddr.hex:vals=len:pause' > \
- /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
-
- # echo 'enable_hist:net:netif_receive_skb if filename==/usr/bin/wget' > \
- /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger
-
- # echo 'disable_hist:net:netif_receive_skb if comm==wget' > \
- /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger
-
- The above sets up an initially paused hist trigger which is unpaused
- and starts aggregating events when a given program is executed, and
- which stops aggregating when the process exits and the hist trigger
- is paused again.
-
- The examples below provide a more concrete illustration of the
- concepts and typical usage patterns discussed above.
-
-
-6.2 'hist' trigger examples
----------------------------
-
- The first set of examples creates aggregations using the kmalloc
- event. The fields that can be used for the hist trigger are listed
- in the kmalloc event's format file:
-
- # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/format
- name: kmalloc
- ID: 374
- format:
- field:unsigned short common_type; offset:0; size:2; signed:0;
- field:unsigned char common_flags; offset:2; size:1; signed:0;
- field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
- field:int common_pid; offset:4; size:4; signed:1;
-
- field:unsigned long call_site; offset:8; size:8; signed:0;
- field:const void * ptr; offset:16; size:8; signed:0;
- field:size_t bytes_req; offset:24; size:8; signed:0;
- field:size_t bytes_alloc; offset:32; size:8; signed:0;
- field:gfp_t gfp_flags; offset:40; size:4; signed:0;
-
- We'll start by creating a hist trigger that generates a simple table
- that lists the total number of bytes requested for each function in
- the kernel that made one or more calls to kmalloc:
-
- # echo 'hist:key=call_site:val=bytes_req' > \
- /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
-
- This tells the tracing system to create a 'hist' trigger using the
- call_site field of the kmalloc event as the key for the table, which
- just means that each unique call_site address will have an entry
- created for it in the table. The 'val=bytes_req' parameter tells
- the hist trigger that for each unique entry (call_site) in the
- table, it should keep a running total of the number of bytes
- requested by that call_site.
-
- We'll let it run for awhile and then dump the contents of the 'hist'
- file in the kmalloc event's subdirectory (for readability, a number
- of entries have been omitted):
-
- # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
- # trigger info: hist:keys=call_site:vals=bytes_req:sort=hitcount:size=2048 [active]
-
- { call_site: 18446744072106379007 } hitcount: 1 bytes_req: 176
- { call_site: 18446744071579557049 } hitcount: 1 bytes_req: 1024
- { call_site: 18446744071580608289 } hitcount: 1 bytes_req: 16384
- { call_site: 18446744071581827654 } hitcount: 1 bytes_req: 24
- { call_site: 18446744071580700980 } hitcount: 1 bytes_req: 8
- { call_site: 18446744071579359876 } hitcount: 1 bytes_req: 152
- { call_site: 18446744071580795365 } hitcount: 3 bytes_req: 144
- { call_site: 18446744071581303129 } hitcount: 3 bytes_req: 144
- { call_site: 18446744071580713234 } hitcount: 4 bytes_req: 2560
- { call_site: 18446744071580933750 } hitcount: 4 bytes_req: 736
- .
- .
- .
- { call_site: 18446744072106047046 } hitcount: 69 bytes_req: 5576
- { call_site: 18446744071582116407 } hitcount: 73 bytes_req: 2336
- { call_site: 18446744072106054684 } hitcount: 136 bytes_req: 140504
- { call_site: 18446744072106224230 } hitcount: 136 bytes_req: 19584
- { call_site: 18446744072106078074 } hitcount: 153 bytes_req: 2448
- { call_site: 18446744072106062406 } hitcount: 153 bytes_req: 36720
- { call_site: 18446744071582507929 } hitcount: 153 bytes_req: 37088
- { call_site: 18446744072102520590 } hitcount: 273 bytes_req: 10920
- { call_site: 18446744071582143559 } hitcount: 358 bytes_req: 716
- { call_site: 18446744072106465852 } hitcount: 417 bytes_req: 56712
- { call_site: 18446744072102523378 } hitcount: 485 bytes_req: 27160
- { call_site: 18446744072099568646 } hitcount: 1676 bytes_req: 33520
-
- Totals:
- Hits: 4610
- Entries: 45
- Dropped: 0
-
- The output displays a line for each entry, beginning with the key
- specified in the trigger, followed by the value(s) also specified in
- the trigger. At the beginning of the output is a line that displays
- the trigger info, which can also be displayed by reading the
- 'trigger' file:
-
- # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
- hist:keys=call_site:vals=bytes_req:sort=hitcount:size=2048 [active]
-
- At the end of the output are a few lines that display the overall
- totals for the run. The 'Hits' field shows the total number of
- times the event trigger was hit, the 'Entries' field shows the total
- number of used entries in the hash table, and the 'Dropped' field
- shows the number of hits that were dropped because the number of
- used entries for the run exceeded the maximum number of entries
- allowed for the table (normally 0, but if not a hint that you may
- want to increase the size of the table using the 'size' parameter).
-
- Notice in the above output that there's an extra field, 'hitcount',
- which wasn't specified in the trigger. Also notice that in the
- trigger info output, there's a parameter, 'sort=hitcount', which
- wasn't specified in the trigger either. The reason for that is that
- every trigger implicitly keeps a count of the total number of hits
- attributed to a given entry, called the 'hitcount'. That hitcount
- information is explicitly displayed in the output, and in the
- absence of a user-specified sort parameter, is used as the default
- sort field.
-
- The value 'hitcount' can be used in place of an explicit value in
- the 'values' parameter if you don't really need to have any
- particular field summed and are mainly interested in hit
- frequencies.
-
- To turn the hist trigger off, simply call up the trigger in the
- command history and re-execute it with a '!' prepended:
-
- # echo '!hist:key=call_site:val=bytes_req' > \
- /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
-
- Finally, notice that the call_site as displayed in the output above
- isn't really very useful. It's an address, but normally addresses
- are displayed in hex. To have a numeric field displayed as a hex
- value, simply append '.hex' to the field name in the trigger:
-
- # echo 'hist:key=call_site.hex:val=bytes_req' > \
- /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
-
- # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
- # trigger info: hist:keys=call_site.hex:vals=bytes_req:sort=hitcount:size=2048 [active]
-
- { call_site: ffffffffa026b291 } hitcount: 1 bytes_req: 433
- { call_site: ffffffffa07186ff } hitcount: 1 bytes_req: 176
- { call_site: ffffffff811ae721 } hitcount: 1 bytes_req: 16384
- { call_site: ffffffff811c5134 } hitcount: 1 bytes_req: 8
- { call_site: ffffffffa04a9ebb } hitcount: 1 bytes_req: 511
- { call_site: ffffffff8122e0a6 } hitcount: 1 bytes_req: 12
- { call_site: ffffffff8107da84 } hitcount: 1 bytes_req: 152
- { call_site: ffffffff812d8246 } hitcount: 1 bytes_req: 24
- { call_site: ffffffff811dc1e5 } hitcount: 3 bytes_req: 144
- { call_site: ffffffffa02515e8 } hitcount: 3 bytes_req: 648
- { call_site: ffffffff81258159 } hitcount: 3 bytes_req: 144
- { call_site: ffffffff811c80f4 } hitcount: 4 bytes_req: 544
- .
- .
- .
- { call_site: ffffffffa06c7646 } hitcount: 106 bytes_req: 8024
- { call_site: ffffffffa06cb246 } hitcount: 132 bytes_req: 31680
- { call_site: ffffffffa06cef7a } hitcount: 132 bytes_req: 2112
- { call_site: ffffffff8137e399 } hitcount: 132 bytes_req: 23232
- { call_site: ffffffffa06c941c } hitcount: 185 bytes_req: 171360
- { call_site: ffffffffa06f2a66 } hitcount: 185 bytes_req: 26640
- { call_site: ffffffffa036a70e } hitcount: 265 bytes_req: 10600
- { call_site: ffffffff81325447 } hitcount: 292 bytes_req: 584
- { call_site: ffffffffa072da3c } hitcount: 446 bytes_req: 60656
- { call_site: ffffffffa036b1f2 } hitcount: 526 bytes_req: 29456
- { call_site: ffffffffa0099c06 } hitcount: 1780 bytes_req: 35600
-
- Totals:
- Hits: 4775
- Entries: 46
- Dropped: 0
-
- Even that's only marginally more useful - while hex values do look
- more like addresses, what users are typically more interested in
- when looking at text addresses are the corresponding symbols
- instead. To have an address displayed as symbolic value instead,
- simply append '.sym' or '.sym-offset' to the field name in the
- trigger:
-
- # echo 'hist:key=call_site.sym:val=bytes_req' > \
- /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
-
- # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
- # trigger info: hist:keys=call_site.sym:vals=bytes_req:sort=hitcount:size=2048 [active]
-
- { call_site: [ffffffff810adcb9] syslog_print_all } hitcount: 1 bytes_req: 1024
- { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8
- { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7
- { call_site: [ffffffff8154acbe] usb_alloc_urb } hitcount: 1 bytes_req: 192
- { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7
- { call_site: [ffffffff811e3a25] __seq_open_private } hitcount: 1 bytes_req: 40
- { call_site: [ffffffff8109524a] alloc_fair_sched_group } hitcount: 2 bytes_req: 128
- { call_site: [ffffffff811febd5] fsnotify_alloc_group } hitcount: 2 bytes_req: 528
- { call_site: [ffffffff81440f58] __tty_buffer_request_room } hitcount: 2 bytes_req: 2624
- { call_site: [ffffffff81200ba6] inotify_new_group } hitcount: 2 bytes_req: 96
- { call_site: [ffffffffa05e19af] ieee80211_start_tx_ba_session [mac80211] } hitcount: 2 bytes_req: 464
- { call_site: [ffffffff81672406] tcp_get_metrics } hitcount: 2 bytes_req: 304
- { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128
- { call_site: [ffffffff81089b05] sched_create_group } hitcount: 2 bytes_req: 1424
- .
- .
- .
- { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 1185 bytes_req: 123240
- { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl [drm] } hitcount: 1185 bytes_req: 104280
- { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 1402 bytes_req: 190672
- { call_site: [ffffffff812891ca] ext4_find_extent } hitcount: 1518 bytes_req: 146208
- { call_site: [ffffffffa029070e] drm_vma_node_allow [drm] } hitcount: 1746 bytes_req: 69840
- { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 2021 bytes_req: 792312
- { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 2592 bytes_req: 145152
- { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 2629 bytes_req: 378576
- { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 2629 bytes_req: 3783248
- { call_site: [ffffffff81325607] apparmor_file_alloc_security } hitcount: 5192 bytes_req: 10384
- { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 5529 bytes_req: 110584
- { call_site: [ffffffff8131ebf7] aa_alloc_task_context } hitcount: 21943 bytes_req: 702176
- { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 55759 bytes_req: 5074265
-
- Totals:
- Hits: 109928
- Entries: 71
- Dropped: 0
-
- Because the default sort key above is 'hitcount', the above shows a
- the list of call_sites by increasing hitcount, so that at the bottom
- we see the functions that made the most kmalloc calls during the
- run. If instead we we wanted to see the top kmalloc callers in
- terms of the number of bytes requested rather than the number of
- calls, and we wanted the top caller to appear at the top, we can use
- the 'sort' parameter, along with the 'descending' modifier:
-
- # echo 'hist:key=call_site.sym:val=bytes_req:sort=bytes_req.descending' > \
- /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
-
- # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
- # trigger info: hist:keys=call_site.sym:vals=bytes_req:sort=bytes_req.descending:size=2048 [active]
-
- { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 2186 bytes_req: 3397464
- { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 1790 bytes_req: 712176
- { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 8132 bytes_req: 513135
- { call_site: [ffffffff811e2a1b] seq_buf_alloc } hitcount: 106 bytes_req: 440128
- { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 2186 bytes_req: 314784
- { call_site: [ffffffff812891ca] ext4_find_extent } hitcount: 2174 bytes_req: 208992
- { call_site: [ffffffff811ae8e1] __kmalloc } hitcount: 8 bytes_req: 131072
- { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 859 bytes_req: 116824
- { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 1834 bytes_req: 102704
- { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 972 bytes_req: 101088
- { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl [drm] } hitcount: 972 bytes_req: 85536
- { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 3333 bytes_req: 66664
- { call_site: [ffffffff8137e559] sg_kmalloc } hitcount: 209 bytes_req: 61632
- .
- .
- .
- { call_site: [ffffffff81095225] alloc_fair_sched_group } hitcount: 2 bytes_req: 128
- { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128
- { call_site: [ffffffff812d8406] copy_semundo } hitcount: 2 bytes_req: 48
- { call_site: [ffffffff81200ba6] inotify_new_group } hitcount: 1 bytes_req: 48
- { call_site: [ffffffffa027121a] drm_getmagic [drm] } hitcount: 1 bytes_req: 48
- { call_site: [ffffffff811e3a25] __seq_open_private } hitcount: 1 bytes_req: 40
- { call_site: [ffffffff811c52f4] bprm_change_interp } hitcount: 2 bytes_req: 16
- { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8
- { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7
- { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7
-
- Totals:
- Hits: 32133
- Entries: 81
- Dropped: 0
-
- To display the offset and size information in addition to the symbol
- name, just use 'sym-offset' instead:
-
- # echo 'hist:key=call_site.sym-offset:val=bytes_req:sort=bytes_req.descending' > \
- /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
-
- # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
- # trigger info: hist:keys=call_site.sym-offset:vals=bytes_req:sort=bytes_req.descending:size=2048 [active]
-
- { call_site: [ffffffffa046041c] i915_gem_execbuffer2+0x6c/0x2c0 [i915] } hitcount: 4569 bytes_req: 3163720
- { call_site: [ffffffffa0489a66] intel_ring_begin+0xc6/0x1f0 [i915] } hitcount: 4569 bytes_req: 657936
- { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23+0x694/0x1020 [i915] } hitcount: 1519 bytes_req: 472936
- { call_site: [ffffffffa045e646] i915_gem_do_execbuffer.isra.23+0x516/0x1020 [i915] } hitcount: 3050 bytes_req: 211832
- { call_site: [ffffffff811e2a1b] seq_buf_alloc+0x1b/0x50 } hitcount: 34 bytes_req: 148384
- { call_site: [ffffffffa04a580c] intel_crtc_page_flip+0xbc/0x870 [i915] } hitcount: 1385 bytes_req: 144040
- { call_site: [ffffffff811ae8e1] __kmalloc+0x191/0x1b0 } hitcount: 8 bytes_req: 131072
- { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl+0x282/0x360 [drm] } hitcount: 1385 bytes_req: 121880
- { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc+0x32/0x100 [drm] } hitcount: 1848 bytes_req: 103488
- { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state+0x2c/0xa0 [i915] } hitcount: 461 bytes_req: 62696
- { call_site: [ffffffffa029070e] drm_vma_node_allow+0x2e/0xd0 [drm] } hitcount: 1541 bytes_req: 61640
- { call_site: [ffffffff815f8d7b] sk_prot_alloc+0xcb/0x1b0 } hitcount: 57 bytes_req: 57456
- .
- .
- .
- { call_site: [ffffffff8109524a] alloc_fair_sched_group+0x5a/0x1a0 } hitcount: 2 bytes_req: 128
- { call_site: [ffffffffa027b921] drm_vm_open_locked+0x31/0xa0 [drm] } hitcount: 3 bytes_req: 96
- { call_site: [ffffffff8122e266] proc_self_follow_link+0x76/0xb0 } hitcount: 8 bytes_req: 96
- { call_site: [ffffffff81213e80] load_elf_binary+0x240/0x1650 } hitcount: 3 bytes_req: 84
- { call_site: [ffffffff8154bc62] usb_control_msg+0x42/0x110 } hitcount: 1 bytes_req: 8
- { call_site: [ffffffffa00bf6fe] hidraw_send_report+0x7e/0x1a0 [hid] } hitcount: 1 bytes_req: 7
- { call_site: [ffffffffa00bf1ca] hidraw_report_event+0x8a/0x120 [hid] } hitcount: 1 bytes_req: 7
-
- Totals:
- Hits: 26098
- Entries: 64
- Dropped: 0
-
- We can also add multiple fields to the 'values' parameter. For
- example, we might want to see the total number of bytes allocated
- alongside bytes requested, and display the result sorted by bytes
- allocated in a descending order:
-
- # echo 'hist:keys=call_site.sym:values=bytes_req,bytes_alloc:sort=bytes_alloc.descending' > \
- /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
-
- # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
- # trigger info: hist:keys=call_site.sym:vals=bytes_req,bytes_alloc:sort=bytes_alloc.descending:size=2048 [active]
-
- { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 7403 bytes_req: 4084360 bytes_alloc: 5958016
- { call_site: [ffffffff811e2a1b] seq_buf_alloc } hitcount: 541 bytes_req: 2213968 bytes_alloc: 2228224
- { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 7404 bytes_req: 1066176 bytes_alloc: 1421568
- { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 1565 bytes_req: 557368 bytes_alloc: 1037760
- { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 9557 bytes_req: 595778 bytes_alloc: 695744
- { call_site: [ffffffffa045e646] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 5839 bytes_req: 430680 bytes_alloc: 470400
- { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 2388 bytes_req: 324768 bytes_alloc: 458496
- { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 3911 bytes_req: 219016 bytes_alloc: 250304
- { call_site: [ffffffff815f8d7b] sk_prot_alloc } hitcount: 235 bytes_req: 236880 bytes_alloc: 240640
- { call_site: [ffffffff8137e559] sg_kmalloc } hitcount: 557 bytes_req: 169024 bytes_alloc: 221760
- { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 9378 bytes_req: 187548 bytes_alloc: 206312
- { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 1519 bytes_req: 157976 bytes_alloc: 194432
- .
- .
- .
- { call_site: [ffffffff8109bd3b] sched_autogroup_create_attach } hitcount: 2 bytes_req: 144 bytes_alloc: 192
- { call_site: [ffffffff81097ee8] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128
- { call_site: [ffffffff8109524a] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128
- { call_site: [ffffffff81095225] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128
- { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128
- { call_site: [ffffffff81213e80] load_elf_binary } hitcount: 3 bytes_req: 84 bytes_alloc: 96
- { call_site: [ffffffff81079a2e] kthread_create_on_node } hitcount: 1 bytes_req: 56 bytes_alloc: 64
- { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7 bytes_alloc: 8
- { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8 bytes_alloc: 8
- { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7 bytes_alloc: 8
-
- Totals:
- Hits: 66598
- Entries: 65
- Dropped: 0
-
- Finally, to finish off our kmalloc example, instead of simply having
- the hist trigger display symbolic call_sites, we can have the hist
- trigger additionally display the complete set of kernel stack traces
- that led to each call_site. To do that, we simply use the special
- value 'stacktrace' for the key parameter:
-
- # echo 'hist:keys=stacktrace:values=bytes_req,bytes_alloc:sort=bytes_alloc' > \
- /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
-
- The above trigger will use the kernel stack trace in effect when an
- event is triggered as the key for the hash table. This allows the
- enumeration of every kernel callpath that led up to a particular
- event, along with a running total of any of the event fields for
- that event. Here we tally bytes requested and bytes allocated for
- every callpath in the system that led up to a kmalloc (in this case
- every callpath to a kmalloc for a kernel compile):
-
- # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
- # trigger info: hist:keys=stacktrace:vals=bytes_req,bytes_alloc:sort=bytes_alloc:size=2048 [active]
-
- { stacktrace:
- __kmalloc_track_caller+0x10b/0x1a0
- kmemdup+0x20/0x50
- hidraw_report_event+0x8a/0x120 [hid]
- hid_report_raw_event+0x3ea/0x440 [hid]
- hid_input_report+0x112/0x190 [hid]
- hid_irq_in+0xc2/0x260 [usbhid]
- __usb_hcd_giveback_urb+0x72/0x120
- usb_giveback_urb_bh+0x9e/0xe0
- tasklet_hi_action+0xf8/0x100
- __do_softirq+0x114/0x2c0
- irq_exit+0xa5/0xb0
- do_IRQ+0x5a/0xf0
- ret_from_intr+0x0/0x30
- cpuidle_enter+0x17/0x20
- cpu_startup_entry+0x315/0x3e0
- rest_init+0x7c/0x80
- } hitcount: 3 bytes_req: 21 bytes_alloc: 24
- { stacktrace:
- __kmalloc_track_caller+0x10b/0x1a0
- kmemdup+0x20/0x50
- hidraw_report_event+0x8a/0x120 [hid]
- hid_report_raw_event+0x3ea/0x440 [hid]
- hid_input_report+0x112/0x190 [hid]
- hid_irq_in+0xc2/0x260 [usbhid]
- __usb_hcd_giveback_urb+0x72/0x120
- usb_giveback_urb_bh+0x9e/0xe0
- tasklet_hi_action+0xf8/0x100
- __do_softirq+0x114/0x2c0
- irq_exit+0xa5/0xb0
- do_IRQ+0x5a/0xf0
- ret_from_intr+0x0/0x30
- } hitcount: 3 bytes_req: 21 bytes_alloc: 24
- { stacktrace:
- kmem_cache_alloc_trace+0xeb/0x150
- aa_alloc_task_context+0x27/0x40
- apparmor_cred_prepare+0x1f/0x50
- security_prepare_creds+0x16/0x20
- prepare_creds+0xdf/0x1a0
- SyS_capset+0xb5/0x200
- system_call_fastpath+0x12/0x6a
- } hitcount: 1 bytes_req: 32 bytes_alloc: 32
- .
- .
- .
- { stacktrace:
- __kmalloc+0x11b/0x1b0
- i915_gem_execbuffer2+0x6c/0x2c0 [i915]
- drm_ioctl+0x349/0x670 [drm]
- do_vfs_ioctl+0x2f0/0x4f0
- SyS_ioctl+0x81/0xa0
- system_call_fastpath+0x12/0x6a
- } hitcount: 17726 bytes_req: 13944120 bytes_alloc: 19593808
- { stacktrace:
- __kmalloc+0x11b/0x1b0
- load_elf_phdrs+0x76/0xa0
- load_elf_binary+0x102/0x1650
- search_binary_handler+0x97/0x1d0
- do_execveat_common.isra.34+0x551/0x6e0
- SyS_execve+0x3a/0x50
- return_from_execve+0x0/0x23
- } hitcount: 33348 bytes_req: 17152128 bytes_alloc: 20226048
- { stacktrace:
- kmem_cache_alloc_trace+0xeb/0x150
- apparmor_file_alloc_security+0x27/0x40
- security_file_alloc+0x16/0x20
- get_empty_filp+0x93/0x1c0
- path_openat+0x31/0x5f0
- do_filp_open+0x3a/0x90
- do_sys_open+0x128/0x220
- SyS_open+0x1e/0x20
- system_call_fastpath+0x12/0x6a
- } hitcount: 4766422 bytes_req: 9532844 bytes_alloc: 38131376
- { stacktrace:
- __kmalloc+0x11b/0x1b0
- seq_buf_alloc+0x1b/0x50
- seq_read+0x2cc/0x370
- proc_reg_read+0x3d/0x80
- __vfs_read+0x28/0xe0
- vfs_read+0x86/0x140
- SyS_read+0x46/0xb0
- system_call_fastpath+0x12/0x6a
- } hitcount: 19133 bytes_req: 78368768 bytes_alloc: 78368768
-
- Totals:
- Hits: 6085872
- Entries: 253
- Dropped: 0
-
- If you key a hist trigger on common_pid, in order for example to
- gather and display sorted totals for each process, you can use the
- special .execname modifier to display the executable names for the
- processes in the table rather than raw pids. The example below
- keeps a per-process sum of total bytes read:
-
- # echo 'hist:key=common_pid.execname:val=count:sort=count.descending' > \
- /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/trigger
-
- # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/hist
- # trigger info: hist:keys=common_pid.execname:vals=count:sort=count.descending:size=2048 [active]
-
- { common_pid: gnome-terminal [ 3196] } hitcount: 280 count: 1093512
- { common_pid: Xorg [ 1309] } hitcount: 525 count: 256640
- { common_pid: compiz [ 2889] } hitcount: 59 count: 254400
- { common_pid: bash [ 8710] } hitcount: 3 count: 66369
- { common_pid: dbus-daemon-lau [ 8703] } hitcount: 49 count: 47739
- { common_pid: irqbalance [ 1252] } hitcount: 27 count: 27648
- { common_pid: 01ifupdown [ 8705] } hitcount: 3 count: 17216
- { common_pid: dbus-daemon [ 772] } hitcount: 10 count: 12396
- { common_pid: Socket Thread [ 8342] } hitcount: 11 count: 11264
- { common_pid: nm-dhcp-client. [ 8701] } hitcount: 6 count: 7424
- { common_pid: gmain [ 1315] } hitcount: 18 count: 6336
- .
- .
- .
- { common_pid: postgres [ 1892] } hitcount: 2 count: 32
- { common_pid: postgres [ 1891] } hitcount: 2 count: 32
- { common_pid: gmain [ 8704] } hitcount: 2 count: 32
- { common_pid: upstart-dbus-br [ 2740] } hitcount: 21 count: 21
- { common_pid: nm-dispatcher.a [ 8696] } hitcount: 1 count: 16
- { common_pid: indicator-datet [ 2904] } hitcount: 1 count: 16
- { common_pid: gdbus [ 2998] } hitcount: 1 count: 16
- { common_pid: rtkit-daemon [ 2052] } hitcount: 1 count: 8
- { common_pid: init [ 1] } hitcount: 2 count: 2
-
- Totals:
- Hits: 2116
- Entries: 51
- Dropped: 0
-
- Similarly, if you key a hist trigger on syscall id, for example to
- gather and display a list of systemwide syscall hits, you can use
- the special .syscall modifier to display the syscall names rather
- than raw ids. The example below keeps a running total of syscall
- counts for the system during the run:
-
- # echo 'hist:key=id.syscall:val=hitcount' > \
- /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger
-
- # cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist
- # trigger info: hist:keys=id.syscall:vals=hitcount:sort=hitcount:size=2048 [active]
-
- { id: sys_fsync [ 74] } hitcount: 1
- { id: sys_newuname [ 63] } hitcount: 1
- { id: sys_prctl [157] } hitcount: 1
- { id: sys_statfs [137] } hitcount: 1
- { id: sys_symlink [ 88] } hitcount: 1
- { id: sys_sendmmsg [307] } hitcount: 1
- { id: sys_semctl [ 66] } hitcount: 1
- { id: sys_readlink [ 89] } hitcount: 3
- { id: sys_bind [ 49] } hitcount: 3
- { id: sys_getsockname [ 51] } hitcount: 3
- { id: sys_unlink [ 87] } hitcount: 3
- { id: sys_rename [ 82] } hitcount: 4
- { id: unknown_syscall [ 58] } hitcount: 4
- { id: sys_connect [ 42] } hitcount: 4
- { id: sys_getpid [ 39] } hitcount: 4
- .
- .
- .
- { id: sys_rt_sigprocmask [ 14] } hitcount: 952
- { id: sys_futex [202] } hitcount: 1534
- { id: sys_write [ 1] } hitcount: 2689
- { id: sys_setitimer [ 38] } hitcount: 2797
- { id: sys_read [ 0] } hitcount: 3202
- { id: sys_select [ 23] } hitcount: 3773
- { id: sys_writev [ 20] } hitcount: 4531
- { id: sys_poll [ 7] } hitcount: 8314
- { id: sys_recvmsg [ 47] } hitcount: 13738
- { id: sys_ioctl [ 16] } hitcount: 21843
-
- Totals:
- Hits: 67612
- Entries: 72
- Dropped: 0
-
- The syscall counts above provide a rough overall picture of system
- call activity on the system; we can see for example that the most
- popular system call on this system was the 'sys_ioctl' system call.
-
- We can use 'compound' keys to refine that number and provide some
- further insight as to which processes exactly contribute to the
- overall ioctl count.
-
- The command below keeps a hitcount for every unique combination of
- system call id and pid - the end result is essentially a table
- that keeps a per-pid sum of system call hits. The results are
- sorted using the system call id as the primary key, and the
- hitcount sum as the secondary key:
-
- # echo 'hist:key=id.syscall,common_pid.execname:val=hitcount:sort=id,hitcount' > \
- /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger
-
- # cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist
- # trigger info: hist:keys=id.syscall,common_pid.execname:vals=hitcount:sort=id.syscall,hitcount:size=2048 [active]
-
- { id: sys_read [ 0], common_pid: rtkit-daemon [ 1877] } hitcount: 1
- { id: sys_read [ 0], common_pid: gdbus [ 2976] } hitcount: 1
- { id: sys_read [ 0], common_pid: console-kit-dae [ 3400] } hitcount: 1
- { id: sys_read [ 0], common_pid: postgres [ 1865] } hitcount: 1
- { id: sys_read [ 0], common_pid: deja-dup-monito [ 3543] } hitcount: 2
- { id: sys_read [ 0], common_pid: NetworkManager [ 890] } hitcount: 2
- { id: sys_read [ 0], common_pid: evolution-calen [ 3048] } hitcount: 2
- { id: sys_read [ 0], common_pid: postgres [ 1864] } hitcount: 2
- { id: sys_read [ 0], common_pid: nm-applet [ 3022] } hitcount: 2
- { id: sys_read [ 0], common_pid: whoopsie [ 1212] } hitcount: 2
- .
- .
- .
- { id: sys_ioctl [ 16], common_pid: bash [ 8479] } hitcount: 1
- { id: sys_ioctl [ 16], common_pid: bash [ 3472] } hitcount: 12
- { id: sys_ioctl [ 16], common_pid: gnome-terminal [ 3199] } hitcount: 16
- { id: sys_ioctl [ 16], common_pid: Xorg [ 1267] } hitcount: 1808
- { id: sys_ioctl [ 16], common_pid: compiz [ 2994] } hitcount: 5580
- .
- .
- .
- { id: sys_waitid [247], common_pid: upstart-dbus-br [ 2690] } hitcount: 3
- { id: sys_waitid [247], common_pid: upstart-dbus-br [ 2688] } hitcount: 16
- { id: sys_inotify_add_watch [254], common_pid: gmain [ 975] } hitcount: 2
- { id: sys_inotify_add_watch [254], common_pid: gmain [ 3204] } hitcount: 4
- { id: sys_inotify_add_watch [254], common_pid: gmain [ 2888] } hitcount: 4
- { id: sys_inotify_add_watch [254], common_pid: gmain [ 3003] } hitcount: 4
- { id: sys_inotify_add_watch [254], common_pid: gmain [ 2873] } hitcount: 4
- { id: sys_inotify_add_watch [254], common_pid: gmain [ 3196] } hitcount: 6
- { id: sys_openat [257], common_pid: java [ 2623] } hitcount: 2
- { id: sys_eventfd2 [290], common_pid: ibus-ui-gtk3 [ 2760] } hitcount: 4
- { id: sys_eventfd2 [290], common_pid: compiz [ 2994] } hitcount: 6
-
- Totals:
- Hits: 31536
- Entries: 323
- Dropped: 0
-
- The above list does give us a breakdown of the ioctl syscall by
- pid, but it also gives us quite a bit more than that, which we
- don't really care about at the moment. Since we know the syscall
- id for sys_ioctl (16, displayed next to the sys_ioctl name), we
- can use that to filter out all the other syscalls:
-
- # echo 'hist:key=id.syscall,common_pid.execname:val=hitcount:sort=id,hitcount if id == 16' > \
- /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger
-
- # cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist
- # trigger info: hist:keys=id.syscall,common_pid.execname:vals=hitcount:sort=id.syscall,hitcount:size=2048 if id == 16 [active]
-
- { id: sys_ioctl [ 16], common_pid: gmain [ 2769] } hitcount: 1
- { id: sys_ioctl [ 16], common_pid: evolution-addre [ 8571] } hitcount: 1
- { id: sys_ioctl [ 16], common_pid: gmain [ 3003] } hitcount: 1
- { id: sys_ioctl [ 16], common_pid: gmain [ 2781] } hitcount: 1
- { id: sys_ioctl [ 16], common_pid: gmain [ 2829] } hitcount: 1
- { id: sys_ioctl [ 16], common_pid: bash [ 8726] } hitcount: 1
- { id: sys_ioctl [ 16], common_pid: bash [ 8508] } hitcount: 1
- { id: sys_ioctl [ 16], common_pid: gmain [ 2970] } hitcount: 1
- { id: sys_ioctl [ 16], common_pid: gmain [ 2768] } hitcount: 1
- .
- .
- .
- { id: sys_ioctl [ 16], common_pid: pool [ 8559] } hitcount: 45
- { id: sys_ioctl [ 16], common_pid: pool [ 8555] } hitcount: 48
- { id: sys_ioctl [ 16], common_pid: pool [ 8551] } hitcount: 48
- { id: sys_ioctl [ 16], common_pid: avahi-daemon [ 896] } hitcount: 66
- { id: sys_ioctl [ 16], common_pid: Xorg [ 1267] } hitcount: 26674
- { id: sys_ioctl [ 16], common_pid: compiz [ 2994] } hitcount: 73443
-
- Totals:
- Hits: 101162
- Entries: 103
- Dropped: 0
-
- The above output shows that 'compiz' and 'Xorg' are far and away
- the heaviest ioctl callers (which might lead to questions about
- whether they really need to be making all those calls and to
- possible avenues for further investigation.)
-
- The compound key examples used a key and a sum value (hitcount) to
- sort the output, but we can just as easily use two keys instead.
- Here's an example where we use a compound key composed of the the
- common_pid and size event fields. Sorting with pid as the primary
- key and 'size' as the secondary key allows us to display an
- ordered summary of the recvfrom sizes, with counts, received by
- each process:
-
- # echo 'hist:key=common_pid.execname,size:val=hitcount:sort=common_pid,size' > \
- /sys/kernel/debug/tracing/events/syscalls/sys_enter_recvfrom/trigger
-
- # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_recvfrom/hist
- # trigger info: hist:keys=common_pid.execname,size:vals=hitcount:sort=common_pid.execname,size:size=2048 [active]
-
- { common_pid: smbd [ 784], size: 4 } hitcount: 1
- { common_pid: dnsmasq [ 1412], size: 4096 } hitcount: 672
- { common_pid: postgres [ 1796], size: 1000 } hitcount: 6
- { common_pid: postgres [ 1867], size: 1000 } hitcount: 10
- { common_pid: bamfdaemon [ 2787], size: 28 } hitcount: 2
- { common_pid: bamfdaemon [ 2787], size: 14360 } hitcount: 1
- { common_pid: compiz [ 2994], size: 8 } hitcount: 1
- { common_pid: compiz [ 2994], size: 20 } hitcount: 11
- { common_pid: gnome-terminal [ 3199], size: 4 } hitcount: 2
- { common_pid: firefox [ 8817], size: 4 } hitcount: 1
- { common_pid: firefox [ 8817], size: 8 } hitcount: 5
- { common_pid: firefox [ 8817], size: 588 } hitcount: 2
- { common_pid: firefox [ 8817], size: 628 } hitcount: 1
- { common_pid: firefox [ 8817], size: 6944 } hitcount: 1
- { common_pid: firefox [ 8817], size: 408880 } hitcount: 2
- { common_pid: firefox [ 8822], size: 8 } hitcount: 2
- { common_pid: firefox [ 8822], size: 160 } hitcount: 2
- { common_pid: firefox [ 8822], size: 320 } hitcount: 2
- { common_pid: firefox [ 8822], size: 352 } hitcount: 1
- .
- .
- .
- { common_pid: pool [ 8923], size: 1960 } hitcount: 10
- { common_pid: pool [ 8923], size: 2048 } hitcount: 10
- { common_pid: pool [ 8924], size: 1960 } hitcount: 10
- { common_pid: pool [ 8924], size: 2048 } hitcount: 10
- { common_pid: pool [ 8928], size: 1964 } hitcount: 4
- { common_pid: pool [ 8928], size: 1965 } hitcount: 2
- { common_pid: pool [ 8928], size: 2048 } hitcount: 6
- { common_pid: pool [ 8929], size: 1982 } hitcount: 1
- { common_pid: pool [ 8929], size: 2048 } hitcount: 1
-
- Totals:
- Hits: 2016
- Entries: 224
- Dropped: 0
-
- The above example also illustrates the fact that although a compound
- key is treated as a single entity for hashing purposes, the sub-keys
- it's composed of can be accessed independently.
-
- The next example uses a string field as the hash key and
- demonstrates how you can manually pause and continue a hist trigger.
- In this example, we'll aggregate fork counts and don't expect a
- large number of entries in the hash table, so we'll drop it to a
- much smaller number, say 256:
-
- # echo 'hist:key=child_comm:val=hitcount:size=256' > \
- /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger
-
- # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist
- # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [active]
-
- { child_comm: dconf worker } hitcount: 1
- { child_comm: ibus-daemon } hitcount: 1
- { child_comm: whoopsie } hitcount: 1
- { child_comm: smbd } hitcount: 1
- { child_comm: gdbus } hitcount: 1
- { child_comm: kthreadd } hitcount: 1
- { child_comm: dconf worker } hitcount: 1
- { child_comm: evolution-alarm } hitcount: 2
- { child_comm: Socket Thread } hitcount: 2
- { child_comm: postgres } hitcount: 2
- { child_comm: bash } hitcount: 3
- { child_comm: compiz } hitcount: 3
- { child_comm: evolution-sourc } hitcount: 4
- { child_comm: dhclient } hitcount: 4
- { child_comm: pool } hitcount: 5
- { child_comm: nm-dispatcher.a } hitcount: 8
- { child_comm: firefox } hitcount: 8
- { child_comm: dbus-daemon } hitcount: 8
- { child_comm: glib-pacrunner } hitcount: 10
- { child_comm: evolution } hitcount: 23
-
- Totals:
- Hits: 89
- Entries: 20
- Dropped: 0
-
- If we want to pause the hist trigger, we can simply append :pause to
- the command that started the trigger. Notice that the trigger info
- displays as [paused]:
-
- # echo 'hist:key=child_comm:val=hitcount:size=256:pause' >> \
- /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger
-
- # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist
- # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [paused]
-
- { child_comm: dconf worker } hitcount: 1
- { child_comm: kthreadd } hitcount: 1
- { child_comm: dconf worker } hitcount: 1
- { child_comm: gdbus } hitcount: 1
- { child_comm: ibus-daemon } hitcount: 1
- { child_comm: Socket Thread } hitcount: 2
- { child_comm: evolution-alarm } hitcount: 2
- { child_comm: smbd } hitcount: 2
- { child_comm: bash } hitcount: 3
- { child_comm: whoopsie } hitcount: 3
- { child_comm: compiz } hitcount: 3
- { child_comm: evolution-sourc } hitcount: 4
- { child_comm: pool } hitcount: 5
- { child_comm: postgres } hitcount: 6
- { child_comm: firefox } hitcount: 8
- { child_comm: dhclient } hitcount: 10
- { child_comm: emacs } hitcount: 12
- { child_comm: dbus-daemon } hitcount: 20
- { child_comm: nm-dispatcher.a } hitcount: 20
- { child_comm: evolution } hitcount: 35
- { child_comm: glib-pacrunner } hitcount: 59
-
- Totals:
- Hits: 199
- Entries: 21
- Dropped: 0
-
- To manually continue having the trigger aggregate events, append
- :cont instead. Notice that the trigger info displays as [active]
- again, and the data has changed:
-
- # echo 'hist:key=child_comm:val=hitcount:size=256:cont' >> \
- /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger
-
- # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist
- # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [active]
-
- { child_comm: dconf worker } hitcount: 1
- { child_comm: dconf worker } hitcount: 1
- { child_comm: kthreadd } hitcount: 1
- { child_comm: gdbus } hitcount: 1
- { child_comm: ibus-daemon } hitcount: 1
- { child_comm: Socket Thread } hitcount: 2
- { child_comm: evolution-alarm } hitcount: 2
- { child_comm: smbd } hitcount: 2
- { child_comm: whoopsie } hitcount: 3
- { child_comm: compiz } hitcount: 3
- { child_comm: evolution-sourc } hitcount: 4
- { child_comm: bash } hitcount: 5
- { child_comm: pool } hitcount: 5
- { child_comm: postgres } hitcount: 6
- { child_comm: firefox } hitcount: 8
- { child_comm: dhclient } hitcount: 11
- { child_comm: emacs } hitcount: 12
- { child_comm: dbus-daemon } hitcount: 22
- { child_comm: nm-dispatcher.a } hitcount: 22
- { child_comm: evolution } hitcount: 35
- { child_comm: glib-pacrunner } hitcount: 59
-
- Totals:
- Hits: 206
- Entries: 21
- Dropped: 0
-
- The previous example showed how to start and stop a hist trigger by
- appending 'pause' and 'continue' to the hist trigger command. A
- hist trigger can also be started in a paused state by initially
- starting the trigger with ':pause' appended. This allows you to
- start the trigger only when you're ready to start collecting data
- and not before. For example, you could start the trigger in a
- paused state, then unpause it and do something you want to measure,
- then pause the trigger again when done.
-
- Of course, doing this manually can be difficult and error-prone, but
- it is possible to automatically start and stop a hist trigger based
- on some condition, via the enable_hist and disable_hist triggers.
-
- For example, suppose we wanted to take a look at the relative
- weights in terms of skb length for each callpath that leads to a
- netif_receieve_skb event when downloading a decent-sized file using
- wget.
-
- First we set up an initially paused stacktrace trigger on the
- netif_receive_skb event:
-
- # echo 'hist:key=stacktrace:vals=len:pause' > \
- /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
-
- Next, we set up an 'enable_hist' trigger on the sched_process_exec
- event, with an 'if filename==/usr/bin/wget' filter. The effect of
- this new trigger is that it will 'unpause' the hist trigger we just
- set up on netif_receive_skb if and only if it sees a
- sched_process_exec event with a filename of '/usr/bin/wget'. When
- that happens, all netif_receive_skb events are aggregated into a
- hash table keyed on stacktrace:
-
- # echo 'enable_hist:net:netif_receive_skb if filename==/usr/bin/wget' > \
- /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger
-
- The aggregation continues until the netif_receive_skb is paused
- again, which is what the following disable_hist event does by
- creating a similar setup on the sched_process_exit event, using the
- filter 'comm==wget':
-
- # echo 'disable_hist:net:netif_receive_skb if comm==wget' > \
- /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger
-
- Whenever a process exits and the comm field of the disable_hist
- trigger filter matches 'comm==wget', the netif_receive_skb hist
- trigger is disabled.
-
- The overall effect is that netif_receive_skb events are aggregated
- into the hash table for only the duration of the wget. Executing a
- wget command and then listing the 'hist' file will display the
- output generated by the wget command:
-
- $ wget https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.19.xz
-
- # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist
- # trigger info: hist:keys=stacktrace:vals=len:sort=hitcount:size=2048 [paused]
-
- { stacktrace:
- __netif_receive_skb_core+0x46d/0x990
- __netif_receive_skb+0x18/0x60
- netif_receive_skb_internal+0x23/0x90
- napi_gro_receive+0xc8/0x100
- ieee80211_deliver_skb+0xd6/0x270 [mac80211]
- ieee80211_rx_handlers+0xccf/0x22f0 [mac80211]
- ieee80211_prepare_and_rx_handle+0x4e7/0xc40 [mac80211]
- ieee80211_rx+0x31d/0x900 [mac80211]
- iwlagn_rx_reply_rx+0x3db/0x6f0 [iwldvm]
- iwl_rx_dispatch+0x8e/0xf0 [iwldvm]
- iwl_pcie_irq_handler+0xe3c/0x12f0 [iwlwifi]
- irq_thread_fn+0x20/0x50
- irq_thread+0x11f/0x150
- kthread+0xd2/0xf0
- ret_from_fork+0x42/0x70
- } hitcount: 85 len: 28884
- { stacktrace:
- __netif_receive_skb_core+0x46d/0x990
- __netif_receive_skb+0x18/0x60
- netif_receive_skb_internal+0x23/0x90
- napi_gro_complete+0xa4/0xe0
- dev_gro_receive+0x23a/0x360
- napi_gro_receive+0x30/0x100
- ieee80211_deliver_skb+0xd6/0x270 [mac80211]
- ieee80211_rx_handlers+0xccf/0x22f0 [mac80211]
- ieee80211_prepare_and_rx_handle+0x4e7/0xc40 [mac80211]
- ieee80211_rx+0x31d/0x900 [mac80211]
- iwlagn_rx_reply_rx+0x3db/0x6f0 [iwldvm]
- iwl_rx_dispatch+0x8e/0xf0 [iwldvm]
- iwl_pcie_irq_handler+0xe3c/0x12f0 [iwlwifi]
- irq_thread_fn+0x20/0x50
- irq_thread+0x11f/0x150
- kthread+0xd2/0xf0
- } hitcount: 98 len: 664329
- { stacktrace:
- __netif_receive_skb_core+0x46d/0x990
- __netif_receive_skb+0x18/0x60
- process_backlog+0xa8/0x150
- net_rx_action+0x15d/0x340
- __do_softirq+0x114/0x2c0
- do_softirq_own_stack+0x1c/0x30
- do_softirq+0x65/0x70
- __local_bh_enable_ip+0xb5/0xc0
- ip_finish_output+0x1f4/0x840
- ip_output+0x6b/0xc0
- ip_local_out_sk+0x31/0x40
- ip_send_skb+0x1a/0x50
- udp_send_skb+0x173/0x2a0
- udp_sendmsg+0x2bf/0x9f0
- inet_sendmsg+0x64/0xa0
- sock_sendmsg+0x3d/0x50
- } hitcount: 115 len: 13030
- { stacktrace:
- __netif_receive_skb_core+0x46d/0x990
- __netif_receive_skb+0x18/0x60
- netif_receive_skb_internal+0x23/0x90
- napi_gro_complete+0xa4/0xe0
- napi_gro_flush+0x6d/0x90
- iwl_pcie_irq_handler+0x92a/0x12f0 [iwlwifi]
- irq_thread_fn+0x20/0x50
- irq_thread+0x11f/0x150
- kthread+0xd2/0xf0
- ret_from_fork+0x42/0x70
- } hitcount: 934 len: 5512212
-
- Totals:
- Hits: 1232
- Entries: 4
- Dropped: 0
-
- The above shows all the netif_receive_skb callpaths and their total
- lengths for the duration of the wget command.
-
- The 'clear' hist trigger param can be used to clear the hash table.
- Suppose we wanted to try another run of the previous example but
- this time also wanted to see the complete list of events that went
- into the histogram. In order to avoid having to set everything up
- again, we can just clear the histogram first:
-
- # echo 'hist:key=stacktrace:vals=len:clear' >> \
- /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
-
- Just to verify that it is in fact cleared, here's what we now see in
- the hist file:
-
- # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist
- # trigger info: hist:keys=stacktrace:vals=len:sort=hitcount:size=2048 [paused]
-
- Totals:
- Hits: 0
- Entries: 0
- Dropped: 0
-
- Since we want to see the detailed list of every netif_receive_skb
- event occurring during the new run, which are in fact the same
- events being aggregated into the hash table, we add some additional
- 'enable_event' events to the triggering sched_process_exec and
- sched_process_exit events as such:
-
- # echo 'enable_event:net:netif_receive_skb if filename==/usr/bin/wget' > \
- /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger
-
- # echo 'disable_event:net:netif_receive_skb if comm==wget' > \
- /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger
-
- If you read the trigger files for the sched_process_exec and
- sched_process_exit triggers, you should see two triggers for each:
- one enabling/disabling the hist aggregation and the other
- enabling/disabling the logging of events:
-
- # cat /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger
- enable_event:net:netif_receive_skb:unlimited if filename==/usr/bin/wget
- enable_hist:net:netif_receive_skb:unlimited if filename==/usr/bin/wget
-
- # cat /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger
- enable_event:net:netif_receive_skb:unlimited if comm==wget
- disable_hist:net:netif_receive_skb:unlimited if comm==wget
-
- In other words, whenever either of the sched_process_exec or
- sched_process_exit events is hit and matches 'wget', it enables or
- disables both the histogram and the event log, and what you end up
- with is a hash table and set of events just covering the specified
- duration. Run the wget command again:
-
- $ wget https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.19.xz
-
- Displaying the 'hist' file should show something similar to what you
- saw in the last run, but this time you should also see the
- individual events in the trace file:
-
- # cat /sys/kernel/debug/tracing/trace
-
- # tracer: nop
- #
- # entries-in-buffer/entries-written: 183/1426 #P:4
- #
- # _-----=> irqs-off
- # / _----=> need-resched
- # | / _---=> hardirq/softirq
- # || / _--=> preempt-depth
- # ||| / delay
- # TASK-PID CPU# |||| TIMESTAMP FUNCTION
- # | | | |||| | |
- wget-15108 [000] ..s1 31769.606929: netif_receive_skb: dev=lo skbaddr=ffff88009c353100 len=60
- wget-15108 [000] ..s1 31769.606999: netif_receive_skb: dev=lo skbaddr=ffff88009c353200 len=60
- dnsmasq-1382 [000] ..s1 31769.677652: netif_receive_skb: dev=lo skbaddr=ffff88009c352b00 len=130
- dnsmasq-1382 [000] ..s1 31769.685917: netif_receive_skb: dev=lo skbaddr=ffff88009c352200 len=138
- ##### CPU 2 buffer started ####
- irq/29-iwlwifi-559 [002] ..s. 31772.031529: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433d00 len=2948
- irq/29-iwlwifi-559 [002] ..s. 31772.031572: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d432200 len=1500
- irq/29-iwlwifi-559 [002] ..s. 31772.032196: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433100 len=2948
- irq/29-iwlwifi-559 [002] ..s. 31772.032761: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433000 len=2948
- irq/29-iwlwifi-559 [002] ..s. 31772.033220: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d432e00 len=1500
- .
- .
- .
-
- The following example demonstrates how multiple hist triggers can be
- attached to a given event. This capability can be useful for
- creating a set of different summaries derived from the same set of
- events, or for comparing the effects of different filters, among
- other things.
-
- # echo 'hist:keys=skbaddr.hex:vals=len if len < 0' >> \
- /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
- # echo 'hist:keys=skbaddr.hex:vals=len if len > 4096' >> \
- /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
- # echo 'hist:keys=skbaddr.hex:vals=len if len == 256' >> \
- /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
- # echo 'hist:keys=skbaddr.hex:vals=len' >> \
- /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
- # echo 'hist:keys=len:vals=common_preempt_count' >> \
- /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
-
- The above set of commands create four triggers differing only in
- their filters, along with a completely different though fairly
- nonsensical trigger. Note that in order to append multiple hist
- triggers to the same file, you should use the '>>' operator to
- append them ('>' will also add the new hist trigger, but will remove
- any existing hist triggers beforehand).
-
- Displaying the contents of the 'hist' file for the event shows the
- contents of all five histograms:
-
- # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist
-
- # event histogram
- #
- # trigger info: hist:keys=len:vals=hitcount,common_preempt_count:sort=hitcount:size=2048 [active]
- #
-
- { len: 176 } hitcount: 1 common_preempt_count: 0
- { len: 223 } hitcount: 1 common_preempt_count: 0
- { len: 4854 } hitcount: 1 common_preempt_count: 0
- { len: 395 } hitcount: 1 common_preempt_count: 0
- { len: 177 } hitcount: 1 common_preempt_count: 0
- { len: 446 } hitcount: 1 common_preempt_count: 0
- { len: 1601 } hitcount: 1 common_preempt_count: 0
- .
- .
- .
- { len: 1280 } hitcount: 66 common_preempt_count: 0
- { len: 116 } hitcount: 81 common_preempt_count: 40
- { len: 708 } hitcount: 112 common_preempt_count: 0
- { len: 46 } hitcount: 221 common_preempt_count: 0
- { len: 1264 } hitcount: 458 common_preempt_count: 0
-
- Totals:
- Hits: 1428
- Entries: 147
- Dropped: 0
-
-
- # event histogram
- #
- # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active]
- #
-
- { skbaddr: ffff8800baee5e00 } hitcount: 1 len: 130
- { skbaddr: ffff88005f3d5600 } hitcount: 1 len: 1280
- { skbaddr: ffff88005f3d4900 } hitcount: 1 len: 1280
- { skbaddr: ffff88009fed6300 } hitcount: 1 len: 115
- { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 115
- { skbaddr: ffff88008cdb1900 } hitcount: 1 len: 46
- { skbaddr: ffff880064b5ef00 } hitcount: 1 len: 118
- { skbaddr: ffff880044e3c700 } hitcount: 1 len: 60
- { skbaddr: ffff880100065900 } hitcount: 1 len: 46
- { skbaddr: ffff8800d46bd500 } hitcount: 1 len: 116
- { skbaddr: ffff88005f3d5f00 } hitcount: 1 len: 1280
- { skbaddr: ffff880100064700 } hitcount: 1 len: 365
- { skbaddr: ffff8800badb6f00 } hitcount: 1 len: 60
- .
- .
- .
- { skbaddr: ffff88009fe0be00 } hitcount: 27 len: 24677
- { skbaddr: ffff88009fe0a400 } hitcount: 27 len: 23052
- { skbaddr: ffff88009fe0b700 } hitcount: 31 len: 25589
- { skbaddr: ffff88009fe0b600 } hitcount: 32 len: 27326
- { skbaddr: ffff88006a462800 } hitcount: 68 len: 71678
- { skbaddr: ffff88006a463700 } hitcount: 70 len: 72678
- { skbaddr: ffff88006a462b00 } hitcount: 71 len: 77589
- { skbaddr: ffff88006a463600 } hitcount: 73 len: 71307
- { skbaddr: ffff88006a462200 } hitcount: 81 len: 81032
-
- Totals:
- Hits: 1451
- Entries: 318
- Dropped: 0
-
-
- # event histogram
- #
- # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len == 256 [active]
- #
-
-
- Totals:
- Hits: 0
- Entries: 0
- Dropped: 0
-
-
- # event histogram
- #
- # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len > 4096 [active]
- #
-
- { skbaddr: ffff88009fd2c300 } hitcount: 1 len: 7212
- { skbaddr: ffff8800d2bcce00 } hitcount: 1 len: 7212
- { skbaddr: ffff8800d2bcd700 } hitcount: 1 len: 7212
- { skbaddr: ffff8800d2bcda00 } hitcount: 1 len: 21492
- { skbaddr: ffff8800ae2e2d00 } hitcount: 1 len: 7212
- { skbaddr: ffff8800d2bcdb00 } hitcount: 1 len: 7212
- { skbaddr: ffff88006a4df500 } hitcount: 1 len: 4854
- { skbaddr: ffff88008ce47b00 } hitcount: 1 len: 18636
- { skbaddr: ffff8800ae2e2200 } hitcount: 1 len: 12924
- { skbaddr: ffff88005f3e1000 } hitcount: 1 len: 4356
- { skbaddr: ffff8800d2bcdc00 } hitcount: 2 len: 24420
- { skbaddr: ffff8800d2bcc200 } hitcount: 2 len: 12996
-
- Totals:
- Hits: 14
- Entries: 12
- Dropped: 0
-
-
- # event histogram
- #
- # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len < 0 [active]
- #
-
-
- Totals:
- Hits: 0
- Entries: 0
- Dropped: 0
-
- Named triggers can be used to have triggers share a common set of
- histogram data. This capability is mostly useful for combining the
- output of events generated by tracepoints contained inside inline
- functions, but names can be used in a hist trigger on any event.
- For example, these two triggers when hit will update the same 'len'
- field in the shared 'foo' histogram data:
-
- # echo 'hist:name=foo:keys=skbaddr.hex:vals=len' > \
- /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
- # echo 'hist:name=foo:keys=skbaddr.hex:vals=len' > \
- /sys/kernel/debug/tracing/events/net/netif_rx/trigger
-
- You can see that they're updating common histogram data by reading
- each event's hist files at the same time:
-
- # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist;
- cat /sys/kernel/debug/tracing/events/net/netif_rx/hist
-
- # event histogram
- #
- # trigger info: hist:name=foo:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active]
- #
-
- { skbaddr: ffff88000ad53500 } hitcount: 1 len: 46
- { skbaddr: ffff8800af5a1500 } hitcount: 1 len: 76
- { skbaddr: ffff8800d62a1900 } hitcount: 1 len: 46
- { skbaddr: ffff8800d2bccb00 } hitcount: 1 len: 468
- { skbaddr: ffff8800d3c69900 } hitcount: 1 len: 46
- { skbaddr: ffff88009ff09100 } hitcount: 1 len: 52
- { skbaddr: ffff88010f13ab00 } hitcount: 1 len: 168
- { skbaddr: ffff88006a54f400 } hitcount: 1 len: 46
- { skbaddr: ffff8800d2bcc500 } hitcount: 1 len: 260
- { skbaddr: ffff880064505000 } hitcount: 1 len: 46
- { skbaddr: ffff8800baf24e00 } hitcount: 1 len: 32
- { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 46
- { skbaddr: ffff8800d3edff00 } hitcount: 1 len: 44
- { skbaddr: ffff88009fe0b400 } hitcount: 1 len: 168
- { skbaddr: ffff8800a1c55a00 } hitcount: 1 len: 40
- { skbaddr: ffff8800d2bcd100 } hitcount: 1 len: 40
- { skbaddr: ffff880064505f00 } hitcount: 1 len: 174
- { skbaddr: ffff8800a8bff200 } hitcount: 1 len: 160
- { skbaddr: ffff880044e3cc00 } hitcount: 1 len: 76
- { skbaddr: ffff8800a8bfe700 } hitcount: 1 len: 46
- { skbaddr: ffff8800d2bcdc00 } hitcount: 1 len: 32
- { skbaddr: ffff8800a1f64800 } hitcount: 1 len: 46
- { skbaddr: ffff8800d2bcde00 } hitcount: 1 len: 988
- { skbaddr: ffff88006a5dea00 } hitcount: 1 len: 46
- { skbaddr: ffff88002e37a200 } hitcount: 1 len: 44
- { skbaddr: ffff8800a1f32c00 } hitcount: 2 len: 676
- { skbaddr: ffff88000ad52600 } hitcount: 2 len: 107
- { skbaddr: ffff8800a1f91e00 } hitcount: 2 len: 92
- { skbaddr: ffff8800af5a0200 } hitcount: 2 len: 142
- { skbaddr: ffff8800d2bcc600 } hitcount: 2 len: 220
- { skbaddr: ffff8800ba36f500 } hitcount: 2 len: 92
- { skbaddr: ffff8800d021f800 } hitcount: 2 len: 92
- { skbaddr: ffff8800a1f33600 } hitcount: 2 len: 675
- { skbaddr: ffff8800a8bfff00 } hitcount: 3 len: 138
- { skbaddr: ffff8800d62a1300 } hitcount: 3 len: 138
- { skbaddr: ffff88002e37a100 } hitcount: 4 len: 184
- { skbaddr: ffff880064504400 } hitcount: 4 len: 184
- { skbaddr: ffff8800a8bfec00 } hitcount: 4 len: 184
- { skbaddr: ffff88000ad53700 } hitcount: 5 len: 230
- { skbaddr: ffff8800d2bcdb00 } hitcount: 5 len: 196
- { skbaddr: ffff8800a1f90000 } hitcount: 6 len: 276
- { skbaddr: ffff88006a54f900 } hitcount: 6 len: 276
-
- Totals:
- Hits: 81
- Entries: 42
- Dropped: 0
- # event histogram
- #
- # trigger info: hist:name=foo:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active]
- #
-
- { skbaddr: ffff88000ad53500 } hitcount: 1 len: 46
- { skbaddr: ffff8800af5a1500 } hitcount: 1 len: 76
- { skbaddr: ffff8800d62a1900 } hitcount: 1 len: 46
- { skbaddr: ffff8800d2bccb00 } hitcount: 1 len: 468
- { skbaddr: ffff8800d3c69900 } hitcount: 1 len: 46
- { skbaddr: ffff88009ff09100 } hitcount: 1 len: 52
- { skbaddr: ffff88010f13ab00 } hitcount: 1 len: 168
- { skbaddr: ffff88006a54f400 } hitcount: 1 len: 46
- { skbaddr: ffff8800d2bcc500 } hitcount: 1 len: 260
- { skbaddr: ffff880064505000 } hitcount: 1 len: 46
- { skbaddr: ffff8800baf24e00 } hitcount: 1 len: 32
- { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 46
- { skbaddr: ffff8800d3edff00 } hitcount: 1 len: 44
- { skbaddr: ffff88009fe0b400 } hitcount: 1 len: 168
- { skbaddr: ffff8800a1c55a00 } hitcount: 1 len: 40
- { skbaddr: ffff8800d2bcd100 } hitcount: 1 len: 40
- { skbaddr: ffff880064505f00 } hitcount: 1 len: 174
- { skbaddr: ffff8800a8bff200 } hitcount: 1 len: 160
- { skbaddr: ffff880044e3cc00 } hitcount: 1 len: 76
- { skbaddr: ffff8800a8bfe700 } hitcount: 1 len: 46
- { skbaddr: ffff8800d2bcdc00 } hitcount: 1 len: 32
- { skbaddr: ffff8800a1f64800 } hitcount: 1 len: 46
- { skbaddr: ffff8800d2bcde00 } hitcount: 1 len: 988
- { skbaddr: ffff88006a5dea00 } hitcount: 1 len: 46
- { skbaddr: ffff88002e37a200 } hitcount: 1 len: 44
- { skbaddr: ffff8800a1f32c00 } hitcount: 2 len: 676
- { skbaddr: ffff88000ad52600 } hitcount: 2 len: 107
- { skbaddr: ffff8800a1f91e00 } hitcount: 2 len: 92
- { skbaddr: ffff8800af5a0200 } hitcount: 2 len: 142
- { skbaddr: ffff8800d2bcc600 } hitcount: 2 len: 220
- { skbaddr: ffff8800ba36f500 } hitcount: 2 len: 92
- { skbaddr: ffff8800d021f800 } hitcount: 2 len: 92
- { skbaddr: ffff8800a1f33600 } hitcount: 2 len: 675
- { skbaddr: ffff8800a8bfff00 } hitcount: 3 len: 138
- { skbaddr: ffff8800d62a1300 } hitcount: 3 len: 138
- { skbaddr: ffff88002e37a100 } hitcount: 4 len: 184
- { skbaddr: ffff880064504400 } hitcount: 4 len: 184
- { skbaddr: ffff8800a8bfec00 } hitcount: 4 len: 184
- { skbaddr: ffff88000ad53700 } hitcount: 5 len: 230
- { skbaddr: ffff8800d2bcdb00 } hitcount: 5 len: 196
- { skbaddr: ffff8800a1f90000 } hitcount: 6 len: 276
- { skbaddr: ffff88006a54f900 } hitcount: 6 len: 276
-
- Totals:
- Hits: 81
- Entries: 42
- Dropped: 0
-
- And here's an example that shows how to combine histogram data from
- any two events even if they don't share any 'compatible' fields
- other than 'hitcount' and 'stacktrace'. These commands create a
- couple of triggers named 'bar' using those fields:
-
- # echo 'hist:name=bar:key=stacktrace:val=hitcount' > \
- /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger
- # echo 'hist:name=bar:key=stacktrace:val=hitcount' > \
- /sys/kernel/debug/tracing/events/net/netif_rx/trigger
-
- And displaying the output of either shows some interesting if
- somewhat confusing output:
-
- # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist
- # cat /sys/kernel/debug/tracing/events/net/netif_rx/hist
-
- # event histogram
- #
- # trigger info: hist:name=bar:keys=stacktrace:vals=hitcount:sort=hitcount:size=2048 [active]
- #
-
- { stacktrace:
- _do_fork+0x18e/0x330
- kernel_thread+0x29/0x30
- kthreadd+0x154/0x1b0
- ret_from_fork+0x3f/0x70
- } hitcount: 1
- { stacktrace:
- netif_rx_internal+0xb2/0xd0
- netif_rx_ni+0x20/0x70
- dev_loopback_xmit+0xaa/0xd0
- ip_mc_output+0x126/0x240
- ip_local_out_sk+0x31/0x40
- igmp_send_report+0x1e9/0x230
- igmp_timer_expire+0xe9/0x120
- call_timer_fn+0x39/0xf0
- run_timer_softirq+0x1e1/0x290
- __do_softirq+0xfd/0x290
- irq_exit+0x98/0xb0
- smp_apic_timer_interrupt+0x4a/0x60
- apic_timer_interrupt+0x6d/0x80
- cpuidle_enter+0x17/0x20
- call_cpuidle+0x3b/0x60
- cpu_startup_entry+0x22d/0x310
- } hitcount: 1
- { stacktrace:
- netif_rx_internal+0xb2/0xd0
- netif_rx_ni+0x20/0x70
- dev_loopback_xmit+0xaa/0xd0
- ip_mc_output+0x17f/0x240
- ip_local_out_sk+0x31/0x40
- ip_send_skb+0x1a/0x50
- udp_send_skb+0x13e/0x270
- udp_sendmsg+0x2bf/0x980
- inet_sendmsg+0x67/0xa0
- sock_sendmsg+0x38/0x50
- SYSC_sendto+0xef/0x170
- SyS_sendto+0xe/0x10
- entry_SYSCALL_64_fastpath+0x12/0x6a
- } hitcount: 2
- { stacktrace:
- netif_rx_internal+0xb2/0xd0
- netif_rx+0x1c/0x60
- loopback_xmit+0x6c/0xb0
- dev_hard_start_xmit+0x219/0x3a0
- __dev_queue_xmit+0x415/0x4f0
- dev_queue_xmit_sk+0x13/0x20
- ip_finish_output2+0x237/0x340
- ip_finish_output+0x113/0x1d0
- ip_output+0x66/0xc0
- ip_local_out_sk+0x31/0x40
- ip_send_skb+0x1a/0x50
- udp_send_skb+0x16d/0x270
- udp_sendmsg+0x2bf/0x980
- inet_sendmsg+0x67/0xa0
- sock_sendmsg+0x38/0x50
- ___sys_sendmsg+0x14e/0x270
- } hitcount: 76
- { stacktrace:
- netif_rx_internal+0xb2/0xd0
- netif_rx+0x1c/0x60
- loopback_xmit+0x6c/0xb0
- dev_hard_start_xmit+0x219/0x3a0
- __dev_queue_xmit+0x415/0x4f0
- dev_queue_xmit_sk+0x13/0x20
- ip_finish_output2+0x237/0x340
- ip_finish_output+0x113/0x1d0
- ip_output+0x66/0xc0
- ip_local_out_sk+0x31/0x40
- ip_send_skb+0x1a/0x50
- udp_send_skb+0x16d/0x270
- udp_sendmsg+0x2bf/0x980
- inet_sendmsg+0x67/0xa0
- sock_sendmsg+0x38/0x50
- ___sys_sendmsg+0x269/0x270
- } hitcount: 77
- { stacktrace:
- netif_rx_internal+0xb2/0xd0
- netif_rx+0x1c/0x60
- loopback_xmit+0x6c/0xb0
- dev_hard_start_xmit+0x219/0x3a0
- __dev_queue_xmit+0x415/0x4f0
- dev_queue_xmit_sk+0x13/0x20
- ip_finish_output2+0x237/0x340
- ip_finish_output+0x113/0x1d0
- ip_output+0x66/0xc0
- ip_local_out_sk+0x31/0x40
- ip_send_skb+0x1a/0x50
- udp_send_skb+0x16d/0x270
- udp_sendmsg+0x2bf/0x980
- inet_sendmsg+0x67/0xa0
- sock_sendmsg+0x38/0x50
- SYSC_sendto+0xef/0x170
- } hitcount: 88
- { stacktrace:
- _do_fork+0x18e/0x330
- SyS_clone+0x19/0x20
- entry_SYSCALL_64_fastpath+0x12/0x6a
- } hitcount: 244
-
- Totals:
- Hits: 489
- Entries: 7
- Dropped: 0
+ See Documentation/trace/histogram.txt for details and examples.
diff --git a/Documentation/trace/histogram.txt b/Documentation/trace/histogram.txt
new file mode 100644
index 000000000000..b2145f44b190
--- /dev/null
+++ b/Documentation/trace/histogram.txt
@@ -0,0 +1,1568 @@
+ Event Histograms
+
+ Documentation written by Tom Zanussi
+
+1. Introduction
+===============
+
+ Histogram triggers are special event triggers that can be used to
+ aggregate trace event data into histograms. For information on
+ trace events and event triggers, see Documentation/trace/events.txt.
+
+
+2. Histogram Trigger Command
+============================
+
+ A histogram trigger command is an event trigger command that
+ aggregates event hits into a hash table keyed on one or more trace
+ event format fields (or stacktrace) and a set of running totals
+ derived from one or more trace event format fields and/or event
+ counts (hitcount).
+
+ The format of a hist trigger is as follows:
+
+ hist:keys=<field1[,field2,...]>[:values=<field1[,field2,...]>]
+ [:sort=<field1[,field2,...]>][:size=#entries][:pause][:continue]
+ [:clear][:name=histname1] [if <filter>]
+
+ When a matching event is hit, an entry is added to a hash table
+ using the key(s) and value(s) named. Keys and values correspond to
+ fields in the event's format description. Values must correspond to
+ numeric fields - on an event hit, the value(s) will be added to a
+ sum kept for that field. The special string 'hitcount' can be used
+ in place of an explicit value field - this is simply a count of
+ event hits. If 'values' isn't specified, an implicit 'hitcount'
+ value will be automatically created and used as the only value.
+ Keys can be any field, or the special string 'stacktrace', which
+ will use the event's kernel stacktrace as the key. The keywords
+ 'keys' or 'key' can be used to specify keys, and the keywords
+ 'values', 'vals', or 'val' can be used to specify values. Compound
+ keys consisting of up to two fields can be specified by the 'keys'
+ keyword. Hashing a compound key produces a unique entry in the
+ table for each unique combination of component keys, and can be
+ useful for providing more fine-grained summaries of event data.
+ Additionally, sort keys consisting of up to two fields can be
+ specified by the 'sort' keyword. If more than one field is
+ specified, the result will be a 'sort within a sort': the first key
+ is taken to be the primary sort key and the second the secondary
+ key. If a hist trigger is given a name using the 'name' parameter,
+ its histogram data will be shared with other triggers of the same
+ name, and trigger hits will update this common data. Only triggers
+ with 'compatible' fields can be combined in this way; triggers are
+ 'compatible' if the fields named in the trigger share the same
+ number and type of fields and those fields also have the same names.
+ Note that any two events always share the compatible 'hitcount' and
+ 'stacktrace' fields and can therefore be combined using those
+ fields, however pointless that may be.
+
+ 'hist' triggers add a 'hist' file to each event's subdirectory.
+ Reading the 'hist' file for the event will dump the hash table in
+ its entirety to stdout. If there are multiple hist triggers
+ attached to an event, there will be a table for each trigger in the
+ output. The table displayed for a named trigger will be the same as
+ any other instance having the same name. Each printed hash table
+ entry is a simple list of the keys and values comprising the entry;
+ keys are printed first and are delineated by curly braces, and are
+ followed by the set of value fields for the entry. By default,
+ numeric fields are displayed as base-10 integers. This can be
+ modified by appending any of the following modifiers to the field
+ name:
+
+ .hex display a number as a hex value
+ .sym display an address as a symbol
+ .sym-offset display an address as a symbol and offset
+ .syscall display a syscall id as a system call name
+ .execname display a common_pid as a program name
+
+ Note that in general the semantics of a given field aren't
+ interpreted when applying a modifier to it, but there are some
+ restrictions to be aware of in this regard:
+
+ - only the 'hex' modifier can be used for values (because values
+ are essentially sums, and the other modifiers don't make sense
+ in that context).
+ - the 'execname' modifier can only be used on a 'common_pid'. The
+ reason for this is that the execname is simply the 'comm' value
+ saved for the 'current' process when an event was triggered,
+ which is the same as the common_pid value saved by the event
+ tracing code. Trying to apply that comm value to other pid
+ values wouldn't be correct, and typically events that care save
+ pid-specific comm fields in the event itself.
+
+ A typical usage scenario would be the following to enable a hist
+ trigger, read its current contents, and then turn it off:
+
+ # echo 'hist:keys=skbaddr.hex:vals=len' > \
+ /sys/kernel/debug/tracing/events/net/netif_rx/trigger
+
+ # cat /sys/kernel/debug/tracing/events/net/netif_rx/hist
+
+ # echo '!hist:keys=skbaddr.hex:vals=len' > \
+ /sys/kernel/debug/tracing/events/net/netif_rx/trigger
+
+ The trigger file itself can be read to show the details of the
+ currently attached hist trigger. This information is also displayed
+ at the top of the 'hist' file when read.
+
+ By default, the size of the hash table is 2048 entries. The 'size'
+ parameter can be used to specify more or fewer than that. The units
+ are in terms of hashtable entries - if a run uses more entries than
+ specified, the results will show the number of 'drops', the number
+ of hits that were ignored. The size should be a power of 2 between
+ 128 and 131072 (any non- power-of-2 number specified will be rounded
+ up).
+
+ The 'sort' parameter can be used to specify a value field to sort
+ on. The default if unspecified is 'hitcount' and the default sort
+ order is 'ascending'. To sort in the opposite direction, append
+ .descending' to the sort key.
+
+ The 'pause' parameter can be used to pause an existing hist trigger
+ or to start a hist trigger but not log any events until told to do
+ so. 'continue' or 'cont' can be used to start or restart a paused
+ hist trigger.
+
+ The 'clear' parameter will clear the contents of a running hist
+ trigger and leave its current paused/active state.
+
+ Note that the 'pause', 'cont', and 'clear' parameters should be
+ applied using 'append' shell operator ('>>') if applied to an
+ existing trigger, rather than via the '>' operator, which will cause
+ the trigger to be removed through truncation.
+
+- enable_hist/disable_hist
+
+ The enable_hist and disable_hist triggers can be used to have one
+ event conditionally start and stop another event's already-attached
+ hist trigger. Any number of enable_hist and disable_hist triggers
+ can be attached to a given event, allowing that event to kick off
+ and stop aggregations on a host of other events.
+
+ The format is very similar to the enable/disable_event triggers:
+
+ enable_hist:<system>:<event>[:count]
+ disable_hist:<system>:<event>[:count]
+
+ Instead of enabling or disabling the tracing of the target event
+ into the trace buffer as the enable/disable_event triggers do, the
+ enable/disable_hist triggers enable or disable the aggregation of
+ the target event into a hash table.
+
+ A typical usage scenario for the enable_hist/disable_hist triggers
+ would be to first set up a paused hist trigger on some event,
+ followed by an enable_hist/disable_hist pair that turns the hist
+ aggregation on and off when conditions of interest are hit:
+
+ # echo 'hist:keys=skbaddr.hex:vals=len:pause' > \
+ /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
+
+ # echo 'enable_hist:net:netif_receive_skb if filename==/usr/bin/wget' > \
+ /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger
+
+ # echo 'disable_hist:net:netif_receive_skb if comm==wget' > \
+ /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger
+
+ The above sets up an initially paused hist trigger which is unpaused
+ and starts aggregating events when a given program is executed, and
+ which stops aggregating when the process exits and the hist trigger
+ is paused again.
+
+ The examples below provide a more concrete illustration of the
+ concepts and typical usage patterns discussed above.
+
+
+6.2 'hist' trigger examples
+---------------------------
+
+ The first set of examples creates aggregations using the kmalloc
+ event. The fields that can be used for the hist trigger are listed
+ in the kmalloc event's format file:
+
+ # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/format
+ name: kmalloc
+ ID: 374
+ format:
+ field:unsigned short common_type; offset:0; size:2; signed:0;
+ field:unsigned char common_flags; offset:2; size:1; signed:0;
+ field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
+ field:int common_pid; offset:4; size:4; signed:1;
+
+ field:unsigned long call_site; offset:8; size:8; signed:0;
+ field:const void * ptr; offset:16; size:8; signed:0;
+ field:size_t bytes_req; offset:24; size:8; signed:0;
+ field:size_t bytes_alloc; offset:32; size:8; signed:0;
+ field:gfp_t gfp_flags; offset:40; size:4; signed:0;
+
+ We'll start by creating a hist trigger that generates a simple table
+ that lists the total number of bytes requested for each function in
+ the kernel that made one or more calls to kmalloc:
+
+ # echo 'hist:key=call_site:val=bytes_req' > \
+ /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
+
+ This tells the tracing system to create a 'hist' trigger using the
+ call_site field of the kmalloc event as the key for the table, which
+ just means that each unique call_site address will have an entry
+ created for it in the table. The 'val=bytes_req' parameter tells
+ the hist trigger that for each unique entry (call_site) in the
+ table, it should keep a running total of the number of bytes
+ requested by that call_site.
+
+ We'll let it run for awhile and then dump the contents of the 'hist'
+ file in the kmalloc event's subdirectory (for readability, a number
+ of entries have been omitted):
+
+ # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
+ # trigger info: hist:keys=call_site:vals=bytes_req:sort=hitcount:size=2048 [active]
+
+ { call_site: 18446744072106379007 } hitcount: 1 bytes_req: 176
+ { call_site: 18446744071579557049 } hitcount: 1 bytes_req: 1024
+ { call_site: 18446744071580608289 } hitcount: 1 bytes_req: 16384
+ { call_site: 18446744071581827654 } hitcount: 1 bytes_req: 24
+ { call_site: 18446744071580700980 } hitcount: 1 bytes_req: 8
+ { call_site: 18446744071579359876 } hitcount: 1 bytes_req: 152
+ { call_site: 18446744071580795365 } hitcount: 3 bytes_req: 144
+ { call_site: 18446744071581303129 } hitcount: 3 bytes_req: 144
+ { call_site: 18446744071580713234 } hitcount: 4 bytes_req: 2560
+ { call_site: 18446744071580933750 } hitcount: 4 bytes_req: 736
+ .
+ .
+ .
+ { call_site: 18446744072106047046 } hitcount: 69 bytes_req: 5576
+ { call_site: 18446744071582116407 } hitcount: 73 bytes_req: 2336
+ { call_site: 18446744072106054684 } hitcount: 136 bytes_req: 140504
+ { call_site: 18446744072106224230 } hitcount: 136 bytes_req: 19584
+ { call_site: 18446744072106078074 } hitcount: 153 bytes_req: 2448
+ { call_site: 18446744072106062406 } hitcount: 153 bytes_req: 36720
+ { call_site: 18446744071582507929 } hitcount: 153 bytes_req: 37088
+ { call_site: 18446744072102520590 } hitcount: 273 bytes_req: 10920
+ { call_site: 18446744071582143559 } hitcount: 358 bytes_req: 716
+ { call_site: 18446744072106465852 } hitcount: 417 bytes_req: 56712
+ { call_site: 18446744072102523378 } hitcount: 485 bytes_req: 27160
+ { call_site: 18446744072099568646 } hitcount: 1676 bytes_req: 33520
+
+ Totals:
+ Hits: 4610
+ Entries: 45
+ Dropped: 0
+
+ The output displays a line for each entry, beginning with the key
+ specified in the trigger, followed by the value(s) also specified in
+ the trigger. At the beginning of the output is a line that displays
+ the trigger info, which can also be displayed by reading the
+ 'trigger' file:
+
+ # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
+ hist:keys=call_site:vals=bytes_req:sort=hitcount:size=2048 [active]
+
+ At the end of the output are a few lines that display the overall
+ totals for the run. The 'Hits' field shows the total number of
+ times the event trigger was hit, the 'Entries' field shows the total
+ number of used entries in the hash table, and the 'Dropped' field
+ shows the number of hits that were dropped because the number of
+ used entries for the run exceeded the maximum number of entries
+ allowed for the table (normally 0, but if not a hint that you may
+ want to increase the size of the table using the 'size' parameter).
+
+ Notice in the above output that there's an extra field, 'hitcount',
+ which wasn't specified in the trigger. Also notice that in the
+ trigger info output, there's a parameter, 'sort=hitcount', which
+ wasn't specified in the trigger either. The reason for that is that
+ every trigger implicitly keeps a count of the total number of hits
+ attributed to a given entry, called the 'hitcount'. That hitcount
+ information is explicitly displayed in the output, and in the
+ absence of a user-specified sort parameter, is used as the default
+ sort field.
+
+ The value 'hitcount' can be used in place of an explicit value in
+ the 'values' parameter if you don't really need to have any
+ particular field summed and are mainly interested in hit
+ frequencies.
+
+ To turn the hist trigger off, simply call up the trigger in the
+ command history and re-execute it with a '!' prepended:
+
+ # echo '!hist:key=call_site:val=bytes_req' > \
+ /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
+
+ Finally, notice that the call_site as displayed in the output above
+ isn't really very useful. It's an address, but normally addresses
+ are displayed in hex. To have a numeric field displayed as a hex
+ value, simply append '.hex' to the field name in the trigger:
+
+ # echo 'hist:key=call_site.hex:val=bytes_req' > \
+ /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
+
+ # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
+ # trigger info: hist:keys=call_site.hex:vals=bytes_req:sort=hitcount:size=2048 [active]
+
+ { call_site: ffffffffa026b291 } hitcount: 1 bytes_req: 433
+ { call_site: ffffffffa07186ff } hitcount: 1 bytes_req: 176
+ { call_site: ffffffff811ae721 } hitcount: 1 bytes_req: 16384
+ { call_site: ffffffff811c5134 } hitcount: 1 bytes_req: 8
+ { call_site: ffffffffa04a9ebb } hitcount: 1 bytes_req: 511
+ { call_site: ffffffff8122e0a6 } hitcount: 1 bytes_req: 12
+ { call_site: ffffffff8107da84 } hitcount: 1 bytes_req: 152
+ { call_site: ffffffff812d8246 } hitcount: 1 bytes_req: 24
+ { call_site: ffffffff811dc1e5 } hitcount: 3 bytes_req: 144
+ { call_site: ffffffffa02515e8 } hitcount: 3 bytes_req: 648
+ { call_site: ffffffff81258159 } hitcount: 3 bytes_req: 144
+ { call_site: ffffffff811c80f4 } hitcount: 4 bytes_req: 544
+ .
+ .
+ .
+ { call_site: ffffffffa06c7646 } hitcount: 106 bytes_req: 8024
+ { call_site: ffffffffa06cb246 } hitcount: 132 bytes_req: 31680
+ { call_site: ffffffffa06cef7a } hitcount: 132 bytes_req: 2112
+ { call_site: ffffffff8137e399 } hitcount: 132 bytes_req: 23232
+ { call_site: ffffffffa06c941c } hitcount: 185 bytes_req: 171360
+ { call_site: ffffffffa06f2a66 } hitcount: 185 bytes_req: 26640
+ { call_site: ffffffffa036a70e } hitcount: 265 bytes_req: 10600
+ { call_site: ffffffff81325447 } hitcount: 292 bytes_req: 584
+ { call_site: ffffffffa072da3c } hitcount: 446 bytes_req: 60656
+ { call_site: ffffffffa036b1f2 } hitcount: 526 bytes_req: 29456
+ { call_site: ffffffffa0099c06 } hitcount: 1780 bytes_req: 35600
+
+ Totals:
+ Hits: 4775
+ Entries: 46
+ Dropped: 0
+
+ Even that's only marginally more useful - while hex values do look
+ more like addresses, what users are typically more interested in
+ when looking at text addresses are the corresponding symbols
+ instead. To have an address displayed as symbolic value instead,
+ simply append '.sym' or '.sym-offset' to the field name in the
+ trigger:
+
+ # echo 'hist:key=call_site.sym:val=bytes_req' > \
+ /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
+
+ # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
+ # trigger info: hist:keys=call_site.sym:vals=bytes_req:sort=hitcount:size=2048 [active]
+
+ { call_site: [ffffffff810adcb9] syslog_print_all } hitcount: 1 bytes_req: 1024
+ { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8
+ { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7
+ { call_site: [ffffffff8154acbe] usb_alloc_urb } hitcount: 1 bytes_req: 192
+ { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7
+ { call_site: [ffffffff811e3a25] __seq_open_private } hitcount: 1 bytes_req: 40
+ { call_site: [ffffffff8109524a] alloc_fair_sched_group } hitcount: 2 bytes_req: 128
+ { call_site: [ffffffff811febd5] fsnotify_alloc_group } hitcount: 2 bytes_req: 528
+ { call_site: [ffffffff81440f58] __tty_buffer_request_room } hitcount: 2 bytes_req: 2624
+ { call_site: [ffffffff81200ba6] inotify_new_group } hitcount: 2 bytes_req: 96
+ { call_site: [ffffffffa05e19af] ieee80211_start_tx_ba_session [mac80211] } hitcount: 2 bytes_req: 464
+ { call_site: [ffffffff81672406] tcp_get_metrics } hitcount: 2 bytes_req: 304
+ { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128
+ { call_site: [ffffffff81089b05] sched_create_group } hitcount: 2 bytes_req: 1424
+ .
+ .
+ .
+ { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 1185 bytes_req: 123240
+ { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl [drm] } hitcount: 1185 bytes_req: 104280
+ { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 1402 bytes_req: 190672
+ { call_site: [ffffffff812891ca] ext4_find_extent } hitcount: 1518 bytes_req: 146208
+ { call_site: [ffffffffa029070e] drm_vma_node_allow [drm] } hitcount: 1746 bytes_req: 69840
+ { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 2021 bytes_req: 792312
+ { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 2592 bytes_req: 145152
+ { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 2629 bytes_req: 378576
+ { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 2629 bytes_req: 3783248
+ { call_site: [ffffffff81325607] apparmor_file_alloc_security } hitcount: 5192 bytes_req: 10384
+ { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 5529 bytes_req: 110584
+ { call_site: [ffffffff8131ebf7] aa_alloc_task_context } hitcount: 21943 bytes_req: 702176
+ { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 55759 bytes_req: 5074265
+
+ Totals:
+ Hits: 109928
+ Entries: 71
+ Dropped: 0
+
+ Because the default sort key above is 'hitcount', the above shows a
+ the list of call_sites by increasing hitcount, so that at the bottom
+ we see the functions that made the most kmalloc calls during the
+ run. If instead we we wanted to see the top kmalloc callers in
+ terms of the number of bytes requested rather than the number of
+ calls, and we wanted the top caller to appear at the top, we can use
+ the 'sort' parameter, along with the 'descending' modifier:
+
+ # echo 'hist:key=call_site.sym:val=bytes_req:sort=bytes_req.descending' > \
+ /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
+
+ # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
+ # trigger info: hist:keys=call_site.sym:vals=bytes_req:sort=bytes_req.descending:size=2048 [active]
+
+ { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 2186 bytes_req: 3397464
+ { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 1790 bytes_req: 712176
+ { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 8132 bytes_req: 513135
+ { call_site: [ffffffff811e2a1b] seq_buf_alloc } hitcount: 106 bytes_req: 440128
+ { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 2186 bytes_req: 314784
+ { call_site: [ffffffff812891ca] ext4_find_extent } hitcount: 2174 bytes_req: 208992
+ { call_site: [ffffffff811ae8e1] __kmalloc } hitcount: 8 bytes_req: 131072
+ { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 859 bytes_req: 116824
+ { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 1834 bytes_req: 102704
+ { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 972 bytes_req: 101088
+ { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl [drm] } hitcount: 972 bytes_req: 85536
+ { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 3333 bytes_req: 66664
+ { call_site: [ffffffff8137e559] sg_kmalloc } hitcount: 209 bytes_req: 61632
+ .
+ .
+ .
+ { call_site: [ffffffff81095225] alloc_fair_sched_group } hitcount: 2 bytes_req: 128
+ { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128
+ { call_site: [ffffffff812d8406] copy_semundo } hitcount: 2 bytes_req: 48
+ { call_site: [ffffffff81200ba6] inotify_new_group } hitcount: 1 bytes_req: 48
+ { call_site: [ffffffffa027121a] drm_getmagic [drm] } hitcount: 1 bytes_req: 48
+ { call_site: [ffffffff811e3a25] __seq_open_private } hitcount: 1 bytes_req: 40
+ { call_site: [ffffffff811c52f4] bprm_change_interp } hitcount: 2 bytes_req: 16
+ { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8
+ { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7
+ { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7
+
+ Totals:
+ Hits: 32133
+ Entries: 81
+ Dropped: 0
+
+ To display the offset and size information in addition to the symbol
+ name, just use 'sym-offset' instead:
+
+ # echo 'hist:key=call_site.sym-offset:val=bytes_req:sort=bytes_req.descending' > \
+ /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
+
+ # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
+ # trigger info: hist:keys=call_site.sym-offset:vals=bytes_req:sort=bytes_req.descending:size=2048 [active]
+
+ { call_site: [ffffffffa046041c] i915_gem_execbuffer2+0x6c/0x2c0 [i915] } hitcount: 4569 bytes_req: 3163720
+ { call_site: [ffffffffa0489a66] intel_ring_begin+0xc6/0x1f0 [i915] } hitcount: 4569 bytes_req: 657936
+ { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23+0x694/0x1020 [i915] } hitcount: 1519 bytes_req: 472936
+ { call_site: [ffffffffa045e646] i915_gem_do_execbuffer.isra.23+0x516/0x1020 [i915] } hitcount: 3050 bytes_req: 211832
+ { call_site: [ffffffff811e2a1b] seq_buf_alloc+0x1b/0x50 } hitcount: 34 bytes_req: 148384
+ { call_site: [ffffffffa04a580c] intel_crtc_page_flip+0xbc/0x870 [i915] } hitcount: 1385 bytes_req: 144040
+ { call_site: [ffffffff811ae8e1] __kmalloc+0x191/0x1b0 } hitcount: 8 bytes_req: 131072
+ { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl+0x282/0x360 [drm] } hitcount: 1385 bytes_req: 121880
+ { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc+0x32/0x100 [drm] } hitcount: 1848 bytes_req: 103488
+ { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state+0x2c/0xa0 [i915] } hitcount: 461 bytes_req: 62696
+ { call_site: [ffffffffa029070e] drm_vma_node_allow+0x2e/0xd0 [drm] } hitcount: 1541 bytes_req: 61640
+ { call_site: [ffffffff815f8d7b] sk_prot_alloc+0xcb/0x1b0 } hitcount: 57 bytes_req: 57456
+ .
+ .
+ .
+ { call_site: [ffffffff8109524a] alloc_fair_sched_group+0x5a/0x1a0 } hitcount: 2 bytes_req: 128
+ { call_site: [ffffffffa027b921] drm_vm_open_locked+0x31/0xa0 [drm] } hitcount: 3 bytes_req: 96
+ { call_site: [ffffffff8122e266] proc_self_follow_link+0x76/0xb0 } hitcount: 8 bytes_req: 96
+ { call_site: [ffffffff81213e80] load_elf_binary+0x240/0x1650 } hitcount: 3 bytes_req: 84
+ { call_site: [ffffffff8154bc62] usb_control_msg+0x42/0x110 } hitcount: 1 bytes_req: 8
+ { call_site: [ffffffffa00bf6fe] hidraw_send_report+0x7e/0x1a0 [hid] } hitcount: 1 bytes_req: 7
+ { call_site: [ffffffffa00bf1ca] hidraw_report_event+0x8a/0x120 [hid] } hitcount: 1 bytes_req: 7
+
+ Totals:
+ Hits: 26098
+ Entries: 64
+ Dropped: 0
+
+ We can also add multiple fields to the 'values' parameter. For
+ example, we might want to see the total number of bytes allocated
+ alongside bytes requested, and display the result sorted by bytes
+ allocated in a descending order:
+
+ # echo 'hist:keys=call_site.sym:values=bytes_req,bytes_alloc:sort=bytes_alloc.descending' > \
+ /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
+
+ # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
+ # trigger info: hist:keys=call_site.sym:vals=bytes_req,bytes_alloc:sort=bytes_alloc.descending:size=2048 [active]
+
+ { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 7403 bytes_req: 4084360 bytes_alloc: 5958016
+ { call_site: [ffffffff811e2a1b] seq_buf_alloc } hitcount: 541 bytes_req: 2213968 bytes_alloc: 2228224
+ { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 7404 bytes_req: 1066176 bytes_alloc: 1421568
+ { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 1565 bytes_req: 557368 bytes_alloc: 1037760
+ { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 9557 bytes_req: 595778 bytes_alloc: 695744
+ { call_site: [ffffffffa045e646] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 5839 bytes_req: 430680 bytes_alloc: 470400
+ { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 2388 bytes_req: 324768 bytes_alloc: 458496
+ { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 3911 bytes_req: 219016 bytes_alloc: 250304
+ { call_site: [ffffffff815f8d7b] sk_prot_alloc } hitcount: 235 bytes_req: 236880 bytes_alloc: 240640
+ { call_site: [ffffffff8137e559] sg_kmalloc } hitcount: 557 bytes_req: 169024 bytes_alloc: 221760
+ { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 9378 bytes_req: 187548 bytes_alloc: 206312
+ { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 1519 bytes_req: 157976 bytes_alloc: 194432
+ .
+ .
+ .
+ { call_site: [ffffffff8109bd3b] sched_autogroup_create_attach } hitcount: 2 bytes_req: 144 bytes_alloc: 192
+ { call_site: [ffffffff81097ee8] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128
+ { call_site: [ffffffff8109524a] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128
+ { call_site: [ffffffff81095225] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128
+ { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128
+ { call_site: [ffffffff81213e80] load_elf_binary } hitcount: 3 bytes_req: 84 bytes_alloc: 96
+ { call_site: [ffffffff81079a2e] kthread_create_on_node } hitcount: 1 bytes_req: 56 bytes_alloc: 64
+ { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7 bytes_alloc: 8
+ { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8 bytes_alloc: 8
+ { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7 bytes_alloc: 8
+
+ Totals:
+ Hits: 66598
+ Entries: 65
+ Dropped: 0
+
+ Finally, to finish off our kmalloc example, instead of simply having
+ the hist trigger display symbolic call_sites, we can have the hist
+ trigger additionally display the complete set of kernel stack traces
+ that led to each call_site. To do that, we simply use the special
+ value 'stacktrace' for the key parameter:
+
+ # echo 'hist:keys=stacktrace:values=bytes_req,bytes_alloc:sort=bytes_alloc' > \
+ /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger
+
+ The above trigger will use the kernel stack trace in effect when an
+ event is triggered as the key for the hash table. This allows the
+ enumeration of every kernel callpath that led up to a particular
+ event, along with a running total of any of the event fields for
+ that event. Here we tally bytes requested and bytes allocated for
+ every callpath in the system that led up to a kmalloc (in this case
+ every callpath to a kmalloc for a kernel compile):
+
+ # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist
+ # trigger info: hist:keys=stacktrace:vals=bytes_req,bytes_alloc:sort=bytes_alloc:size=2048 [active]
+
+ { stacktrace:
+ __kmalloc_track_caller+0x10b/0x1a0
+ kmemdup+0x20/0x50
+ hidraw_report_event+0x8a/0x120 [hid]
+ hid_report_raw_event+0x3ea/0x440 [hid]
+ hid_input_report+0x112/0x190 [hid]
+ hid_irq_in+0xc2/0x260 [usbhid]
+ __usb_hcd_giveback_urb+0x72/0x120
+ usb_giveback_urb_bh+0x9e/0xe0
+ tasklet_hi_action+0xf8/0x100
+ __do_softirq+0x114/0x2c0
+ irq_exit+0xa5/0xb0
+ do_IRQ+0x5a/0xf0
+ ret_from_intr+0x0/0x30
+ cpuidle_enter+0x17/0x20
+ cpu_startup_entry+0x315/0x3e0
+ rest_init+0x7c/0x80
+ } hitcount: 3 bytes_req: 21 bytes_alloc: 24
+ { stacktrace:
+ __kmalloc_track_caller+0x10b/0x1a0
+ kmemdup+0x20/0x50
+ hidraw_report_event+0x8a/0x120 [hid]
+ hid_report_raw_event+0x3ea/0x440 [hid]
+ hid_input_report+0x112/0x190 [hid]
+ hid_irq_in+0xc2/0x260 [usbhid]
+ __usb_hcd_giveback_urb+0x72/0x120
+ usb_giveback_urb_bh+0x9e/0xe0
+ tasklet_hi_action+0xf8/0x100
+ __do_softirq+0x114/0x2c0
+ irq_exit+0xa5/0xb0
+ do_IRQ+0x5a/0xf0
+ ret_from_intr+0x0/0x30
+ } hitcount: 3 bytes_req: 21 bytes_alloc: 24
+ { stacktrace:
+ kmem_cache_alloc_trace+0xeb/0x150
+ aa_alloc_task_context+0x27/0x40
+ apparmor_cred_prepare+0x1f/0x50
+ security_prepare_creds+0x16/0x20
+ prepare_creds+0xdf/0x1a0
+ SyS_capset+0xb5/0x200
+ system_call_fastpath+0x12/0x6a
+ } hitcount: 1 bytes_req: 32 bytes_alloc: 32
+ .
+ .
+ .
+ { stacktrace:
+ __kmalloc+0x11b/0x1b0
+ i915_gem_execbuffer2+0x6c/0x2c0 [i915]
+ drm_ioctl+0x349/0x670 [drm]
+ do_vfs_ioctl+0x2f0/0x4f0
+ SyS_ioctl+0x81/0xa0
+ system_call_fastpath+0x12/0x6a
+ } hitcount: 17726 bytes_req: 13944120 bytes_alloc: 19593808
+ { stacktrace:
+ __kmalloc+0x11b/0x1b0
+ load_elf_phdrs+0x76/0xa0
+ load_elf_binary+0x102/0x1650
+ search_binary_handler+0x97/0x1d0
+ do_execveat_common.isra.34+0x551/0x6e0
+ SyS_execve+0x3a/0x50
+ return_from_execve+0x0/0x23
+ } hitcount: 33348 bytes_req: 17152128 bytes_alloc: 20226048
+ { stacktrace:
+ kmem_cache_alloc_trace+0xeb/0x150
+ apparmor_file_alloc_security+0x27/0x40
+ security_file_alloc+0x16/0x20
+ get_empty_filp+0x93/0x1c0
+ path_openat+0x31/0x5f0
+ do_filp_open+0x3a/0x90
+ do_sys_open+0x128/0x220
+ SyS_open+0x1e/0x20
+ system_call_fastpath+0x12/0x6a
+ } hitcount: 4766422 bytes_req: 9532844 bytes_alloc: 38131376
+ { stacktrace:
+ __kmalloc+0x11b/0x1b0
+ seq_buf_alloc+0x1b/0x50
+ seq_read+0x2cc/0x370
+ proc_reg_read+0x3d/0x80
+ __vfs_read+0x28/0xe0
+ vfs_read+0x86/0x140
+ SyS_read+0x46/0xb0
+ system_call_fastpath+0x12/0x6a
+ } hitcount: 19133 bytes_req: 78368768 bytes_alloc: 78368768
+
+ Totals:
+ Hits: 6085872
+ Entries: 253
+ Dropped: 0
+
+ If you key a hist trigger on common_pid, in order for example to
+ gather and display sorted totals for each process, you can use the
+ special .execname modifier to display the executable names for the
+ processes in the table rather than raw pids. The example below
+ keeps a per-process sum of total bytes read:
+
+ # echo 'hist:key=common_pid.execname:val=count:sort=count.descending' > \
+ /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/trigger
+
+ # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/hist
+ # trigger info: hist:keys=common_pid.execname:vals=count:sort=count.descending:size=2048 [active]
+
+ { common_pid: gnome-terminal [ 3196] } hitcount: 280 count: 1093512
+ { common_pid: Xorg [ 1309] } hitcount: 525 count: 256640
+ { common_pid: compiz [ 2889] } hitcount: 59 count: 254400
+ { common_pid: bash [ 8710] } hitcount: 3 count: 66369
+ { common_pid: dbus-daemon-lau [ 8703] } hitcount: 49 count: 47739
+ { common_pid: irqbalance [ 1252] } hitcount: 27 count: 27648
+ { common_pid: 01ifupdown [ 8705] } hitcount: 3 count: 17216
+ { common_pid: dbus-daemon [ 772] } hitcount: 10 count: 12396
+ { common_pid: Socket Thread [ 8342] } hitcount: 11 count: 11264
+ { common_pid: nm-dhcp-client. [ 8701] } hitcount: 6 count: 7424
+ { common_pid: gmain [ 1315] } hitcount: 18 count: 6336
+ .
+ .
+ .
+ { common_pid: postgres [ 1892] } hitcount: 2 count: 32
+ { common_pid: postgres [ 1891] } hitcount: 2 count: 32
+ { common_pid: gmain [ 8704] } hitcount: 2 count: 32
+ { common_pid: upstart-dbus-br [ 2740] } hitcount: 21 count: 21
+ { common_pid: nm-dispatcher.a [ 8696] } hitcount: 1 count: 16
+ { common_pid: indicator-datet [ 2904] } hitcount: 1 count: 16
+ { common_pid: gdbus [ 2998] } hitcount: 1 count: 16
+ { common_pid: rtkit-daemon [ 2052] } hitcount: 1 count: 8
+ { common_pid: init [ 1] } hitcount: 2 count: 2
+
+ Totals:
+ Hits: 2116
+ Entries: 51
+ Dropped: 0
+
+ Similarly, if you key a hist trigger on syscall id, for example to
+ gather and display a list of systemwide syscall hits, you can use
+ the special .syscall modifier to display the syscall names rather
+ than raw ids. The example below keeps a running total of syscall
+ counts for the system during the run:
+
+ # echo 'hist:key=id.syscall:val=hitcount' > \
+ /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger
+
+ # cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist
+ # trigger info: hist:keys=id.syscall:vals=hitcount:sort=hitcount:size=2048 [active]
+
+ { id: sys_fsync [ 74] } hitcount: 1
+ { id: sys_newuname [ 63] } hitcount: 1
+ { id: sys_prctl [157] } hitcount: 1
+ { id: sys_statfs [137] } hitcount: 1
+ { id: sys_symlink [ 88] } hitcount: 1
+ { id: sys_sendmmsg [307] } hitcount: 1
+ { id: sys_semctl [ 66] } hitcount: 1
+ { id: sys_readlink [ 89] } hitcount: 3
+ { id: sys_bind [ 49] } hitcount: 3
+ { id: sys_getsockname [ 51] } hitcount: 3
+ { id: sys_unlink [ 87] } hitcount: 3
+ { id: sys_rename [ 82] } hitcount: 4
+ { id: unknown_syscall [ 58] } hitcount: 4
+ { id: sys_connect [ 42] } hitcount: 4
+ { id: sys_getpid [ 39] } hitcount: 4
+ .
+ .
+ .
+ { id: sys_rt_sigprocmask [ 14] } hitcount: 952
+ { id: sys_futex [202] } hitcount: 1534
+ { id: sys_write [ 1] } hitcount: 2689
+ { id: sys_setitimer [ 38] } hitcount: 2797
+ { id: sys_read [ 0] } hitcount: 3202
+ { id: sys_select [ 23] } hitcount: 3773
+ { id: sys_writev [ 20] } hitcount: 4531
+ { id: sys_poll [ 7] } hitcount: 8314
+ { id: sys_recvmsg [ 47] } hitcount: 13738
+ { id: sys_ioctl [ 16] } hitcount: 21843
+
+ Totals:
+ Hits: 67612
+ Entries: 72
+ Dropped: 0
+
+ The syscall counts above provide a rough overall picture of system
+ call activity on the system; we can see for example that the most
+ popular system call on this system was the 'sys_ioctl' system call.
+
+ We can use 'compound' keys to refine that number and provide some
+ further insight as to which processes exactly contribute to the
+ overall ioctl count.
+
+ The command below keeps a hitcount for every unique combination of
+ system call id and pid - the end result is essentially a table
+ that keeps a per-pid sum of system call hits. The results are
+ sorted using the system call id as the primary key, and the
+ hitcount sum as the secondary key:
+
+ # echo 'hist:key=id.syscall,common_pid.execname:val=hitcount:sort=id,hitcount' > \
+ /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger
+
+ # cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist
+ # trigger info: hist:keys=id.syscall,common_pid.execname:vals=hitcount:sort=id.syscall,hitcount:size=2048 [active]
+
+ { id: sys_read [ 0], common_pid: rtkit-daemon [ 1877] } hitcount: 1
+ { id: sys_read [ 0], common_pid: gdbus [ 2976] } hitcount: 1
+ { id: sys_read [ 0], common_pid: console-kit-dae [ 3400] } hitcount: 1
+ { id: sys_read [ 0], common_pid: postgres [ 1865] } hitcount: 1
+ { id: sys_read [ 0], common_pid: deja-dup-monito [ 3543] } hitcount: 2
+ { id: sys_read [ 0], common_pid: NetworkManager [ 890] } hitcount: 2
+ { id: sys_read [ 0], common_pid: evolution-calen [ 3048] } hitcount: 2
+ { id: sys_read [ 0], common_pid: postgres [ 1864] } hitcount: 2
+ { id: sys_read [ 0], common_pid: nm-applet [ 3022] } hitcount: 2
+ { id: sys_read [ 0], common_pid: whoopsie [ 1212] } hitcount: 2
+ .
+ .
+ .
+ { id: sys_ioctl [ 16], common_pid: bash [ 8479] } hitcount: 1
+ { id: sys_ioctl [ 16], common_pid: bash [ 3472] } hitcount: 12
+ { id: sys_ioctl [ 16], common_pid: gnome-terminal [ 3199] } hitcount: 16
+ { id: sys_ioctl [ 16], common_pid: Xorg [ 1267] } hitcount: 1808
+ { id: sys_ioctl [ 16], common_pid: compiz [ 2994] } hitcount: 5580
+ .
+ .
+ .
+ { id: sys_waitid [247], common_pid: upstart-dbus-br [ 2690] } hitcount: 3
+ { id: sys_waitid [247], common_pid: upstart-dbus-br [ 2688] } hitcount: 16
+ { id: sys_inotify_add_watch [254], common_pid: gmain [ 975] } hitcount: 2
+ { id: sys_inotify_add_watch [254], common_pid: gmain [ 3204] } hitcount: 4
+ { id: sys_inotify_add_watch [254], common_pid: gmain [ 2888] } hitcount: 4
+ { id: sys_inotify_add_watch [254], common_pid: gmain [ 3003] } hitcount: 4
+ { id: sys_inotify_add_watch [254], common_pid: gmain [ 2873] } hitcount: 4
+ { id: sys_inotify_add_watch [254], common_pid: gmain [ 3196] } hitcount: 6
+ { id: sys_openat [257], common_pid: java [ 2623] } hitcount: 2
+ { id: sys_eventfd2 [290], common_pid: ibus-ui-gtk3 [ 2760] } hitcount: 4
+ { id: sys_eventfd2 [290], common_pid: compiz [ 2994] } hitcount: 6
+
+ Totals:
+ Hits: 31536
+ Entries: 323
+ Dropped: 0
+
+ The above list does give us a breakdown of the ioctl syscall by
+ pid, but it also gives us quite a bit more than that, which we
+ don't really care about at the moment. Since we know the syscall
+ id for sys_ioctl (16, displayed next to the sys_ioctl name), we
+ can use that to filter out all the other syscalls:
+
+ # echo 'hist:key=id.syscall,common_pid.execname:val=hitcount:sort=id,hitcount if id == 16' > \
+ /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger
+
+ # cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist
+ # trigger info: hist:keys=id.syscall,common_pid.execname:vals=hitcount:sort=id.syscall,hitcount:size=2048 if id == 16 [active]
+
+ { id: sys_ioctl [ 16], common_pid: gmain [ 2769] } hitcount: 1
+ { id: sys_ioctl [ 16], common_pid: evolution-addre [ 8571] } hitcount: 1
+ { id: sys_ioctl [ 16], common_pid: gmain [ 3003] } hitcount: 1
+ { id: sys_ioctl [ 16], common_pid: gmain [ 2781] } hitcount: 1
+ { id: sys_ioctl [ 16], common_pid: gmain [ 2829] } hitcount: 1
+ { id: sys_ioctl [ 16], common_pid: bash [ 8726] } hitcount: 1
+ { id: sys_ioctl [ 16], common_pid: bash [ 8508] } hitcount: 1
+ { id: sys_ioctl [ 16], common_pid: gmain [ 2970] } hitcount: 1
+ { id: sys_ioctl [ 16], common_pid: gmain [ 2768] } hitcount: 1
+ .
+ .
+ .
+ { id: sys_ioctl [ 16], common_pid: pool [ 8559] } hitcount: 45
+ { id: sys_ioctl [ 16], common_pid: pool [ 8555] } hitcount: 48
+ { id: sys_ioctl [ 16], common_pid: pool [ 8551] } hitcount: 48
+ { id: sys_ioctl [ 16], common_pid: avahi-daemon [ 896] } hitcount: 66
+ { id: sys_ioctl [ 16], common_pid: Xorg [ 1267] } hitcount: 26674
+ { id: sys_ioctl [ 16], common_pid: compiz [ 2994] } hitcount: 73443
+
+ Totals:
+ Hits: 101162
+ Entries: 103
+ Dropped: 0
+
+ The above output shows that 'compiz' and 'Xorg' are far and away
+ the heaviest ioctl callers (which might lead to questions about
+ whether they really need to be making all those calls and to
+ possible avenues for further investigation.)
+
+ The compound key examples used a key and a sum value (hitcount) to
+ sort the output, but we can just as easily use two keys instead.
+ Here's an example where we use a compound key composed of the the
+ common_pid and size event fields. Sorting with pid as the primary
+ key and 'size' as the secondary key allows us to display an
+ ordered summary of the recvfrom sizes, with counts, received by
+ each process:
+
+ # echo 'hist:key=common_pid.execname,size:val=hitcount:sort=common_pid,size' > \
+ /sys/kernel/debug/tracing/events/syscalls/sys_enter_recvfrom/trigger
+
+ # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_recvfrom/hist
+ # trigger info: hist:keys=common_pid.execname,size:vals=hitcount:sort=common_pid.execname,size:size=2048 [active]
+
+ { common_pid: smbd [ 784], size: 4 } hitcount: 1
+ { common_pid: dnsmasq [ 1412], size: 4096 } hitcount: 672
+ { common_pid: postgres [ 1796], size: 1000 } hitcount: 6
+ { common_pid: postgres [ 1867], size: 1000 } hitcount: 10
+ { common_pid: bamfdaemon [ 2787], size: 28 } hitcount: 2
+ { common_pid: bamfdaemon [ 2787], size: 14360 } hitcount: 1
+ { common_pid: compiz [ 2994], size: 8 } hitcount: 1
+ { common_pid: compiz [ 2994], size: 20 } hitcount: 11
+ { common_pid: gnome-terminal [ 3199], size: 4 } hitcount: 2
+ { common_pid: firefox [ 8817], size: 4 } hitcount: 1
+ { common_pid: firefox [ 8817], size: 8 } hitcount: 5
+ { common_pid: firefox [ 8817], size: 588 } hitcount: 2
+ { common_pid: firefox [ 8817], size: 628 } hitcount: 1
+ { common_pid: firefox [ 8817], size: 6944 } hitcount: 1
+ { common_pid: firefox [ 8817], size: 408880 } hitcount: 2
+ { common_pid: firefox [ 8822], size: 8 } hitcount: 2
+ { common_pid: firefox [ 8822], size: 160 } hitcount: 2
+ { common_pid: firefox [ 8822], size: 320 } hitcount: 2
+ { common_pid: firefox [ 8822], size: 352 } hitcount: 1
+ .
+ .
+ .
+ { common_pid: pool [ 8923], size: 1960 } hitcount: 10
+ { common_pid: pool [ 8923], size: 2048 } hitcount: 10
+ { common_pid: pool [ 8924], size: 1960 } hitcount: 10
+ { common_pid: pool [ 8924], size: 2048 } hitcount: 10
+ { common_pid: pool [ 8928], size: 1964 } hitcount: 4
+ { common_pid: pool [ 8928], size: 1965 } hitcount: 2
+ { common_pid: pool [ 8928], size: 2048 } hitcount: 6
+ { common_pid: pool [ 8929], size: 1982 } hitcount: 1
+ { common_pid: pool [ 8929], size: 2048 } hitcount: 1
+
+ Totals:
+ Hits: 2016
+ Entries: 224
+ Dropped: 0
+
+ The above example also illustrates the fact that although a compound
+ key is treated as a single entity for hashing purposes, the sub-keys
+ it's composed of can be accessed independently.
+
+ The next example uses a string field as the hash key and
+ demonstrates how you can manually pause and continue a hist trigger.
+ In this example, we'll aggregate fork counts and don't expect a
+ large number of entries in the hash table, so we'll drop it to a
+ much smaller number, say 256:
+
+ # echo 'hist:key=child_comm:val=hitcount:size=256' > \
+ /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger
+
+ # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist
+ # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [active]
+
+ { child_comm: dconf worker } hitcount: 1
+ { child_comm: ibus-daemon } hitcount: 1
+ { child_comm: whoopsie } hitcount: 1
+ { child_comm: smbd } hitcount: 1
+ { child_comm: gdbus } hitcount: 1
+ { child_comm: kthreadd } hitcount: 1
+ { child_comm: dconf worker } hitcount: 1
+ { child_comm: evolution-alarm } hitcount: 2
+ { child_comm: Socket Thread } hitcount: 2
+ { child_comm: postgres } hitcount: 2
+ { child_comm: bash } hitcount: 3
+ { child_comm: compiz } hitcount: 3
+ { child_comm: evolution-sourc } hitcount: 4
+ { child_comm: dhclient } hitcount: 4
+ { child_comm: pool } hitcount: 5
+ { child_comm: nm-dispatcher.a } hitcount: 8
+ { child_comm: firefox } hitcount: 8
+ { child_comm: dbus-daemon } hitcount: 8
+ { child_comm: glib-pacrunner } hitcount: 10
+ { child_comm: evolution } hitcount: 23
+
+ Totals:
+ Hits: 89
+ Entries: 20
+ Dropped: 0
+
+ If we want to pause the hist trigger, we can simply append :pause to
+ the command that started the trigger. Notice that the trigger info
+ displays as [paused]:
+
+ # echo 'hist:key=child_comm:val=hitcount:size=256:pause' >> \
+ /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger
+
+ # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist
+ # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [paused]
+
+ { child_comm: dconf worker } hitcount: 1
+ { child_comm: kthreadd } hitcount: 1
+ { child_comm: dconf worker } hitcount: 1
+ { child_comm: gdbus } hitcount: 1
+ { child_comm: ibus-daemon } hitcount: 1
+ { child_comm: Socket Thread } hitcount: 2
+ { child_comm: evolution-alarm } hitcount: 2
+ { child_comm: smbd } hitcount: 2
+ { child_comm: bash } hitcount: 3
+ { child_comm: whoopsie } hitcount: 3
+ { child_comm: compiz } hitcount: 3
+ { child_comm: evolution-sourc } hitcount: 4
+ { child_comm: pool } hitcount: 5
+ { child_comm: postgres } hitcount: 6
+ { child_comm: firefox } hitcount: 8
+ { child_comm: dhclient } hitcount: 10
+ { child_comm: emacs } hitcount: 12
+ { child_comm: dbus-daemon } hitcount: 20
+ { child_comm: nm-dispatcher.a } hitcount: 20
+ { child_comm: evolution } hitcount: 35
+ { child_comm: glib-pacrunner } hitcount: 59
+
+ Totals:
+ Hits: 199
+ Entries: 21
+ Dropped: 0
+
+ To manually continue having the trigger aggregate events, append
+ :cont instead. Notice that the trigger info displays as [active]
+ again, and the data has changed:
+
+ # echo 'hist:key=child_comm:val=hitcount:size=256:cont' >> \
+ /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger
+
+ # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist
+ # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [active]
+
+ { child_comm: dconf worker } hitcount: 1
+ { child_comm: dconf worker } hitcount: 1
+ { child_comm: kthreadd } hitcount: 1
+ { child_comm: gdbus } hitcount: 1
+ { child_comm: ibus-daemon } hitcount: 1
+ { child_comm: Socket Thread } hitcount: 2
+ { child_comm: evolution-alarm } hitcount: 2
+ { child_comm: smbd } hitcount: 2
+ { child_comm: whoopsie } hitcount: 3
+ { child_comm: compiz } hitcount: 3
+ { child_comm: evolution-sourc } hitcount: 4
+ { child_comm: bash } hitcount: 5
+ { child_comm: pool } hitcount: 5
+ { child_comm: postgres } hitcount: 6
+ { child_comm: firefox } hitcount: 8
+ { child_comm: dhclient } hitcount: 11
+ { child_comm: emacs } hitcount: 12
+ { child_comm: dbus-daemon } hitcount: 22
+ { child_comm: nm-dispatcher.a } hitcount: 22
+ { child_comm: evolution } hitcount: 35
+ { child_comm: glib-pacrunner } hitcount: 59
+
+ Totals:
+ Hits: 206
+ Entries: 21
+ Dropped: 0
+
+ The previous example showed how to start and stop a hist trigger by
+ appending 'pause' and 'continue' to the hist trigger command. A
+ hist trigger can also be started in a paused state by initially
+ starting the trigger with ':pause' appended. This allows you to
+ start the trigger only when you're ready to start collecting data
+ and not before. For example, you could start the trigger in a
+ paused state, then unpause it and do something you want to measure,
+ then pause the trigger again when done.
+
+ Of course, doing this manually can be difficult and error-prone, but
+ it is possible to automatically start and stop a hist trigger based
+ on some condition, via the enable_hist and disable_hist triggers.
+
+ For example, suppose we wanted to take a look at the relative
+ weights in terms of skb length for each callpath that leads to a
+ netif_receieve_skb event when downloading a decent-sized file using
+ wget.
+
+ First we set up an initially paused stacktrace trigger on the
+ netif_receive_skb event:
+
+ # echo 'hist:key=stacktrace:vals=len:pause' > \
+ /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
+
+ Next, we set up an 'enable_hist' trigger on the sched_process_exec
+ event, with an 'if filename==/usr/bin/wget' filter. The effect of
+ this new trigger is that it will 'unpause' the hist trigger we just
+ set up on netif_receive_skb if and only if it sees a
+ sched_process_exec event with a filename of '/usr/bin/wget'. When
+ that happens, all netif_receive_skb events are aggregated into a
+ hash table keyed on stacktrace:
+
+ # echo 'enable_hist:net:netif_receive_skb if filename==/usr/bin/wget' > \
+ /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger
+
+ The aggregation continues until the netif_receive_skb is paused
+ again, which is what the following disable_hist event does by
+ creating a similar setup on the sched_process_exit event, using the
+ filter 'comm==wget':
+
+ # echo 'disable_hist:net:netif_receive_skb if comm==wget' > \
+ /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger
+
+ Whenever a process exits and the comm field of the disable_hist
+ trigger filter matches 'comm==wget', the netif_receive_skb hist
+ trigger is disabled.
+
+ The overall effect is that netif_receive_skb events are aggregated
+ into the hash table for only the duration of the wget. Executing a
+ wget command and then listing the 'hist' file will display the
+ output generated by the wget command:
+
+ $ wget https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.19.xz
+
+ # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist
+ # trigger info: hist:keys=stacktrace:vals=len:sort=hitcount:size=2048 [paused]
+
+ { stacktrace:
+ __netif_receive_skb_core+0x46d/0x990
+ __netif_receive_skb+0x18/0x60
+ netif_receive_skb_internal+0x23/0x90
+ napi_gro_receive+0xc8/0x100
+ ieee80211_deliver_skb+0xd6/0x270 [mac80211]
+ ieee80211_rx_handlers+0xccf/0x22f0 [mac80211]
+ ieee80211_prepare_and_rx_handle+0x4e7/0xc40 [mac80211]
+ ieee80211_rx+0x31d/0x900 [mac80211]
+ iwlagn_rx_reply_rx+0x3db/0x6f0 [iwldvm]
+ iwl_rx_dispatch+0x8e/0xf0 [iwldvm]
+ iwl_pcie_irq_handler+0xe3c/0x12f0 [iwlwifi]
+ irq_thread_fn+0x20/0x50
+ irq_thread+0x11f/0x150
+ kthread+0xd2/0xf0
+ ret_from_fork+0x42/0x70
+ } hitcount: 85 len: 28884
+ { stacktrace:
+ __netif_receive_skb_core+0x46d/0x990
+ __netif_receive_skb+0x18/0x60
+ netif_receive_skb_internal+0x23/0x90
+ napi_gro_complete+0xa4/0xe0
+ dev_gro_receive+0x23a/0x360
+ napi_gro_receive+0x30/0x100
+ ieee80211_deliver_skb+0xd6/0x270 [mac80211]
+ ieee80211_rx_handlers+0xccf/0x22f0 [mac80211]
+ ieee80211_prepare_and_rx_handle+0x4e7/0xc40 [mac80211]
+ ieee80211_rx+0x31d/0x900 [mac80211]
+ iwlagn_rx_reply_rx+0x3db/0x6f0 [iwldvm]
+ iwl_rx_dispatch+0x8e/0xf0 [iwldvm]
+ iwl_pcie_irq_handler+0xe3c/0x12f0 [iwlwifi]
+ irq_thread_fn+0x20/0x50
+ irq_thread+0x11f/0x150
+ kthread+0xd2/0xf0
+ } hitcount: 98 len: 664329
+ { stacktrace:
+ __netif_receive_skb_core+0x46d/0x990
+ __netif_receive_skb+0x18/0x60
+ process_backlog+0xa8/0x150
+ net_rx_action+0x15d/0x340
+ __do_softirq+0x114/0x2c0
+ do_softirq_own_stack+0x1c/0x30
+ do_softirq+0x65/0x70
+ __local_bh_enable_ip+0xb5/0xc0
+ ip_finish_output+0x1f4/0x840
+ ip_output+0x6b/0xc0
+ ip_local_out_sk+0x31/0x40
+ ip_send_skb+0x1a/0x50
+ udp_send_skb+0x173/0x2a0
+ udp_sendmsg+0x2bf/0x9f0
+ inet_sendmsg+0x64/0xa0
+ sock_sendmsg+0x3d/0x50
+ } hitcount: 115 len: 13030
+ { stacktrace:
+ __netif_receive_skb_core+0x46d/0x990
+ __netif_receive_skb+0x18/0x60
+ netif_receive_skb_internal+0x23/0x90
+ napi_gro_complete+0xa4/0xe0
+ napi_gro_flush+0x6d/0x90
+ iwl_pcie_irq_handler+0x92a/0x12f0 [iwlwifi]
+ irq_thread_fn+0x20/0x50
+ irq_thread+0x11f/0x150
+ kthread+0xd2/0xf0
+ ret_from_fork+0x42/0x70
+ } hitcount: 934 len: 5512212
+
+ Totals:
+ Hits: 1232
+ Entries: 4
+ Dropped: 0
+
+ The above shows all the netif_receive_skb callpaths and their total
+ lengths for the duration of the wget command.
+
+ The 'clear' hist trigger param can be used to clear the hash table.
+ Suppose we wanted to try another run of the previous example but
+ this time also wanted to see the complete list of events that went
+ into the histogram. In order to avoid having to set everything up
+ again, we can just clear the histogram first:
+
+ # echo 'hist:key=stacktrace:vals=len:clear' >> \
+ /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
+
+ Just to verify that it is in fact cleared, here's what we now see in
+ the hist file:
+
+ # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist
+ # trigger info: hist:keys=stacktrace:vals=len:sort=hitcount:size=2048 [paused]
+
+ Totals:
+ Hits: 0
+ Entries: 0
+ Dropped: 0
+
+ Since we want to see the detailed list of every netif_receive_skb
+ event occurring during the new run, which are in fact the same
+ events being aggregated into the hash table, we add some additional
+ 'enable_event' events to the triggering sched_process_exec and
+ sched_process_exit events as such:
+
+ # echo 'enable_event:net:netif_receive_skb if filename==/usr/bin/wget' > \
+ /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger
+
+ # echo 'disable_event:net:netif_receive_skb if comm==wget' > \
+ /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger
+
+ If you read the trigger files for the sched_process_exec and
+ sched_process_exit triggers, you should see two triggers for each:
+ one enabling/disabling the hist aggregation and the other
+ enabling/disabling the logging of events:
+
+ # cat /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger
+ enable_event:net:netif_receive_skb:unlimited if filename==/usr/bin/wget
+ enable_hist:net:netif_receive_skb:unlimited if filename==/usr/bin/wget
+
+ # cat /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger
+ enable_event:net:netif_receive_skb:unlimited if comm==wget
+ disable_hist:net:netif_receive_skb:unlimited if comm==wget
+
+ In other words, whenever either of the sched_process_exec or
+ sched_process_exit events is hit and matches 'wget', it enables or
+ disables both the histogram and the event log, and what you end up
+ with is a hash table and set of events just covering the specified
+ duration. Run the wget command again:
+
+ $ wget https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.19.xz
+
+ Displaying the 'hist' file should show something similar to what you
+ saw in the last run, but this time you should also see the
+ individual events in the trace file:
+
+ # cat /sys/kernel/debug/tracing/trace
+
+ # tracer: nop
+ #
+ # entries-in-buffer/entries-written: 183/1426 #P:4
+ #
+ # _-----=> irqs-off
+ # / _----=> need-resched
+ # | / _---=> hardirq/softirq
+ # || / _--=> preempt-depth
+ # ||| / delay
+ # TASK-PID CPU# |||| TIMESTAMP FUNCTION
+ # | | | |||| | |
+ wget-15108 [000] ..s1 31769.606929: netif_receive_skb: dev=lo skbaddr=ffff88009c353100 len=60
+ wget-15108 [000] ..s1 31769.606999: netif_receive_skb: dev=lo skbaddr=ffff88009c353200 len=60
+ dnsmasq-1382 [000] ..s1 31769.677652: netif_receive_skb: dev=lo skbaddr=ffff88009c352b00 len=130
+ dnsmasq-1382 [000] ..s1 31769.685917: netif_receive_skb: dev=lo skbaddr=ffff88009c352200 len=138
+ ##### CPU 2 buffer started ####
+ irq/29-iwlwifi-559 [002] ..s. 31772.031529: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433d00 len=2948
+ irq/29-iwlwifi-559 [002] ..s. 31772.031572: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d432200 len=1500
+ irq/29-iwlwifi-559 [002] ..s. 31772.032196: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433100 len=2948
+ irq/29-iwlwifi-559 [002] ..s. 31772.032761: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433000 len=2948
+ irq/29-iwlwifi-559 [002] ..s. 31772.033220: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d432e00 len=1500
+ .
+ .
+ .
+
+ The following example demonstrates how multiple hist triggers can be
+ attached to a given event. This capability can be useful for
+ creating a set of different summaries derived from the same set of
+ events, or for comparing the effects of different filters, among
+ other things.
+
+ # echo 'hist:keys=skbaddr.hex:vals=len if len < 0' >> \
+ /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
+ # echo 'hist:keys=skbaddr.hex:vals=len if len > 4096' >> \
+ /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
+ # echo 'hist:keys=skbaddr.hex:vals=len if len == 256' >> \
+ /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
+ # echo 'hist:keys=skbaddr.hex:vals=len' >> \
+ /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
+ # echo 'hist:keys=len:vals=common_preempt_count' >> \
+ /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
+
+ The above set of commands create four triggers differing only in
+ their filters, along with a completely different though fairly
+ nonsensical trigger. Note that in order to append multiple hist
+ triggers to the same file, you should use the '>>' operator to
+ append them ('>' will also add the new hist trigger, but will remove
+ any existing hist triggers beforehand).
+
+ Displaying the contents of the 'hist' file for the event shows the
+ contents of all five histograms:
+
+ # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist
+
+ # event histogram
+ #
+ # trigger info: hist:keys=len:vals=hitcount,common_preempt_count:sort=hitcount:size=2048 [active]
+ #
+
+ { len: 176 } hitcount: 1 common_preempt_count: 0
+ { len: 223 } hitcount: 1 common_preempt_count: 0
+ { len: 4854 } hitcount: 1 common_preempt_count: 0
+ { len: 395 } hitcount: 1 common_preempt_count: 0
+ { len: 177 } hitcount: 1 common_preempt_count: 0
+ { len: 446 } hitcount: 1 common_preempt_count: 0
+ { len: 1601 } hitcount: 1 common_preempt_count: 0
+ .
+ .
+ .
+ { len: 1280 } hitcount: 66 common_preempt_count: 0
+ { len: 116 } hitcount: 81 common_preempt_count: 40
+ { len: 708 } hitcount: 112 common_preempt_count: 0
+ { len: 46 } hitcount: 221 common_preempt_count: 0
+ { len: 1264 } hitcount: 458 common_preempt_count: 0
+
+ Totals:
+ Hits: 1428
+ Entries: 147
+ Dropped: 0
+
+
+ # event histogram
+ #
+ # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active]
+ #
+
+ { skbaddr: ffff8800baee5e00 } hitcount: 1 len: 130
+ { skbaddr: ffff88005f3d5600 } hitcount: 1 len: 1280
+ { skbaddr: ffff88005f3d4900 } hitcount: 1 len: 1280
+ { skbaddr: ffff88009fed6300 } hitcount: 1 len: 115
+ { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 115
+ { skbaddr: ffff88008cdb1900 } hitcount: 1 len: 46
+ { skbaddr: ffff880064b5ef00 } hitcount: 1 len: 118
+ { skbaddr: ffff880044e3c700 } hitcount: 1 len: 60
+ { skbaddr: ffff880100065900 } hitcount: 1 len: 46
+ { skbaddr: ffff8800d46bd500 } hitcount: 1 len: 116
+ { skbaddr: ffff88005f3d5f00 } hitcount: 1 len: 1280
+ { skbaddr: ffff880100064700 } hitcount: 1 len: 365
+ { skbaddr: ffff8800badb6f00 } hitcount: 1 len: 60
+ .
+ .
+ .
+ { skbaddr: ffff88009fe0be00 } hitcount: 27 len: 24677
+ { skbaddr: ffff88009fe0a400 } hitcount: 27 len: 23052
+ { skbaddr: ffff88009fe0b700 } hitcount: 31 len: 25589
+ { skbaddr: ffff88009fe0b600 } hitcount: 32 len: 27326
+ { skbaddr: ffff88006a462800 } hitcount: 68 len: 71678
+ { skbaddr: ffff88006a463700 } hitcount: 70 len: 72678
+ { skbaddr: ffff88006a462b00 } hitcount: 71 len: 77589
+ { skbaddr: ffff88006a463600 } hitcount: 73 len: 71307
+ { skbaddr: ffff88006a462200 } hitcount: 81 len: 81032
+
+ Totals:
+ Hits: 1451
+ Entries: 318
+ Dropped: 0
+
+
+ # event histogram
+ #
+ # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len == 256 [active]
+ #
+
+
+ Totals:
+ Hits: 0
+ Entries: 0
+ Dropped: 0
+
+
+ # event histogram
+ #
+ # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len > 4096 [active]
+ #
+
+ { skbaddr: ffff88009fd2c300 } hitcount: 1 len: 7212
+ { skbaddr: ffff8800d2bcce00 } hitcount: 1 len: 7212
+ { skbaddr: ffff8800d2bcd700 } hitcount: 1 len: 7212
+ { skbaddr: ffff8800d2bcda00 } hitcount: 1 len: 21492
+ { skbaddr: ffff8800ae2e2d00 } hitcount: 1 len: 7212
+ { skbaddr: ffff8800d2bcdb00 } hitcount: 1 len: 7212
+ { skbaddr: ffff88006a4df500 } hitcount: 1 len: 4854
+ { skbaddr: ffff88008ce47b00 } hitcount: 1 len: 18636
+ { skbaddr: ffff8800ae2e2200 } hitcount: 1 len: 12924
+ { skbaddr: ffff88005f3e1000 } hitcount: 1 len: 4356
+ { skbaddr: ffff8800d2bcdc00 } hitcount: 2 len: 24420
+ { skbaddr: ffff8800d2bcc200 } hitcount: 2 len: 12996
+
+ Totals:
+ Hits: 14
+ Entries: 12
+ Dropped: 0
+
+
+ # event histogram
+ #
+ # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len < 0 [active]
+ #
+
+
+ Totals:
+ Hits: 0
+ Entries: 0
+ Dropped: 0
+
+ Named triggers can be used to have triggers share a common set of
+ histogram data. This capability is mostly useful for combining the
+ output of events generated by tracepoints contained inside inline
+ functions, but names can be used in a hist trigger on any event.
+ For example, these two triggers when hit will update the same 'len'
+ field in the shared 'foo' histogram data:
+
+ # echo 'hist:name=foo:keys=skbaddr.hex:vals=len' > \
+ /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger
+ # echo 'hist:name=foo:keys=skbaddr.hex:vals=len' > \
+ /sys/kernel/debug/tracing/events/net/netif_rx/trigger
+
+ You can see that they're updating common histogram data by reading
+ each event's hist files at the same time:
+
+ # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist;
+ cat /sys/kernel/debug/tracing/events/net/netif_rx/hist
+
+ # event histogram
+ #
+ # trigger info: hist:name=foo:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active]
+ #
+
+ { skbaddr: ffff88000ad53500 } hitcount: 1 len: 46
+ { skbaddr: ffff8800af5a1500 } hitcount: 1 len: 76
+ { skbaddr: ffff8800d62a1900 } hitcount: 1 len: 46
+ { skbaddr: ffff8800d2bccb00 } hitcount: 1 len: 468
+ { skbaddr: ffff8800d3c69900 } hitcount: 1 len: 46
+ { skbaddr: ffff88009ff09100 } hitcount: 1 len: 52
+ { skbaddr: ffff88010f13ab00 } hitcount: 1 len: 168
+ { skbaddr: ffff88006a54f400 } hitcount: 1 len: 46
+ { skbaddr: ffff8800d2bcc500 } hitcount: 1 len: 260
+ { skbaddr: ffff880064505000 } hitcount: 1 len: 46
+ { skbaddr: ffff8800baf24e00 } hitcount: 1 len: 32
+ { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 46
+ { skbaddr: ffff8800d3edff00 } hitcount: 1 len: 44
+ { skbaddr: ffff88009fe0b400 } hitcount: 1 len: 168
+ { skbaddr: ffff8800a1c55a00 } hitcount: 1 len: 40
+ { skbaddr: ffff8800d2bcd100 } hitcount: 1 len: 40
+ { skbaddr: ffff880064505f00 } hitcount: 1 len: 174
+ { skbaddr: ffff8800a8bff200 } hitcount: 1 len: 160
+ { skbaddr: ffff880044e3cc00 } hitcount: 1 len: 76
+ { skbaddr: ffff8800a8bfe700 } hitcount: 1 len: 46
+ { skbaddr: ffff8800d2bcdc00 } hitcount: 1 len: 32
+ { skbaddr: ffff8800a1f64800 } hitcount: 1 len: 46
+ { skbaddr: ffff8800d2bcde00 } hitcount: 1 len: 988
+ { skbaddr: ffff88006a5dea00 } hitcount: 1 len: 46
+ { skbaddr: ffff88002e37a200 } hitcount: 1 len: 44
+ { skbaddr: ffff8800a1f32c00 } hitcount: 2 len: 676
+ { skbaddr: ffff88000ad52600 } hitcount: 2 len: 107
+ { skbaddr: ffff8800a1f91e00 } hitcount: 2 len: 92
+ { skbaddr: ffff8800af5a0200 } hitcount: 2 len: 142
+ { skbaddr: ffff8800d2bcc600 } hitcount: 2 len: 220
+ { skbaddr: ffff8800ba36f500 } hitcount: 2 len: 92
+ { skbaddr: ffff8800d021f800 } hitcount: 2 len: 92
+ { skbaddr: ffff8800a1f33600 } hitcount: 2 len: 675
+ { skbaddr: ffff8800a8bfff00 } hitcount: 3 len: 138
+ { skbaddr: ffff8800d62a1300 } hitcount: 3 len: 138
+ { skbaddr: ffff88002e37a100 } hitcount: 4 len: 184
+ { skbaddr: ffff880064504400 } hitcount: 4 len: 184
+ { skbaddr: ffff8800a8bfec00 } hitcount: 4 len: 184
+ { skbaddr: ffff88000ad53700 } hitcount: 5 len: 230
+ { skbaddr: ffff8800d2bcdb00 } hitcount: 5 len: 196
+ { skbaddr: ffff8800a1f90000 } hitcount: 6 len: 276
+ { skbaddr: ffff88006a54f900 } hitcount: 6 len: 276
+
+ Totals:
+ Hits: 81
+ Entries: 42
+ Dropped: 0
+ # event histogram
+ #
+ # trigger info: hist:name=foo:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active]
+ #
+
+ { skbaddr: ffff88000ad53500 } hitcount: 1 len: 46
+ { skbaddr: ffff8800af5a1500 } hitcount: 1 len: 76
+ { skbaddr: ffff8800d62a1900 } hitcount: 1 len: 46
+ { skbaddr: ffff8800d2bccb00 } hitcount: 1 len: 468
+ { skbaddr: ffff8800d3c69900 } hitcount: 1 len: 46
+ { skbaddr: ffff88009ff09100 } hitcount: 1 len: 52
+ { skbaddr: ffff88010f13ab00 } hitcount: 1 len: 168
+ { skbaddr: ffff88006a54f400 } hitcount: 1 len: 46
+ { skbaddr: ffff8800d2bcc500 } hitcount: 1 len: 260
+ { skbaddr: ffff880064505000 } hitcount: 1 len: 46
+ { skbaddr: ffff8800baf24e00 } hitcount: 1 len: 32
+ { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 46
+ { skbaddr: ffff8800d3edff00 } hitcount: 1 len: 44
+ { skbaddr: ffff88009fe0b400 } hitcount: 1 len: 168
+ { skbaddr: ffff8800a1c55a00 } hitcount: 1 len: 40
+ { skbaddr: ffff8800d2bcd100 } hitcount: 1 len: 40
+ { skbaddr: ffff880064505f00 } hitcount: 1 len: 174
+ { skbaddr: ffff8800a8bff200 } hitcount: 1 len: 160
+ { skbaddr: ffff880044e3cc00 } hitcount: 1 len: 76
+ { skbaddr: ffff8800a8bfe700 } hitcount: 1 len: 46
+ { skbaddr: ffff8800d2bcdc00 } hitcount: 1 len: 32
+ { skbaddr: ffff8800a1f64800 } hitcount: 1 len: 46
+ { skbaddr: ffff8800d2bcde00 } hitcount: 1 len: 988
+ { skbaddr: ffff88006a5dea00 } hitcount: 1 len: 46
+ { skbaddr: ffff88002e37a200 } hitcount: 1 len: 44
+ { skbaddr: ffff8800a1f32c00 } hitcount: 2 len: 676
+ { skbaddr: ffff88000ad52600 } hitcount: 2 len: 107
+ { skbaddr: ffff8800a1f91e00 } hitcount: 2 len: 92
+ { skbaddr: ffff8800af5a0200 } hitcount: 2 len: 142
+ { skbaddr: ffff8800d2bcc600 } hitcount: 2 len: 220
+ { skbaddr: ffff8800ba36f500 } hitcount: 2 len: 92
+ { skbaddr: ffff8800d021f800 } hitcount: 2 len: 92
+ { skbaddr: ffff8800a1f33600 } hitcount: 2 len: 675
+ { skbaddr: ffff8800a8bfff00 } hitcount: 3 len: 138
+ { skbaddr: ffff8800d62a1300 } hitcount: 3 len: 138
+ { skbaddr: ffff88002e37a100 } hitcount: 4 len: 184
+ { skbaddr: ffff880064504400 } hitcount: 4 len: 184
+ { skbaddr: ffff8800a8bfec00 } hitcount: 4 len: 184
+ { skbaddr: ffff88000ad53700 } hitcount: 5 len: 230
+ { skbaddr: ffff8800d2bcdb00 } hitcount: 5 len: 196
+ { skbaddr: ffff8800a1f90000 } hitcount: 6 len: 276
+ { skbaddr: ffff88006a54f900 } hitcount: 6 len: 276
+
+ Totals:
+ Hits: 81
+ Entries: 42
+ Dropped: 0
+
+ And here's an example that shows how to combine histogram data from
+ any two events even if they don't share any 'compatible' fields
+ other than 'hitcount' and 'stacktrace'. These commands create a
+ couple of triggers named 'bar' using those fields:
+
+ # echo 'hist:name=bar:key=stacktrace:val=hitcount' > \
+ /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger
+ # echo 'hist:name=bar:key=stacktrace:val=hitcount' > \
+ /sys/kernel/debug/tracing/events/net/netif_rx/trigger
+
+ And displaying the output of either shows some interesting if
+ somewhat confusing output:
+
+ # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist
+ # cat /sys/kernel/debug/tracing/events/net/netif_rx/hist
+
+ # event histogram
+ #
+ # trigger info: hist:name=bar:keys=stacktrace:vals=hitcount:sort=hitcount:size=2048 [active]
+ #
+
+ { stacktrace:
+ _do_fork+0x18e/0x330
+ kernel_thread+0x29/0x30
+ kthreadd+0x154/0x1b0
+ ret_from_fork+0x3f/0x70
+ } hitcount: 1
+ { stacktrace:
+ netif_rx_internal+0xb2/0xd0
+ netif_rx_ni+0x20/0x70
+ dev_loopback_xmit+0xaa/0xd0
+ ip_mc_output+0x126/0x240
+ ip_local_out_sk+0x31/0x40
+ igmp_send_report+0x1e9/0x230
+ igmp_timer_expire+0xe9/0x120
+ call_timer_fn+0x39/0xf0
+ run_timer_softirq+0x1e1/0x290
+ __do_softirq+0xfd/0x290
+ irq_exit+0x98/0xb0
+ smp_apic_timer_interrupt+0x4a/0x60
+ apic_timer_interrupt+0x6d/0x80
+ cpuidle_enter+0x17/0x20
+ call_cpuidle+0x3b/0x60
+ cpu_startup_entry+0x22d/0x310
+ } hitcount: 1
+ { stacktrace:
+ netif_rx_internal+0xb2/0xd0
+ netif_rx_ni+0x20/0x70
+ dev_loopback_xmit+0xaa/0xd0
+ ip_mc_output+0x17f/0x240
+ ip_local_out_sk+0x31/0x40
+ ip_send_skb+0x1a/0x50
+ udp_send_skb+0x13e/0x270
+ udp_sendmsg+0x2bf/0x980
+ inet_sendmsg+0x67/0xa0
+ sock_sendmsg+0x38/0x50
+ SYSC_sendto+0xef/0x170
+ SyS_sendto+0xe/0x10
+ entry_SYSCALL_64_fastpath+0x12/0x6a
+ } hitcount: 2
+ { stacktrace:
+ netif_rx_internal+0xb2/0xd0
+ netif_rx+0x1c/0x60
+ loopback_xmit+0x6c/0xb0
+ dev_hard_start_xmit+0x219/0x3a0
+ __dev_queue_xmit+0x415/0x4f0
+ dev_queue_xmit_sk+0x13/0x20
+ ip_finish_output2+0x237/0x340
+ ip_finish_output+0x113/0x1d0
+ ip_output+0x66/0xc0
+ ip_local_out_sk+0x31/0x40
+ ip_send_skb+0x1a/0x50
+ udp_send_skb+0x16d/0x270
+ udp_sendmsg+0x2bf/0x980
+ inet_sendmsg+0x67/0xa0
+ sock_sendmsg+0x38/0x50
+ ___sys_sendmsg+0x14e/0x270
+ } hitcount: 76
+ { stacktrace:
+ netif_rx_internal+0xb2/0xd0
+ netif_rx+0x1c/0x60
+ loopback_xmit+0x6c/0xb0
+ dev_hard_start_xmit+0x219/0x3a0
+ __dev_queue_xmit+0x415/0x4f0
+ dev_queue_xmit_sk+0x13/0x20
+ ip_finish_output2+0x237/0x340
+ ip_finish_output+0x113/0x1d0
+ ip_output+0x66/0xc0
+ ip_local_out_sk+0x31/0x40
+ ip_send_skb+0x1a/0x50
+ udp_send_skb+0x16d/0x270
+ udp_sendmsg+0x2bf/0x980
+ inet_sendmsg+0x67/0xa0
+ sock_sendmsg+0x38/0x50
+ ___sys_sendmsg+0x269/0x270
+ } hitcount: 77
+ { stacktrace:
+ netif_rx_internal+0xb2/0xd0
+ netif_rx+0x1c/0x60
+ loopback_xmit+0x6c/0xb0
+ dev_hard_start_xmit+0x219/0x3a0
+ __dev_queue_xmit+0x415/0x4f0
+ dev_queue_xmit_sk+0x13/0x20
+ ip_finish_output2+0x237/0x340
+ ip_finish_output+0x113/0x1d0
+ ip_output+0x66/0xc0
+ ip_local_out_sk+0x31/0x40
+ ip_send_skb+0x1a/0x50
+ udp_send_skb+0x16d/0x270
+ udp_sendmsg+0x2bf/0x980
+ inet_sendmsg+0x67/0xa0
+ sock_sendmsg+0x38/0x50
+ SYSC_sendto+0xef/0x170
+ } hitcount: 88
+ { stacktrace:
+ _do_fork+0x18e/0x330
+ SyS_clone+0x19/0x20
+ entry_SYSCALL_64_fastpath+0x12/0x6a
+ } hitcount: 244
+
+ Totals:
+ Hits: 489
+ Entries: 7
+ Dropped: 0
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 02/46] tracing: Add Documentation for log2 modifier
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
2018-03-21 2:20 ` [for-next][PATCH 01/46] tracing: Move hist trigger Documentation to histogram.txt Steven Rostedt
@ 2018-03-21 2:20 ` Steven Rostedt
2018-03-21 2:20 ` [for-next][PATCH 03/46] tracing: Add support to detect and avoid duplicates Steven Rostedt
` (43 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:20 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0002-tracing-Add-Documentation-for-log2-modifier.patch --]
[-- Type: text/plain, Size: 1020 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Add a line for the log2 modifier, to keep it aligned with
tracing/README.
Link: http://lkml.kernel.org/r/a419028bccab155749a4b8702d5b97af75f1578f.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
Documentation/trace/histogram.txt | 1 +
1 file changed, 1 insertion(+)
diff --git a/Documentation/trace/histogram.txt b/Documentation/trace/histogram.txt
index b2145f44b190..a4143f04a097 100644
--- a/Documentation/trace/histogram.txt
+++ b/Documentation/trace/histogram.txt
@@ -73,6 +73,7 @@
.sym-offset display an address as a symbol and offset
.syscall display a syscall id as a system call name
.execname display a common_pid as a program name
+ .log2 display log2 value rather than raw number
Note that in general the semantics of a given field aren't
interpreted when applying a modifier to it, but there are some
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 03/46] tracing: Add support to detect and avoid duplicates
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
2018-03-21 2:20 ` [for-next][PATCH 01/46] tracing: Move hist trigger Documentation to histogram.txt Steven Rostedt
2018-03-21 2:20 ` [for-next][PATCH 02/46] tracing: Add Documentation for log2 modifier Steven Rostedt
@ 2018-03-21 2:20 ` Steven Rostedt
2018-03-21 2:20 ` [for-next][PATCH 04/46] tracing: Remove code which merges duplicates Steven Rostedt
` (42 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:20 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Vedang Patel, Tom Zanussi
[-- Attachment #1: 0003-tracing-Add-support-to-detect-and-avoid-duplicates.patch --]
[-- Type: text/plain, Size: 4426 bytes --]
From: Vedang Patel <vedang.patel@intel.com>
A duplicate in the tracing_map hash table is when 2 different entries
have the same key and, as a result, the key_hash. This is possible due
to a race condition in the algorithm. This race condition is inherent to
the algorithm and not a bug. This was fine because, until now, we were
only interested in the sum of all the values related to a particular
key (the duplicates are dealt with in tracing_map_sort_entries()). But,
with the inclusion of variables[1], we are interested in individual
values. So, it will not be clear what value to choose when
there are duplicates. So, the duplicates need to be removed.
The duplicates can occur in the code in the following scenarios:
- A thread is in the process of adding a new element. It has
successfully executed cmpxchg() and inserted the key. But, it is still
not done acquiring the trace_map_elt struct, populating it and storing
the pointer to the struct in the value field of tracing_map hash table.
If another thread comes in at this time and wants to add an element with
the same key, it will not see the current element and add a new one.
- There are multiple threads trying to execute cmpxchg at the same time,
one of the threads will succeed and the others will fail. The ones which
fail will go ahead increment 'idx' and add a new element there creating
a duplicate.
This patch detects and avoids the first condition by asking the thread
which detects the duplicate to loop one more time. There is also a
possibility of infinite loop if the thread which is trying to insert
goes to sleep indefinitely and the one which is trying to insert a new
element detects a duplicate. Which is why, the thread loops for
map_size iterations before returning NULL.
The second scenario is avoided by preventing the threads which failed
cmpxchg() from incrementing idx. This way, they will loop
around and check if the thread which succeeded in executing cmpxchg()
had the same key.
[1] http://lkml.kernel.org/r/cover.1498510759.git.tom.zanussi@linux.intel.com
Link: http://lkml.kernel.org/r/e178e89ec399240331d383bd5913d649713110f4.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Vedang Patel <vedang.patel@intel.com>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/tracing_map.c | 41 ++++++++++++++++++++++++++++++++++++-----
1 file changed, 36 insertions(+), 5 deletions(-)
diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c
index 07e75344725b..b30f3439f27f 100644
--- a/kernel/trace/tracing_map.c
+++ b/kernel/trace/tracing_map.c
@@ -414,7 +414,9 @@ static inline struct tracing_map_elt *
__tracing_map_insert(struct tracing_map *map, void *key, bool lookup_only)
{
u32 idx, key_hash, test_key;
+ int dup_try = 0;
struct tracing_map_entry *entry;
+ struct tracing_map_elt *val;
key_hash = jhash(key, map->key_size, 0);
if (key_hash == 0)
@@ -426,11 +428,33 @@ __tracing_map_insert(struct tracing_map *map, void *key, bool lookup_only)
entry = TRACING_MAP_ENTRY(map->map, idx);
test_key = entry->key;
- if (test_key && test_key == key_hash && entry->val &&
- keys_match(key, entry->val->key, map->key_size)) {
- if (!lookup_only)
- atomic64_inc(&map->hits);
- return entry->val;
+ if (test_key && test_key == key_hash) {
+ val = READ_ONCE(entry->val);
+ if (val &&
+ keys_match(key, val->key, map->key_size)) {
+ if (!lookup_only)
+ atomic64_inc(&map->hits);
+ return val;
+ } else if (unlikely(!val)) {
+ /*
+ * The key is present. But, val (pointer to elt
+ * struct) is still NULL. which means some other
+ * thread is in the process of inserting an
+ * element.
+ *
+ * On top of that, it's key_hash is same as the
+ * one being inserted right now. So, it's
+ * possible that the element has the same
+ * key as well.
+ */
+
+ dup_try++;
+ if (dup_try > map->map_size) {
+ atomic64_inc(&map->drops);
+ break;
+ }
+ continue;
+ }
}
if (!test_key) {
@@ -452,6 +476,13 @@ __tracing_map_insert(struct tracing_map *map, void *key, bool lookup_only)
atomic64_inc(&map->hits);
return entry->val;
+ } else {
+ /*
+ * cmpxchg() failed. Loop around once
+ * more to check what key was inserted.
+ */
+ dup_try++;
+ continue;
}
}
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 04/46] tracing: Remove code which merges duplicates
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (2 preceding siblings ...)
2018-03-21 2:20 ` [for-next][PATCH 03/46] tracing: Add support to detect and avoid duplicates Steven Rostedt
@ 2018-03-21 2:20 ` Steven Rostedt
2018-03-21 2:20 ` [for-next][PATCH 05/46] ring-buffer: Add interface for setting absolute time stamps Steven Rostedt
` (41 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:20 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Vedang Patel, Tom Zanussi
[-- Attachment #1: 0004-tracing-Remove-code-which-merges-duplicates.patch --]
[-- Type: text/plain, Size: 6211 bytes --]
From: Vedang Patel <vedang.patel@intel.com>
We now have the logic to detect and remove duplicates in the
tracing_map hash table. The code which merges duplicates in the
histogram is redundant now. So, modify this code just to detect
duplicates. The duplication detection code is still kept to ensure
that any rare race condition which might cause duplicates does not go
unnoticed.
Link: http://lkml.kernel.org/r/55215cf59e2674391bdaf772fdafc4c393352b03.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Vedang Patel <vedang.patel@intel.com>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 11 ------
kernel/trace/tracing_map.c | 83 +++-------------------------------------
kernel/trace/tracing_map.h | 7 ----
3 files changed, 6 insertions(+), 95 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 1e1558c99d56..712260e72be5 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -340,16 +340,6 @@ static int hist_trigger_elt_comm_alloc(struct tracing_map_elt *elt)
return 0;
}
-static void hist_trigger_elt_comm_copy(struct tracing_map_elt *to,
- struct tracing_map_elt *from)
-{
- char *comm_from = from->private_data;
- char *comm_to = to->private_data;
-
- if (comm_from)
- memcpy(comm_to, comm_from, TASK_COMM_LEN + 1);
-}
-
static void hist_trigger_elt_comm_init(struct tracing_map_elt *elt)
{
char *comm = elt->private_data;
@@ -360,7 +350,6 @@ static void hist_trigger_elt_comm_init(struct tracing_map_elt *elt)
static const struct tracing_map_ops hist_trigger_elt_comm_ops = {
.elt_alloc = hist_trigger_elt_comm_alloc,
- .elt_copy = hist_trigger_elt_comm_copy,
.elt_free = hist_trigger_elt_comm_free,
.elt_init = hist_trigger_elt_comm_init,
};
diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c
index b30f3439f27f..f47a4d54bcf0 100644
--- a/kernel/trace/tracing_map.c
+++ b/kernel/trace/tracing_map.c
@@ -847,67 +847,15 @@ create_sort_entry(void *key, struct tracing_map_elt *elt)
return sort_entry;
}
-static struct tracing_map_elt *copy_elt(struct tracing_map_elt *elt)
-{
- struct tracing_map_elt *dup_elt;
- unsigned int i;
-
- dup_elt = tracing_map_elt_alloc(elt->map);
- if (IS_ERR(dup_elt))
- return NULL;
-
- if (elt->map->ops && elt->map->ops->elt_copy)
- elt->map->ops->elt_copy(dup_elt, elt);
-
- dup_elt->private_data = elt->private_data;
- memcpy(dup_elt->key, elt->key, elt->map->key_size);
-
- for (i = 0; i < elt->map->n_fields; i++) {
- atomic64_set(&dup_elt->fields[i].sum,
- atomic64_read(&elt->fields[i].sum));
- dup_elt->fields[i].cmp_fn = elt->fields[i].cmp_fn;
- }
-
- return dup_elt;
-}
-
-static int merge_dup(struct tracing_map_sort_entry **sort_entries,
- unsigned int target, unsigned int dup)
-{
- struct tracing_map_elt *target_elt, *elt;
- bool first_dup = (target - dup) == 1;
- int i;
-
- if (first_dup) {
- elt = sort_entries[target]->elt;
- target_elt = copy_elt(elt);
- if (!target_elt)
- return -ENOMEM;
- sort_entries[target]->elt = target_elt;
- sort_entries[target]->elt_copied = true;
- } else
- target_elt = sort_entries[target]->elt;
-
- elt = sort_entries[dup]->elt;
-
- for (i = 0; i < elt->map->n_fields; i++)
- atomic64_add(atomic64_read(&elt->fields[i].sum),
- &target_elt->fields[i].sum);
-
- sort_entries[dup]->dup = true;
-
- return 0;
-}
-
-static int merge_dups(struct tracing_map_sort_entry **sort_entries,
+static void detect_dups(struct tracing_map_sort_entry **sort_entries,
int n_entries, unsigned int key_size)
{
unsigned int dups = 0, total_dups = 0;
- int err, i, j;
+ int i;
void *key;
if (n_entries < 2)
- return total_dups;
+ return;
sort(sort_entries, n_entries, sizeof(struct tracing_map_sort_entry *),
(int (*)(const void *, const void *))cmp_entries_dup, NULL);
@@ -916,30 +864,14 @@ static int merge_dups(struct tracing_map_sort_entry **sort_entries,
for (i = 1; i < n_entries; i++) {
if (!memcmp(sort_entries[i]->key, key, key_size)) {
dups++; total_dups++;
- err = merge_dup(sort_entries, i - dups, i);
- if (err)
- return err;
continue;
}
key = sort_entries[i]->key;
dups = 0;
}
- if (!total_dups)
- return total_dups;
-
- for (i = 0, j = 0; i < n_entries; i++) {
- if (!sort_entries[i]->dup) {
- sort_entries[j] = sort_entries[i];
- if (j++ != i)
- sort_entries[i] = NULL;
- } else {
- destroy_sort_entry(sort_entries[i]);
- sort_entries[i] = NULL;
- }
- }
-
- return total_dups;
+ WARN_ONCE(total_dups > 0,
+ "Duplicates detected: %d\n", total_dups);
}
static bool is_key(struct tracing_map *map, unsigned int field_idx)
@@ -1065,10 +997,7 @@ int tracing_map_sort_entries(struct tracing_map *map,
return 1;
}
- ret = merge_dups(entries, n_entries, map->key_size);
- if (ret < 0)
- goto free;
- n_entries -= ret;
+ detect_dups(entries, n_entries, map->key_size);
if (is_key(map, sort_keys[0].field_idx))
cmp_entries_fn = cmp_entries_key;
diff --git a/kernel/trace/tracing_map.h b/kernel/trace/tracing_map.h
index 5b5bbf8ae550..de57887c0670 100644
--- a/kernel/trace/tracing_map.h
+++ b/kernel/trace/tracing_map.h
@@ -215,11 +215,6 @@ struct tracing_map {
* Element allocation occurs before tracing begins, when the
* tracing_map_init() call is made by client code.
*
- * @elt_copy: At certain points in the lifetime of an element, it may
- * need to be copied. The copy should include a copy of the
- * client-allocated data, which can be copied into the 'to'
- * element from the 'from' element.
- *
* @elt_free: When a tracing_map_elt is freed, this function is called
* and allows client-allocated per-element data to be freed.
*
@@ -233,8 +228,6 @@ struct tracing_map {
*/
struct tracing_map_ops {
int (*elt_alloc)(struct tracing_map_elt *elt);
- void (*elt_copy)(struct tracing_map_elt *to,
- struct tracing_map_elt *from);
void (*elt_free)(struct tracing_map_elt *elt);
void (*elt_clear)(struct tracing_map_elt *elt);
void (*elt_init)(struct tracing_map_elt *elt);
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 05/46] ring-buffer: Add interface for setting absolute time stamps
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (3 preceding siblings ...)
2018-03-21 2:20 ` [for-next][PATCH 04/46] tracing: Remove code which merges duplicates Steven Rostedt
@ 2018-03-21 2:20 ` Steven Rostedt
2018-03-21 2:20 ` [for-next][PATCH 06/46] ring-buffer: Redefine the unimplemented RINGBUF_TYPE_TIME_STAMP Steven Rostedt
` (40 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:20 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi, Baohong Liu
[-- Attachment #1: 0005-ring-buffer-Add-interface-for-setting-absolute-time-.patch --]
[-- Type: text/plain, Size: 4200 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Define a new function, tracing_set_time_stamp_abs(), which can be used
to enable or disable the use of absolute timestamps rather than time
deltas for a trace array.
Only the interface is added here; a subsequent patch will add the
underlying implementation.
Link: http://lkml.kernel.org/r/ce96119de44c7fe0ee44786d15254e9b493040d3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Baohong Liu <baohong.liu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
include/linux/ring_buffer.h | 2 ++
kernel/trace/ring_buffer.c | 11 +++++++++++
kernel/trace/trace.c | 33 ++++++++++++++++++++++++++++++++-
kernel/trace/trace.h | 3 +++
4 files changed, 48 insertions(+), 1 deletion(-)
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index 7d9eb39fa76a..025159e17e1b 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -178,6 +178,8 @@ void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer,
int cpu, u64 *ts);
void ring_buffer_set_clock(struct ring_buffer *buffer,
u64 (*clock)(void));
+void ring_buffer_set_time_stamp_abs(struct ring_buffer *buffer, bool abs);
+bool ring_buffer_time_stamp_abs(struct ring_buffer *buffer);
size_t ring_buffer_page_len(void *page);
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index dcf1c4dd3efe..2a03e069bbc6 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -488,6 +488,7 @@ struct ring_buffer {
u64 (*clock)(void);
struct rb_irq_work irq_work;
+ bool time_stamp_abs;
};
struct ring_buffer_iter {
@@ -1382,6 +1383,16 @@ void ring_buffer_set_clock(struct ring_buffer *buffer,
buffer->clock = clock;
}
+void ring_buffer_set_time_stamp_abs(struct ring_buffer *buffer, bool abs)
+{
+ buffer->time_stamp_abs = abs;
+}
+
+bool ring_buffer_time_stamp_abs(struct ring_buffer *buffer)
+{
+ return buffer->time_stamp_abs;
+}
+
static void rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer);
static inline unsigned long rb_page_entries(struct buffer_page *bpage)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 20a2300ae4e8..cba003f0362e 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2269,7 +2269,7 @@ trace_event_buffer_lock_reserve(struct ring_buffer **current_rb,
*current_rb = trace_file->tr->trace_buffer.buffer;
- if ((trace_file->flags &
+ if (!ring_buffer_time_stamp_abs(*current_rb) && (trace_file->flags &
(EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED)) &&
(entry = this_cpu_read(trace_buffered_event))) {
/* Try to use the per cpu buffer first */
@@ -6282,6 +6282,37 @@ static int tracing_clock_open(struct inode *inode, struct file *file)
return ret;
}
+int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs)
+{
+ int ret = 0;
+
+ mutex_lock(&trace_types_lock);
+
+ if (abs && tr->time_stamp_abs_ref++)
+ goto out;
+
+ if (!abs) {
+ if (WARN_ON_ONCE(!tr->time_stamp_abs_ref)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (--tr->time_stamp_abs_ref)
+ goto out;
+ }
+
+ ring_buffer_set_time_stamp_abs(tr->trace_buffer.buffer, abs);
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ if (tr->max_buffer.buffer)
+ ring_buffer_set_time_stamp_abs(tr->max_buffer.buffer, abs);
+#endif
+ out:
+ mutex_unlock(&trace_types_lock);
+
+ return ret;
+}
+
struct ftrace_buffer_info {
struct trace_iterator iter;
void *spare;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 2a6d0325a761..477341710ebf 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -273,6 +273,7 @@ struct trace_array {
/* function tracing enabled */
int function_enabled;
#endif
+ int time_stamp_abs_ref;
};
enum {
@@ -286,6 +287,8 @@ extern struct mutex trace_types_lock;
extern int trace_array_get(struct trace_array *tr);
extern void trace_array_put(struct trace_array *tr);
+extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
+
/*
* The global tracer (top) should be the first trace array added,
* but we check the flag anyway.
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 06/46] ring-buffer: Redefine the unimplemented RINGBUF_TYPE_TIME_STAMP
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (4 preceding siblings ...)
2018-03-21 2:20 ` [for-next][PATCH 05/46] ring-buffer: Add interface for setting absolute time stamps Steven Rostedt
@ 2018-03-21 2:20 ` Steven Rostedt
2018-03-21 2:20 ` [for-next][PATCH 07/46] tracing: Add timestamp_mode trace file Steven Rostedt
` (39 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:20 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0006-ring-buffer-Redefine-the-unimplemented-RINGBUF_TYPE_.patch --]
[-- Type: text/plain, Size: 10911 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
RINGBUF_TYPE_TIME_STAMP is defined but not used, and from what I can
gather was reserved for something like an absolute timestamp feature
for the ring buffer, if not a complete replacement of the current
time_delta scheme.
This code redefines RINGBUF_TYPE_TIME_STAMP to implement absolute time
stamps. Another way to look at it is that it essentially forces
extended time_deltas for all events.
The motivation for doing this is to enable time_deltas that aren't
dependent on previous events in the ring buffer, making it feasible to
use the ring_buffer_event timetamps in a more random-access way, for
purposes other than serial event printing.
To set/reset this mode, use tracing_set_timestamp_abs() from the
previous interface patch.
Link: http://lkml.kernel.org/r/477b362dba1ce7fab9889a1a8e885a62c472f041.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
include/linux/ring_buffer.h | 12 ++---
kernel/trace/ring_buffer.c | 104 ++++++++++++++++++++++++++++++++------------
2 files changed, 83 insertions(+), 33 deletions(-)
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index 025159e17e1b..7cb84774c20d 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -34,10 +34,12 @@ struct ring_buffer_event {
* array[0] = time delta (28 .. 59)
* size = 8 bytes
*
- * @RINGBUF_TYPE_TIME_STAMP: Sync time stamp with external clock
- * array[0] = tv_nsec
- * array[1..2] = tv_sec
- * size = 16 bytes
+ * @RINGBUF_TYPE_TIME_STAMP: Absolute timestamp
+ * Same format as TIME_EXTEND except that the
+ * value is an absolute timestamp, not a delta
+ * event.time_delta contains bottom 27 bits
+ * array[0] = top (28 .. 59) bits
+ * size = 8 bytes
*
* <= @RINGBUF_TYPE_DATA_TYPE_LEN_MAX:
* Data record
@@ -54,12 +56,12 @@ enum ring_buffer_type {
RINGBUF_TYPE_DATA_TYPE_LEN_MAX = 28,
RINGBUF_TYPE_PADDING,
RINGBUF_TYPE_TIME_EXTEND,
- /* FIXME: RINGBUF_TYPE_TIME_STAMP not implemented */
RINGBUF_TYPE_TIME_STAMP,
};
unsigned ring_buffer_event_length(struct ring_buffer_event *event);
void *ring_buffer_event_data(struct ring_buffer_event *event);
+u64 ring_buffer_event_time_stamp(struct ring_buffer_event *event);
/*
* ring_buffer_discard_commit will remove an event that has not
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 2a03e069bbc6..33073cdebb26 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -41,6 +41,8 @@ int ring_buffer_print_entry_header(struct trace_seq *s)
RINGBUF_TYPE_PADDING);
trace_seq_printf(s, "\ttime_extend : type == %d\n",
RINGBUF_TYPE_TIME_EXTEND);
+ trace_seq_printf(s, "\ttime_stamp : type == %d\n",
+ RINGBUF_TYPE_TIME_STAMP);
trace_seq_printf(s, "\tdata max type_len == %d\n",
RINGBUF_TYPE_DATA_TYPE_LEN_MAX);
@@ -140,12 +142,15 @@ int ring_buffer_print_entry_header(struct trace_seq *s)
enum {
RB_LEN_TIME_EXTEND = 8,
- RB_LEN_TIME_STAMP = 16,
+ RB_LEN_TIME_STAMP = 8,
};
#define skip_time_extend(event) \
((struct ring_buffer_event *)((char *)event + RB_LEN_TIME_EXTEND))
+#define extended_time(event) \
+ (event->type_len >= RINGBUF_TYPE_TIME_EXTEND)
+
static inline int rb_null_event(struct ring_buffer_event *event)
{
return event->type_len == RINGBUF_TYPE_PADDING && !event->time_delta;
@@ -209,7 +214,7 @@ rb_event_ts_length(struct ring_buffer_event *event)
{
unsigned len = 0;
- if (event->type_len == RINGBUF_TYPE_TIME_EXTEND) {
+ if (extended_time(event)) {
/* time extends include the data event after it */
len = RB_LEN_TIME_EXTEND;
event = skip_time_extend(event);
@@ -231,7 +236,7 @@ unsigned ring_buffer_event_length(struct ring_buffer_event *event)
{
unsigned length;
- if (event->type_len == RINGBUF_TYPE_TIME_EXTEND)
+ if (extended_time(event))
event = skip_time_extend(event);
length = rb_event_length(event);
@@ -248,7 +253,7 @@ EXPORT_SYMBOL_GPL(ring_buffer_event_length);
static __always_inline void *
rb_event_data(struct ring_buffer_event *event)
{
- if (event->type_len == RINGBUF_TYPE_TIME_EXTEND)
+ if (extended_time(event))
event = skip_time_extend(event);
BUG_ON(event->type_len > RINGBUF_TYPE_DATA_TYPE_LEN_MAX);
/* If length is in len field, then array[0] has the data */
@@ -275,6 +280,27 @@ EXPORT_SYMBOL_GPL(ring_buffer_event_data);
#define TS_MASK ((1ULL << TS_SHIFT) - 1)
#define TS_DELTA_TEST (~TS_MASK)
+/**
+ * ring_buffer_event_time_stamp - return the event's extended timestamp
+ * @event: the event to get the timestamp of
+ *
+ * Returns the extended timestamp associated with a data event.
+ * An extended time_stamp is a 64-bit timestamp represented
+ * internally in a special way that makes the best use of space
+ * contained within a ring buffer event. This function decodes
+ * it and maps it to a straight u64 value.
+ */
+u64 ring_buffer_event_time_stamp(struct ring_buffer_event *event)
+{
+ u64 ts;
+
+ ts = event->array[0];
+ ts <<= TS_SHIFT;
+ ts += event->time_delta;
+
+ return ts;
+}
+
/* Flag when events were overwritten */
#define RB_MISSED_EVENTS (1 << 31)
/* Missed count stored at end */
@@ -2217,12 +2243,15 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer,
/* Slow path, do not inline */
static noinline struct ring_buffer_event *
-rb_add_time_stamp(struct ring_buffer_event *event, u64 delta)
+rb_add_time_stamp(struct ring_buffer_event *event, u64 delta, bool abs)
{
- event->type_len = RINGBUF_TYPE_TIME_EXTEND;
+ if (abs)
+ event->type_len = RINGBUF_TYPE_TIME_STAMP;
+ else
+ event->type_len = RINGBUF_TYPE_TIME_EXTEND;
- /* Not the first event on the page? */
- if (rb_event_index(event)) {
+ /* Not the first event on the page, or not delta? */
+ if (abs || rb_event_index(event)) {
event->time_delta = delta & TS_MASK;
event->array[0] = delta >> TS_SHIFT;
} else {
@@ -2265,7 +2294,9 @@ rb_update_event(struct ring_buffer_per_cpu *cpu_buffer,
* add it to the start of the resevered space.
*/
if (unlikely(info->add_timestamp)) {
- event = rb_add_time_stamp(event, delta);
+ bool abs = ring_buffer_time_stamp_abs(cpu_buffer->buffer);
+
+ event = rb_add_time_stamp(event, info->delta, abs);
length -= RB_LEN_TIME_EXTEND;
delta = 0;
}
@@ -2453,7 +2484,7 @@ static __always_inline void rb_end_commit(struct ring_buffer_per_cpu *cpu_buffer
static inline void rb_event_discard(struct ring_buffer_event *event)
{
- if (event->type_len == RINGBUF_TYPE_TIME_EXTEND)
+ if (extended_time(event))
event = skip_time_extend(event);
/* array[0] holds the actual length for the discarded event */
@@ -2497,10 +2528,11 @@ rb_update_write_stamp(struct ring_buffer_per_cpu *cpu_buffer,
cpu_buffer->write_stamp =
cpu_buffer->commit_page->page->time_stamp;
else if (event->type_len == RINGBUF_TYPE_TIME_EXTEND) {
- delta = event->array[0];
- delta <<= TS_SHIFT;
- delta += event->time_delta;
+ delta = ring_buffer_event_time_stamp(event);
cpu_buffer->write_stamp += delta;
+ } else if (event->type_len == RINGBUF_TYPE_TIME_STAMP) {
+ delta = ring_buffer_event_time_stamp(event);
+ cpu_buffer->write_stamp = delta;
} else
cpu_buffer->write_stamp += event->time_delta;
}
@@ -2680,7 +2712,7 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
* If this is the first commit on the page, then it has the same
* timestamp as the page itself.
*/
- if (!tail)
+ if (!tail && !ring_buffer_time_stamp_abs(cpu_buffer->buffer))
info->delta = 0;
/* See if we shot pass the end of this buffer page */
@@ -2757,8 +2789,11 @@ rb_reserve_next_event(struct ring_buffer *buffer,
/* make sure this diff is calculated here */
barrier();
- /* Did the write stamp get updated already? */
- if (likely(info.ts >= cpu_buffer->write_stamp)) {
+ if (ring_buffer_time_stamp_abs(buffer)) {
+ info.delta = info.ts;
+ rb_handle_timestamp(cpu_buffer, &info);
+ } else /* Did the write stamp get updated already? */
+ if (likely(info.ts >= cpu_buffer->write_stamp)) {
info.delta = diff;
if (unlikely(test_time_stamp(info.delta)))
rb_handle_timestamp(cpu_buffer, &info);
@@ -3440,14 +3475,13 @@ rb_update_read_stamp(struct ring_buffer_per_cpu *cpu_buffer,
return;
case RINGBUF_TYPE_TIME_EXTEND:
- delta = event->array[0];
- delta <<= TS_SHIFT;
- delta += event->time_delta;
+ delta = ring_buffer_event_time_stamp(event);
cpu_buffer->read_stamp += delta;
return;
case RINGBUF_TYPE_TIME_STAMP:
- /* FIXME: not implemented */
+ delta = ring_buffer_event_time_stamp(event);
+ cpu_buffer->read_stamp = delta;
return;
case RINGBUF_TYPE_DATA:
@@ -3471,14 +3505,13 @@ rb_update_iter_read_stamp(struct ring_buffer_iter *iter,
return;
case RINGBUF_TYPE_TIME_EXTEND:
- delta = event->array[0];
- delta <<= TS_SHIFT;
- delta += event->time_delta;
+ delta = ring_buffer_event_time_stamp(event);
iter->read_stamp += delta;
return;
case RINGBUF_TYPE_TIME_STAMP:
- /* FIXME: not implemented */
+ delta = ring_buffer_event_time_stamp(event);
+ iter->read_stamp = delta;
return;
case RINGBUF_TYPE_DATA:
@@ -3702,6 +3735,8 @@ rb_buffer_peek(struct ring_buffer_per_cpu *cpu_buffer, u64 *ts,
struct buffer_page *reader;
int nr_loops = 0;
+ if (ts)
+ *ts = 0;
again:
/*
* We repeat when a time extend is encountered.
@@ -3738,12 +3773,17 @@ rb_buffer_peek(struct ring_buffer_per_cpu *cpu_buffer, u64 *ts,
goto again;
case RINGBUF_TYPE_TIME_STAMP:
- /* FIXME: not implemented */
+ if (ts) {
+ *ts = ring_buffer_event_time_stamp(event);
+ ring_buffer_normalize_time_stamp(cpu_buffer->buffer,
+ cpu_buffer->cpu, ts);
+ }
+ /* Internal data, OK to advance */
rb_advance_reader(cpu_buffer);
goto again;
case RINGBUF_TYPE_DATA:
- if (ts) {
+ if (ts && !(*ts)) {
*ts = cpu_buffer->read_stamp + event->time_delta;
ring_buffer_normalize_time_stamp(cpu_buffer->buffer,
cpu_buffer->cpu, ts);
@@ -3768,6 +3808,9 @@ rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
struct ring_buffer_event *event;
int nr_loops = 0;
+ if (ts)
+ *ts = 0;
+
cpu_buffer = iter->cpu_buffer;
buffer = cpu_buffer->buffer;
@@ -3820,12 +3863,17 @@ rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
goto again;
case RINGBUF_TYPE_TIME_STAMP:
- /* FIXME: not implemented */
+ if (ts) {
+ *ts = ring_buffer_event_time_stamp(event);
+ ring_buffer_normalize_time_stamp(cpu_buffer->buffer,
+ cpu_buffer->cpu, ts);
+ }
+ /* Internal data, OK to advance */
rb_advance_iter(iter);
goto again;
case RINGBUF_TYPE_DATA:
- if (ts) {
+ if (ts && !(*ts)) {
*ts = iter->read_stamp + event->time_delta;
ring_buffer_normalize_time_stamp(buffer,
cpu_buffer->cpu, ts);
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 07/46] tracing: Add timestamp_mode trace file
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (5 preceding siblings ...)
2018-03-21 2:20 ` [for-next][PATCH 06/46] ring-buffer: Redefine the unimplemented RINGBUF_TYPE_TIME_STAMP Steven Rostedt
@ 2018-03-21 2:20 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 08/46] tracing: Give event triggers access to ring_buffer_event Steven Rostedt
` (38 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:20 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0007-tracing-Add-timestamp_mode-trace-file.patch --]
[-- Type: text/plain, Size: 4646 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Add a new option flag indicating whether or not the ring buffer is in
'absolute timestamp' mode.
Currently this is only set/unset by hist triggers that make use of a
common_timestamp. As such, there's no reason to make this writeable
for users - its purpose is only to allow users to determine
unequivocally whether or not the ring buffer is in that mode (although
absolute timestamps can coexist with the normal delta timestamps, when
the ring buffer is in absolute mode, timestamps written while absolute
mode is in effect take up more space in the buffer, and are not as
efficient).
Link: http://lkml.kernel.org/r/e8aa7b1cde1cf15014e66545d06ac6ef2ebba456.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
Documentation/trace/ftrace.txt | 24 +++++++++++++++++++++
kernel/trace/trace.c | 47 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 71 insertions(+)
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index d4601df6e72e..54213e5c23f6 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -539,6 +539,30 @@ of ftrace. Here is a list of some of the key files:
See events.txt for more information.
+ timestamp_mode:
+
+ Certain tracers may change the timestamp mode used when
+ logging trace events into the event buffer. Events with
+ different modes can coexist within a buffer but the mode in
+ effect when an event is logged determines which timestamp mode
+ is used for that event. The default timestamp mode is
+ 'delta'.
+
+ Usual timestamp modes for tracing:
+
+ # cat timestamp_mode
+ [delta] absolute
+
+ The timestamp mode with the square brackets around it is the
+ one in effect.
+
+ delta: Default timestamp mode - timestamp is a delta against
+ a per-buffer timestamp.
+
+ absolute: The timestamp is a full timestamp, not a delta
+ against some other value. As such it takes up more
+ space and is less efficient.
+
hwlat_detector:
Directory for the Hardware Latency Detector.
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index cba003f0362e..988d94a05e81 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4515,6 +4515,9 @@ static const char readme_msg[] =
#ifdef CONFIG_X86_64
" x86-tsc: TSC cycle counter\n"
#endif
+ "\n timestamp_mode\t-view the mode used to timestamp events\n"
+ " delta: Delta difference against a buffer-wide timestamp\n"
+ " absolute: Absolute (standalone) timestamp\n"
"\n trace_marker\t\t- Writes into this file writes into the kernel buffer\n"
"\n trace_marker_raw\t\t- Writes into this file writes binary data into the kernel buffer\n"
" tracing_cpumask\t- Limit which CPUs to trace\n"
@@ -6282,6 +6285,40 @@ static int tracing_clock_open(struct inode *inode, struct file *file)
return ret;
}
+static int tracing_time_stamp_mode_show(struct seq_file *m, void *v)
+{
+ struct trace_array *tr = m->private;
+
+ mutex_lock(&trace_types_lock);
+
+ if (ring_buffer_time_stamp_abs(tr->trace_buffer.buffer))
+ seq_puts(m, "delta [absolute]\n");
+ else
+ seq_puts(m, "[delta] absolute\n");
+
+ mutex_unlock(&trace_types_lock);
+
+ return 0;
+}
+
+static int tracing_time_stamp_mode_open(struct inode *inode, struct file *file)
+{
+ struct trace_array *tr = inode->i_private;
+ int ret;
+
+ if (tracing_disabled)
+ return -ENODEV;
+
+ if (trace_array_get(tr))
+ return -ENODEV;
+
+ ret = single_open(file, tracing_time_stamp_mode_show, inode->i_private);
+ if (ret < 0)
+ trace_array_put(tr);
+
+ return ret;
+}
+
int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs)
{
int ret = 0;
@@ -6560,6 +6597,13 @@ static const struct file_operations trace_clock_fops = {
.write = tracing_clock_write,
};
+static const struct file_operations trace_time_stamp_mode_fops = {
+ .open = tracing_time_stamp_mode_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = tracing_single_release_tr,
+};
+
#ifdef CONFIG_TRACER_SNAPSHOT
static const struct file_operations snapshot_fops = {
.open = tracing_snapshot_open,
@@ -7882,6 +7926,9 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
trace_create_file("tracing_on", 0644, d_tracer,
tr, &rb_simple_fops);
+ trace_create_file("timestamp_mode", 0444, d_tracer, tr,
+ &trace_time_stamp_mode_fops);
+
create_trace_options_dir(tr);
#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER)
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 08/46] tracing: Give event triggers access to ring_buffer_event
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (6 preceding siblings ...)
2018-03-21 2:20 ` [for-next][PATCH 07/46] tracing: Add timestamp_mode trace file Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 09/46] tracing: Add ring buffer event param to hist field functions Steven Rostedt
` (37 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0008-tracing-Give-event-triggers-access-to-ring_buffer_ev.patch --]
[-- Type: text/plain, Size: 10451 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
The ring_buffer event can provide a timestamp that may be useful to
various triggers - pass it into the handlers for that purpose.
Link: http://lkml.kernel.org/r/6de592683b59fa70ffa5d43d0109896623fc1367.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
include/linux/trace_events.h | 14 ++++++-----
kernel/trace/trace.h | 9 +++----
kernel/trace/trace_events_hist.c | 11 +++++----
kernel/trace/trace_events_trigger.c | 47 +++++++++++++++++++++++--------------
4 files changed, 49 insertions(+), 32 deletions(-)
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 8a1442c4e513..0cf48c61cc6d 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -430,11 +430,13 @@ enum event_trigger_type {
extern int filter_match_preds(struct event_filter *filter, void *rec);
-extern enum event_trigger_type event_triggers_call(struct trace_event_file *file,
- void *rec);
-extern void event_triggers_post_call(struct trace_event_file *file,
- enum event_trigger_type tt,
- void *rec);
+extern enum event_trigger_type
+event_triggers_call(struct trace_event_file *file, void *rec,
+ struct ring_buffer_event *event);
+extern void
+event_triggers_post_call(struct trace_event_file *file,
+ enum event_trigger_type tt,
+ void *rec, struct ring_buffer_event *event);
bool trace_event_ignore_this_pid(struct trace_event_file *trace_file);
@@ -454,7 +456,7 @@ trace_trigger_soft_disabled(struct trace_event_file *file)
if (!(eflags & EVENT_FILE_FL_TRIGGER_COND)) {
if (eflags & EVENT_FILE_FL_TRIGGER_MODE)
- event_triggers_call(file, NULL);
+ event_triggers_call(file, NULL, NULL);
if (eflags & EVENT_FILE_FL_SOFT_DISABLED)
return true;
if (eflags & EVENT_FILE_FL_PID_FILTER)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 477341710ebf..99060f7eebbd 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1294,7 +1294,7 @@ __event_trigger_test_discard(struct trace_event_file *file,
unsigned long eflags = file->flags;
if (eflags & EVENT_FILE_FL_TRIGGER_COND)
- *tt = event_triggers_call(file, entry);
+ *tt = event_triggers_call(file, entry, event);
if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) ||
(unlikely(file->flags & EVENT_FILE_FL_FILTERED) &&
@@ -1331,7 +1331,7 @@ event_trigger_unlock_commit(struct trace_event_file *file,
trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc);
if (tt)
- event_triggers_post_call(file, tt, entry);
+ event_triggers_post_call(file, tt, entry, event);
}
/**
@@ -1364,7 +1364,7 @@ event_trigger_unlock_commit_regs(struct trace_event_file *file,
irq_flags, pc, regs);
if (tt)
- event_triggers_post_call(file, tt, entry);
+ event_triggers_post_call(file, tt, entry, event);
}
#define FILTER_PRED_INVALID ((unsigned short)-1)
@@ -1589,7 +1589,8 @@ extern int register_trigger_hist_enable_disable_cmds(void);
*/
struct event_trigger_ops {
void (*func)(struct event_trigger_data *data,
- void *rec);
+ void *rec,
+ struct ring_buffer_event *rbe);
int (*init)(struct event_trigger_ops *ops,
struct event_trigger_data *data);
void (*free)(struct event_trigger_ops *ops,
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 712260e72be5..63a19123cf47 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -909,7 +909,8 @@ static inline void add_to_key(char *compound_key, void *key,
memcpy(compound_key + key_field->offset, key, size);
}
-static void event_hist_trigger(struct event_trigger_data *data, void *rec)
+static void event_hist_trigger(struct event_trigger_data *data, void *rec,
+ struct ring_buffer_event *event)
{
struct hist_trigger_data *hist_data = data->private_data;
bool use_compound_key = (hist_data->n_keys > 1);
@@ -1658,7 +1659,8 @@ __init int register_trigger_hist_cmd(void)
}
static void
-hist_enable_trigger(struct event_trigger_data *data, void *rec)
+hist_enable_trigger(struct event_trigger_data *data, void *rec,
+ struct ring_buffer_event *event)
{
struct enable_trigger_data *enable_data = data->private_data;
struct event_trigger_data *test;
@@ -1674,7 +1676,8 @@ hist_enable_trigger(struct event_trigger_data *data, void *rec)
}
static void
-hist_enable_count_trigger(struct event_trigger_data *data, void *rec)
+hist_enable_count_trigger(struct event_trigger_data *data, void *rec,
+ struct ring_buffer_event *event)
{
if (!data->count)
return;
@@ -1682,7 +1685,7 @@ hist_enable_count_trigger(struct event_trigger_data *data, void *rec)
if (data->count != -1)
(data->count)--;
- hist_enable_trigger(data, rec);
+ hist_enable_trigger(data, rec, event);
}
static struct event_trigger_ops hist_enable_trigger_ops = {
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 87411482a46f..632471692462 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -63,7 +63,8 @@ void trigger_data_free(struct event_trigger_data *data)
* any trigger that should be deferred, ETT_NONE if nothing to defer.
*/
enum event_trigger_type
-event_triggers_call(struct trace_event_file *file, void *rec)
+event_triggers_call(struct trace_event_file *file, void *rec,
+ struct ring_buffer_event *event)
{
struct event_trigger_data *data;
enum event_trigger_type tt = ETT_NONE;
@@ -76,7 +77,7 @@ event_triggers_call(struct trace_event_file *file, void *rec)
if (data->paused)
continue;
if (!rec) {
- data->ops->func(data, rec);
+ data->ops->func(data, rec, event);
continue;
}
filter = rcu_dereference_sched(data->filter);
@@ -86,7 +87,7 @@ event_triggers_call(struct trace_event_file *file, void *rec)
tt |= data->cmd_ops->trigger_type;
continue;
}
- data->ops->func(data, rec);
+ data->ops->func(data, rec, event);
}
return tt;
}
@@ -108,7 +109,7 @@ EXPORT_SYMBOL_GPL(event_triggers_call);
void
event_triggers_post_call(struct trace_event_file *file,
enum event_trigger_type tt,
- void *rec)
+ void *rec, struct ring_buffer_event *event)
{
struct event_trigger_data *data;
@@ -116,7 +117,7 @@ event_triggers_post_call(struct trace_event_file *file,
if (data->paused)
continue;
if (data->cmd_ops->trigger_type & tt)
- data->ops->func(data, rec);
+ data->ops->func(data, rec, event);
}
}
EXPORT_SYMBOL_GPL(event_triggers_post_call);
@@ -909,7 +910,8 @@ void set_named_trigger_data(struct event_trigger_data *data,
}
static void
-traceon_trigger(struct event_trigger_data *data, void *rec)
+traceon_trigger(struct event_trigger_data *data, void *rec,
+ struct ring_buffer_event *event)
{
if (tracing_is_on())
return;
@@ -918,7 +920,8 @@ traceon_trigger(struct event_trigger_data *data, void *rec)
}
static void
-traceon_count_trigger(struct event_trigger_data *data, void *rec)
+traceon_count_trigger(struct event_trigger_data *data, void *rec,
+ struct ring_buffer_event *event)
{
if (tracing_is_on())
return;
@@ -933,7 +936,8 @@ traceon_count_trigger(struct event_trigger_data *data, void *rec)
}
static void
-traceoff_trigger(struct event_trigger_data *data, void *rec)
+traceoff_trigger(struct event_trigger_data *data, void *rec,
+ struct ring_buffer_event *event)
{
if (!tracing_is_on())
return;
@@ -942,7 +946,8 @@ traceoff_trigger(struct event_trigger_data *data, void *rec)
}
static void
-traceoff_count_trigger(struct event_trigger_data *data, void *rec)
+traceoff_count_trigger(struct event_trigger_data *data, void *rec,
+ struct ring_buffer_event *event)
{
if (!tracing_is_on())
return;
@@ -1039,13 +1044,15 @@ static struct event_command trigger_traceoff_cmd = {
#ifdef CONFIG_TRACER_SNAPSHOT
static void
-snapshot_trigger(struct event_trigger_data *data, void *rec)
+snapshot_trigger(struct event_trigger_data *data, void *rec,
+ struct ring_buffer_event *event)
{
tracing_snapshot();
}
static void
-snapshot_count_trigger(struct event_trigger_data *data, void *rec)
+snapshot_count_trigger(struct event_trigger_data *data, void *rec,
+ struct ring_buffer_event *event)
{
if (!data->count)
return;
@@ -1053,7 +1060,7 @@ snapshot_count_trigger(struct event_trigger_data *data, void *rec)
if (data->count != -1)
(data->count)--;
- snapshot_trigger(data, rec);
+ snapshot_trigger(data, rec, event);
}
static int
@@ -1141,13 +1148,15 @@ static __init int register_trigger_snapshot_cmd(void) { return 0; }
#endif
static void
-stacktrace_trigger(struct event_trigger_data *data, void *rec)
+stacktrace_trigger(struct event_trigger_data *data, void *rec,
+ struct ring_buffer_event *event)
{
trace_dump_stack(STACK_SKIP);
}
static void
-stacktrace_count_trigger(struct event_trigger_data *data, void *rec)
+stacktrace_count_trigger(struct event_trigger_data *data, void *rec,
+ struct ring_buffer_event *event)
{
if (!data->count)
return;
@@ -1155,7 +1164,7 @@ stacktrace_count_trigger(struct event_trigger_data *data, void *rec)
if (data->count != -1)
(data->count)--;
- stacktrace_trigger(data, rec);
+ stacktrace_trigger(data, rec, event);
}
static int
@@ -1217,7 +1226,8 @@ static __init void unregister_trigger_traceon_traceoff_cmds(void)
}
static void
-event_enable_trigger(struct event_trigger_data *data, void *rec)
+event_enable_trigger(struct event_trigger_data *data, void *rec,
+ struct ring_buffer_event *event)
{
struct enable_trigger_data *enable_data = data->private_data;
@@ -1228,7 +1238,8 @@ event_enable_trigger(struct event_trigger_data *data, void *rec)
}
static void
-event_enable_count_trigger(struct event_trigger_data *data, void *rec)
+event_enable_count_trigger(struct event_trigger_data *data, void *rec,
+ struct ring_buffer_event *event)
{
struct enable_trigger_data *enable_data = data->private_data;
@@ -1242,7 +1253,7 @@ event_enable_count_trigger(struct event_trigger_data *data, void *rec)
if (data->count != -1)
(data->count)--;
- event_enable_trigger(data, rec);
+ event_enable_trigger(data, rec, event);
}
int event_enable_trigger_print(struct seq_file *m,
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 09/46] tracing: Add ring buffer event param to hist field functions
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (7 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 08/46] tracing: Give event triggers access to ring_buffer_event Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 10/46] tracing: Break out hist trigger assignment parsing Steven Rostedt
` (36 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0009-tracing-Add-ring-buffer-event-param-to-hist-field-fu.patch --]
[-- Type: text/plain, Size: 4987 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Some events such as timestamps require access to a ring_buffer_event
struct; add a param so that hist field functions can access that.
Link: http://lkml.kernel.org/r/2ff4af18e72b6002eb86b26b2a7f39cef7d1dfe4.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 39 ++++++++++++++++++++++++---------------
1 file changed, 24 insertions(+), 15 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 63a19123cf47..37f5acefdc6c 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -26,7 +26,8 @@
struct hist_field;
-typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event);
+typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event,
+ struct ring_buffer_event *rbe);
#define HIST_FIELD_OPERANDS_MAX 2
@@ -40,24 +41,28 @@ struct hist_field {
struct hist_field *operands[HIST_FIELD_OPERANDS_MAX];
};
-static u64 hist_field_none(struct hist_field *field, void *event)
+static u64 hist_field_none(struct hist_field *field, void *event,
+ struct ring_buffer_event *rbe)
{
return 0;
}
-static u64 hist_field_counter(struct hist_field *field, void *event)
+static u64 hist_field_counter(struct hist_field *field, void *event,
+ struct ring_buffer_event *rbe)
{
return 1;
}
-static u64 hist_field_string(struct hist_field *hist_field, void *event)
+static u64 hist_field_string(struct hist_field *hist_field, void *event,
+ struct ring_buffer_event *rbe)
{
char *addr = (char *)(event + hist_field->field->offset);
return (u64)(unsigned long)addr;
}
-static u64 hist_field_dynstring(struct hist_field *hist_field, void *event)
+static u64 hist_field_dynstring(struct hist_field *hist_field, void *event,
+ struct ring_buffer_event *rbe)
{
u32 str_item = *(u32 *)(event + hist_field->field->offset);
int str_loc = str_item & 0xffff;
@@ -66,24 +71,28 @@ static u64 hist_field_dynstring(struct hist_field *hist_field, void *event)
return (u64)(unsigned long)addr;
}
-static u64 hist_field_pstring(struct hist_field *hist_field, void *event)
+static u64 hist_field_pstring(struct hist_field *hist_field, void *event,
+ struct ring_buffer_event *rbe)
{
char **addr = (char **)(event + hist_field->field->offset);
return (u64)(unsigned long)*addr;
}
-static u64 hist_field_log2(struct hist_field *hist_field, void *event)
+static u64 hist_field_log2(struct hist_field *hist_field, void *event,
+ struct ring_buffer_event *rbe)
{
struct hist_field *operand = hist_field->operands[0];
- u64 val = operand->fn(operand, event);
+ u64 val = operand->fn(operand, event, rbe);
return (u64) ilog2(roundup_pow_of_two(val));
}
#define DEFINE_HIST_FIELD_FN(type) \
-static u64 hist_field_##type(struct hist_field *hist_field, void *event)\
+ static u64 hist_field_##type(struct hist_field *hist_field, \
+ void *event, \
+ struct ring_buffer_event *rbe) \
{ \
type *addr = (type *)(event + hist_field->field->offset); \
\
@@ -871,8 +880,8 @@ create_hist_data(unsigned int map_bits,
}
static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
- struct tracing_map_elt *elt,
- void *rec)
+ struct tracing_map_elt *elt, void *rec,
+ struct ring_buffer_event *rbe)
{
struct hist_field *hist_field;
unsigned int i;
@@ -880,7 +889,7 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
for_each_hist_val_field(i, hist_data) {
hist_field = hist_data->fields[i];
- hist_val = hist_field->fn(hist_field, rec);
+ hist_val = hist_field->fn(hist_field, rec, rbe);
tracing_map_update_sum(elt, i, hist_val);
}
}
@@ -910,7 +919,7 @@ static inline void add_to_key(char *compound_key, void *key,
}
static void event_hist_trigger(struct event_trigger_data *data, void *rec,
- struct ring_buffer_event *event)
+ struct ring_buffer_event *rbe)
{
struct hist_trigger_data *hist_data = data->private_data;
bool use_compound_key = (hist_data->n_keys > 1);
@@ -939,7 +948,7 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec,
key = entries;
} else {
- field_contents = key_field->fn(key_field, rec);
+ field_contents = key_field->fn(key_field, rec, rbe);
if (key_field->flags & HIST_FIELD_FL_STRING) {
key = (void *)(unsigned long)field_contents;
use_compound_key = true;
@@ -956,7 +965,7 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec,
elt = tracing_map_insert(hist_data->map, key);
if (elt)
- hist_trigger_elt_update(hist_data, elt, rec);
+ hist_trigger_elt_update(hist_data, elt, rec, rbe);
}
static void hist_trigger_stacktrace_print(struct seq_file *m,
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 10/46] tracing: Break out hist trigger assignment parsing
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (8 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 09/46] tracing: Add ring buffer event param to hist field functions Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 11/46] tracing: Add hist trigger timestamp support Steven Rostedt
` (35 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi, Rajvi Jingar
[-- Attachment #1: 0010-tracing-Break-out-hist-trigger-assignment-parsing.patch --]
[-- Type: text/plain, Size: 3573 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
This will make it easier to add variables, and makes the parsing code
cleaner regardless.
Link: http://lkml.kernel.org/r/e574b3291bbe15e35a4dfc87e5395aa715701c98.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Rajvi Jingar <rajvi.jingar@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 72 ++++++++++++++++++++++++++++------------
1 file changed, 51 insertions(+), 21 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 37f5acefdc6c..e4368bb7ba30 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -251,6 +251,51 @@ static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs)
kfree(attrs);
}
+static int parse_assignment(char *str, struct hist_trigger_attrs *attrs)
+{
+ int ret = 0;
+
+ if ((strncmp(str, "key=", strlen("key=")) == 0) ||
+ (strncmp(str, "keys=", strlen("keys=")) == 0)) {
+ attrs->keys_str = kstrdup(str, GFP_KERNEL);
+ if (!attrs->keys_str) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ } else if ((strncmp(str, "val=", strlen("val=")) == 0) ||
+ (strncmp(str, "vals=", strlen("vals=")) == 0) ||
+ (strncmp(str, "values=", strlen("values=")) == 0)) {
+ attrs->vals_str = kstrdup(str, GFP_KERNEL);
+ if (!attrs->vals_str) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ } else if (strncmp(str, "sort=", strlen("sort=")) == 0) {
+ attrs->sort_key_str = kstrdup(str, GFP_KERNEL);
+ if (!attrs->sort_key_str) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ } else if (strncmp(str, "name=", strlen("name=")) == 0) {
+ attrs->name = kstrdup(str, GFP_KERNEL);
+ if (!attrs->name) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ } else if (strncmp(str, "size=", strlen("size=")) == 0) {
+ int map_bits = parse_map_size(str);
+
+ if (map_bits < 0) {
+ ret = map_bits;
+ goto out;
+ }
+ attrs->map_bits = map_bits;
+ } else
+ ret = -EINVAL;
+ out:
+ return ret;
+}
+
static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str)
{
struct hist_trigger_attrs *attrs;
@@ -263,33 +308,18 @@ static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str)
while (trigger_str) {
char *str = strsep(&trigger_str, ":");
- if ((strncmp(str, "key=", strlen("key=")) == 0) ||
- (strncmp(str, "keys=", strlen("keys=")) == 0))
- attrs->keys_str = kstrdup(str, GFP_KERNEL);
- else if ((strncmp(str, "val=", strlen("val=")) == 0) ||
- (strncmp(str, "vals=", strlen("vals=")) == 0) ||
- (strncmp(str, "values=", strlen("values=")) == 0))
- attrs->vals_str = kstrdup(str, GFP_KERNEL);
- else if (strncmp(str, "sort=", strlen("sort=")) == 0)
- attrs->sort_key_str = kstrdup(str, GFP_KERNEL);
- else if (strncmp(str, "name=", strlen("name=")) == 0)
- attrs->name = kstrdup(str, GFP_KERNEL);
- else if (strcmp(str, "pause") == 0)
+ if (strchr(str, '=')) {
+ ret = parse_assignment(str, attrs);
+ if (ret)
+ goto free;
+ } else if (strcmp(str, "pause") == 0)
attrs->pause = true;
else if ((strcmp(str, "cont") == 0) ||
(strcmp(str, "continue") == 0))
attrs->cont = true;
else if (strcmp(str, "clear") == 0)
attrs->clear = true;
- else if (strncmp(str, "size=", strlen("size=")) == 0) {
- int map_bits = parse_map_size(str);
-
- if (map_bits < 0) {
- ret = map_bits;
- goto free;
- }
- attrs->map_bits = map_bits;
- } else {
+ else {
ret = -EINVAL;
goto free;
}
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 11/46] tracing: Add hist trigger timestamp support
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (9 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 10/46] tracing: Break out hist trigger assignment parsing Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 12/46] tracing: Add per-element variable support to tracing_map Steven Rostedt
` (34 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel
Cc: Ingo Molnar, Andrew Morton, Tom Zanussi, Baohong Liu,
Vedang Patel
[-- Attachment #1: 0011-tracing-Add-hist-trigger-timestamp-support.patch --]
[-- Type: text/plain, Size: 7895 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Add support for a timestamp event field. This is actually a 'pseudo-'
event field in that it behaves like it's part of the event record, but
is really part of the corresponding ring buffer event.
To make use of the timestamp field, users can specify
"common_timestamp" as a field name for any histogram. Note that this
doesn't make much sense on its own either as either a key or value,
but needs to be supported even so, since follow-on patches will add
support for making use of this field in time deltas. The
common_timestamp 'field' is not a bona fide event field - so you won't
find it in the event description - but rather it's a synthetic field
that can be used like a real field.
Note that the use of this field requires the ring buffer be put into
'absolute timestamp' mode, which saves the complete timestamp for each
event rather than an offset. This mode will be enabled if and only if
a histogram makes use of the "common_timestamp" field.
Link: http://lkml.kernel.org/r/97afbd646ed146e26271f3458b4b33e16d7817c2.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Baohong Liu <baohong.liu@intel.com>
[kasan use-after-free fix]
Signed-off-by: Vedang Patel <vedang.patel@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 94 ++++++++++++++++++++++++++++++----------
1 file changed, 71 insertions(+), 23 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index e4368bb7ba30..a793f8c04830 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -89,6 +89,12 @@ static u64 hist_field_log2(struct hist_field *hist_field, void *event,
return (u64) ilog2(roundup_pow_of_two(val));
}
+static u64 hist_field_timestamp(struct hist_field *hist_field, void *event,
+ struct ring_buffer_event *rbe)
+{
+ return ring_buffer_event_time_stamp(rbe);
+}
+
#define DEFINE_HIST_FIELD_FN(type) \
static u64 hist_field_##type(struct hist_field *hist_field, \
void *event, \
@@ -135,6 +141,7 @@ enum hist_field_flags {
HIST_FIELD_FL_SYSCALL = 1 << 7,
HIST_FIELD_FL_STACKTRACE = 1 << 8,
HIST_FIELD_FL_LOG2 = 1 << 9,
+ HIST_FIELD_FL_TIMESTAMP = 1 << 10,
};
struct hist_trigger_attrs {
@@ -159,6 +166,7 @@ struct hist_trigger_data {
struct trace_event_file *event_file;
struct hist_trigger_attrs *attrs;
struct tracing_map *map;
+ bool enable_timestamps;
};
static const char *hist_field_name(struct hist_field *field,
@@ -173,6 +181,8 @@ static const char *hist_field_name(struct hist_field *field,
field_name = field->field->name;
else if (field->flags & HIST_FIELD_FL_LOG2)
field_name = hist_field_name(field->operands[0], ++level);
+ else if (field->flags & HIST_FIELD_FL_TIMESTAMP)
+ field_name = "common_timestamp";
if (field_name == NULL)
field_name = "";
@@ -440,6 +450,12 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field,
goto out;
}
+ if (flags & HIST_FIELD_FL_TIMESTAMP) {
+ hist_field->fn = hist_field_timestamp;
+ hist_field->size = sizeof(u64);
+ goto out;
+ }
+
if (WARN_ON_ONCE(!field))
goto out;
@@ -517,10 +533,15 @@ static int create_val_field(struct hist_trigger_data *hist_data,
}
}
- field = trace_find_event_field(file->event_call, field_name);
- if (!field || !field->size) {
- ret = -EINVAL;
- goto out;
+ if (strcmp(field_name, "common_timestamp") == 0) {
+ flags |= HIST_FIELD_FL_TIMESTAMP;
+ hist_data->enable_timestamps = true;
+ } else {
+ field = trace_find_event_field(file->event_call, field_name);
+ if (!field || !field->size) {
+ ret = -EINVAL;
+ goto out;
+ }
}
hist_data->fields[val_idx] = create_hist_field(field, flags);
@@ -615,16 +636,22 @@ static int create_key_field(struct hist_trigger_data *hist_data,
}
}
- field = trace_find_event_field(file->event_call, field_name);
- if (!field || !field->size) {
- ret = -EINVAL;
- goto out;
- }
+ if (strcmp(field_name, "common_timestamp") == 0) {
+ flags |= HIST_FIELD_FL_TIMESTAMP;
+ hist_data->enable_timestamps = true;
+ key_size = sizeof(u64);
+ } else {
+ field = trace_find_event_field(file->event_call, field_name);
+ if (!field || !field->size) {
+ ret = -EINVAL;
+ goto out;
+ }
- if (is_string_field(field))
- key_size = MAX_FILTER_STR_VAL;
- else
- key_size = field->size;
+ if (is_string_field(field))
+ key_size = MAX_FILTER_STR_VAL;
+ else
+ key_size = field->size;
+ }
}
hist_data->fields[key_idx] = create_hist_field(field, flags);
@@ -820,6 +847,9 @@ static int create_tracing_map_fields(struct hist_trigger_data *hist_data)
if (hist_field->flags & HIST_FIELD_FL_STACKTRACE)
cmp_fn = tracing_map_cmp_none;
+ else if (!field)
+ cmp_fn = tracing_map_cmp_num(hist_field->size,
+ hist_field->is_signed);
else if (is_string_field(field))
cmp_fn = tracing_map_cmp_string;
else
@@ -1215,7 +1245,11 @@ static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
{
const char *field_name = hist_field_name(hist_field, 0);
- seq_printf(m, "%s", field_name);
+ if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP)
+ seq_puts(m, "common_timestamp");
+ else if (field_name)
+ seq_printf(m, "%s", field_name);
+
if (hist_field->flags) {
const char *flags_str = get_hist_field_flags(hist_field);
@@ -1266,27 +1300,25 @@ static int event_hist_trigger_print(struct seq_file *m,
for (i = 0; i < hist_data->n_sort_keys; i++) {
struct tracing_map_sort_key *sort_key;
+ unsigned int idx;
sort_key = &hist_data->sort_keys[i];
+ idx = sort_key->field_idx;
+
+ if (WARN_ON(idx >= TRACING_MAP_FIELDS_MAX))
+ return -EINVAL;
if (i > 0)
seq_puts(m, ",");
- if (sort_key->field_idx == HITCOUNT_IDX)
+ if (idx == HITCOUNT_IDX)
seq_puts(m, "hitcount");
- else {
- unsigned int idx = sort_key->field_idx;
-
- if (WARN_ON(idx >= TRACING_MAP_FIELDS_MAX))
- return -EINVAL;
-
+ else
hist_field_print(m, hist_data->fields[idx]);
- }
if (sort_key->descending)
seq_puts(m, ".descending");
}
-
seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits));
if (data->filter_str)
@@ -1454,6 +1486,10 @@ static bool hist_trigger_match(struct event_trigger_data *data,
return false;
if (key_field->offset != key_field_test->offset)
return false;
+ if (key_field->size != key_field_test->size)
+ return false;
+ if (key_field->is_signed != key_field_test->is_signed)
+ return false;
}
for (i = 0; i < hist_data->n_sort_keys; i++) {
@@ -1536,6 +1572,9 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops,
update_cond_flag(file);
+ if (hist_data->enable_timestamps)
+ tracing_set_time_stamp_abs(file->tr, true);
+
if (trace_event_trigger_enable_disable(file, 1) < 0) {
list_del_rcu(&data->list);
update_cond_flag(file);
@@ -1570,17 +1609,26 @@ static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops,
if (unregistered && test->ops->free)
test->ops->free(test->ops, test);
+
+ if (hist_data->enable_timestamps) {
+ if (unregistered)
+ tracing_set_time_stamp_abs(file->tr, false);
+ }
}
static void hist_unreg_all(struct trace_event_file *file)
{
struct event_trigger_data *test, *n;
+ struct hist_trigger_data *hist_data;
list_for_each_entry_safe(test, n, &file->triggers, list) {
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
+ hist_data = test->private_data;
list_del_rcu(&test->list);
trace_event_trigger_enable_disable(file, 0);
update_cond_flag(file);
+ if (hist_data->enable_timestamps)
+ tracing_set_time_stamp_abs(file->tr, false);
if (test->ops->free)
test->ops->free(test->ops, test);
}
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 12/46] tracing: Add per-element variable support to tracing_map
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (10 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 11/46] tracing: Add hist trigger timestamp support Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 13/46] tracing: Add hist_data member to hist_field Steven Rostedt
` (33 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0012-tracing-Add-per-element-variable-support-to-tracing_.patch --]
[-- Type: text/plain, Size: 7983 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
In order to allow information to be passed between trace events, add
support for per-element variables to tracing_map. This provides a
means for histograms to associate a value or values with an entry when
it's saved or updated, and retrieved by a subsequent event occurrences.
Variables can be set using tracing_map_set_var() and read using
tracing_map_read_var(). tracing_map_var_set() returns true or false
depending on whether or not the variable has been set or not, which is
important for event-matching applications.
tracing_map_read_var_once() reads the variable and resets it to the
'unset' state, implementing read-once variables, which are also
important for event-matching uses.
Link: http://lkml.kernel.org/r/7fa001108252556f0c6dd9d63145eabfe3370d1a.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/tracing_map.c | 108 +++++++++++++++++++++++++++++++++++++++++++++
kernel/trace/tracing_map.h | 11 +++++
2 files changed, 119 insertions(+)
diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c
index f47a4d54bcf0..5cadb1b8b5fe 100644
--- a/kernel/trace/tracing_map.c
+++ b/kernel/trace/tracing_map.c
@@ -66,6 +66,73 @@ u64 tracing_map_read_sum(struct tracing_map_elt *elt, unsigned int i)
return (u64)atomic64_read(&elt->fields[i].sum);
}
+/**
+ * tracing_map_set_var - Assign a tracing_map_elt's variable field
+ * @elt: The tracing_map_elt
+ * @i: The index of the given variable associated with the tracing_map_elt
+ * @n: The value to assign
+ *
+ * Assign n to variable i associated with the specified tracing_map_elt
+ * instance. The index i is the index returned by the call to
+ * tracing_map_add_var() when the tracing map was set up.
+ */
+void tracing_map_set_var(struct tracing_map_elt *elt, unsigned int i, u64 n)
+{
+ atomic64_set(&elt->vars[i], n);
+ elt->var_set[i] = true;
+}
+
+/**
+ * tracing_map_var_set - Return whether or not a variable has been set
+ * @elt: The tracing_map_elt
+ * @i: The index of the given variable associated with the tracing_map_elt
+ *
+ * Return true if the variable has been set, false otherwise. The
+ * index i is the index returned by the call to tracing_map_add_var()
+ * when the tracing map was set up.
+ */
+bool tracing_map_var_set(struct tracing_map_elt *elt, unsigned int i)
+{
+ return elt->var_set[i];
+}
+
+/**
+ * tracing_map_read_var - Return the value of a tracing_map_elt's variable field
+ * @elt: The tracing_map_elt
+ * @i: The index of the given variable associated with the tracing_map_elt
+ *
+ * Retrieve the value of the variable i associated with the specified
+ * tracing_map_elt instance. The index i is the index returned by the
+ * call to tracing_map_add_var() when the tracing map was set
+ * up.
+ *
+ * Return: The variable value associated with field i for elt.
+ */
+u64 tracing_map_read_var(struct tracing_map_elt *elt, unsigned int i)
+{
+ return (u64)atomic64_read(&elt->vars[i]);
+}
+
+/**
+ * tracing_map_read_var_once - Return and reset a tracing_map_elt's variable field
+ * @elt: The tracing_map_elt
+ * @i: The index of the given variable associated with the tracing_map_elt
+ *
+ * Retrieve the value of the variable i associated with the specified
+ * tracing_map_elt instance, and reset the variable to the 'not set'
+ * state. The index i is the index returned by the call to
+ * tracing_map_add_var() when the tracing map was set up. The reset
+ * essentially makes the variable a read-once variable if it's only
+ * accessed using this function.
+ *
+ * Return: The variable value associated with field i for elt.
+ */
+u64 tracing_map_read_var_once(struct tracing_map_elt *elt, unsigned int i)
+{
+ elt->var_set[i] = false;
+ return (u64)atomic64_read(&elt->vars[i]);
+}
+
int tracing_map_cmp_string(void *val_a, void *val_b)
{
char *a = val_a;
@@ -170,6 +237,28 @@ int tracing_map_add_sum_field(struct tracing_map *map)
return tracing_map_add_field(map, tracing_map_cmp_atomic64);
}
+/**
+ * tracing_map_add_var - Add a field describing a tracing_map var
+ * @map: The tracing_map
+ *
+ * Add a var to the map and return the index identifying it in the map
+ * and associated tracing_map_elts. This is the index used for
+ * instance to update a var for a particular tracing_map_elt using
+ * tracing_map_update_var() or reading it via tracing_map_read_var().
+ *
+ * Return: The index identifying the var in the map and associated
+ * tracing_map_elts, or -EINVAL on error.
+ */
+int tracing_map_add_var(struct tracing_map *map)
+{
+ int ret = -EINVAL;
+
+ if (map->n_vars < TRACING_MAP_VARS_MAX)
+ ret = map->n_vars++;
+
+ return ret;
+}
+
/**
* tracing_map_add_key_field - Add a field describing a tracing_map key
* @map: The tracing_map
@@ -280,6 +369,11 @@ static void tracing_map_elt_clear(struct tracing_map_elt *elt)
if (elt->fields[i].cmp_fn == tracing_map_cmp_atomic64)
atomic64_set(&elt->fields[i].sum, 0);
+ for (i = 0; i < elt->map->n_vars; i++) {
+ atomic64_set(&elt->vars[i], 0);
+ elt->var_set[i] = false;
+ }
+
if (elt->map->ops && elt->map->ops->elt_clear)
elt->map->ops->elt_clear(elt);
}
@@ -306,6 +400,8 @@ static void tracing_map_elt_free(struct tracing_map_elt *elt)
if (elt->map->ops && elt->map->ops->elt_free)
elt->map->ops->elt_free(elt);
kfree(elt->fields);
+ kfree(elt->vars);
+ kfree(elt->var_set);
kfree(elt->key);
kfree(elt);
}
@@ -333,6 +429,18 @@ static struct tracing_map_elt *tracing_map_elt_alloc(struct tracing_map *map)
goto free;
}
+ elt->vars = kcalloc(map->n_vars, sizeof(*elt->vars), GFP_KERNEL);
+ if (!elt->vars) {
+ err = -ENOMEM;
+ goto free;
+ }
+
+ elt->var_set = kcalloc(map->n_vars, sizeof(*elt->var_set), GFP_KERNEL);
+ if (!elt->var_set) {
+ err = -ENOMEM;
+ goto free;
+ }
+
tracing_map_elt_init_fields(elt);
if (map->ops && map->ops->elt_alloc) {
diff --git a/kernel/trace/tracing_map.h b/kernel/trace/tracing_map.h
index de57887c0670..053eb92b2d31 100644
--- a/kernel/trace/tracing_map.h
+++ b/kernel/trace/tracing_map.h
@@ -10,6 +10,7 @@
#define TRACING_MAP_VALS_MAX 3
#define TRACING_MAP_FIELDS_MAX (TRACING_MAP_KEYS_MAX + \
TRACING_MAP_VALS_MAX)
+#define TRACING_MAP_VARS_MAX 16
#define TRACING_MAP_SORT_KEYS_MAX 2
typedef int (*tracing_map_cmp_fn_t) (void *val_a, void *val_b);
@@ -137,6 +138,8 @@ struct tracing_map_field {
struct tracing_map_elt {
struct tracing_map *map;
struct tracing_map_field *fields;
+ atomic64_t *vars;
+ bool *var_set;
void *key;
void *private_data;
};
@@ -192,6 +195,7 @@ struct tracing_map {
int key_idx[TRACING_MAP_KEYS_MAX];
unsigned int n_keys;
struct tracing_map_sort_key sort_key;
+ unsigned int n_vars;
atomic64_t hits;
atomic64_t drops;
};
@@ -241,6 +245,7 @@ tracing_map_create(unsigned int map_bits,
extern int tracing_map_init(struct tracing_map *map);
extern int tracing_map_add_sum_field(struct tracing_map *map);
+extern int tracing_map_add_var(struct tracing_map *map);
extern int tracing_map_add_key_field(struct tracing_map *map,
unsigned int offset,
tracing_map_cmp_fn_t cmp_fn);
@@ -260,7 +265,13 @@ extern int tracing_map_cmp_none(void *val_a, void *val_b);
extern void tracing_map_update_sum(struct tracing_map_elt *elt,
unsigned int i, u64 n);
+extern void tracing_map_set_var(struct tracing_map_elt *elt,
+ unsigned int i, u64 n);
+extern bool tracing_map_var_set(struct tracing_map_elt *elt, unsigned int i);
extern u64 tracing_map_read_sum(struct tracing_map_elt *elt, unsigned int i);
+extern u64 tracing_map_read_var(struct tracing_map_elt *elt, unsigned int i);
+extern u64 tracing_map_read_var_once(struct tracing_map_elt *elt, unsigned int i);
+
extern void tracing_map_set_field_descr(struct tracing_map *map,
unsigned int i,
unsigned int key_offset,
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 13/46] tracing: Add hist_data member to hist_field
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (11 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 12/46] tracing: Add per-element variable support to tracing_map Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 14/46] tracing: Add usecs modifier for hist trigger timestamps Steven Rostedt
` (32 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0013-tracing-Add-hist_data-member-to-hist_field.patch --]
[-- Type: text/plain, Size: 3057 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Allow hist_data access via hist_field. Some users of hist_fields
require or will require more access to the associated hist_data.
Link: http://lkml.kernel.org/r/d04cd0768f5228ebb4ac0ba4a847bc4d14d4826f.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index a793f8c04830..77ebe6b410ba 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -39,6 +39,7 @@ struct hist_field {
unsigned int offset;
unsigned int is_signed;
struct hist_field *operands[HIST_FIELD_OPERANDS_MAX];
+ struct hist_trigger_data *hist_data;
};
static u64 hist_field_none(struct hist_field *field, void *event,
@@ -420,7 +421,8 @@ static void destroy_hist_field(struct hist_field *hist_field,
kfree(hist_field);
}
-static struct hist_field *create_hist_field(struct ftrace_event_field *field,
+static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
+ struct ftrace_event_field *field,
unsigned long flags)
{
struct hist_field *hist_field;
@@ -432,6 +434,8 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field,
if (!hist_field)
return NULL;
+ hist_field->hist_data = hist_data;
+
if (flags & HIST_FIELD_FL_HITCOUNT) {
hist_field->fn = hist_field_counter;
goto out;
@@ -445,7 +449,7 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field,
if (flags & HIST_FIELD_FL_LOG2) {
unsigned long fl = flags & ~HIST_FIELD_FL_LOG2;
hist_field->fn = hist_field_log2;
- hist_field->operands[0] = create_hist_field(field, fl);
+ hist_field->operands[0] = create_hist_field(hist_data, field, fl);
hist_field->size = hist_field->operands[0]->size;
goto out;
}
@@ -498,7 +502,7 @@ static void destroy_hist_fields(struct hist_trigger_data *hist_data)
static int create_hitcount_val(struct hist_trigger_data *hist_data)
{
hist_data->fields[HITCOUNT_IDX] =
- create_hist_field(NULL, HIST_FIELD_FL_HITCOUNT);
+ create_hist_field(hist_data, NULL, HIST_FIELD_FL_HITCOUNT);
if (!hist_data->fields[HITCOUNT_IDX])
return -ENOMEM;
@@ -544,7 +548,7 @@ static int create_val_field(struct hist_trigger_data *hist_data,
}
}
- hist_data->fields[val_idx] = create_hist_field(field, flags);
+ hist_data->fields[val_idx] = create_hist_field(hist_data, field, flags);
if (!hist_data->fields[val_idx]) {
ret = -ENOMEM;
goto out;
@@ -654,7 +658,7 @@ static int create_key_field(struct hist_trigger_data *hist_data,
}
}
- hist_data->fields[key_idx] = create_hist_field(field, flags);
+ hist_data->fields[key_idx] = create_hist_field(hist_data, field, flags);
if (!hist_data->fields[key_idx]) {
ret = -ENOMEM;
goto out;
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 14/46] tracing: Add usecs modifier for hist trigger timestamps
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (12 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 13/46] tracing: Add hist_data member to hist_field Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 15/46] tracing: Add variable support to hist triggers Steven Rostedt
` (31 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0014-tracing-Add-usecs-modifier-for-hist-trigger-timestam.patch --]
[-- Type: text/plain, Size: 5913 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Appending .usecs onto a common_timestamp field will cause the
timestamp value to be in microseconds instead of the default
nanoseconds. A typical latency histogram using usecs would look like
this:
# echo 'hist:keys=pid,prio:ts0=common_timestamp.usecs ...
# echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0 ...
This also adds an external trace_clock_in_ns() to trace.c for the
timestamp conversion.
Link: http://lkml.kernel.org/r/4e813705a170b3e13e97dc3135047362fb1a39f3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
Documentation/trace/histogram.txt | 1 +
kernel/trace/trace.c | 13 +++++++++++--
kernel/trace/trace.h | 2 ++
kernel/trace/trace_events_hist.c | 28 ++++++++++++++++++++++------
4 files changed, 36 insertions(+), 8 deletions(-)
diff --git a/Documentation/trace/histogram.txt b/Documentation/trace/histogram.txt
index a4143f04a097..25c94730d3fe 100644
--- a/Documentation/trace/histogram.txt
+++ b/Documentation/trace/histogram.txt
@@ -74,6 +74,7 @@
.syscall display a syscall id as a system call name
.execname display a common_pid as a program name
.log2 display log2 value rather than raw number
+ .usecs display a common_timestamp in microseconds
Note that in general the semantics of a given field aren't
interpreted when applying a modifier to it, but there are some
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 988d94a05e81..82cc8891fda6 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1168,6 +1168,14 @@ static struct {
ARCH_TRACE_CLOCKS
};
+bool trace_clock_in_ns(struct trace_array *tr)
+{
+ if (trace_clocks[tr->clock_id].in_ns)
+ return true;
+
+ return false;
+}
+
/*
* trace_parser_get_init - gets the buffer for trace parser
*/
@@ -4694,8 +4702,9 @@ static const char readme_msg[] =
"\t .sym display an address as a symbol\n"
"\t .sym-offset display an address as a symbol and offset\n"
"\t .execname display a common_pid as a program name\n"
- "\t .syscall display a syscall id as a syscall name\n\n"
- "\t .log2 display log2 value rather than raw number\n\n"
+ "\t .syscall display a syscall id as a syscall name\n"
+ "\t .log2 display log2 value rather than raw number\n"
+ "\t .usecs display a common_timestamp in microseconds\n\n"
"\t The 'pause' parameter can be used to pause an existing hist\n"
"\t trigger or to start a hist trigger but not log any events\n"
"\t until told to do so. 'continue' can be used to start or\n"
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 99060f7eebbd..89771b4f16df 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -289,6 +289,8 @@ extern void trace_array_put(struct trace_array *tr);
extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
+extern bool trace_clock_in_ns(struct trace_array *tr);
+
/*
* The global tracer (top) should be the first trace array added,
* but we check the flag anyway.
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 77ebe6b410ba..7f5f0b8f6558 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -90,12 +90,6 @@ static u64 hist_field_log2(struct hist_field *hist_field, void *event,
return (u64) ilog2(roundup_pow_of_two(val));
}
-static u64 hist_field_timestamp(struct hist_field *hist_field, void *event,
- struct ring_buffer_event *rbe)
-{
- return ring_buffer_event_time_stamp(rbe);
-}
-
#define DEFINE_HIST_FIELD_FN(type) \
static u64 hist_field_##type(struct hist_field *hist_field, \
void *event, \
@@ -143,6 +137,7 @@ enum hist_field_flags {
HIST_FIELD_FL_STACKTRACE = 1 << 8,
HIST_FIELD_FL_LOG2 = 1 << 9,
HIST_FIELD_FL_TIMESTAMP = 1 << 10,
+ HIST_FIELD_FL_TIMESTAMP_USECS = 1 << 11,
};
struct hist_trigger_attrs {
@@ -153,6 +148,7 @@ struct hist_trigger_attrs {
bool pause;
bool cont;
bool clear;
+ bool ts_in_usecs;
unsigned int map_bits;
};
@@ -170,6 +166,20 @@ struct hist_trigger_data {
bool enable_timestamps;
};
+static u64 hist_field_timestamp(struct hist_field *hist_field, void *event,
+ struct ring_buffer_event *rbe)
+{
+ struct hist_trigger_data *hist_data = hist_field->hist_data;
+ struct trace_array *tr = hist_data->event_file->tr;
+
+ u64 ts = ring_buffer_event_time_stamp(rbe);
+
+ if (hist_data->attrs->ts_in_usecs && trace_clock_in_ns(tr))
+ ts = ns2usecs(ts);
+
+ return ts;
+}
+
static const char *hist_field_name(struct hist_field *field,
unsigned int level)
{
@@ -634,6 +644,8 @@ static int create_key_field(struct hist_trigger_data *hist_data,
flags |= HIST_FIELD_FL_SYSCALL;
else if (strcmp(field_str, "log2") == 0)
flags |= HIST_FIELD_FL_LOG2;
+ else if (strcmp(field_str, "usecs") == 0)
+ flags |= HIST_FIELD_FL_TIMESTAMP_USECS;
else {
ret = -EINVAL;
goto out;
@@ -643,6 +655,8 @@ static int create_key_field(struct hist_trigger_data *hist_data,
if (strcmp(field_name, "common_timestamp") == 0) {
flags |= HIST_FIELD_FL_TIMESTAMP;
hist_data->enable_timestamps = true;
+ if (flags & HIST_FIELD_FL_TIMESTAMP_USECS)
+ hist_data->attrs->ts_in_usecs = true;
key_size = sizeof(u64);
} else {
field = trace_find_event_field(file->event_call, field_name);
@@ -1241,6 +1255,8 @@ static const char *get_hist_field_flags(struct hist_field *hist_field)
flags_str = "syscall";
else if (hist_field->flags & HIST_FIELD_FL_LOG2)
flags_str = "log2";
+ else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP_USECS)
+ flags_str = "usecs";
return flags_str;
}
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 15/46] tracing: Add variable support to hist triggers
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (13 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 14/46] tracing: Add usecs modifier for hist trigger timestamps Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 16/46] tracing: Account for variables in named trigger compatibility Steven Rostedt
` (30 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi, Baohong Liu
[-- Attachment #1: 0015-tracing-Add-variable-support-to-hist-triggers.patch --]
[-- Type: text/plain, Size: 22010 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Add support for saving the value of a current event's event field by
assigning it to a variable that can be read by a subsequent event.
The basic syntax for saving a variable is to simply prefix a unique
variable name not corresponding to any keyword along with an '=' sign
to any event field.
Both keys and values can be saved and retrieved in this way:
# echo 'hist:keys=next_pid:vals=$ts0:ts0=common_timestamp ...
# echo 'hist:timer_pid=common_pid:key=$timer_pid ...'
If a variable isn't a key variable or prefixed with 'vals=', the
associated event field will be saved in a variable but won't be summed
as a value:
# echo 'hist:keys=next_pid:ts1=common_timestamp:...
Multiple variables can be assigned at the same time:
# echo 'hist:keys=pid:vals=$ts0,$b,field2:ts0=common_timestamp,b=field1 ...
Multiple (or single) variables can also be assigned at the same time
using separate assignments:
# echo 'hist:keys=pid:vals=$ts0:ts0=common_timestamp:b=field1:c=field2 ...
Variables set as above can be used by being referenced from another
event, as described in a subsequent patch.
Link: http://lkml.kernel.org/r/fc93c4944d9719dbcb1d0067be627d44e98e2adc.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Baohong Liu <baohong.liu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 370 ++++++++++++++++++++++++++++++++++-----
1 file changed, 331 insertions(+), 39 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 7f5f0b8f6558..8f43f24bf49c 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -30,6 +30,13 @@ typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event,
struct ring_buffer_event *rbe);
#define HIST_FIELD_OPERANDS_MAX 2
+#define HIST_FIELDS_MAX (TRACING_MAP_FIELDS_MAX + TRACING_MAP_VARS_MAX)
+
+struct hist_var {
+ char *name;
+ struct hist_trigger_data *hist_data;
+ unsigned int idx;
+};
struct hist_field {
struct ftrace_event_field *field;
@@ -40,6 +47,7 @@ struct hist_field {
unsigned int is_signed;
struct hist_field *operands[HIST_FIELD_OPERANDS_MAX];
struct hist_trigger_data *hist_data;
+ struct hist_var var;
};
static u64 hist_field_none(struct hist_field *field, void *event,
@@ -138,6 +146,13 @@ enum hist_field_flags {
HIST_FIELD_FL_LOG2 = 1 << 9,
HIST_FIELD_FL_TIMESTAMP = 1 << 10,
HIST_FIELD_FL_TIMESTAMP_USECS = 1 << 11,
+ HIST_FIELD_FL_VAR = 1 << 12,
+};
+
+struct var_defs {
+ unsigned int n_vars;
+ char *name[TRACING_MAP_VARS_MAX];
+ char *expr[TRACING_MAP_VARS_MAX];
};
struct hist_trigger_attrs {
@@ -150,13 +165,19 @@ struct hist_trigger_attrs {
bool clear;
bool ts_in_usecs;
unsigned int map_bits;
+
+ char *assignment_str[TRACING_MAP_VARS_MAX];
+ unsigned int n_assignments;
+
+ struct var_defs var_defs;
};
struct hist_trigger_data {
- struct hist_field *fields[TRACING_MAP_FIELDS_MAX];
+ struct hist_field *fields[HIST_FIELDS_MAX];
unsigned int n_vals;
unsigned int n_keys;
unsigned int n_fields;
+ unsigned int n_vars;
unsigned int key_size;
struct tracing_map_sort_key sort_keys[TRACING_MAP_SORT_KEYS_MAX];
unsigned int n_sort_keys;
@@ -164,6 +185,7 @@ struct hist_trigger_data {
struct hist_trigger_attrs *attrs;
struct tracing_map *map;
bool enable_timestamps;
+ bool remove;
};
static u64 hist_field_timestamp(struct hist_field *hist_field, void *event,
@@ -180,6 +202,48 @@ static u64 hist_field_timestamp(struct hist_field *hist_field, void *event,
return ts;
}
+static struct hist_field *find_var_field(struct hist_trigger_data *hist_data,
+ const char *var_name)
+{
+ struct hist_field *hist_field, *found = NULL;
+ int i;
+
+ for_each_hist_field(i, hist_data) {
+ hist_field = hist_data->fields[i];
+ if (hist_field && hist_field->flags & HIST_FIELD_FL_VAR &&
+ strcmp(hist_field->var.name, var_name) == 0) {
+ found = hist_field;
+ break;
+ }
+ }
+
+ return found;
+}
+
+static struct hist_field *find_var(struct hist_trigger_data *hist_data,
+ struct trace_event_file *file,
+ const char *var_name)
+{
+ struct hist_trigger_data *test_data;
+ struct event_trigger_data *test;
+ struct hist_field *hist_field;
+
+ hist_field = find_var_field(hist_data, var_name);
+ if (hist_field)
+ return hist_field;
+
+ list_for_each_entry_rcu(test, &file->triggers, list) {
+ if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
+ test_data = test->private_data;
+ hist_field = find_var_field(test_data, var_name);
+ if (hist_field)
+ return hist_field;
+ }
+ }
+
+ return NULL;
+}
+
static const char *hist_field_name(struct hist_field *field,
unsigned int level)
{
@@ -262,9 +326,14 @@ static int parse_map_size(char *str)
static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs)
{
+ unsigned int i;
+
if (!attrs)
return;
+ for (i = 0; i < attrs->n_assignments; i++)
+ kfree(attrs->assignment_str[i]);
+
kfree(attrs->name);
kfree(attrs->sort_key_str);
kfree(attrs->keys_str);
@@ -311,8 +380,22 @@ static int parse_assignment(char *str, struct hist_trigger_attrs *attrs)
goto out;
}
attrs->map_bits = map_bits;
- } else
- ret = -EINVAL;
+ } else {
+ char *assignment;
+
+ if (attrs->n_assignments == TRACING_MAP_VARS_MAX) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ assignment = kstrdup(str, GFP_KERNEL);
+ if (!assignment) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ attrs->assignment_str[attrs->n_assignments++] = assignment;
+ }
out:
return ret;
}
@@ -428,12 +511,15 @@ static void destroy_hist_field(struct hist_field *hist_field,
for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++)
destroy_hist_field(hist_field->operands[i], level + 1);
+ kfree(hist_field->var.name);
+
kfree(hist_field);
}
static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
struct ftrace_event_field *field,
- unsigned long flags)
+ unsigned long flags,
+ char *var_name)
{
struct hist_field *hist_field;
@@ -459,7 +545,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
if (flags & HIST_FIELD_FL_LOG2) {
unsigned long fl = flags & ~HIST_FIELD_FL_LOG2;
hist_field->fn = hist_field_log2;
- hist_field->operands[0] = create_hist_field(hist_data, field, fl);
+ hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL);
hist_field->size = hist_field->operands[0]->size;
goto out;
}
@@ -494,14 +580,23 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
hist_field->field = field;
hist_field->flags = flags;
+ if (var_name) {
+ hist_field->var.name = kstrdup(var_name, GFP_KERNEL);
+ if (!hist_field->var.name)
+ goto free;
+ }
+
return hist_field;
+ free:
+ destroy_hist_field(hist_field, 0);
+ return NULL;
}
static void destroy_hist_fields(struct hist_trigger_data *hist_data)
{
unsigned int i;
- for (i = 0; i < TRACING_MAP_FIELDS_MAX; i++) {
+ for (i = 0; i < HIST_FIELDS_MAX; i++) {
if (hist_data->fields[i]) {
destroy_hist_field(hist_data->fields[i], 0);
hist_data->fields[i] = NULL;
@@ -512,11 +607,12 @@ static void destroy_hist_fields(struct hist_trigger_data *hist_data)
static int create_hitcount_val(struct hist_trigger_data *hist_data)
{
hist_data->fields[HITCOUNT_IDX] =
- create_hist_field(hist_data, NULL, HIST_FIELD_FL_HITCOUNT);
+ create_hist_field(hist_data, NULL, HIST_FIELD_FL_HITCOUNT, NULL);
if (!hist_data->fields[HITCOUNT_IDX])
return -ENOMEM;
hist_data->n_vals++;
+ hist_data->n_fields++;
if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))
return -EINVAL;
@@ -524,19 +620,16 @@ static int create_hitcount_val(struct hist_trigger_data *hist_data)
return 0;
}
-static int create_val_field(struct hist_trigger_data *hist_data,
- unsigned int val_idx,
- struct trace_event_file *file,
- char *field_str)
+static int __create_val_field(struct hist_trigger_data *hist_data,
+ unsigned int val_idx,
+ struct trace_event_file *file,
+ char *var_name, char *field_str,
+ unsigned long flags)
{
struct ftrace_event_field *field = NULL;
- unsigned long flags = 0;
char *field_name;
int ret = 0;
- if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX))
- return -EINVAL;
-
field_name = strsep(&field_str, ".");
if (field_str) {
if (strcmp(field_str, "hex") == 0)
@@ -558,25 +651,58 @@ static int create_val_field(struct hist_trigger_data *hist_data,
}
}
- hist_data->fields[val_idx] = create_hist_field(hist_data, field, flags);
+ hist_data->fields[val_idx] = create_hist_field(hist_data, field, flags, var_name);
if (!hist_data->fields[val_idx]) {
ret = -ENOMEM;
goto out;
}
++hist_data->n_vals;
+ ++hist_data->n_fields;
- if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))
+ if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX))
ret = -EINVAL;
out:
return ret;
}
+static int create_val_field(struct hist_trigger_data *hist_data,
+ unsigned int val_idx,
+ struct trace_event_file *file,
+ char *field_str)
+{
+ if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX))
+ return -EINVAL;
+
+ return __create_val_field(hist_data, val_idx, file, NULL, field_str, 0);
+}
+
+static int create_var_field(struct hist_trigger_data *hist_data,
+ unsigned int val_idx,
+ struct trace_event_file *file,
+ char *var_name, char *expr_str)
+{
+ unsigned long flags = 0;
+
+ if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX))
+ return -EINVAL;
+ if (find_var(hist_data, file, var_name) && !hist_data->remove) {
+ return -EINVAL;
+ }
+
+ flags |= HIST_FIELD_FL_VAR;
+ hist_data->n_vars++;
+ if (WARN_ON(hist_data->n_vars > TRACING_MAP_VARS_MAX))
+ return -EINVAL;
+
+ return __create_val_field(hist_data, val_idx, file, var_name, expr_str, flags);
+}
+
static int create_val_fields(struct hist_trigger_data *hist_data,
struct trace_event_file *file)
{
char *fields_str, *field_str;
- unsigned int i, j;
+ unsigned int i, j = 1;
int ret;
ret = create_hitcount_val(hist_data);
@@ -596,12 +722,15 @@ static int create_val_fields(struct hist_trigger_data *hist_data,
field_str = strsep(&fields_str, ",");
if (!field_str)
break;
+
if (strcmp(field_str, "hitcount") == 0)
continue;
+
ret = create_val_field(hist_data, j++, file, field_str);
if (ret)
goto out;
}
+
if (fields_str && (strcmp(fields_str, "hitcount") != 0))
ret = -EINVAL;
out:
@@ -615,11 +744,12 @@ static int create_key_field(struct hist_trigger_data *hist_data,
char *field_str)
{
struct ftrace_event_field *field = NULL;
+ struct hist_field *hist_field = NULL;
unsigned long flags = 0;
unsigned int key_size;
int ret = 0;
- if (WARN_ON(key_idx >= TRACING_MAP_FIELDS_MAX))
+ if (WARN_ON(key_idx >= HIST_FIELDS_MAX))
return -EINVAL;
flags |= HIST_FIELD_FL_KEY;
@@ -627,6 +757,7 @@ static int create_key_field(struct hist_trigger_data *hist_data,
if (strcmp(field_str, "stacktrace") == 0) {
flags |= HIST_FIELD_FL_STACKTRACE;
key_size = sizeof(unsigned long) * HIST_STACKTRACE_DEPTH;
+ hist_field = create_hist_field(hist_data, NULL, flags, NULL);
} else {
char *field_name = strsep(&field_str, ".");
@@ -672,7 +803,7 @@ static int create_key_field(struct hist_trigger_data *hist_data,
}
}
- hist_data->fields[key_idx] = create_hist_field(hist_data, field, flags);
+ hist_data->fields[key_idx] = create_hist_field(hist_data, field, flags, NULL);
if (!hist_data->fields[key_idx]) {
ret = -ENOMEM;
goto out;
@@ -688,6 +819,7 @@ static int create_key_field(struct hist_trigger_data *hist_data,
}
hist_data->n_keys++;
+ hist_data->n_fields++;
if (WARN_ON(hist_data->n_keys > TRACING_MAP_KEYS_MAX))
return -EINVAL;
@@ -731,21 +863,111 @@ static int create_key_fields(struct hist_trigger_data *hist_data,
return ret;
}
+static int create_var_fields(struct hist_trigger_data *hist_data,
+ struct trace_event_file *file)
+{
+ unsigned int i, j = hist_data->n_vals;
+ int ret = 0;
+
+ unsigned int n_vars = hist_data->attrs->var_defs.n_vars;
+
+ for (i = 0; i < n_vars; i++) {
+ char *var_name = hist_data->attrs->var_defs.name[i];
+ char *expr = hist_data->attrs->var_defs.expr[i];
+
+ ret = create_var_field(hist_data, j++, file, var_name, expr);
+ if (ret)
+ goto out;
+ }
+ out:
+ return ret;
+}
+
+static void free_var_defs(struct hist_trigger_data *hist_data)
+{
+ unsigned int i;
+
+ for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) {
+ kfree(hist_data->attrs->var_defs.name[i]);
+ kfree(hist_data->attrs->var_defs.expr[i]);
+ }
+
+ hist_data->attrs->var_defs.n_vars = 0;
+}
+
+static int parse_var_defs(struct hist_trigger_data *hist_data)
+{
+ char *s, *str, *var_name, *field_str;
+ unsigned int i, j, n_vars = 0;
+ int ret = 0;
+
+ for (i = 0; i < hist_data->attrs->n_assignments; i++) {
+ str = hist_data->attrs->assignment_str[i];
+ for (j = 0; j < TRACING_MAP_VARS_MAX; j++) {
+ field_str = strsep(&str, ",");
+ if (!field_str)
+ break;
+
+ var_name = strsep(&field_str, "=");
+ if (!var_name || !field_str) {
+ ret = -EINVAL;
+ goto free;
+ }
+
+ if (n_vars == TRACING_MAP_VARS_MAX) {
+ ret = -EINVAL;
+ goto free;
+ }
+
+ s = kstrdup(var_name, GFP_KERNEL);
+ if (!s) {
+ ret = -ENOMEM;
+ goto free;
+ }
+ hist_data->attrs->var_defs.name[n_vars] = s;
+
+ s = kstrdup(field_str, GFP_KERNEL);
+ if (!s) {
+ kfree(hist_data->attrs->var_defs.name[n_vars]);
+ ret = -ENOMEM;
+ goto free;
+ }
+ hist_data->attrs->var_defs.expr[n_vars++] = s;
+
+ hist_data->attrs->var_defs.n_vars = n_vars;
+ }
+ }
+
+ return ret;
+ free:
+ free_var_defs(hist_data);
+
+ return ret;
+}
+
static int create_hist_fields(struct hist_trigger_data *hist_data,
struct trace_event_file *file)
{
int ret;
+ ret = parse_var_defs(hist_data);
+ if (ret)
+ goto out;
+
ret = create_val_fields(hist_data, file);
if (ret)
goto out;
- ret = create_key_fields(hist_data, file);
+ ret = create_var_fields(hist_data, file);
if (ret)
goto out;
- hist_data->n_fields = hist_data->n_vals + hist_data->n_keys;
+ ret = create_key_fields(hist_data, file);
+ if (ret)
+ goto out;
out:
+ free_var_defs(hist_data);
+
return ret;
}
@@ -768,7 +990,7 @@ static int create_sort_keys(struct hist_trigger_data *hist_data)
char *fields_str = hist_data->attrs->sort_key_str;
struct tracing_map_sort_key *sort_key;
int descending, ret = 0;
- unsigned int i, j;
+ unsigned int i, j, k;
hist_data->n_sort_keys = 1; /* we always have at least one, hitcount */
@@ -816,12 +1038,19 @@ static int create_sort_keys(struct hist_trigger_data *hist_data)
continue;
}
- for (j = 1; j < hist_data->n_fields; j++) {
+ for (j = 1, k = 1; j < hist_data->n_fields; j++) {
+ unsigned int idx;
+
hist_field = hist_data->fields[j];
+ if (hist_field->flags & HIST_FIELD_FL_VAR)
+ continue;
+
+ idx = k++;
+
test_name = hist_field_name(hist_field, 0);
if (strcmp(field_name, test_name) == 0) {
- sort_key->field_idx = j;
+ sort_key->field_idx = idx;
descending = is_descending(field_str);
if (descending < 0) {
ret = descending;
@@ -836,6 +1065,7 @@ static int create_sort_keys(struct hist_trigger_data *hist_data)
break;
}
}
+
hist_data->n_sort_keys = i;
out:
return ret;
@@ -876,12 +1106,19 @@ static int create_tracing_map_fields(struct hist_trigger_data *hist_data)
idx = tracing_map_add_key_field(map,
hist_field->offset,
cmp_fn);
-
- } else
+ } else if (!(hist_field->flags & HIST_FIELD_FL_VAR))
idx = tracing_map_add_sum_field(map);
if (idx < 0)
return idx;
+
+ if (hist_field->flags & HIST_FIELD_FL_VAR) {
+ idx = tracing_map_add_var(map);
+ if (idx < 0)
+ return idx;
+ hist_field->var.idx = idx;
+ hist_field->var.hist_data = hist_data;
+ }
}
return 0;
@@ -905,7 +1142,8 @@ static bool need_tracing_map_ops(struct hist_trigger_data *hist_data)
static struct hist_trigger_data *
create_hist_data(unsigned int map_bits,
struct hist_trigger_attrs *attrs,
- struct trace_event_file *file)
+ struct trace_event_file *file,
+ bool remove)
{
const struct tracing_map_ops *map_ops = NULL;
struct hist_trigger_data *hist_data;
@@ -916,6 +1154,7 @@ create_hist_data(unsigned int map_bits,
return ERR_PTR(-ENOMEM);
hist_data->attrs = attrs;
+ hist_data->remove = remove;
ret = create_hist_fields(hist_data, file);
if (ret)
@@ -962,14 +1201,28 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
struct ring_buffer_event *rbe)
{
struct hist_field *hist_field;
- unsigned int i;
+ unsigned int i, var_idx;
u64 hist_val;
for_each_hist_val_field(i, hist_data) {
hist_field = hist_data->fields[i];
hist_val = hist_field->fn(hist_field, rec, rbe);
+ if (hist_field->flags & HIST_FIELD_FL_VAR) {
+ var_idx = hist_field->var.idx;
+ tracing_map_set_var(elt, var_idx, hist_val);
+ continue;
+ }
tracing_map_update_sum(elt, i, hist_val);
}
+
+ for_each_hist_key_field(i, hist_data) {
+ hist_field = hist_data->fields[i];
+ if (hist_field->flags & HIST_FIELD_FL_VAR) {
+ hist_val = hist_field->fn(hist_field, rec, rbe);
+ var_idx = hist_field->var.idx;
+ tracing_map_set_var(elt, var_idx, hist_val);
+ }
+ }
}
static inline void add_to_key(char *compound_key, void *key,
@@ -1144,6 +1397,9 @@ hist_trigger_entry_print(struct seq_file *m,
for (i = 1; i < hist_data->n_vals; i++) {
field_name = hist_field_name(hist_data->fields[i], 0);
+ if (hist_data->fields[i]->flags & HIST_FIELD_FL_VAR)
+ continue;
+
if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) {
seq_printf(m, " %s: %10llx", field_name,
tracing_map_read_sum(elt, i));
@@ -1265,6 +1521,9 @@ static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
{
const char *field_name = hist_field_name(hist_field, 0);
+ if (hist_field->var.name)
+ seq_printf(m, "%s=", hist_field->var.name);
+
if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP)
seq_puts(m, "common_timestamp");
else if (field_name)
@@ -1283,7 +1542,8 @@ static int event_hist_trigger_print(struct seq_file *m,
struct event_trigger_data *data)
{
struct hist_trigger_data *hist_data = data->private_data;
- struct hist_field *key_field;
+ struct hist_field *field;
+ bool have_var = false;
unsigned int i;
seq_puts(m, "hist:");
@@ -1294,25 +1554,47 @@ static int event_hist_trigger_print(struct seq_file *m,
seq_puts(m, "keys=");
for_each_hist_key_field(i, hist_data) {
- key_field = hist_data->fields[i];
+ field = hist_data->fields[i];
if (i > hist_data->n_vals)
seq_puts(m, ",");
- if (key_field->flags & HIST_FIELD_FL_STACKTRACE)
+ if (field->flags & HIST_FIELD_FL_STACKTRACE)
seq_puts(m, "stacktrace");
else
- hist_field_print(m, key_field);
+ hist_field_print(m, field);
}
seq_puts(m, ":vals=");
for_each_hist_val_field(i, hist_data) {
+ field = hist_data->fields[i];
+ if (field->flags & HIST_FIELD_FL_VAR) {
+ have_var = true;
+ continue;
+ }
+
if (i == HITCOUNT_IDX)
seq_puts(m, "hitcount");
else {
seq_puts(m, ",");
- hist_field_print(m, hist_data->fields[i]);
+ hist_field_print(m, field);
+ }
+ }
+
+ if (have_var) {
+ unsigned int n = 0;
+
+ seq_puts(m, ":");
+
+ for_each_hist_val_field(i, hist_data) {
+ field = hist_data->fields[i];
+
+ if (field->flags & HIST_FIELD_FL_VAR) {
+ if (n++)
+ seq_puts(m, ",");
+ hist_field_print(m, field);
+ }
}
}
@@ -1320,7 +1602,10 @@ static int event_hist_trigger_print(struct seq_file *m,
for (i = 0; i < hist_data->n_sort_keys; i++) {
struct tracing_map_sort_key *sort_key;
- unsigned int idx;
+ unsigned int idx, first_key_idx;
+
+ /* skip VAR vals */
+ first_key_idx = hist_data->n_vals - hist_data->n_vars;
sort_key = &hist_data->sort_keys[i];
idx = sort_key->field_idx;
@@ -1333,8 +1618,11 @@ static int event_hist_trigger_print(struct seq_file *m,
if (idx == HITCOUNT_IDX)
seq_puts(m, "hitcount");
- else
+ else {
+ if (idx >= first_key_idx)
+ idx += hist_data->n_vars;
hist_field_print(m, hist_data->fields[idx]);
+ }
if (sort_key->descending)
seq_puts(m, ".descending");
@@ -1631,7 +1919,7 @@ static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops,
test->ops->free(test->ops, test);
if (hist_data->enable_timestamps) {
- if (unregistered)
+ if (!hist_data->remove || unregistered)
tracing_set_time_stamp_abs(file->tr, false);
}
}
@@ -1664,12 +1952,16 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
struct hist_trigger_attrs *attrs;
struct event_trigger_ops *trigger_ops;
struct hist_trigger_data *hist_data;
+ bool remove = false;
char *trigger;
int ret = 0;
if (!param)
return -EINVAL;
+ if (glob[0] == '!')
+ remove = true;
+
/* separate the trigger from the filter (k:v [if filter]) */
trigger = strsep(¶m, " \t");
if (!trigger)
@@ -1682,7 +1974,7 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
if (attrs->map_bits)
hist_trigger_bits = attrs->map_bits;
- hist_data = create_hist_data(hist_trigger_bits, attrs, file);
+ hist_data = create_hist_data(hist_trigger_bits, attrs, file, remove);
if (IS_ERR(hist_data)) {
destroy_hist_trigger_attrs(attrs);
return PTR_ERR(hist_data);
@@ -1711,7 +2003,7 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
goto out_free;
}
- if (glob[0] == '!') {
+ if (remove) {
cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
ret = 0;
goto out_free;
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 16/46] tracing: Account for variables in named trigger compatibility
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (14 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 15/46] tracing: Add variable support to hist triggers Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 17/46] tracing: Move get_hist_field_flags() Steven Rostedt
` (29 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0016-tracing-Account-for-variables-in-named-trigger-compa.patch --]
[-- Type: text/plain, Size: 1576 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Named triggers must also have the same set of variables in order to be
considered compatible - update the trigger match test to account for
that.
The reason for this requirement is that named triggers with variables
are meant to allow one or more events to set the same variable.
Link: http://lkml.kernel.org/r/a17eae6328a99917f9d5c66129c9fcd355279ee9.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 8f43f24bf49c..ba326260c034 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1610,7 +1610,7 @@ static int event_hist_trigger_print(struct seq_file *m,
sort_key = &hist_data->sort_keys[i];
idx = sort_key->field_idx;
- if (WARN_ON(idx >= TRACING_MAP_FIELDS_MAX))
+ if (WARN_ON(idx >= HIST_FIELDS_MAX))
return -EINVAL;
if (i > 0)
@@ -1798,6 +1798,11 @@ static bool hist_trigger_match(struct event_trigger_data *data,
return false;
if (key_field->is_signed != key_field_test->is_signed)
return false;
+ if (!!key_field->var.name != !!key_field_test->var.name)
+ return false;
+ if (key_field->var.name &&
+ strcmp(key_field->var.name, key_field_test->var.name) != 0)
+ return false;
}
for (i = 0; i < hist_data->n_sort_keys; i++) {
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 17/46] tracing: Move get_hist_field_flags()
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (15 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 16/46] tracing: Account for variables in named trigger compatibility Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 18/46] tracing: Add simple expression support to hist triggers Steven Rostedt
` (28 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0017-tracing-Move-get_hist_field_flags.patch --]
[-- Type: text/plain, Size: 2606 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Move get_hist_field_flags() to make it more easily accessible for new
code (and keep the move separate from new functionality).
Link: http://lkml.kernel.org/r/32470f0a7047ec7a6e84ba5ec89d6142cc6ede7d.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 44 ++++++++++++++++++++--------------------
1 file changed, 22 insertions(+), 22 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index ba326260c034..a81a709dc703 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -497,6 +497,28 @@ static const struct tracing_map_ops hist_trigger_elt_comm_ops = {
.elt_init = hist_trigger_elt_comm_init,
};
+static const char *get_hist_field_flags(struct hist_field *hist_field)
+{
+ const char *flags_str = NULL;
+
+ if (hist_field->flags & HIST_FIELD_FL_HEX)
+ flags_str = "hex";
+ else if (hist_field->flags & HIST_FIELD_FL_SYM)
+ flags_str = "sym";
+ else if (hist_field->flags & HIST_FIELD_FL_SYM_OFFSET)
+ flags_str = "sym-offset";
+ else if (hist_field->flags & HIST_FIELD_FL_EXECNAME)
+ flags_str = "execname";
+ else if (hist_field->flags & HIST_FIELD_FL_SYSCALL)
+ flags_str = "syscall";
+ else if (hist_field->flags & HIST_FIELD_FL_LOG2)
+ flags_str = "log2";
+ else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP_USECS)
+ flags_str = "usecs";
+
+ return flags_str;
+}
+
static void destroy_hist_field(struct hist_field *hist_field,
unsigned int level)
{
@@ -1495,28 +1517,6 @@ const struct file_operations event_hist_fops = {
.release = single_release,
};
-static const char *get_hist_field_flags(struct hist_field *hist_field)
-{
- const char *flags_str = NULL;
-
- if (hist_field->flags & HIST_FIELD_FL_HEX)
- flags_str = "hex";
- else if (hist_field->flags & HIST_FIELD_FL_SYM)
- flags_str = "sym";
- else if (hist_field->flags & HIST_FIELD_FL_SYM_OFFSET)
- flags_str = "sym-offset";
- else if (hist_field->flags & HIST_FIELD_FL_EXECNAME)
- flags_str = "execname";
- else if (hist_field->flags & HIST_FIELD_FL_SYSCALL)
- flags_str = "syscall";
- else if (hist_field->flags & HIST_FIELD_FL_LOG2)
- flags_str = "log2";
- else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP_USECS)
- flags_str = "usecs";
-
- return flags_str;
-}
-
static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
{
const char *field_name = hist_field_name(hist_field, 0);
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 18/46] tracing: Add simple expression support to hist triggers
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (16 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 17/46] tracing: Move get_hist_field_flags() Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 19/46] tracing: Generalize per-element hist trigger data Steven Rostedt
` (27 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi, Fengguang Wu
[-- Attachment #1: 0018-tracing-Add-simple-expression-support-to-hist-trigge.patch --]
[-- Type: text/plain, Size: 16445 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Add support for simple addition, subtraction, and unary expressions
(-(expr) and expr, where expr = b-a, a+b, a+b+c) to hist triggers, in
order to support a minimal set of useful inter-event calculations.
These operations are needed for calculating latencies between events
(timestamp1-timestamp0) and for combined latencies (latencies over 3
or more events).
In the process, factor out some common code from key and value
parsing.
Link: http://lkml.kernel.org/r/9a9308ead4fe32a433d9c7e95921fb798394f6b2.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[kbuild test robot fix, add static to parse_atom()]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
[ Replaced '//' comments with normal /* */ comments ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 487 +++++++++++++++++++++++++++++++++------
1 file changed, 413 insertions(+), 74 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index a81a709dc703..4c3c7d784bfd 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -32,6 +32,13 @@ typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event,
#define HIST_FIELD_OPERANDS_MAX 2
#define HIST_FIELDS_MAX (TRACING_MAP_FIELDS_MAX + TRACING_MAP_VARS_MAX)
+enum field_op_id {
+ FIELD_OP_NONE,
+ FIELD_OP_PLUS,
+ FIELD_OP_MINUS,
+ FIELD_OP_UNARY_MINUS,
+};
+
struct hist_var {
char *name;
struct hist_trigger_data *hist_data;
@@ -48,6 +55,8 @@ struct hist_field {
struct hist_field *operands[HIST_FIELD_OPERANDS_MAX];
struct hist_trigger_data *hist_data;
struct hist_var var;
+ enum field_op_id operator;
+ char *name;
};
static u64 hist_field_none(struct hist_field *field, void *event,
@@ -98,6 +107,41 @@ static u64 hist_field_log2(struct hist_field *hist_field, void *event,
return (u64) ilog2(roundup_pow_of_two(val));
}
+static u64 hist_field_plus(struct hist_field *hist_field, void *event,
+ struct ring_buffer_event *rbe)
+{
+ struct hist_field *operand1 = hist_field->operands[0];
+ struct hist_field *operand2 = hist_field->operands[1];
+
+ u64 val1 = operand1->fn(operand1, event, rbe);
+ u64 val2 = operand2->fn(operand2, event, rbe);
+
+ return val1 + val2;
+}
+
+static u64 hist_field_minus(struct hist_field *hist_field, void *event,
+ struct ring_buffer_event *rbe)
+{
+ struct hist_field *operand1 = hist_field->operands[0];
+ struct hist_field *operand2 = hist_field->operands[1];
+
+ u64 val1 = operand1->fn(operand1, event, rbe);
+ u64 val2 = operand2->fn(operand2, event, rbe);
+
+ return val1 - val2;
+}
+
+static u64 hist_field_unary_minus(struct hist_field *hist_field, void *event,
+ struct ring_buffer_event *rbe)
+{
+ struct hist_field *operand = hist_field->operands[0];
+
+ s64 sval = (s64)operand->fn(operand, event, rbe);
+ u64 val = (u64)-sval;
+
+ return val;
+}
+
#define DEFINE_HIST_FIELD_FN(type) \
static u64 hist_field_##type(struct hist_field *hist_field, \
void *event, \
@@ -147,6 +191,7 @@ enum hist_field_flags {
HIST_FIELD_FL_TIMESTAMP = 1 << 10,
HIST_FIELD_FL_TIMESTAMP_USECS = 1 << 11,
HIST_FIELD_FL_VAR = 1 << 12,
+ HIST_FIELD_FL_EXPR = 1 << 13,
};
struct var_defs {
@@ -258,6 +303,8 @@ static const char *hist_field_name(struct hist_field *field,
field_name = hist_field_name(field->operands[0], ++level);
else if (field->flags & HIST_FIELD_FL_TIMESTAMP)
field_name = "common_timestamp";
+ else if (field->flags & HIST_FIELD_FL_EXPR)
+ field_name = field->name;
if (field_name == NULL)
field_name = "";
@@ -519,12 +566,104 @@ static const char *get_hist_field_flags(struct hist_field *hist_field)
return flags_str;
}
+static void expr_field_str(struct hist_field *field, char *expr)
+{
+ strcat(expr, hist_field_name(field, 0));
+
+ if (field->flags) {
+ const char *flags_str = get_hist_field_flags(field);
+
+ if (flags_str) {
+ strcat(expr, ".");
+ strcat(expr, flags_str);
+ }
+ }
+}
+
+static char *expr_str(struct hist_field *field, unsigned int level)
+{
+ char *expr;
+
+ if (level > 1)
+ return NULL;
+
+ expr = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
+ if (!expr)
+ return NULL;
+
+ if (!field->operands[0]) {
+ expr_field_str(field, expr);
+ return expr;
+ }
+
+ if (field->operator == FIELD_OP_UNARY_MINUS) {
+ char *subexpr;
+
+ strcat(expr, "-(");
+ subexpr = expr_str(field->operands[0], ++level);
+ if (!subexpr) {
+ kfree(expr);
+ return NULL;
+ }
+ strcat(expr, subexpr);
+ strcat(expr, ")");
+
+ kfree(subexpr);
+
+ return expr;
+ }
+
+ expr_field_str(field->operands[0], expr);
+
+ switch (field->operator) {
+ case FIELD_OP_MINUS:
+ strcat(expr, "-");
+ break;
+ case FIELD_OP_PLUS:
+ strcat(expr, "+");
+ break;
+ default:
+ kfree(expr);
+ return NULL;
+ }
+
+ expr_field_str(field->operands[1], expr);
+
+ return expr;
+}
+
+static int contains_operator(char *str)
+{
+ enum field_op_id field_op = FIELD_OP_NONE;
+ char *op;
+
+ op = strpbrk(str, "+-");
+ if (!op)
+ return FIELD_OP_NONE;
+
+ switch (*op) {
+ case '-':
+ if (*str == '-')
+ field_op = FIELD_OP_UNARY_MINUS;
+ else
+ field_op = FIELD_OP_MINUS;
+ break;
+ case '+':
+ field_op = FIELD_OP_PLUS;
+ break;
+ default:
+ break;
+ }
+
+ return field_op;
+}
+
static void destroy_hist_field(struct hist_field *hist_field,
unsigned int level)
{
unsigned int i;
- if (level > 2)
+ if (level > 3)
return;
if (!hist_field)
@@ -534,6 +673,7 @@ static void destroy_hist_field(struct hist_field *hist_field,
destroy_hist_field(hist_field->operands[i], level + 1);
kfree(hist_field->var.name);
+ kfree(hist_field->name);
kfree(hist_field);
}
@@ -554,6 +694,9 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
hist_field->hist_data = hist_data;
+ if (flags & HIST_FIELD_FL_EXPR)
+ goto out; /* caller will populate */
+
if (flags & HIST_FIELD_FL_HITCOUNT) {
hist_field->fn = hist_field_counter;
goto out;
@@ -626,6 +769,257 @@ static void destroy_hist_fields(struct hist_trigger_data *hist_data)
}
}
+static struct ftrace_event_field *
+parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file,
+ char *field_str, unsigned long *flags)
+{
+ struct ftrace_event_field *field = NULL;
+ char *field_name, *modifier, *str;
+
+ modifier = str = kstrdup(field_str, GFP_KERNEL);
+ if (!modifier)
+ return ERR_PTR(-ENOMEM);
+
+ field_name = strsep(&modifier, ".");
+ if (modifier) {
+ if (strcmp(modifier, "hex") == 0)
+ *flags |= HIST_FIELD_FL_HEX;
+ else if (strcmp(modifier, "sym") == 0)
+ *flags |= HIST_FIELD_FL_SYM;
+ else if (strcmp(modifier, "sym-offset") == 0)
+ *flags |= HIST_FIELD_FL_SYM_OFFSET;
+ else if ((strcmp(modifier, "execname") == 0) &&
+ (strcmp(field_name, "common_pid") == 0))
+ *flags |= HIST_FIELD_FL_EXECNAME;
+ else if (strcmp(modifier, "syscall") == 0)
+ *flags |= HIST_FIELD_FL_SYSCALL;
+ else if (strcmp(modifier, "log2") == 0)
+ *flags |= HIST_FIELD_FL_LOG2;
+ else if (strcmp(modifier, "usecs") == 0)
+ *flags |= HIST_FIELD_FL_TIMESTAMP_USECS;
+ else {
+ field = ERR_PTR(-EINVAL);
+ goto out;
+ }
+ }
+
+ if (strcmp(field_name, "common_timestamp") == 0) {
+ *flags |= HIST_FIELD_FL_TIMESTAMP;
+ hist_data->enable_timestamps = true;
+ if (*flags & HIST_FIELD_FL_TIMESTAMP_USECS)
+ hist_data->attrs->ts_in_usecs = true;
+ } else {
+ field = trace_find_event_field(file->event_call, field_name);
+ if (!field || !field->size) {
+ field = ERR_PTR(-EINVAL);
+ goto out;
+ }
+ }
+ out:
+ kfree(str);
+
+ return field;
+}
+
+static struct hist_field *parse_atom(struct hist_trigger_data *hist_data,
+ struct trace_event_file *file, char *str,
+ unsigned long *flags, char *var_name)
+{
+ struct ftrace_event_field *field = NULL;
+ struct hist_field *hist_field = NULL;
+ int ret = 0;
+
+ field = parse_field(hist_data, file, str, flags);
+ if (IS_ERR(field)) {
+ ret = PTR_ERR(field);
+ goto out;
+ }
+
+ hist_field = create_hist_field(hist_data, field, *flags, var_name);
+ if (!hist_field) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ return hist_field;
+ out:
+ return ERR_PTR(ret);
+}
+
+static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
+ struct trace_event_file *file,
+ char *str, unsigned long flags,
+ char *var_name, unsigned int level);
+
+static struct hist_field *parse_unary(struct hist_trigger_data *hist_data,
+ struct trace_event_file *file,
+ char *str, unsigned long flags,
+ char *var_name, unsigned int level)
+{
+ struct hist_field *operand1, *expr = NULL;
+ unsigned long operand_flags;
+ int ret = 0;
+ char *s;
+
+ /* we support only -(xxx) i.e. explicit parens required */
+
+ if (level > 3) {
+ ret = -EINVAL;
+ goto free;
+ }
+
+ str++; /* skip leading '-' */
+
+ s = strchr(str, '(');
+ if (s)
+ str++;
+ else {
+ ret = -EINVAL;
+ goto free;
+ }
+
+ s = strrchr(str, ')');
+ if (s)
+ *s = '\0';
+ else {
+ ret = -EINVAL; /* no closing ')' */
+ goto free;
+ }
+
+ flags |= HIST_FIELD_FL_EXPR;
+ expr = create_hist_field(hist_data, NULL, flags, var_name);
+ if (!expr) {
+ ret = -ENOMEM;
+ goto free;
+ }
+
+ operand_flags = 0;
+ operand1 = parse_expr(hist_data, file, str, operand_flags, NULL, ++level);
+ if (IS_ERR(operand1)) {
+ ret = PTR_ERR(operand1);
+ goto free;
+ }
+
+ expr->flags |= operand1->flags &
+ (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
+ expr->fn = hist_field_unary_minus;
+ expr->operands[0] = operand1;
+ expr->operator = FIELD_OP_UNARY_MINUS;
+ expr->name = expr_str(expr, 0);
+
+ return expr;
+ free:
+ destroy_hist_field(expr, 0);
+ return ERR_PTR(ret);
+}
+
+static int check_expr_operands(struct hist_field *operand1,
+ struct hist_field *operand2)
+{
+ unsigned long operand1_flags = operand1->flags;
+ unsigned long operand2_flags = operand2->flags;
+
+ if ((operand1_flags & HIST_FIELD_FL_TIMESTAMP_USECS) !=
+ (operand2_flags & HIST_FIELD_FL_TIMESTAMP_USECS))
+ return -EINVAL;
+
+ return 0;
+}
+
+static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
+ struct trace_event_file *file,
+ char *str, unsigned long flags,
+ char *var_name, unsigned int level)
+{
+ struct hist_field *operand1 = NULL, *operand2 = NULL, *expr = NULL;
+ unsigned long operand_flags;
+ int field_op, ret = -EINVAL;
+ char *sep, *operand1_str;
+
+ if (level > 3)
+ return ERR_PTR(-EINVAL);
+
+ field_op = contains_operator(str);
+
+ if (field_op == FIELD_OP_NONE)
+ return parse_atom(hist_data, file, str, &flags, var_name);
+
+ if (field_op == FIELD_OP_UNARY_MINUS)
+ return parse_unary(hist_data, file, str, flags, var_name, ++level);
+
+ switch (field_op) {
+ case FIELD_OP_MINUS:
+ sep = "-";
+ break;
+ case FIELD_OP_PLUS:
+ sep = "+";
+ break;
+ default:
+ goto free;
+ }
+
+ operand1_str = strsep(&str, sep);
+ if (!operand1_str || !str)
+ goto free;
+
+ operand_flags = 0;
+ operand1 = parse_atom(hist_data, file, operand1_str,
+ &operand_flags, NULL);
+ if (IS_ERR(operand1)) {
+ ret = PTR_ERR(operand1);
+ operand1 = NULL;
+ goto free;
+ }
+
+ /* rest of string could be another expression e.g. b+c in a+b+c */
+ operand_flags = 0;
+ operand2 = parse_expr(hist_data, file, str, operand_flags, NULL, ++level);
+ if (IS_ERR(operand2)) {
+ ret = PTR_ERR(operand2);
+ operand2 = NULL;
+ goto free;
+ }
+
+ ret = check_expr_operands(operand1, operand2);
+ if (ret)
+ goto free;
+
+ flags |= HIST_FIELD_FL_EXPR;
+
+ flags |= operand1->flags &
+ (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
+
+ expr = create_hist_field(hist_data, NULL, flags, var_name);
+ if (!expr) {
+ ret = -ENOMEM;
+ goto free;
+ }
+
+ expr->operands[0] = operand1;
+ expr->operands[1] = operand2;
+ expr->operator = field_op;
+ expr->name = expr_str(expr, 0);
+
+ switch (field_op) {
+ case FIELD_OP_MINUS:
+ expr->fn = hist_field_minus;
+ break;
+ case FIELD_OP_PLUS:
+ expr->fn = hist_field_plus;
+ break;
+ default:
+ goto free;
+ }
+
+ return expr;
+ free:
+ destroy_hist_field(operand1, 0);
+ destroy_hist_field(operand2, 0);
+ destroy_hist_field(expr, 0);
+
+ return ERR_PTR(ret);
+}
+
static int create_hitcount_val(struct hist_trigger_data *hist_data)
{
hist_data->fields[HITCOUNT_IDX] =
@@ -648,37 +1042,17 @@ static int __create_val_field(struct hist_trigger_data *hist_data,
char *var_name, char *field_str,
unsigned long flags)
{
- struct ftrace_event_field *field = NULL;
- char *field_name;
+ struct hist_field *hist_field;
int ret = 0;
- field_name = strsep(&field_str, ".");
- if (field_str) {
- if (strcmp(field_str, "hex") == 0)
- flags |= HIST_FIELD_FL_HEX;
- else {
- ret = -EINVAL;
- goto out;
- }
- }
-
- if (strcmp(field_name, "common_timestamp") == 0) {
- flags |= HIST_FIELD_FL_TIMESTAMP;
- hist_data->enable_timestamps = true;
- } else {
- field = trace_find_event_field(file->event_call, field_name);
- if (!field || !field->size) {
- ret = -EINVAL;
- goto out;
- }
- }
-
- hist_data->fields[val_idx] = create_hist_field(hist_data, field, flags, var_name);
- if (!hist_data->fields[val_idx]) {
- ret = -ENOMEM;
+ hist_field = parse_expr(hist_data, file, field_str, flags, var_name, 0);
+ if (IS_ERR(hist_field)) {
+ ret = PTR_ERR(hist_field);
goto out;
}
+ hist_data->fields[val_idx] = hist_field;
+
++hist_data->n_vals;
++hist_data->n_fields;
@@ -765,8 +1139,8 @@ static int create_key_field(struct hist_trigger_data *hist_data,
struct trace_event_file *file,
char *field_str)
{
- struct ftrace_event_field *field = NULL;
struct hist_field *hist_field = NULL;
+
unsigned long flags = 0;
unsigned int key_size;
int ret = 0;
@@ -781,60 +1155,24 @@ static int create_key_field(struct hist_trigger_data *hist_data,
key_size = sizeof(unsigned long) * HIST_STACKTRACE_DEPTH;
hist_field = create_hist_field(hist_data, NULL, flags, NULL);
} else {
- char *field_name = strsep(&field_str, ".");
-
- if (field_str) {
- if (strcmp(field_str, "hex") == 0)
- flags |= HIST_FIELD_FL_HEX;
- else if (strcmp(field_str, "sym") == 0)
- flags |= HIST_FIELD_FL_SYM;
- else if (strcmp(field_str, "sym-offset") == 0)
- flags |= HIST_FIELD_FL_SYM_OFFSET;
- else if ((strcmp(field_str, "execname") == 0) &&
- (strcmp(field_name, "common_pid") == 0))
- flags |= HIST_FIELD_FL_EXECNAME;
- else if (strcmp(field_str, "syscall") == 0)
- flags |= HIST_FIELD_FL_SYSCALL;
- else if (strcmp(field_str, "log2") == 0)
- flags |= HIST_FIELD_FL_LOG2;
- else if (strcmp(field_str, "usecs") == 0)
- flags |= HIST_FIELD_FL_TIMESTAMP_USECS;
- else {
- ret = -EINVAL;
- goto out;
- }
+ hist_field = parse_expr(hist_data, file, field_str, flags,
+ NULL, 0);
+ if (IS_ERR(hist_field)) {
+ ret = PTR_ERR(hist_field);
+ goto out;
}
- if (strcmp(field_name, "common_timestamp") == 0) {
- flags |= HIST_FIELD_FL_TIMESTAMP;
- hist_data->enable_timestamps = true;
- if (flags & HIST_FIELD_FL_TIMESTAMP_USECS)
- hist_data->attrs->ts_in_usecs = true;
- key_size = sizeof(u64);
- } else {
- field = trace_find_event_field(file->event_call, field_name);
- if (!field || !field->size) {
- ret = -EINVAL;
- goto out;
- }
-
- if (is_string_field(field))
- key_size = MAX_FILTER_STR_VAL;
- else
- key_size = field->size;
- }
+ key_size = hist_field->size;
}
- hist_data->fields[key_idx] = create_hist_field(hist_data, field, flags, NULL);
- if (!hist_data->fields[key_idx]) {
- ret = -ENOMEM;
- goto out;
- }
+ hist_data->fields[key_idx] = hist_field;
key_size = ALIGN(key_size, sizeof(u64));
hist_data->fields[key_idx]->size = key_size;
hist_data->fields[key_idx]->offset = key_offset;
+
hist_data->key_size += key_size;
+
if (hist_data->key_size > HIST_KEY_SIZE_MAX) {
ret = -EINVAL;
goto out;
@@ -1419,7 +1757,8 @@ hist_trigger_entry_print(struct seq_file *m,
for (i = 1; i < hist_data->n_vals; i++) {
field_name = hist_field_name(hist_data->fields[i], 0);
- if (hist_data->fields[i]->flags & HIST_FIELD_FL_VAR)
+ if (hist_data->fields[i]->flags & HIST_FIELD_FL_VAR ||
+ hist_data->fields[i]->flags & HIST_FIELD_FL_EXPR)
continue;
if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) {
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 19/46] tracing: Generalize per-element hist trigger data
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (17 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 18/46] tracing: Add simple expression support to hist triggers Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 20/46] tracing: Pass tracing_map_elt to hist_field accessor functions Steven Rostedt
` (26 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0019-tracing-Generalize-per-element-hist-trigger-data.patch --]
[-- Type: text/plain, Size: 4708 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Up until now, hist triggers only needed per-element support for saving
'comm' data, which was saved directly as a private data pointer.
In anticipation of the need to save other data besides 'comm', add a
new hist_elt_data struct for the purpose, and switch the current
'comm'-related code over to that.
Link: http://lkml.kernel.org/r/4502c338c965ddf5fc19fb1ec4764391e001ed4b.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 76 +++++++++++++++++++++++-----------------
1 file changed, 43 insertions(+), 33 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 4c3c7d784bfd..f072ed3122c8 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -289,6 +289,10 @@ static struct hist_field *find_var(struct hist_trigger_data *hist_data,
return NULL;
}
+struct hist_elt_data {
+ char *comm;
+};
+
static const char *hist_field_name(struct hist_field *field,
unsigned int level)
{
@@ -503,45 +507,61 @@ static inline void save_comm(char *comm, struct task_struct *task)
memcpy(comm, task->comm, TASK_COMM_LEN);
}
-static void hist_trigger_elt_comm_free(struct tracing_map_elt *elt)
+static void hist_elt_data_free(struct hist_elt_data *elt_data)
+{
+ kfree(elt_data->comm);
+ kfree(elt_data);
+}
+
+static void hist_trigger_elt_data_free(struct tracing_map_elt *elt)
{
- kfree((char *)elt->private_data);
+ struct hist_elt_data *elt_data = elt->private_data;
+
+ hist_elt_data_free(elt_data);
}
-static int hist_trigger_elt_comm_alloc(struct tracing_map_elt *elt)
+static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt)
{
struct hist_trigger_data *hist_data = elt->map->private_data;
+ unsigned int size = TASK_COMM_LEN;
+ struct hist_elt_data *elt_data;
struct hist_field *key_field;
unsigned int i;
+ elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL);
+ if (!elt_data)
+ return -ENOMEM;
+
for_each_hist_key_field(i, hist_data) {
key_field = hist_data->fields[i];
if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
- unsigned int size = TASK_COMM_LEN + 1;
-
- elt->private_data = kzalloc(size, GFP_KERNEL);
- if (!elt->private_data)
+ elt_data->comm = kzalloc(size, GFP_KERNEL);
+ if (!elt_data->comm) {
+ kfree(elt_data);
return -ENOMEM;
+ }
break;
}
}
+ elt->private_data = elt_data;
+
return 0;
}
-static void hist_trigger_elt_comm_init(struct tracing_map_elt *elt)
+static void hist_trigger_elt_data_init(struct tracing_map_elt *elt)
{
- char *comm = elt->private_data;
+ struct hist_elt_data *elt_data = elt->private_data;
- if (comm)
- save_comm(comm, current);
+ if (elt_data->comm)
+ save_comm(elt_data->comm, current);
}
-static const struct tracing_map_ops hist_trigger_elt_comm_ops = {
- .elt_alloc = hist_trigger_elt_comm_alloc,
- .elt_free = hist_trigger_elt_comm_free,
- .elt_init = hist_trigger_elt_comm_init,
+static const struct tracing_map_ops hist_trigger_elt_data_ops = {
+ .elt_alloc = hist_trigger_elt_data_alloc,
+ .elt_free = hist_trigger_elt_data_free,
+ .elt_init = hist_trigger_elt_data_init,
};
static const char *get_hist_field_flags(struct hist_field *hist_field)
@@ -1484,21 +1504,6 @@ static int create_tracing_map_fields(struct hist_trigger_data *hist_data)
return 0;
}
-static bool need_tracing_map_ops(struct hist_trigger_data *hist_data)
-{
- struct hist_field *key_field;
- unsigned int i;
-
- for_each_hist_key_field(i, hist_data) {
- key_field = hist_data->fields[i];
-
- if (key_field->flags & HIST_FIELD_FL_EXECNAME)
- return true;
- }
-
- return false;
-}
-
static struct hist_trigger_data *
create_hist_data(unsigned int map_bits,
struct hist_trigger_attrs *attrs,
@@ -1524,8 +1529,7 @@ create_hist_data(unsigned int map_bits,
if (ret)
goto free;
- if (need_tracing_map_ops(hist_data))
- map_ops = &hist_trigger_elt_comm_ops;
+ map_ops = &hist_trigger_elt_data_ops;
hist_data->map = tracing_map_create(map_bits, hist_data->key_size,
map_ops, hist_data);
@@ -1713,7 +1717,13 @@ hist_trigger_entry_print(struct seq_file *m,
seq_printf(m, "%s: [%llx] %-55s", field_name,
uval, str);
} else if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
- char *comm = elt->private_data;
+ struct hist_elt_data *elt_data = elt->private_data;
+ char *comm;
+
+ if (WARN_ON_ONCE(!elt_data))
+ return;
+
+ comm = elt_data->comm;
uval = *(u64 *)(key + key_field->offset);
seq_printf(m, "%s: %-16s[%10llu]", field_name,
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 20/46] tracing: Pass tracing_map_elt to hist_field accessor functions
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (18 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 19/46] tracing: Generalize per-element hist trigger data Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 21/46] tracing: Add hist_field type field Steven Rostedt
` (25 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0020-tracing-Pass-tracing_map_elt-to-hist_field-accessor-.patch --]
[-- Type: text/plain, Size: 7932 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Some accessor functions, such as for variable references, require
access to a corrsponding tracing_map_elt.
Add a tracing_map_elt param to the function signature and update the
accessor functions accordingly.
Link: http://lkml.kernel.org/r/e0f292b068e9e4948da1d5af21b5ae0efa9b5717.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 91 +++++++++++++++++++++++++---------------
1 file changed, 57 insertions(+), 34 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index f072ed3122c8..7a54ab50176b 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -26,8 +26,10 @@
struct hist_field;
-typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event,
- struct ring_buffer_event *rbe);
+typedef u64 (*hist_field_fn_t) (struct hist_field *field,
+ struct tracing_map_elt *elt,
+ struct ring_buffer_event *rbe,
+ void *event);
#define HIST_FIELD_OPERANDS_MAX 2
#define HIST_FIELDS_MAX (TRACING_MAP_FIELDS_MAX + TRACING_MAP_VARS_MAX)
@@ -59,28 +61,36 @@ struct hist_field {
char *name;
};
-static u64 hist_field_none(struct hist_field *field, void *event,
- struct ring_buffer_event *rbe)
+static u64 hist_field_none(struct hist_field *field,
+ struct tracing_map_elt *elt,
+ struct ring_buffer_event *rbe,
+ void *event)
{
return 0;
}
-static u64 hist_field_counter(struct hist_field *field, void *event,
- struct ring_buffer_event *rbe)
+static u64 hist_field_counter(struct hist_field *field,
+ struct tracing_map_elt *elt,
+ struct ring_buffer_event *rbe,
+ void *event)
{
return 1;
}
-static u64 hist_field_string(struct hist_field *hist_field, void *event,
- struct ring_buffer_event *rbe)
+static u64 hist_field_string(struct hist_field *hist_field,
+ struct tracing_map_elt *elt,
+ struct ring_buffer_event *rbe,
+ void *event)
{
char *addr = (char *)(event + hist_field->field->offset);
return (u64)(unsigned long)addr;
}
-static u64 hist_field_dynstring(struct hist_field *hist_field, void *event,
- struct ring_buffer_event *rbe)
+static u64 hist_field_dynstring(struct hist_field *hist_field,
+ struct tracing_map_elt *elt,
+ struct ring_buffer_event *rbe,
+ void *event)
{
u32 str_item = *(u32 *)(event + hist_field->field->offset);
int str_loc = str_item & 0xffff;
@@ -89,54 +99,64 @@ static u64 hist_field_dynstring(struct hist_field *hist_field, void *event,
return (u64)(unsigned long)addr;
}
-static u64 hist_field_pstring(struct hist_field *hist_field, void *event,
- struct ring_buffer_event *rbe)
+static u64 hist_field_pstring(struct hist_field *hist_field,
+ struct tracing_map_elt *elt,
+ struct ring_buffer_event *rbe,
+ void *event)
{
char **addr = (char **)(event + hist_field->field->offset);
return (u64)(unsigned long)*addr;
}
-static u64 hist_field_log2(struct hist_field *hist_field, void *event,
- struct ring_buffer_event *rbe)
+static u64 hist_field_log2(struct hist_field *hist_field,
+ struct tracing_map_elt *elt,
+ struct ring_buffer_event *rbe,
+ void *event)
{
struct hist_field *operand = hist_field->operands[0];
- u64 val = operand->fn(operand, event, rbe);
+ u64 val = operand->fn(operand, elt, rbe, event);
return (u64) ilog2(roundup_pow_of_two(val));
}
-static u64 hist_field_plus(struct hist_field *hist_field, void *event,
- struct ring_buffer_event *rbe)
+static u64 hist_field_plus(struct hist_field *hist_field,
+ struct tracing_map_elt *elt,
+ struct ring_buffer_event *rbe,
+ void *event)
{
struct hist_field *operand1 = hist_field->operands[0];
struct hist_field *operand2 = hist_field->operands[1];
- u64 val1 = operand1->fn(operand1, event, rbe);
- u64 val2 = operand2->fn(operand2, event, rbe);
+ u64 val1 = operand1->fn(operand1, elt, rbe, event);
+ u64 val2 = operand2->fn(operand2, elt, rbe, event);
return val1 + val2;
}
-static u64 hist_field_minus(struct hist_field *hist_field, void *event,
- struct ring_buffer_event *rbe)
+static u64 hist_field_minus(struct hist_field *hist_field,
+ struct tracing_map_elt *elt,
+ struct ring_buffer_event *rbe,
+ void *event)
{
struct hist_field *operand1 = hist_field->operands[0];
struct hist_field *operand2 = hist_field->operands[1];
- u64 val1 = operand1->fn(operand1, event, rbe);
- u64 val2 = operand2->fn(operand2, event, rbe);
+ u64 val1 = operand1->fn(operand1, elt, rbe, event);
+ u64 val2 = operand2->fn(operand2, elt, rbe, event);
return val1 - val2;
}
-static u64 hist_field_unary_minus(struct hist_field *hist_field, void *event,
- struct ring_buffer_event *rbe)
+static u64 hist_field_unary_minus(struct hist_field *hist_field,
+ struct tracing_map_elt *elt,
+ struct ring_buffer_event *rbe,
+ void *event)
{
struct hist_field *operand = hist_field->operands[0];
- s64 sval = (s64)operand->fn(operand, event, rbe);
+ s64 sval = (s64)operand->fn(operand, elt, rbe, event);
u64 val = (u64)-sval;
return val;
@@ -144,8 +164,9 @@ static u64 hist_field_unary_minus(struct hist_field *hist_field, void *event,
#define DEFINE_HIST_FIELD_FN(type) \
static u64 hist_field_##type(struct hist_field *hist_field, \
- void *event, \
- struct ring_buffer_event *rbe) \
+ struct tracing_map_elt *elt, \
+ struct ring_buffer_event *rbe, \
+ void *event) \
{ \
type *addr = (type *)(event + hist_field->field->offset); \
\
@@ -233,8 +254,10 @@ struct hist_trigger_data {
bool remove;
};
-static u64 hist_field_timestamp(struct hist_field *hist_field, void *event,
- struct ring_buffer_event *rbe)
+static u64 hist_field_timestamp(struct hist_field *hist_field,
+ struct tracing_map_elt *elt,
+ struct ring_buffer_event *rbe,
+ void *event)
{
struct hist_trigger_data *hist_data = hist_field->hist_data;
struct trace_array *tr = hist_data->event_file->tr;
@@ -1570,7 +1593,7 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
for_each_hist_val_field(i, hist_data) {
hist_field = hist_data->fields[i];
- hist_val = hist_field->fn(hist_field, rec, rbe);
+ hist_val = hist_field->fn(hist_field, elt, rbe, rec);
if (hist_field->flags & HIST_FIELD_FL_VAR) {
var_idx = hist_field->var.idx;
tracing_map_set_var(elt, var_idx, hist_val);
@@ -1582,7 +1605,7 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
for_each_hist_key_field(i, hist_data) {
hist_field = hist_data->fields[i];
if (hist_field->flags & HIST_FIELD_FL_VAR) {
- hist_val = hist_field->fn(hist_field, rec, rbe);
+ hist_val = hist_field->fn(hist_field, elt, rbe, rec);
var_idx = hist_field->var.idx;
tracing_map_set_var(elt, var_idx, hist_val);
}
@@ -1620,9 +1643,9 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec,
bool use_compound_key = (hist_data->n_keys > 1);
unsigned long entries[HIST_STACKTRACE_DEPTH];
char compound_key[HIST_KEY_SIZE_MAX];
+ struct tracing_map_elt *elt = NULL;
struct stack_trace stacktrace;
struct hist_field *key_field;
- struct tracing_map_elt *elt;
u64 field_contents;
void *key = NULL;
unsigned int i;
@@ -1643,7 +1666,7 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec,
key = entries;
} else {
- field_contents = key_field->fn(key_field, rec, rbe);
+ field_contents = key_field->fn(key_field, elt, rbe, rec);
if (key_field->flags & HIST_FIELD_FL_STRING) {
key = (void *)(unsigned long)field_contents;
use_compound_key = true;
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 21/46] tracing: Add hist_field type field
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (19 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 20/46] tracing: Pass tracing_map_elt to hist_field accessor functions Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 22/46] tracing: Add variable reference handling to hist triggers Steven Rostedt
` (24 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0021-tracing-Add-hist_field-type-field.patch --]
[-- Type: text/plain, Size: 3799 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Future support for synthetic events requires hist_field 'type'
information, so add a field for that.
Also, make other hist_field attribute usage consistent (size,
is_signed, etc).
Link: http://lkml.kernel.org/r/3fd12a2e86316b05151ba0d7c68268e780af2c9d.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 7a54ab50176b..e30bd86bee8e 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -54,6 +54,7 @@ struct hist_field {
unsigned int size;
unsigned int offset;
unsigned int is_signed;
+ const char *type;
struct hist_field *operands[HIST_FIELD_OPERANDS_MAX];
struct hist_trigger_data *hist_data;
struct hist_var var;
@@ -717,6 +718,7 @@ static void destroy_hist_field(struct hist_field *hist_field,
kfree(hist_field->var.name);
kfree(hist_field->name);
+ kfree(hist_field->type);
kfree(hist_field);
}
@@ -742,6 +744,10 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
if (flags & HIST_FIELD_FL_HITCOUNT) {
hist_field->fn = hist_field_counter;
+ hist_field->size = sizeof(u64);
+ hist_field->type = kstrdup("u64", GFP_KERNEL);
+ if (!hist_field->type)
+ goto free;
goto out;
}
@@ -755,12 +761,18 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
hist_field->fn = hist_field_log2;
hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL);
hist_field->size = hist_field->operands[0]->size;
+ hist_field->type = kstrdup(hist_field->operands[0]->type, GFP_KERNEL);
+ if (!hist_field->type)
+ goto free;
goto out;
}
if (flags & HIST_FIELD_FL_TIMESTAMP) {
hist_field->fn = hist_field_timestamp;
hist_field->size = sizeof(u64);
+ hist_field->type = kstrdup("u64", GFP_KERNEL);
+ if (!hist_field->type)
+ goto free;
goto out;
}
@@ -770,6 +782,11 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
if (is_string_field(field)) {
flags |= HIST_FIELD_FL_STRING;
+ hist_field->size = MAX_FILTER_STR_VAL;
+ hist_field->type = kstrdup(field->type, GFP_KERNEL);
+ if (!hist_field->type)
+ goto free;
+
if (field->filter_type == FILTER_STATIC_STRING)
hist_field->fn = hist_field_string;
else if (field->filter_type == FILTER_DYN_STRING)
@@ -777,6 +794,12 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
else
hist_field->fn = hist_field_pstring;
} else {
+ hist_field->size = field->size;
+ hist_field->is_signed = field->is_signed;
+ hist_field->type = kstrdup(field->type, GFP_KERNEL);
+ if (!hist_field->type)
+ goto free;
+
hist_field->fn = select_value_fn(field->size,
field->is_signed);
if (!hist_field->fn) {
@@ -949,6 +972,11 @@ static struct hist_field *parse_unary(struct hist_trigger_data *hist_data,
expr->operands[0] = operand1;
expr->operator = FIELD_OP_UNARY_MINUS;
expr->name = expr_str(expr, 0);
+ expr->type = kstrdup(operand1->type, GFP_KERNEL);
+ if (!expr->type) {
+ ret = -ENOMEM;
+ goto free;
+ }
return expr;
free:
@@ -1042,6 +1070,11 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
expr->operands[1] = operand2;
expr->operator = field_op;
expr->name = expr_str(expr, 0);
+ expr->type = kstrdup(operand1->type, GFP_KERNEL);
+ if (!expr->type) {
+ ret = -ENOMEM;
+ goto free;
+ }
switch (field_op) {
case FIELD_OP_MINUS:
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 22/46] tracing: Add variable reference handling to hist triggers
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (20 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 21/46] tracing: Add hist_field type field Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 23/46] tracing: Add hist trigger action hook Steven Rostedt
` (23 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0022-tracing-Add-variable-reference-handling-to-hist-trig.patch --]
[-- Type: text/plain, Size: 25214 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Add the necessary infrastructure to allow the variables defined on one
event to be referenced in another. This allows variables set by a
previous event to be referenced and used in expressions combining the
variable values saved by that previous event and the event fields of
the current event. For example, here's how a latency can be
calculated and saved into yet another variable named 'wakeup_lat':
# echo 'hist:keys=pid,prio:ts0=common_timestamp ...
# echo 'hist:keys=next_pid:wakeup_lat=common_timestamp-$ts0 ...
In the first event, the event's timetamp is saved into the variable
ts0. In the next line, ts0 is subtracted from the second event's
timestamp to produce the latency.
Further users of variable references will be described in subsequent
patches, such as for instance how the 'wakeup_lat' variable above can
be displayed in a latency histogram.
Link: http://lkml.kernel.org/r/b1d3e6975374e34d501ff417c20189c3f9b2c7b8.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace.c | 2 +
kernel/trace/trace.h | 3 +
kernel/trace/trace_events_hist.c | 661 +++++++++++++++++++++++++++++++++++-
kernel/trace/trace_events_trigger.c | 6 +
4 files changed, 656 insertions(+), 16 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 82cc8891fda6..68f8702af9fb 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -7783,6 +7783,7 @@ static int instance_mkdir(const char *name)
INIT_LIST_HEAD(&tr->systems);
INIT_LIST_HEAD(&tr->events);
+ INIT_LIST_HEAD(&tr->hist_vars);
if (allocate_trace_buffers(tr, trace_buf_size) < 0)
goto out_free_tr;
@@ -8533,6 +8534,7 @@ __init static int tracer_alloc_buffers(void)
INIT_LIST_HEAD(&global_trace.systems);
INIT_LIST_HEAD(&global_trace.events);
+ INIT_LIST_HEAD(&global_trace.hist_vars);
list_add(&global_trace.list, &ftrace_trace_arrays);
apply_trace_boot_options();
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 89771b4f16df..99b7ee7ed127 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -274,6 +274,7 @@ struct trace_array {
int function_enabled;
#endif
int time_stamp_abs_ref;
+ struct list_head hist_vars;
};
enum {
@@ -1548,6 +1549,8 @@ extern void pause_named_trigger(struct event_trigger_data *data);
extern void unpause_named_trigger(struct event_trigger_data *data);
extern void set_named_trigger_data(struct event_trigger_data *data,
struct event_trigger_data *named_data);
+extern struct event_trigger_data *
+get_named_trigger_data(struct event_trigger_data *data);
extern int register_event_command(struct event_command *cmd);
extern int unregister_event_command(struct event_command *cmd);
extern int register_trigger_hist_enable_disable_cmds(void);
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index e30bd86bee8e..dbcdd2ff76a4 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -59,7 +59,12 @@ struct hist_field {
struct hist_trigger_data *hist_data;
struct hist_var var;
enum field_op_id operator;
+ char *system;
+ char *event_name;
char *name;
+ unsigned int var_idx;
+ unsigned int var_ref_idx;
+ bool read_once;
};
static u64 hist_field_none(struct hist_field *field,
@@ -214,6 +219,7 @@ enum hist_field_flags {
HIST_FIELD_FL_TIMESTAMP_USECS = 1 << 11,
HIST_FIELD_FL_VAR = 1 << 12,
HIST_FIELD_FL_EXPR = 1 << 13,
+ HIST_FIELD_FL_VAR_REF = 1 << 14,
};
struct var_defs {
@@ -253,6 +259,8 @@ struct hist_trigger_data {
struct tracing_map *map;
bool enable_timestamps;
bool remove;
+ struct hist_field *var_refs[TRACING_MAP_VARS_MAX];
+ unsigned int n_var_refs;
};
static u64 hist_field_timestamp(struct hist_field *hist_field,
@@ -271,6 +279,214 @@ static u64 hist_field_timestamp(struct hist_field *hist_field,
return ts;
}
+struct hist_var_data {
+ struct list_head list;
+ struct hist_trigger_data *hist_data;
+};
+
+static struct hist_field *
+check_field_for_var_ref(struct hist_field *hist_field,
+ struct hist_trigger_data *var_data,
+ unsigned int var_idx)
+{
+ struct hist_field *found = NULL;
+
+ if (hist_field && hist_field->flags & HIST_FIELD_FL_VAR_REF) {
+ if (hist_field->var.idx == var_idx &&
+ hist_field->var.hist_data == var_data) {
+ found = hist_field;
+ }
+ }
+
+ return found;
+}
+
+static struct hist_field *
+check_field_for_var_refs(struct hist_trigger_data *hist_data,
+ struct hist_field *hist_field,
+ struct hist_trigger_data *var_data,
+ unsigned int var_idx,
+ unsigned int level)
+{
+ struct hist_field *found = NULL;
+ unsigned int i;
+
+ if (level > 3)
+ return found;
+
+ if (!hist_field)
+ return found;
+
+ found = check_field_for_var_ref(hist_field, var_data, var_idx);
+ if (found)
+ return found;
+
+ for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++) {
+ struct hist_field *operand;
+
+ operand = hist_field->operands[i];
+ found = check_field_for_var_refs(hist_data, operand, var_data,
+ var_idx, level + 1);
+ if (found)
+ return found;
+ }
+
+ return found;
+}
+
+static struct hist_field *find_var_ref(struct hist_trigger_data *hist_data,
+ struct hist_trigger_data *var_data,
+ unsigned int var_idx)
+{
+ struct hist_field *hist_field, *found = NULL;
+ unsigned int i;
+
+ for_each_hist_field(i, hist_data) {
+ hist_field = hist_data->fields[i];
+ found = check_field_for_var_refs(hist_data, hist_field,
+ var_data, var_idx, 0);
+ if (found)
+ return found;
+ }
+
+ return found;
+}
+
+static struct hist_field *find_any_var_ref(struct hist_trigger_data *hist_data,
+ unsigned int var_idx)
+{
+ struct trace_array *tr = hist_data->event_file->tr;
+ struct hist_field *found = NULL;
+ struct hist_var_data *var_data;
+
+ list_for_each_entry(var_data, &tr->hist_vars, list) {
+ if (var_data->hist_data == hist_data)
+ continue;
+ found = find_var_ref(var_data->hist_data, hist_data, var_idx);
+ if (found)
+ break;
+ }
+
+ return found;
+}
+
+static bool check_var_refs(struct hist_trigger_data *hist_data)
+{
+ struct hist_field *field;
+ bool found = false;
+ int i;
+
+ for_each_hist_field(i, hist_data) {
+ field = hist_data->fields[i];
+ if (field && field->flags & HIST_FIELD_FL_VAR) {
+ if (find_any_var_ref(hist_data, field->var.idx)) {
+ found = true;
+ break;
+ }
+ }
+ }
+
+ return found;
+}
+
+static struct hist_var_data *find_hist_vars(struct hist_trigger_data *hist_data)
+{
+ struct trace_array *tr = hist_data->event_file->tr;
+ struct hist_var_data *var_data, *found = NULL;
+
+ list_for_each_entry(var_data, &tr->hist_vars, list) {
+ if (var_data->hist_data == hist_data) {
+ found = var_data;
+ break;
+ }
+ }
+
+ return found;
+}
+
+static bool field_has_hist_vars(struct hist_field *hist_field,
+ unsigned int level)
+{
+ int i;
+
+ if (level > 3)
+ return false;
+
+ if (!hist_field)
+ return false;
+
+ if (hist_field->flags & HIST_FIELD_FL_VAR ||
+ hist_field->flags & HIST_FIELD_FL_VAR_REF)
+ return true;
+
+ for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++) {
+ struct hist_field *operand;
+
+ operand = hist_field->operands[i];
+ if (field_has_hist_vars(operand, level + 1))
+ return true;
+ }
+
+ return false;
+}
+
+static bool has_hist_vars(struct hist_trigger_data *hist_data)
+{
+ struct hist_field *hist_field;
+ int i;
+
+ for_each_hist_field(i, hist_data) {
+ hist_field = hist_data->fields[i];
+ if (field_has_hist_vars(hist_field, 0))
+ return true;
+ }
+
+ return false;
+}
+
+static int save_hist_vars(struct hist_trigger_data *hist_data)
+{
+ struct trace_array *tr = hist_data->event_file->tr;
+ struct hist_var_data *var_data;
+
+ var_data = find_hist_vars(hist_data);
+ if (var_data)
+ return 0;
+
+ if (trace_array_get(tr) < 0)
+ return -ENODEV;
+
+ var_data = kzalloc(sizeof(*var_data), GFP_KERNEL);
+ if (!var_data) {
+ trace_array_put(tr);
+ return -ENOMEM;
+ }
+
+ var_data->hist_data = hist_data;
+ list_add(&var_data->list, &tr->hist_vars);
+
+ return 0;
+}
+
+static void remove_hist_vars(struct hist_trigger_data *hist_data)
+{
+ struct trace_array *tr = hist_data->event_file->tr;
+ struct hist_var_data *var_data;
+
+ var_data = find_hist_vars(hist_data);
+ if (!var_data)
+ return;
+
+ if (WARN_ON(check_var_refs(hist_data)))
+ return;
+
+ list_del(&var_data->list);
+
+ kfree(var_data);
+
+ trace_array_put(tr);
+}
+
static struct hist_field *find_var_field(struct hist_trigger_data *hist_data,
const char *var_name)
{
@@ -313,10 +529,137 @@ static struct hist_field *find_var(struct hist_trigger_data *hist_data,
return NULL;
}
+static struct trace_event_file *find_var_file(struct trace_array *tr,
+ char *system,
+ char *event_name,
+ char *var_name)
+{
+ struct hist_trigger_data *var_hist_data;
+ struct hist_var_data *var_data;
+ struct trace_event_file *file, *found = NULL;
+
+ if (system)
+ return find_event_file(tr, system, event_name);
+
+ list_for_each_entry(var_data, &tr->hist_vars, list) {
+ var_hist_data = var_data->hist_data;
+ file = var_hist_data->event_file;
+ if (file == found)
+ continue;
+
+ if (find_var_field(var_hist_data, var_name)) {
+ if (found)
+ return NULL;
+
+ found = file;
+ }
+ }
+
+ return found;
+}
+
+static struct hist_field *find_file_var(struct trace_event_file *file,
+ const char *var_name)
+{
+ struct hist_trigger_data *test_data;
+ struct event_trigger_data *test;
+ struct hist_field *hist_field;
+
+ list_for_each_entry_rcu(test, &file->triggers, list) {
+ if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
+ test_data = test->private_data;
+ hist_field = find_var_field(test_data, var_name);
+ if (hist_field)
+ return hist_field;
+ }
+ }
+
+ return NULL;
+}
+
+static struct hist_field *find_event_var(struct hist_trigger_data *hist_data,
+ char *system,
+ char *event_name,
+ char *var_name)
+{
+ struct trace_array *tr = hist_data->event_file->tr;
+ struct hist_field *hist_field = NULL;
+ struct trace_event_file *file;
+
+ file = find_var_file(tr, system, event_name, var_name);
+ if (!file)
+ return NULL;
+
+ hist_field = find_file_var(file, var_name);
+
+ return hist_field;
+}
+
struct hist_elt_data {
char *comm;
+ u64 *var_ref_vals;
};
+static u64 hist_field_var_ref(struct hist_field *hist_field,
+ struct tracing_map_elt *elt,
+ struct ring_buffer_event *rbe,
+ void *event)
+{
+ struct hist_elt_data *elt_data;
+ u64 var_val = 0;
+
+ elt_data = elt->private_data;
+ var_val = elt_data->var_ref_vals[hist_field->var_ref_idx];
+
+ return var_val;
+}
+
+static bool resolve_var_refs(struct hist_trigger_data *hist_data, void *key,
+ u64 *var_ref_vals, bool self)
+{
+ struct hist_trigger_data *var_data;
+ struct tracing_map_elt *var_elt;
+ struct hist_field *hist_field;
+ unsigned int i, var_idx;
+ bool resolved = true;
+ u64 var_val = 0;
+
+ for (i = 0; i < hist_data->n_var_refs; i++) {
+ hist_field = hist_data->var_refs[i];
+ var_idx = hist_field->var.idx;
+ var_data = hist_field->var.hist_data;
+
+ if (var_data == NULL) {
+ resolved = false;
+ break;
+ }
+
+ if ((self && var_data != hist_data) ||
+ (!self && var_data == hist_data))
+ continue;
+
+ var_elt = tracing_map_lookup(var_data->map, key);
+ if (!var_elt) {
+ resolved = false;
+ break;
+ }
+
+ if (!tracing_map_var_set(var_elt, var_idx)) {
+ resolved = false;
+ break;
+ }
+
+ if (self || !hist_field->read_once)
+ var_val = tracing_map_read_var(var_elt, var_idx);
+ else
+ var_val = tracing_map_read_var_once(var_elt, var_idx);
+
+ var_ref_vals[i] = var_val;
+ }
+
+ return resolved;
+}
+
static const char *hist_field_name(struct hist_field *field,
unsigned int level)
{
@@ -331,8 +674,20 @@ static const char *hist_field_name(struct hist_field *field,
field_name = hist_field_name(field->operands[0], ++level);
else if (field->flags & HIST_FIELD_FL_TIMESTAMP)
field_name = "common_timestamp";
- else if (field->flags & HIST_FIELD_FL_EXPR)
- field_name = field->name;
+ else if (field->flags & HIST_FIELD_FL_EXPR ||
+ field->flags & HIST_FIELD_FL_VAR_REF) {
+ if (field->system) {
+ static char full_name[MAX_FILTER_STR_VAL];
+
+ strcat(full_name, field->system);
+ strcat(full_name, ".");
+ strcat(full_name, field->event_name);
+ strcat(full_name, ".");
+ strcat(full_name, field->name);
+ field_name = full_name;
+ } else
+ field_name = field->name;
+ }
if (field_name == NULL)
field_name = "";
@@ -612,6 +967,9 @@ static const char *get_hist_field_flags(struct hist_field *hist_field)
static void expr_field_str(struct hist_field *field, char *expr)
{
+ if (field->flags & HIST_FIELD_FL_VAR_REF)
+ strcat(expr, "$");
+
strcat(expr, hist_field_name(field, 0));
if (field->flags) {
@@ -742,6 +1100,11 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
if (flags & HIST_FIELD_FL_EXPR)
goto out; /* caller will populate */
+ if (flags & HIST_FIELD_FL_VAR_REF) {
+ hist_field->fn = hist_field_var_ref;
+ goto out;
+ }
+
if (flags & HIST_FIELD_FL_HITCOUNT) {
hist_field->fn = hist_field_counter;
hist_field->size = sizeof(u64);
@@ -835,6 +1198,144 @@ static void destroy_hist_fields(struct hist_trigger_data *hist_data)
}
}
+static int init_var_ref(struct hist_field *ref_field,
+ struct hist_field *var_field,
+ char *system, char *event_name)
+{
+ int err = 0;
+
+ ref_field->var.idx = var_field->var.idx;
+ ref_field->var.hist_data = var_field->hist_data;
+ ref_field->size = var_field->size;
+ ref_field->is_signed = var_field->is_signed;
+ ref_field->flags |= var_field->flags &
+ (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
+
+ if (system) {
+ ref_field->system = kstrdup(system, GFP_KERNEL);
+ if (!ref_field->system)
+ return -ENOMEM;
+ }
+
+ if (event_name) {
+ ref_field->event_name = kstrdup(event_name, GFP_KERNEL);
+ if (!ref_field->event_name) {
+ err = -ENOMEM;
+ goto free;
+ }
+ }
+
+ ref_field->name = kstrdup(var_field->var.name, GFP_KERNEL);
+ if (!ref_field->name) {
+ err = -ENOMEM;
+ goto free;
+ }
+
+ ref_field->type = kstrdup(var_field->type, GFP_KERNEL);
+ if (!ref_field->type) {
+ err = -ENOMEM;
+ goto free;
+ }
+ out:
+ return err;
+ free:
+ kfree(ref_field->system);
+ kfree(ref_field->event_name);
+ kfree(ref_field->name);
+
+ goto out;
+}
+
+static struct hist_field *create_var_ref(struct hist_field *var_field,
+ char *system, char *event_name)
+{
+ unsigned long flags = HIST_FIELD_FL_VAR_REF;
+ struct hist_field *ref_field;
+
+ ref_field = create_hist_field(var_field->hist_data, NULL, flags, NULL);
+ if (ref_field) {
+ if (init_var_ref(ref_field, var_field, system, event_name)) {
+ destroy_hist_field(ref_field, 0);
+ return NULL;
+ }
+ }
+
+ return ref_field;
+}
+
+static bool is_var_ref(char *var_name)
+{
+ if (!var_name || strlen(var_name) < 2 || var_name[0] != '$')
+ return false;
+
+ return true;
+}
+
+static char *field_name_from_var(struct hist_trigger_data *hist_data,
+ char *var_name)
+{
+ char *name, *field;
+ unsigned int i;
+
+ for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) {
+ name = hist_data->attrs->var_defs.name[i];
+
+ if (strcmp(var_name, name) == 0) {
+ field = hist_data->attrs->var_defs.expr[i];
+ if (contains_operator(field) || is_var_ref(field))
+ continue;
+ return field;
+ }
+ }
+
+ return NULL;
+}
+
+static char *local_field_var_ref(struct hist_trigger_data *hist_data,
+ char *system, char *event_name,
+ char *var_name)
+{
+ struct trace_event_call *call;
+
+ if (system && event_name) {
+ call = hist_data->event_file->event_call;
+
+ if (strcmp(system, call->class->system) != 0)
+ return NULL;
+
+ if (strcmp(event_name, trace_event_name(call)) != 0)
+ return NULL;
+ }
+
+ if (!!system != !!event_name)
+ return NULL;
+
+ if (!is_var_ref(var_name))
+ return NULL;
+
+ var_name++;
+
+ return field_name_from_var(hist_data, var_name);
+}
+
+static struct hist_field *parse_var_ref(struct hist_trigger_data *hist_data,
+ char *system, char *event_name,
+ char *var_name)
+{
+ struct hist_field *var_field = NULL, *ref_field = NULL;
+
+ if (!is_var_ref(var_name))
+ return NULL;
+
+ var_name++;
+
+ var_field = find_event_var(hist_data, system, event_name, var_name);
+ if (var_field)
+ ref_field = create_var_ref(var_field, system, event_name);
+
+ return ref_field;
+}
+
static struct ftrace_event_field *
parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file,
char *field_str, unsigned long *flags)
@@ -891,10 +1392,40 @@ static struct hist_field *parse_atom(struct hist_trigger_data *hist_data,
struct trace_event_file *file, char *str,
unsigned long *flags, char *var_name)
{
+ char *s, *ref_system = NULL, *ref_event = NULL, *ref_var = str;
struct ftrace_event_field *field = NULL;
struct hist_field *hist_field = NULL;
int ret = 0;
+ s = strchr(str, '.');
+ if (s) {
+ s = strchr(++s, '.');
+ if (s) {
+ ref_system = strsep(&str, ".");
+ if (!str) {
+ ret = -EINVAL;
+ goto out;
+ }
+ ref_event = strsep(&str, ".");
+ if (!str) {
+ ret = -EINVAL;
+ goto out;
+ }
+ ref_var = str;
+ }
+ }
+
+ s = local_field_var_ref(hist_data, ref_system, ref_event, ref_var);
+ if (!s) {
+ hist_field = parse_var_ref(hist_data, ref_system, ref_event, ref_var);
+ if (hist_field) {
+ hist_data->var_refs[hist_data->n_var_refs] = hist_field;
+ hist_field->var_ref_idx = hist_data->n_var_refs++;
+ return hist_field;
+ }
+ } else
+ str = s;
+
field = parse_field(hist_data, file, str, flags);
if (IS_ERR(field)) {
ret = PTR_ERR(field);
@@ -1066,6 +1597,9 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
goto free;
}
+ operand1->read_once = true;
+ operand2->read_once = true;
+
expr->operands[0] = operand1;
expr->operands[1] = operand2;
expr->operator = field_op;
@@ -1238,6 +1772,12 @@ static int create_key_field(struct hist_trigger_data *hist_data,
goto out;
}
+ if (hist_field->flags & HIST_FIELD_FL_VAR_REF) {
+ destroy_hist_field(hist_field, 0);
+ ret = -EINVAL;
+ goto out;
+ }
+
key_size = hist_field->size;
}
@@ -1576,6 +2116,7 @@ create_hist_data(unsigned int map_bits,
hist_data->attrs = attrs;
hist_data->remove = remove;
+ hist_data->event_file = file;
ret = create_hist_fields(hist_data, file);
if (ret)
@@ -1598,12 +2139,6 @@ create_hist_data(unsigned int map_bits,
ret = create_tracing_map_fields(hist_data);
if (ret)
goto free;
-
- ret = tracing_map_init(hist_data->map);
- if (ret)
- goto free;
-
- hist_data->event_file = file;
out:
return hist_data;
free:
@@ -1618,12 +2153,17 @@ create_hist_data(unsigned int map_bits,
static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
struct tracing_map_elt *elt, void *rec,
- struct ring_buffer_event *rbe)
+ struct ring_buffer_event *rbe,
+ u64 *var_ref_vals)
{
+ struct hist_elt_data *elt_data;
struct hist_field *hist_field;
unsigned int i, var_idx;
u64 hist_val;
+ elt_data = elt->private_data;
+ elt_data->var_ref_vals = var_ref_vals;
+
for_each_hist_val_field(i, hist_data) {
hist_field = hist_data->fields[i];
hist_val = hist_field->fn(hist_field, elt, rbe, rec);
@@ -1675,6 +2215,7 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec,
struct hist_trigger_data *hist_data = data->private_data;
bool use_compound_key = (hist_data->n_keys > 1);
unsigned long entries[HIST_STACKTRACE_DEPTH];
+ u64 var_ref_vals[TRACING_MAP_VARS_MAX];
char compound_key[HIST_KEY_SIZE_MAX];
struct tracing_map_elt *elt = NULL;
struct stack_trace stacktrace;
@@ -1714,9 +2255,15 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec,
if (use_compound_key)
key = compound_key;
+ if (hist_data->n_var_refs &&
+ !resolve_var_refs(hist_data, key, var_ref_vals, false))
+ return;
+
elt = tracing_map_insert(hist_data->map, key);
- if (elt)
- hist_trigger_elt_update(hist_data, elt, rec, rbe);
+ if (!elt)
+ return;
+
+ hist_trigger_elt_update(hist_data, elt, rec, rbe, var_ref_vals);
}
static void hist_trigger_stacktrace_print(struct seq_file *m,
@@ -1931,8 +2478,11 @@ static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP)
seq_puts(m, "common_timestamp");
- else if (field_name)
+ else if (field_name) {
+ if (hist_field->flags & HIST_FIELD_FL_VAR_REF)
+ seq_putc(m, '$');
seq_printf(m, "%s", field_name);
+ }
if (hist_field->flags) {
const char *flags_str = get_hist_field_flags(hist_field);
@@ -2072,7 +2622,11 @@ static void event_hist_trigger_free(struct event_trigger_ops *ops,
if (!data->ref) {
if (data->name)
del_named_trigger(data);
+
trigger_data_free(data);
+
+ remove_hist_vars(hist_data);
+
destroy_hist_data(hist_data);
}
}
@@ -2285,23 +2839,55 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops,
goto out;
}
- list_add_rcu(&data->list, &file->triggers);
ret++;
- update_cond_flag(file);
-
if (hist_data->enable_timestamps)
tracing_set_time_stamp_abs(file->tr, true);
+ out:
+ return ret;
+}
+
+static int hist_trigger_enable(struct event_trigger_data *data,
+ struct trace_event_file *file)
+{
+ int ret = 0;
+
+ list_add_tail_rcu(&data->list, &file->triggers);
+
+ update_cond_flag(file);
if (trace_event_trigger_enable_disable(file, 1) < 0) {
list_del_rcu(&data->list);
update_cond_flag(file);
ret--;
}
- out:
+
return ret;
}
+static bool hist_trigger_check_refs(struct event_trigger_data *data,
+ struct trace_event_file *file)
+{
+ struct hist_trigger_data *hist_data = data->private_data;
+ struct event_trigger_data *test, *named_data = NULL;
+
+ if (hist_data->attrs->name)
+ named_data = find_named_trigger(hist_data->attrs->name);
+
+ list_for_each_entry_rcu(test, &file->triggers, list) {
+ if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
+ if (!hist_trigger_match(data, test, named_data, false))
+ continue;
+ hist_data = test->private_data;
+ if (check_var_refs(hist_data))
+ return true;
+ break;
+ }
+ }
+
+ return false;
+}
+
static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops,
struct event_trigger_data *data,
struct trace_event_file *file)
@@ -2334,11 +2920,30 @@ static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops,
}
}
+static bool hist_file_check_refs(struct trace_event_file *file)
+{
+ struct hist_trigger_data *hist_data;
+ struct event_trigger_data *test;
+
+ list_for_each_entry_rcu(test, &file->triggers, list) {
+ if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
+ hist_data = test->private_data;
+ if (check_var_refs(hist_data))
+ return true;
+ }
+ }
+
+ return false;
+}
+
static void hist_unreg_all(struct trace_event_file *file)
{
struct event_trigger_data *test, *n;
struct hist_trigger_data *hist_data;
+ if (hist_file_check_refs(file))
+ return;
+
list_for_each_entry_safe(test, n, &file->triggers, list) {
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
hist_data = test->private_data;
@@ -2414,6 +3019,11 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
}
if (remove) {
+ if (hist_trigger_check_refs(trigger_data, file)) {
+ ret = -EBUSY;
+ goto out_free;
+ }
+
cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
ret = 0;
goto out_free;
@@ -2431,14 +3041,33 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
goto out_free;
} else if (ret < 0)
goto out_free;
+
+ if (get_named_trigger_data(trigger_data))
+ goto enable;
+
+ if (has_hist_vars(hist_data))
+ save_hist_vars(hist_data);
+
+ ret = tracing_map_init(hist_data->map);
+ if (ret)
+ goto out_unreg;
+enable:
+ ret = hist_trigger_enable(trigger_data, file);
+ if (ret)
+ goto out_unreg;
+
/* Just return zero, not the number of registered triggers */
ret = 0;
out:
return ret;
+ out_unreg:
+ cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
out_free:
if (cmd_ops->set_filter)
cmd_ops->set_filter(NULL, trigger_data, NULL);
+ remove_hist_vars(hist_data);
+
kfree(trigger_data);
destroy_hist_data(hist_data);
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 632471692462..d251cabcf69a 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -909,6 +909,12 @@ void set_named_trigger_data(struct event_trigger_data *data,
data->named_data = named_data;
}
+struct event_trigger_data *
+get_named_trigger_data(struct event_trigger_data *data)
+{
+ return data->named_data;
+}
+
static void
traceon_trigger(struct event_trigger_data *data, void *rec,
struct ring_buffer_event *event)
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 23/46] tracing: Add hist trigger action hook
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (21 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 22/46] tracing: Add variable reference handling to hist triggers Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 24/46] tracing: Add support for synthetic events Steven Rostedt
` (22 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0023-tracing-Add-hist-trigger-action-hook.patch --]
[-- Type: text/plain, Size: 5860 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Add a hook for executing extra actions whenever a histogram entry is
added or updated.
The default 'action' when a hist entry is added to a histogram is to
update the set of values associated with it. Some applications may
want to perform additional actions at that point, such as generate
another event, or compare and save a maximum.
Add a simple framework for doing that; specific actions will be
implemented on top of it in later patches.
Link: http://lkml.kernel.org/r/9482ba6a3eaf5ca6e60954314beacd0e25c05b24.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 106 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 104 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index dbcdd2ff76a4..68b9d6d396a6 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -33,6 +33,7 @@ typedef u64 (*hist_field_fn_t) (struct hist_field *field,
#define HIST_FIELD_OPERANDS_MAX 2
#define HIST_FIELDS_MAX (TRACING_MAP_FIELDS_MAX + TRACING_MAP_VARS_MAX)
+#define HIST_ACTIONS_MAX 8
enum field_op_id {
FIELD_OP_NONE,
@@ -242,6 +243,9 @@ struct hist_trigger_attrs {
char *assignment_str[TRACING_MAP_VARS_MAX];
unsigned int n_assignments;
+ char *action_str[HIST_ACTIONS_MAX];
+ unsigned int n_actions;
+
struct var_defs var_defs;
};
@@ -261,6 +265,21 @@ struct hist_trigger_data {
bool remove;
struct hist_field *var_refs[TRACING_MAP_VARS_MAX];
unsigned int n_var_refs;
+
+ struct action_data *actions[HIST_ACTIONS_MAX];
+ unsigned int n_actions;
+};
+
+struct action_data;
+
+typedef void (*action_fn_t) (struct hist_trigger_data *hist_data,
+ struct tracing_map_elt *elt, void *rec,
+ struct ring_buffer_event *rbe,
+ struct action_data *data, u64 *var_ref_vals);
+
+struct action_data {
+ action_fn_t fn;
+ unsigned int var_ref_idx;
};
static u64 hist_field_timestamp(struct hist_field *hist_field,
@@ -764,6 +783,9 @@ static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs)
for (i = 0; i < attrs->n_assignments; i++)
kfree(attrs->assignment_str[i]);
+ for (i = 0; i < attrs->n_actions; i++)
+ kfree(attrs->action_str[i]);
+
kfree(attrs->name);
kfree(attrs->sort_key_str);
kfree(attrs->keys_str);
@@ -771,6 +793,16 @@ static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs)
kfree(attrs);
}
+static int parse_action(char *str, struct hist_trigger_attrs *attrs)
+{
+ int ret = 0;
+
+ if (attrs->n_actions >= HIST_ACTIONS_MAX)
+ return ret;
+
+ return ret;
+}
+
static int parse_assignment(char *str, struct hist_trigger_attrs *attrs)
{
int ret = 0;
@@ -854,8 +886,9 @@ static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str)
else if (strcmp(str, "clear") == 0)
attrs->clear = true;
else {
- ret = -EINVAL;
- goto free;
+ ret = parse_action(str, attrs);
+ if (ret)
+ goto free;
}
}
@@ -2047,11 +2080,55 @@ static int create_sort_keys(struct hist_trigger_data *hist_data)
return ret;
}
+static void destroy_actions(struct hist_trigger_data *hist_data)
+{
+ unsigned int i;
+
+ for (i = 0; i < hist_data->n_actions; i++) {
+ struct action_data *data = hist_data->actions[i];
+
+ kfree(data);
+ }
+}
+
+static int parse_actions(struct hist_trigger_data *hist_data)
+{
+ unsigned int i;
+ int ret = 0;
+ char *str;
+
+ for (i = 0; i < hist_data->attrs->n_actions; i++) {
+ str = hist_data->attrs->action_str[i];
+ }
+
+ return ret;
+}
+
+static int create_actions(struct hist_trigger_data *hist_data,
+ struct trace_event_file *file)
+{
+ struct action_data *data;
+ unsigned int i;
+ int ret = 0;
+
+ for (i = 0; i < hist_data->attrs->n_actions; i++) {
+ data = hist_data->actions[i];
+ }
+
+ return ret;
+}
+
static void destroy_hist_data(struct hist_trigger_data *hist_data)
{
+ if (!hist_data)
+ return;
+
destroy_hist_trigger_attrs(hist_data->attrs);
destroy_hist_fields(hist_data);
tracing_map_destroy(hist_data->map);
+
+ destroy_actions(hist_data);
+
kfree(hist_data);
}
@@ -2118,6 +2195,10 @@ create_hist_data(unsigned int map_bits,
hist_data->remove = remove;
hist_data->event_file = file;
+ ret = parse_actions(hist_data);
+ if (ret)
+ goto free;
+
ret = create_hist_fields(hist_data, file);
if (ret)
goto free;
@@ -2209,6 +2290,20 @@ static inline void add_to_key(char *compound_key, void *key,
memcpy(compound_key + key_field->offset, key, size);
}
+static void
+hist_trigger_actions(struct hist_trigger_data *hist_data,
+ struct tracing_map_elt *elt, void *rec,
+ struct ring_buffer_event *rbe, u64 *var_ref_vals)
+{
+ struct action_data *data;
+ unsigned int i;
+
+ for (i = 0; i < hist_data->n_actions; i++) {
+ data = hist_data->actions[i];
+ data->fn(hist_data, elt, rec, rbe, data, var_ref_vals);
+ }
+}
+
static void event_hist_trigger(struct event_trigger_data *data, void *rec,
struct ring_buffer_event *rbe)
{
@@ -2264,6 +2359,9 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec,
return;
hist_trigger_elt_update(hist_data, elt, rec, rbe, var_ref_vals);
+
+ if (resolve_var_refs(hist_data, key, var_ref_vals, true))
+ hist_trigger_actions(hist_data, elt, rec, rbe, var_ref_vals);
}
static void hist_trigger_stacktrace_print(struct seq_file *m,
@@ -3048,6 +3146,10 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
if (has_hist_vars(hist_data))
save_hist_vars(hist_data);
+ ret = create_actions(hist_data, file);
+ if (ret)
+ goto out_unreg;
+
ret = tracing_map_init(hist_data->map);
if (ret)
goto out_unreg;
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 24/46] tracing: Add support for synthetic events
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (22 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 23/46] tracing: Add hist trigger action hook Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 25/46] tracing: Add support for field variables Steven Rostedt
` (21 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi, Fengguang Wu
[-- Attachment #1: 0024-tracing-Add-support-for-synthetic-events.patch --]
[-- Type: text/plain, Size: 25012 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 895 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 893 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 68b9d6d396a6..80d16d33ad5e 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -20,10 +20,16 @@
#include <linux/slab.h>
#include <linux/stacktrace.h>
#include <linux/rculist.h>
+#include <linux/tracefs.h>
#include "tracing_map.h"
#include "trace.h"
+#define SYNTH_SYSTEM "synthetic"
+#define SYNTH_FIELDS_MAX 16
+
+#define STR_VAR_LEN_MAX 32 /* must be multiple of sizeof(u64) */
+
struct hist_field;
typedef u64 (*hist_field_fn_t) (struct hist_field *field,
@@ -270,6 +276,26 @@ struct hist_trigger_data {
unsigned int n_actions;
};
+struct synth_field {
+ char *type;
+ char *name;
+ size_t size;
+ bool is_signed;
+ bool is_string;
+};
+
+struct synth_event {
+ struct list_head list;
+ int ref;
+ char *name;
+ struct synth_field **fields;
+ unsigned int n_fields;
+ unsigned int n_u64;
+ struct trace_event_class class;
+ struct trace_event_call call;
+ struct tracepoint *tp;
+};
+
struct action_data;
typedef void (*action_fn_t) (struct hist_trigger_data *hist_data,
@@ -282,6 +308,790 @@ struct action_data {
unsigned int var_ref_idx;
};
+static LIST_HEAD(synth_event_list);
+static DEFINE_MUTEX(synth_event_mutex);
+
+struct synth_trace_event {
+ struct trace_entry ent;
+ u64 fields[];
+};
+
+static int synth_event_define_fields(struct trace_event_call *call)
+{
+ struct synth_trace_event trace;
+ int offset = offsetof(typeof(trace), fields);
+ struct synth_event *event = call->data;
+ unsigned int i, size, n_u64;
+ char *name, *type;
+ bool is_signed;
+ int ret = 0;
+
+ for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
+ size = event->fields[i]->size;
+ is_signed = event->fields[i]->is_signed;
+ type = event->fields[i]->type;
+ name = event->fields[i]->name;
+ ret = trace_define_field(call, type, name, offset, size,
+ is_signed, FILTER_OTHER);
+ if (ret)
+ break;
+
+ if (event->fields[i]->is_string) {
+ offset += STR_VAR_LEN_MAX;
+ n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
+ } else {
+ offset += sizeof(u64);
+ n_u64++;
+ }
+ }
+
+ event->n_u64 = n_u64;
+
+ return ret;
+}
+
+static bool synth_field_signed(char *type)
+{
+ if (strncmp(type, "u", 1) == 0)
+ return false;
+
+ return true;
+}
+
+static int synth_field_is_string(char *type)
+{
+ if (strstr(type, "char[") != NULL)
+ return true;
+
+ return false;
+}
+
+static int synth_field_string_size(char *type)
+{
+ char buf[4], *end, *start;
+ unsigned int len;
+ int size, err;
+
+ start = strstr(type, "char[");
+ if (start == NULL)
+ return -EINVAL;
+ start += strlen("char[");
+
+ end = strchr(type, ']');
+ if (!end || end < start)
+ return -EINVAL;
+
+ len = end - start;
+ if (len > 3)
+ return -EINVAL;
+
+ strncpy(buf, start, len);
+ buf[len] = '\0';
+
+ err = kstrtouint(buf, 0, &size);
+ if (err)
+ return err;
+
+ if (size > STR_VAR_LEN_MAX)
+ return -EINVAL;
+
+ return size;
+}
+
+static int synth_field_size(char *type)
+{
+ int size = 0;
+
+ if (strcmp(type, "s64") == 0)
+ size = sizeof(s64);
+ else if (strcmp(type, "u64") == 0)
+ size = sizeof(u64);
+ else if (strcmp(type, "s32") == 0)
+ size = sizeof(s32);
+ else if (strcmp(type, "u32") == 0)
+ size = sizeof(u32);
+ else if (strcmp(type, "s16") == 0)
+ size = sizeof(s16);
+ else if (strcmp(type, "u16") == 0)
+ size = sizeof(u16);
+ else if (strcmp(type, "s8") == 0)
+ size = sizeof(s8);
+ else if (strcmp(type, "u8") == 0)
+ size = sizeof(u8);
+ else if (strcmp(type, "char") == 0)
+ size = sizeof(char);
+ else if (strcmp(type, "unsigned char") == 0)
+ size = sizeof(unsigned char);
+ else if (strcmp(type, "int") == 0)
+ size = sizeof(int);
+ else if (strcmp(type, "unsigned int") == 0)
+ size = sizeof(unsigned int);
+ else if (strcmp(type, "long") == 0)
+ size = sizeof(long);
+ else if (strcmp(type, "unsigned long") == 0)
+ size = sizeof(unsigned long);
+ else if (strcmp(type, "pid_t") == 0)
+ size = sizeof(pid_t);
+ else if (synth_field_is_string(type))
+ size = synth_field_string_size(type);
+
+ return size;
+}
+
+static const char *synth_field_fmt(char *type)
+{
+ const char *fmt = "%llu";
+
+ if (strcmp(type, "s64") == 0)
+ fmt = "%lld";
+ else if (strcmp(type, "u64") == 0)
+ fmt = "%llu";
+ else if (strcmp(type, "s32") == 0)
+ fmt = "%d";
+ else if (strcmp(type, "u32") == 0)
+ fmt = "%u";
+ else if (strcmp(type, "s16") == 0)
+ fmt = "%d";
+ else if (strcmp(type, "u16") == 0)
+ fmt = "%u";
+ else if (strcmp(type, "s8") == 0)
+ fmt = "%d";
+ else if (strcmp(type, "u8") == 0)
+ fmt = "%u";
+ else if (strcmp(type, "char") == 0)
+ fmt = "%d";
+ else if (strcmp(type, "unsigned char") == 0)
+ fmt = "%u";
+ else if (strcmp(type, "int") == 0)
+ fmt = "%d";
+ else if (strcmp(type, "unsigned int") == 0)
+ fmt = "%u";
+ else if (strcmp(type, "long") == 0)
+ fmt = "%ld";
+ else if (strcmp(type, "unsigned long") == 0)
+ fmt = "%lu";
+ else if (strcmp(type, "pid_t") == 0)
+ fmt = "%d";
+ else if (synth_field_is_string(type))
+ fmt = "%s";
+
+ return fmt;
+}
+
+static enum print_line_t print_synth_event(struct trace_iterator *iter,
+ int flags,
+ struct trace_event *event)
+{
+ struct trace_array *tr = iter->tr;
+ struct trace_seq *s = &iter->seq;
+ struct synth_trace_event *entry;
+ struct synth_event *se;
+ unsigned int i, n_u64;
+ char print_fmt[32];
+ const char *fmt;
+
+ entry = (struct synth_trace_event *)iter->ent;
+ se = container_of(event, struct synth_event, call.event);
+
+ trace_seq_printf(s, "%s: ", se->name);
+
+ for (i = 0, n_u64 = 0; i < se->n_fields; i++) {
+ if (trace_seq_has_overflowed(s))
+ goto end;
+
+ fmt = synth_field_fmt(se->fields[i]->type);
+
+ /* parameter types */
+ if (tr->trace_flags & TRACE_ITER_VERBOSE)
+ trace_seq_printf(s, "%s ", fmt);
+
+ snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt);
+
+ /* parameter values */
+ if (se->fields[i]->is_string) {
+ trace_seq_printf(s, print_fmt, se->fields[i]->name,
+ (char *)&entry->fields[n_u64],
+ i == se->n_fields - 1 ? "" : " ");
+ n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
+ } else {
+ trace_seq_printf(s, print_fmt, se->fields[i]->name,
+ entry->fields[n_u64],
+ i == se->n_fields - 1 ? "" : " ");
+ n_u64++;
+ }
+ }
+end:
+ trace_seq_putc(s, '\n');
+
+ return trace_handle_return(s);
+}
+
+static struct trace_event_functions synth_event_funcs = {
+ .trace = print_synth_event
+};
+
+static notrace void trace_event_raw_event_synth(void *__data,
+ u64 *var_ref_vals,
+ unsigned int var_ref_idx)
+{
+ struct trace_event_file *trace_file = __data;
+ struct synth_trace_event *entry;
+ struct trace_event_buffer fbuffer;
+ struct synth_event *event;
+ unsigned int i, n_u64;
+ int fields_size = 0;
+
+ event = trace_file->event_call->data;
+
+ if (trace_trigger_soft_disabled(trace_file))
+ return;
+
+ fields_size = event->n_u64 * sizeof(u64);
+
+ entry = trace_event_buffer_reserve(&fbuffer, trace_file,
+ sizeof(*entry) + fields_size);
+ if (!entry)
+ return;
+
+ for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
+ if (event->fields[i]->is_string) {
+ char *str_val = (char *)(long)var_ref_vals[var_ref_idx + i];
+ char *str_field = (char *)&entry->fields[n_u64];
+
+ strncpy(str_field, str_val, STR_VAR_LEN_MAX);
+ n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
+ } else {
+ entry->fields[n_u64] = var_ref_vals[var_ref_idx + i];
+ n_u64++;
+ }
+ }
+
+ trace_event_buffer_commit(&fbuffer);
+}
+
+static void free_synth_event_print_fmt(struct trace_event_call *call)
+{
+ if (call) {
+ kfree(call->print_fmt);
+ call->print_fmt = NULL;
+ }
+}
+
+static int __set_synth_event_print_fmt(struct synth_event *event,
+ char *buf, int len)
+{
+ const char *fmt;
+ int pos = 0;
+ int i;
+
+ /* When len=0, we just calculate the needed length */
+#define LEN_OR_ZERO (len ? len - pos : 0)
+
+ pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
+ for (i = 0; i < event->n_fields; i++) {
+ fmt = synth_field_fmt(event->fields[i]->type);
+ pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s%s",
+ event->fields[i]->name, fmt,
+ i == event->n_fields - 1 ? "" : ", ");
+ }
+ pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
+
+ for (i = 0; i < event->n_fields; i++) {
+ pos += snprintf(buf + pos, LEN_OR_ZERO,
+ ", REC->%s", event->fields[i]->name);
+ }
+
+#undef LEN_OR_ZERO
+
+ /* return the length of print_fmt */
+ return pos;
+}
+
+static int set_synth_event_print_fmt(struct trace_event_call *call)
+{
+ struct synth_event *event = call->data;
+ char *print_fmt;
+ int len;
+
+ /* First: called with 0 length to calculate the needed length */
+ len = __set_synth_event_print_fmt(event, NULL, 0);
+
+ print_fmt = kmalloc(len + 1, GFP_KERNEL);
+ if (!print_fmt)
+ return -ENOMEM;
+
+ /* Second: actually write the @print_fmt */
+ __set_synth_event_print_fmt(event, print_fmt, len + 1);
+ call->print_fmt = print_fmt;
+
+ return 0;
+}
+
+static void free_synth_field(struct synth_field *field)
+{
+ kfree(field->type);
+ kfree(field->name);
+ kfree(field);
+}
+
+static struct synth_field *parse_synth_field(char *field_type,
+ char *field_name)
+{
+ struct synth_field *field;
+ int len, ret = 0;
+ char *array;
+
+ if (field_type[0] == ';')
+ field_type++;
+
+ len = strlen(field_name);
+ if (field_name[len - 1] == ';')
+ field_name[len - 1] = '\0';
+
+ field = kzalloc(sizeof(*field), GFP_KERNEL);
+ if (!field)
+ return ERR_PTR(-ENOMEM);
+
+ len = strlen(field_type) + 1;
+ array = strchr(field_name, '[');
+ if (array)
+ len += strlen(array);
+ field->type = kzalloc(len, GFP_KERNEL);
+ if (!field->type) {
+ ret = -ENOMEM;
+ goto free;
+ }
+ strcat(field->type, field_type);
+ if (array) {
+ strcat(field->type, array);
+ *array = '\0';
+ }
+
+ field->size = synth_field_size(field->type);
+ if (!field->size) {
+ ret = -EINVAL;
+ goto free;
+ }
+
+ if (synth_field_is_string(field->type))
+ field->is_string = true;
+
+ field->is_signed = synth_field_signed(field->type);
+
+ field->name = kstrdup(field_name, GFP_KERNEL);
+ if (!field->name) {
+ ret = -ENOMEM;
+ goto free;
+ }
+ out:
+ return field;
+ free:
+ free_synth_field(field);
+ field = ERR_PTR(ret);
+ goto out;
+}
+
+static void free_synth_tracepoint(struct tracepoint *tp)
+{
+ if (!tp)
+ return;
+
+ kfree(tp->name);
+ kfree(tp);
+}
+
+static struct tracepoint *alloc_synth_tracepoint(char *name)
+{
+ struct tracepoint *tp;
+
+ tp = kzalloc(sizeof(*tp), GFP_KERNEL);
+ if (!tp)
+ return ERR_PTR(-ENOMEM);
+
+ tp->name = kstrdup(name, GFP_KERNEL);
+ if (!tp->name) {
+ kfree(tp);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ return tp;
+}
+
+typedef void (*synth_probe_func_t) (void *__data, u64 *var_ref_vals,
+ unsigned int var_ref_idx);
+
+static inline void trace_synth(struct synth_event *event, u64 *var_ref_vals,
+ unsigned int var_ref_idx)
+{
+ struct tracepoint *tp = event->tp;
+
+ if (unlikely(atomic_read(&tp->key.enabled) > 0)) {
+ struct tracepoint_func *probe_func_ptr;
+ synth_probe_func_t probe_func;
+ void *__data;
+
+ if (!(cpu_online(raw_smp_processor_id())))
+ return;
+
+ probe_func_ptr = rcu_dereference_sched((tp)->funcs);
+ if (probe_func_ptr) {
+ do {
+ probe_func = probe_func_ptr->func;
+ __data = probe_func_ptr->data;
+ probe_func(__data, var_ref_vals, var_ref_idx);
+ } while ((++probe_func_ptr)->func);
+ }
+ }
+}
+
+static struct synth_event *find_synth_event(const char *name)
+{
+ struct synth_event *event;
+
+ list_for_each_entry(event, &synth_event_list, list) {
+ if (strcmp(event->name, name) == 0)
+ return event;
+ }
+
+ return NULL;
+}
+
+static int register_synth_event(struct synth_event *event)
+{
+ struct trace_event_call *call = &event->call;
+ int ret = 0;
+
+ event->call.class = &event->class;
+ event->class.system = kstrdup(SYNTH_SYSTEM, GFP_KERNEL);
+ if (!event->class.system) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ event->tp = alloc_synth_tracepoint(event->name);
+ if (IS_ERR(event->tp)) {
+ ret = PTR_ERR(event->tp);
+ event->tp = NULL;
+ goto out;
+ }
+
+ INIT_LIST_HEAD(&call->class->fields);
+ call->event.funcs = &synth_event_funcs;
+ call->class->define_fields = synth_event_define_fields;
+
+ ret = register_trace_event(&call->event);
+ if (!ret) {
+ ret = -ENODEV;
+ goto out;
+ }
+ call->flags = TRACE_EVENT_FL_TRACEPOINT;
+ call->class->reg = trace_event_reg;
+ call->class->probe = trace_event_raw_event_synth;
+ call->data = event;
+ call->tp = event->tp;
+
+ ret = trace_add_event_call(call);
+ if (ret) {
+ pr_warn("Failed to register synthetic event: %s\n",
+ trace_event_name(call));
+ goto err;
+ }
+
+ ret = set_synth_event_print_fmt(call);
+ if (ret < 0) {
+ trace_remove_event_call(call);
+ goto err;
+ }
+ out:
+ return ret;
+ err:
+ unregister_trace_event(&call->event);
+ goto out;
+}
+
+static int unregister_synth_event(struct synth_event *event)
+{
+ struct trace_event_call *call = &event->call;
+ int ret;
+
+ ret = trace_remove_event_call(call);
+
+ return ret;
+}
+
+static void free_synth_event(struct synth_event *event)
+{
+ unsigned int i;
+
+ if (!event)
+ return;
+
+ for (i = 0; i < event->n_fields; i++)
+ free_synth_field(event->fields[i]);
+
+ kfree(event->fields);
+ kfree(event->name);
+ kfree(event->class.system);
+ free_synth_tracepoint(event->tp);
+ free_synth_event_print_fmt(&event->call);
+ kfree(event);
+}
+
+static struct synth_event *alloc_synth_event(char *event_name, int n_fields,
+ struct synth_field **fields)
+{
+ struct synth_event *event;
+ unsigned int i;
+
+ event = kzalloc(sizeof(*event), GFP_KERNEL);
+ if (!event) {
+ event = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+
+ event->name = kstrdup(event_name, GFP_KERNEL);
+ if (!event->name) {
+ kfree(event);
+ event = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+
+ event->fields = kcalloc(n_fields, sizeof(*event->fields), GFP_KERNEL);
+ if (!event->fields) {
+ free_synth_event(event);
+ event = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+
+ for (i = 0; i < n_fields; i++)
+ event->fields[i] = fields[i];
+
+ event->n_fields = n_fields;
+ out:
+ return event;
+}
+
+static void add_or_delete_synth_event(struct synth_event *event, int delete)
+{
+ if (delete)
+ free_synth_event(event);
+ else {
+ mutex_lock(&synth_event_mutex);
+ if (!find_synth_event(event->name))
+ list_add(&event->list, &synth_event_list);
+ else
+ free_synth_event(event);
+ mutex_unlock(&synth_event_mutex);
+ }
+}
+
+static int create_synth_event(int argc, char **argv)
+{
+ struct synth_field *field, *fields[SYNTH_FIELDS_MAX];
+ struct synth_event *event = NULL;
+ bool delete_event = false;
+ int i, n_fields = 0, ret = 0;
+ char *name;
+
+ mutex_lock(&synth_event_mutex);
+
+ /*
+ * Argument syntax:
+ * - Add synthetic event: <event_name> field[;field] ...
+ * - Remove synthetic event: !<event_name> field[;field] ...
+ * where 'field' = type field_name
+ */
+ if (argc < 1) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ name = argv[0];
+ if (name[0] == '!') {
+ delete_event = true;
+ name++;
+ }
+
+ event = find_synth_event(name);
+ if (event) {
+ if (delete_event) {
+ if (event->ref) {
+ event = NULL;
+ ret = -EBUSY;
+ goto out;
+ }
+ list_del(&event->list);
+ goto out;
+ }
+ event = NULL;
+ ret = -EEXIST;
+ goto out;
+ } else if (delete_event)
+ goto out;
+
+ if (argc < 2) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ for (i = 1; i < argc - 1; i++) {
+ if (strcmp(argv[i], ";") == 0)
+ continue;
+ if (n_fields == SYNTH_FIELDS_MAX) {
+ ret = -EINVAL;
+ goto err;
+ }
+
+ field = parse_synth_field(argv[i], argv[i + 1]);
+ if (IS_ERR(field)) {
+ ret = PTR_ERR(field);
+ goto err;
+ }
+ fields[n_fields] = field;
+ i++; n_fields++;
+ }
+
+ if (i < argc) {
+ ret = -EINVAL;
+ goto err;
+ }
+
+ event = alloc_synth_event(name, n_fields, fields);
+ if (IS_ERR(event)) {
+ ret = PTR_ERR(event);
+ event = NULL;
+ goto err;
+ }
+ out:
+ mutex_unlock(&synth_event_mutex);
+
+ if (event) {
+ if (delete_event) {
+ ret = unregister_synth_event(event);
+ add_or_delete_synth_event(event, !ret);
+ } else {
+ ret = register_synth_event(event);
+ add_or_delete_synth_event(event, ret);
+ }
+ }
+
+ return ret;
+ err:
+ mutex_unlock(&synth_event_mutex);
+
+ for (i = 0; i < n_fields; i++)
+ free_synth_field(fields[i]);
+ free_synth_event(event);
+
+ return ret;
+}
+
+static int release_all_synth_events(void)
+{
+ struct list_head release_events;
+ struct synth_event *event, *e;
+ int ret = 0;
+
+ INIT_LIST_HEAD(&release_events);
+
+ mutex_lock(&synth_event_mutex);
+
+ list_for_each_entry(event, &synth_event_list, list) {
+ if (event->ref) {
+ mutex_unlock(&synth_event_mutex);
+ return -EBUSY;
+ }
+ }
+
+ list_splice_init(&event->list, &release_events);
+
+ mutex_unlock(&synth_event_mutex);
+
+ list_for_each_entry_safe(event, e, &release_events, list) {
+ list_del(&event->list);
+
+ ret = unregister_synth_event(event);
+ add_or_delete_synth_event(event, !ret);
+ }
+
+ return ret;
+}
+
+
+static void *synth_events_seq_start(struct seq_file *m, loff_t *pos)
+{
+ mutex_lock(&synth_event_mutex);
+
+ return seq_list_start(&synth_event_list, *pos);
+}
+
+static void *synth_events_seq_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ return seq_list_next(v, &synth_event_list, pos);
+}
+
+static void synth_events_seq_stop(struct seq_file *m, void *v)
+{
+ mutex_unlock(&synth_event_mutex);
+}
+
+static int synth_events_seq_show(struct seq_file *m, void *v)
+{
+ struct synth_field *field;
+ struct synth_event *event = v;
+ unsigned int i;
+
+ seq_printf(m, "%s\t", event->name);
+
+ for (i = 0; i < event->n_fields; i++) {
+ field = event->fields[i];
+
+ /* parameter values */
+ seq_printf(m, "%s %s%s", field->type, field->name,
+ i == event->n_fields - 1 ? "" : "; ");
+ }
+
+ seq_putc(m, '\n');
+
+ return 0;
+}
+
+static const struct seq_operations synth_events_seq_op = {
+ .start = synth_events_seq_start,
+ .next = synth_events_seq_next,
+ .stop = synth_events_seq_stop,
+ .show = synth_events_seq_show
+};
+
+static int synth_events_open(struct inode *inode, struct file *file)
+{
+ int ret;
+
+ if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
+ ret = release_all_synth_events();
+ if (ret < 0)
+ return ret;
+ }
+
+ return seq_open(file, &synth_events_seq_op);
+}
+
+static ssize_t synth_events_write(struct file *file,
+ const char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ return trace_parse_run_command(file, buffer, count, ppos,
+ create_synth_event);
+}
+
+static const struct file_operations synth_events_fops = {
+ .open = synth_events_open,
+ .write = synth_events_write,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
static u64 hist_field_timestamp(struct hist_field *hist_field,
struct tracing_map_elt *elt,
struct ring_buffer_event *rbe,
@@ -2963,6 +3773,28 @@ static int hist_trigger_enable(struct event_trigger_data *data,
return ret;
}
+static bool have_hist_trigger_match(struct event_trigger_data *data,
+ struct trace_event_file *file)
+{
+ struct hist_trigger_data *hist_data = data->private_data;
+ struct event_trigger_data *test, *named_data = NULL;
+ bool match = false;
+
+ if (hist_data->attrs->name)
+ named_data = find_named_trigger(hist_data->attrs->name);
+
+ list_for_each_entry_rcu(test, &file->triggers, list) {
+ if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
+ if (hist_trigger_match(data, test, named_data, false)) {
+ match = true;
+ break;
+ }
+ }
+ }
+
+ return match;
+}
+
static bool hist_trigger_check_refs(struct event_trigger_data *data,
struct trace_event_file *file)
{
@@ -3038,6 +3870,8 @@ static void hist_unreg_all(struct trace_event_file *file)
{
struct event_trigger_data *test, *n;
struct hist_trigger_data *hist_data;
+ struct synth_event *se;
+ const char *se_name;
if (hist_file_check_refs(file))
return;
@@ -3047,6 +3881,14 @@ static void hist_unreg_all(struct trace_event_file *file)
hist_data = test->private_data;
list_del_rcu(&test->list);
trace_event_trigger_enable_disable(file, 0);
+
+ mutex_lock(&synth_event_mutex);
+ se_name = trace_event_name(file->event_call);
+ se = find_synth_event(se_name);
+ if (se)
+ se->ref--;
+ mutex_unlock(&synth_event_mutex);
+
update_cond_flag(file);
if (hist_data->enable_timestamps)
tracing_set_time_stamp_abs(file->tr, false);
@@ -3065,6 +3907,8 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
struct hist_trigger_attrs *attrs;
struct event_trigger_ops *trigger_ops;
struct hist_trigger_data *hist_data;
+ struct synth_event *se;
+ const char *se_name;
bool remove = false;
char *trigger;
int ret = 0;
@@ -3095,10 +3939,11 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
- ret = -ENOMEM;
trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
- if (!trigger_data)
+ if (!trigger_data) {
+ ret = -ENOMEM;
goto out_free;
+ }
trigger_data->count = -1;
trigger_data->ops = trigger_ops;
@@ -3117,12 +3962,23 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
}
if (remove) {
+ if (!have_hist_trigger_match(trigger_data, file))
+ goto out_free;
+
if (hist_trigger_check_refs(trigger_data, file)) {
ret = -EBUSY;
goto out_free;
}
cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
+
+ mutex_lock(&synth_event_mutex);
+ se_name = trace_event_name(file->event_call);
+ se = find_synth_event(se_name);
+ if (se)
+ se->ref--;
+ mutex_unlock(&synth_event_mutex);
+
ret = 0;
goto out_free;
}
@@ -3158,6 +4014,13 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
if (ret)
goto out_unreg;
+ mutex_lock(&synth_event_mutex);
+ se_name = trace_event_name(file->event_call);
+ se = find_synth_event(se_name);
+ if (se)
+ se->ref++;
+ mutex_unlock(&synth_event_mutex);
+
/* Just return zero, not the number of registered triggers */
ret = 0;
out:
@@ -3330,3 +4193,31 @@ __init int register_trigger_hist_enable_disable_cmds(void)
return ret;
}
+
+static __init int trace_events_hist_init(void)
+{
+ struct dentry *entry = NULL;
+ struct dentry *d_tracer;
+ int err = 0;
+
+ d_tracer = tracing_init_dentry();
+ if (IS_ERR(d_tracer)) {
+ err = PTR_ERR(d_tracer);
+ goto err;
+ }
+
+ entry = tracefs_create_file("synthetic_events", 0644, d_tracer,
+ NULL, &synth_events_fops);
+ if (!entry) {
+ err = -ENODEV;
+ goto err;
+ }
+
+ return err;
+ err:
+ pr_warn("Could not create tracefs 'synthetic_events' entry\n");
+
+ return err;
+}
+
+fs_initcall(trace_events_hist_init);
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 25/46] tracing: Add support for field variables
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (23 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 24/46] tracing: Add support for synthetic events Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 26/46] tracing: Add onmatch hist trigger action support Steven Rostedt
` (20 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0025-tracing-Add-support-for-field-variables.patch --]
[-- Type: text/plain, Size: 19165 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 531 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 530 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 80d16d33ad5e..ad96fd110707 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -255,6 +255,16 @@ struct hist_trigger_attrs {
struct var_defs var_defs;
};
+struct field_var {
+ struct hist_field *var;
+ struct hist_field *val;
+};
+
+struct field_var_hist {
+ struct hist_trigger_data *hist_data;
+ char *cmd;
+};
+
struct hist_trigger_data {
struct hist_field *fields[HIST_FIELDS_MAX];
unsigned int n_vals;
@@ -274,6 +284,12 @@ struct hist_trigger_data {
struct action_data *actions[HIST_ACTIONS_MAX];
unsigned int n_actions;
+
+ struct field_var *field_vars[SYNTH_FIELDS_MAX];
+ unsigned int n_field_vars;
+ unsigned int n_field_var_str;
+ struct field_var_hist *field_var_hists[SYNTH_FIELDS_MAX];
+ unsigned int n_field_var_hists;
};
struct synth_field {
@@ -1427,6 +1443,7 @@ static struct hist_field *find_event_var(struct hist_trigger_data *hist_data,
struct hist_elt_data {
char *comm;
u64 *var_ref_vals;
+ char *field_var_str[SYNTH_FIELDS_MAX];
};
static u64 hist_field_var_ref(struct hist_field *hist_field,
@@ -1731,6 +1748,11 @@ static inline void save_comm(char *comm, struct task_struct *task)
static void hist_elt_data_free(struct hist_elt_data *elt_data)
{
+ unsigned int i;
+
+ for (i = 0; i < SYNTH_FIELDS_MAX; i++)
+ kfree(elt_data->field_var_str[i]);
+
kfree(elt_data->comm);
kfree(elt_data);
}
@@ -1748,7 +1770,7 @@ static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt)
unsigned int size = TASK_COMM_LEN;
struct hist_elt_data *elt_data;
struct hist_field *key_field;
- unsigned int i;
+ unsigned int i, n_str;
elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL);
if (!elt_data)
@@ -1767,6 +1789,18 @@ static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt)
}
}
+ n_str = hist_data->n_field_var_str;
+
+ size = STR_VAR_LEN_MAX;
+
+ for (i = 0; i < n_str; i++) {
+ elt_data->field_var_str[i] = kzalloc(size, GFP_KERNEL);
+ if (!elt_data->field_var_str[i]) {
+ hist_elt_data_free(elt_data);
+ return -ENOMEM;
+ }
+ }
+
elt->private_data = elt_data;
return 0;
@@ -2473,6 +2507,470 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
return ERR_PTR(ret);
}
+static char *find_trigger_filter(struct hist_trigger_data *hist_data,
+ struct trace_event_file *file)
+{
+ struct event_trigger_data *test;
+
+ list_for_each_entry_rcu(test, &file->triggers, list) {
+ if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
+ if (test->private_data == hist_data)
+ return test->filter_str;
+ }
+ }
+
+ return NULL;
+}
+
+static struct event_command trigger_hist_cmd;
+static int event_hist_trigger_func(struct event_command *cmd_ops,
+ struct trace_event_file *file,
+ char *glob, char *cmd, char *param);
+
+static bool compatible_keys(struct hist_trigger_data *target_hist_data,
+ struct hist_trigger_data *hist_data,
+ unsigned int n_keys)
+{
+ struct hist_field *target_hist_field, *hist_field;
+ unsigned int n, i, j;
+
+ if (hist_data->n_fields - hist_data->n_vals != n_keys)
+ return false;
+
+ i = hist_data->n_vals;
+ j = target_hist_data->n_vals;
+
+ for (n = 0; n < n_keys; n++) {
+ hist_field = hist_data->fields[i + n];
+ target_hist_field = target_hist_data->fields[j + n];
+
+ if (strcmp(hist_field->type, target_hist_field->type) != 0)
+ return false;
+ if (hist_field->size != target_hist_field->size)
+ return false;
+ if (hist_field->is_signed != target_hist_field->is_signed)
+ return false;
+ }
+
+ return true;
+}
+
+static struct hist_trigger_data *
+find_compatible_hist(struct hist_trigger_data *target_hist_data,
+ struct trace_event_file *file)
+{
+ struct hist_trigger_data *hist_data;
+ struct event_trigger_data *test;
+ unsigned int n_keys;
+
+ n_keys = target_hist_data->n_fields - target_hist_data->n_vals;
+
+ list_for_each_entry_rcu(test, &file->triggers, list) {
+ if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
+ hist_data = test->private_data;
+
+ if (compatible_keys(target_hist_data, hist_data, n_keys))
+ return hist_data;
+ }
+ }
+
+ return NULL;
+}
+
+static struct trace_event_file *event_file(struct trace_array *tr,
+ char *system, char *event_name)
+{
+ struct trace_event_file *file;
+
+ file = find_event_file(tr, system, event_name);
+ if (!file)
+ return ERR_PTR(-EINVAL);
+
+ return file;
+}
+
+static struct hist_field *
+find_synthetic_field_var(struct hist_trigger_data *target_hist_data,
+ char *system, char *event_name, char *field_name)
+{
+ struct hist_field *event_var;
+ char *synthetic_name;
+
+ synthetic_name = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
+ if (!synthetic_name)
+ return ERR_PTR(-ENOMEM);
+
+ strcpy(synthetic_name, "synthetic_");
+ strcat(synthetic_name, field_name);
+
+ event_var = find_event_var(target_hist_data, system, event_name, synthetic_name);
+
+ kfree(synthetic_name);
+
+ return event_var;
+}
+
+/**
+ * create_field_var_hist - Automatically create a histogram and var for a field
+ * @target_hist_data: The target hist trigger
+ * @subsys_name: Optional subsystem name
+ * @event_name: Optional event name
+ * @field_name: The name of the field (and the resulting variable)
+ *
+ * Hist trigger actions fetch data from variables, not directly from
+ * events. However, for convenience, users are allowed to directly
+ * specify an event field in an action, which will be automatically
+ * converted into a variable on their behalf.
+
+ * If a user specifies a field on an event that isn't the event the
+ * histogram currently being defined (the target event histogram), the
+ * only way that can be accomplished is if a new hist trigger is
+ * created and the field variable defined on that.
+ *
+ * This function creates a new histogram compatible with the target
+ * event (meaning a histogram with the same key as the target
+ * histogram), and creates a variable for the specified field, but
+ * with 'synthetic_' prepended to the variable name in order to avoid
+ * collision with normal field variables.
+ *
+ * Return: The variable created for the field.
+ */
+struct hist_field *
+create_field_var_hist(struct hist_trigger_data *target_hist_data,
+ char *subsys_name, char *event_name, char *field_name)
+{
+ struct trace_array *tr = target_hist_data->event_file->tr;
+ struct hist_field *event_var = ERR_PTR(-EINVAL);
+ struct hist_trigger_data *hist_data;
+ unsigned int i, n, first = true;
+ struct field_var_hist *var_hist;
+ struct trace_event_file *file;
+ struct hist_field *key_field;
+ char *saved_filter;
+ char *cmd;
+ int ret;
+
+ if (target_hist_data->n_field_var_hists >= SYNTH_FIELDS_MAX)
+ return ERR_PTR(-EINVAL);
+
+ file = event_file(tr, subsys_name, event_name);
+
+ if (IS_ERR(file)) {
+ ret = PTR_ERR(file);
+ return ERR_PTR(ret);
+ }
+
+ /*
+ * Look for a histogram compatible with target. We'll use the
+ * found histogram specification to create a new matching
+ * histogram with our variable on it. target_hist_data is not
+ * yet a registered histogram so we can't use that.
+ */
+ hist_data = find_compatible_hist(target_hist_data, file);
+ if (!hist_data)
+ return ERR_PTR(-EINVAL);
+
+ /* See if a synthetic field variable has already been created */
+ event_var = find_synthetic_field_var(target_hist_data, subsys_name,
+ event_name, field_name);
+ if (!IS_ERR_OR_NULL(event_var))
+ return event_var;
+
+ var_hist = kzalloc(sizeof(*var_hist), GFP_KERNEL);
+ if (!var_hist)
+ return ERR_PTR(-ENOMEM);
+
+ cmd = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
+ if (!cmd) {
+ kfree(var_hist);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ /* Use the same keys as the compatible histogram */
+ strcat(cmd, "keys=");
+
+ for_each_hist_key_field(i, hist_data) {
+ key_field = hist_data->fields[i];
+ if (!first)
+ strcat(cmd, ",");
+ strcat(cmd, key_field->field->name);
+ first = false;
+ }
+
+ /* Create the synthetic field variable specification */
+ strcat(cmd, ":synthetic_");
+ strcat(cmd, field_name);
+ strcat(cmd, "=");
+ strcat(cmd, field_name);
+
+ /* Use the same filter as the compatible histogram */
+ saved_filter = find_trigger_filter(hist_data, file);
+ if (saved_filter) {
+ strcat(cmd, " if ");
+ strcat(cmd, saved_filter);
+ }
+
+ var_hist->cmd = kstrdup(cmd, GFP_KERNEL);
+ if (!var_hist->cmd) {
+ kfree(cmd);
+ kfree(var_hist);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ /* Save the compatible histogram information */
+ var_hist->hist_data = hist_data;
+
+ /* Create the new histogram with our variable */
+ ret = event_hist_trigger_func(&trigger_hist_cmd, file,
+ "", "hist", cmd);
+ if (ret) {
+ kfree(cmd);
+ kfree(var_hist->cmd);
+ kfree(var_hist);
+ return ERR_PTR(ret);
+ }
+
+ kfree(cmd);
+
+ /* If we can't find the variable, something went wrong */
+ event_var = find_synthetic_field_var(target_hist_data, subsys_name,
+ event_name, field_name);
+ if (IS_ERR_OR_NULL(event_var)) {
+ kfree(var_hist->cmd);
+ kfree(var_hist);
+ return ERR_PTR(-EINVAL);
+ }
+
+ n = target_hist_data->n_field_var_hists;
+ target_hist_data->field_var_hists[n] = var_hist;
+ target_hist_data->n_field_var_hists++;
+
+ return event_var;
+}
+
+struct hist_field *
+find_target_event_var(struct hist_trigger_data *hist_data,
+ char *subsys_name, char *event_name, char *var_name)
+{
+ struct trace_event_file *file = hist_data->event_file;
+ struct hist_field *hist_field = NULL;
+
+ if (subsys_name) {
+ struct trace_event_call *call;
+
+ if (!event_name)
+ return NULL;
+
+ call = file->event_call;
+
+ if (strcmp(subsys_name, call->class->system) != 0)
+ return NULL;
+
+ if (strcmp(event_name, trace_event_name(call)) != 0)
+ return NULL;
+ }
+
+ hist_field = find_var_field(hist_data, var_name);
+
+ return hist_field;
+}
+
+static inline void __update_field_vars(struct tracing_map_elt *elt,
+ struct ring_buffer_event *rbe,
+ void *rec,
+ struct field_var **field_vars,
+ unsigned int n_field_vars,
+ unsigned int field_var_str_start)
+{
+ struct hist_elt_data *elt_data = elt->private_data;
+ unsigned int i, j, var_idx;
+ u64 var_val;
+
+ for (i = 0, j = field_var_str_start; i < n_field_vars; i++) {
+ struct field_var *field_var = field_vars[i];
+ struct hist_field *var = field_var->var;
+ struct hist_field *val = field_var->val;
+
+ var_val = val->fn(val, elt, rbe, rec);
+ var_idx = var->var.idx;
+
+ if (val->flags & HIST_FIELD_FL_STRING) {
+ char *str = elt_data->field_var_str[j++];
+ char *val_str = (char *)(uintptr_t)var_val;
+
+ strncpy(str, val_str, STR_VAR_LEN_MAX);
+ var_val = (u64)(uintptr_t)str;
+ }
+ tracing_map_set_var(elt, var_idx, var_val);
+ }
+}
+
+static void update_field_vars(struct hist_trigger_data *hist_data,
+ struct tracing_map_elt *elt,
+ struct ring_buffer_event *rbe,
+ void *rec)
+{
+ __update_field_vars(elt, rbe, rec, hist_data->field_vars,
+ hist_data->n_field_vars, 0);
+}
+
+static struct hist_field *create_var(struct hist_trigger_data *hist_data,
+ struct trace_event_file *file,
+ char *name, int size, const char *type)
+{
+ struct hist_field *var;
+ int idx;
+
+ if (find_var(hist_data, file, name) && !hist_data->remove) {
+ var = ERR_PTR(-EINVAL);
+ goto out;
+ }
+
+ var = kzalloc(sizeof(struct hist_field), GFP_KERNEL);
+ if (!var) {
+ var = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+
+ idx = tracing_map_add_var(hist_data->map);
+ if (idx < 0) {
+ kfree(var);
+ var = ERR_PTR(-EINVAL);
+ goto out;
+ }
+
+ var->flags = HIST_FIELD_FL_VAR;
+ var->var.idx = idx;
+ var->var.hist_data = var->hist_data = hist_data;
+ var->size = size;
+ var->var.name = kstrdup(name, GFP_KERNEL);
+ var->type = kstrdup(type, GFP_KERNEL);
+ if (!var->var.name || !var->type) {
+ kfree(var->var.name);
+ kfree(var->type);
+ kfree(var);
+ var = ERR_PTR(-ENOMEM);
+ }
+ out:
+ return var;
+}
+
+static struct field_var *create_field_var(struct hist_trigger_data *hist_data,
+ struct trace_event_file *file,
+ char *field_name)
+{
+ struct hist_field *val = NULL, *var = NULL;
+ unsigned long flags = HIST_FIELD_FL_VAR;
+ struct field_var *field_var;
+ int ret = 0;
+
+ if (hist_data->n_field_vars >= SYNTH_FIELDS_MAX) {
+ ret = -EINVAL;
+ goto err;
+ }
+
+ val = parse_atom(hist_data, file, field_name, &flags, NULL);
+ if (IS_ERR(val)) {
+ ret = PTR_ERR(val);
+ goto err;
+ }
+
+ var = create_var(hist_data, file, field_name, val->size, val->type);
+ if (IS_ERR(var)) {
+ kfree(val);
+ ret = PTR_ERR(var);
+ goto err;
+ }
+
+ field_var = kzalloc(sizeof(struct field_var), GFP_KERNEL);
+ if (!field_var) {
+ kfree(val);
+ kfree(var);
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ field_var->var = var;
+ field_var->val = val;
+ out:
+ return field_var;
+ err:
+ field_var = ERR_PTR(ret);
+ goto out;
+}
+
+/**
+ * create_target_field_var - Automatically create a variable for a field
+ * @target_hist_data: The target hist trigger
+ * @subsys_name: Optional subsystem name
+ * @event_name: Optional event name
+ * @var_name: The name of the field (and the resulting variable)
+ *
+ * Hist trigger actions fetch data from variables, not directly from
+ * events. However, for convenience, users are allowed to directly
+ * specify an event field in an action, which will be automatically
+ * converted into a variable on their behalf.
+
+ * This function creates a field variable with the name var_name on
+ * the hist trigger currently being defined on the target event. If
+ * subsys_name and event_name are specified, this function simply
+ * verifies that they do in fact match the target event subsystem and
+ * event name.
+ *
+ * Return: The variable created for the field.
+ */
+struct field_var *
+create_target_field_var(struct hist_trigger_data *target_hist_data,
+ char *subsys_name, char *event_name, char *var_name)
+{
+ struct trace_event_file *file = target_hist_data->event_file;
+
+ if (subsys_name) {
+ struct trace_event_call *call;
+
+ if (!event_name)
+ return NULL;
+
+ call = file->event_call;
+
+ if (strcmp(subsys_name, call->class->system) != 0)
+ return NULL;
+
+ if (strcmp(event_name, trace_event_name(call)) != 0)
+ return NULL;
+ }
+
+ return create_field_var(target_hist_data, file, var_name);
+}
+
+static void destroy_field_var(struct field_var *field_var)
+{
+ if (!field_var)
+ return;
+
+ destroy_hist_field(field_var->var, 0);
+ destroy_hist_field(field_var->val, 0);
+
+ kfree(field_var);
+}
+
+static void destroy_field_vars(struct hist_trigger_data *hist_data)
+{
+ unsigned int i;
+
+ for (i = 0; i < hist_data->n_field_vars; i++)
+ destroy_field_var(hist_data->field_vars[i]);
+}
+
+void save_field_var(struct hist_trigger_data *hist_data,
+ struct field_var *field_var)
+{
+ hist_data->field_vars[hist_data->n_field_vars++] = field_var;
+
+ if (field_var->val->flags & HIST_FIELD_FL_STRING)
+ hist_data->n_field_var_str++;
+}
+
static int create_hitcount_val(struct hist_trigger_data *hist_data)
{
hist_data->fields[HITCOUNT_IDX] =
@@ -2928,6 +3426,16 @@ static int create_actions(struct hist_trigger_data *hist_data,
return ret;
}
+static void destroy_field_var_hists(struct hist_trigger_data *hist_data)
+{
+ unsigned int i;
+
+ for (i = 0; i < hist_data->n_field_var_hists; i++) {
+ kfree(hist_data->field_var_hists[i]->cmd);
+ kfree(hist_data->field_var_hists[i]);
+ }
+}
+
static void destroy_hist_data(struct hist_trigger_data *hist_data)
{
if (!hist_data)
@@ -2938,6 +3446,8 @@ static void destroy_hist_data(struct hist_trigger_data *hist_data)
tracing_map_destroy(hist_data->map);
destroy_actions(hist_data);
+ destroy_field_vars(hist_data);
+ destroy_field_var_hists(hist_data);
kfree(hist_data);
}
@@ -3074,6 +3584,8 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
tracing_map_set_var(elt, var_idx, hist_val);
}
}
+
+ update_field_vars(hist_data, elt, rbe, rec);
}
static inline void add_to_key(char *compound_key, void *key,
@@ -3518,6 +4030,21 @@ static int event_hist_trigger_init(struct event_trigger_ops *ops,
return 0;
}
+static void unregister_field_var_hists(struct hist_trigger_data *hist_data)
+{
+ struct trace_event_file *file;
+ unsigned int i;
+ char *cmd;
+ int ret;
+
+ for (i = 0; i < hist_data->n_field_var_hists; i++) {
+ file = hist_data->field_var_hists[i]->hist_data->event_file;
+ cmd = hist_data->field_var_hists[i]->cmd;
+ ret = event_hist_trigger_func(&trigger_hist_cmd, file,
+ "!hist", "hist", cmd);
+ }
+}
+
static void event_hist_trigger_free(struct event_trigger_ops *ops,
struct event_trigger_data *data)
{
@@ -3535,6 +4062,8 @@ static void event_hist_trigger_free(struct event_trigger_ops *ops,
remove_hist_vars(hist_data);
+ unregister_field_var_hists(hist_data);
+
destroy_hist_data(hist_data);
}
}
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 26/46] tracing: Add onmatch hist trigger action support
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (24 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 25/46] tracing: Add support for field variables Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 27/46] tracing: Add onmax " Steven Rostedt
` (19 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi, Rajvi Jingar
[-- Attachment #1: 0026-tracing-Add-onmatch-hist-trigger-action-support.patch --]
[-- Type: text/plain, Size: 18215 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Add an 'onmatch(matching.event).<synthetic_event_name>(param list)'
hist trigger action which is invoked with the set of variables or
event fields named in the 'param list'. The result is the generation
of a synthetic event that consists of the values contained in those
variables and/or fields at the time the invoking event was hit.
As an example the below defines a simple synthetic event using a
variable defined on the sched_wakeup_new event, and shows the event
definition with unresolved fields, since the sched_wakeup_new event
with the testpid variable hasn't been defined yet:
# echo 'wakeup_new_test pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_new_test pid_t pid; int prio
The following hist trigger both defines a testpid variable and
specifies an onmatch() trace action that uses that variable along with
a non-variable field to generate a wakeup_new_test synthetic event
whenever a sched_wakeup_new event occurs, which because of the 'if
comm == "cyclictest"' filter only happens when the executable is
cyclictest:
# echo 'hist:testpid=pid:keys=$testpid:\
onmatch(sched.sched_wakeup_new).wakeup_new_test($testpid, prio) \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup_new/trigger
Creating and displaying a histogram based on those events is now just
a matter of using the fields and new synthetic event in the
tracing/events/synthetic directory, as usual:
# echo 'hist:keys=pid,prio:sort=pid,prio' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_new_test/trigger
Link: http://lkml.kernel.org/r/8c2a574bcb7530c876629c901ecd23911b14afe8.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Rajvi Jingar <rajvi.jingar@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 488 +++++++++++++++++++++++++++++++++++++--
1 file changed, 475 insertions(+), 13 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index ad96fd110707..9ac6089b7513 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -285,6 +285,8 @@ struct hist_trigger_data {
struct action_data *actions[HIST_ACTIONS_MAX];
unsigned int n_actions;
+ struct hist_field *synth_var_refs[SYNTH_FIELDS_MAX];
+ unsigned int n_synth_var_refs;
struct field_var *field_vars[SYNTH_FIELDS_MAX];
unsigned int n_field_vars;
unsigned int n_field_var_str;
@@ -321,7 +323,18 @@ typedef void (*action_fn_t) (struct hist_trigger_data *hist_data,
struct action_data {
action_fn_t fn;
- unsigned int var_ref_idx;
+ unsigned int n_params;
+ char *params[SYNTH_FIELDS_MAX];
+
+ union {
+ struct {
+ unsigned int var_ref_idx;
+ char *match_event;
+ char *match_event_system;
+ char *synth_event_name;
+ struct synth_event *synth_event;
+ } onmatch;
+ };
};
static LIST_HEAD(synth_event_list);
@@ -887,6 +900,21 @@ static struct synth_event *alloc_synth_event(char *event_name, int n_fields,
return event;
}
+static void action_trace(struct hist_trigger_data *hist_data,
+ struct tracing_map_elt *elt, void *rec,
+ struct ring_buffer_event *rbe,
+ struct action_data *data, u64 *var_ref_vals)
+{
+ struct synth_event *event = data->onmatch.synth_event;
+
+ trace_synth(event, var_ref_vals, data->onmatch.var_ref_idx);
+}
+
+struct hist_var_data {
+ struct list_head list;
+ struct hist_trigger_data *hist_data;
+};
+
static void add_or_delete_synth_event(struct synth_event *event, int delete)
{
if (delete)
@@ -1124,11 +1152,6 @@ static u64 hist_field_timestamp(struct hist_field *hist_field,
return ts;
}
-struct hist_var_data {
- struct list_head list;
- struct hist_trigger_data *hist_data;
-};
-
static struct hist_field *
check_field_for_var_ref(struct hist_field *hist_field,
struct hist_trigger_data *var_data,
@@ -1194,6 +1217,14 @@ static struct hist_field *find_var_ref(struct hist_trigger_data *hist_data,
return found;
}
+ for (i = 0; i < hist_data->n_synth_var_refs; i++) {
+ hist_field = hist_data->synth_var_refs[i];
+ found = check_field_for_var_refs(hist_data, hist_field,
+ var_data, var_idx, 0);
+ if (found)
+ return found;
+ }
+
return found;
}
@@ -1422,6 +1453,37 @@ static struct hist_field *find_file_var(struct trace_event_file *file,
return NULL;
}
+static struct hist_field *
+find_match_var(struct hist_trigger_data *hist_data, char *var_name)
+{
+ struct trace_array *tr = hist_data->event_file->tr;
+ struct hist_field *hist_field, *found = NULL;
+ struct trace_event_file *file;
+ unsigned int i;
+
+ for (i = 0; i < hist_data->n_actions; i++) {
+ struct action_data *data = hist_data->actions[i];
+
+ if (data->fn == action_trace) {
+ char *system = data->onmatch.match_event_system;
+ char *event_name = data->onmatch.match_event;
+
+ file = find_var_file(tr, system, event_name, var_name);
+ if (!file)
+ continue;
+ hist_field = find_file_var(file, var_name);
+ if (hist_field) {
+ if (found) {
+ return ERR_PTR(-EINVAL);
+ }
+
+ found = hist_field;
+ }
+ }
+ }
+ return found;
+}
+
static struct hist_field *find_event_var(struct hist_trigger_data *hist_data,
char *system,
char *event_name,
@@ -1431,6 +1493,14 @@ static struct hist_field *find_event_var(struct hist_trigger_data *hist_data,
struct hist_field *hist_field = NULL;
struct trace_event_file *file;
+ if (!system || !event_name) {
+ hist_field = find_match_var(hist_data, var_name);
+ if (IS_ERR(hist_field))
+ return NULL;
+ if (hist_field)
+ return hist_field;
+ }
+
file = find_var_file(tr, system, event_name, var_name);
if (!file)
return NULL;
@@ -1622,11 +1692,21 @@ static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs)
static int parse_action(char *str, struct hist_trigger_attrs *attrs)
{
- int ret = 0;
+ int ret = -EINVAL;
if (attrs->n_actions >= HIST_ACTIONS_MAX)
return ret;
+ if ((strncmp(str, "onmatch(", strlen("onmatch(")) == 0)) {
+ attrs->action_str[attrs->n_actions] = kstrdup(str, GFP_KERNEL);
+ if (!attrs->action_str[attrs->n_actions]) {
+ ret = -ENOMEM;
+ return ret;
+ }
+ attrs->n_actions++;
+ ret = 0;
+ }
+
return ret;
}
@@ -2635,7 +2715,7 @@ find_synthetic_field_var(struct hist_trigger_data *target_hist_data,
*
* Return: The variable created for the field.
*/
-struct hist_field *
+static struct hist_field *
create_field_var_hist(struct hist_trigger_data *target_hist_data,
char *subsys_name, char *event_name, char *field_name)
{
@@ -2748,7 +2828,7 @@ create_field_var_hist(struct hist_trigger_data *target_hist_data,
return event_var;
}
-struct hist_field *
+static struct hist_field *
find_target_event_var(struct hist_trigger_data *hist_data,
char *subsys_name, char *event_name, char *var_name)
{
@@ -2919,7 +2999,7 @@ static struct field_var *create_field_var(struct hist_trigger_data *hist_data,
*
* Return: The variable created for the field.
*/
-struct field_var *
+static struct field_var *
create_target_field_var(struct hist_trigger_data *target_hist_data,
char *subsys_name, char *event_name, char *var_name)
{
@@ -2943,6 +3023,27 @@ create_target_field_var(struct hist_trigger_data *target_hist_data,
return create_field_var(target_hist_data, file, var_name);
}
+static void onmatch_destroy(struct action_data *data)
+{
+ unsigned int i;
+
+ mutex_lock(&synth_event_mutex);
+
+ kfree(data->onmatch.match_event);
+ kfree(data->onmatch.match_event_system);
+ kfree(data->onmatch.synth_event_name);
+
+ for (i = 0; i < data->n_params; i++)
+ kfree(data->params[i]);
+
+ if (data->onmatch.synth_event)
+ data->onmatch.synth_event->ref--;
+
+ kfree(data);
+
+ mutex_unlock(&synth_event_mutex);
+}
+
static void destroy_field_var(struct field_var *field_var)
{
if (!field_var)
@@ -2962,8 +3063,8 @@ static void destroy_field_vars(struct hist_trigger_data *hist_data)
destroy_field_var(hist_data->field_vars[i]);
}
-void save_field_var(struct hist_trigger_data *hist_data,
- struct field_var *field_var)
+static void save_field_var(struct hist_trigger_data *hist_data,
+ struct field_var *field_var)
{
hist_data->field_vars[hist_data->n_field_vars++] = field_var;
@@ -2971,6 +3072,304 @@ void save_field_var(struct hist_trigger_data *hist_data,
hist_data->n_field_var_str++;
}
+
+static void destroy_synth_var_refs(struct hist_trigger_data *hist_data)
+{
+ unsigned int i;
+
+ for (i = 0; i < hist_data->n_synth_var_refs; i++)
+ destroy_hist_field(hist_data->synth_var_refs[i], 0);
+}
+
+static void save_synth_var_ref(struct hist_trigger_data *hist_data,
+ struct hist_field *var_ref)
+{
+ hist_data->synth_var_refs[hist_data->n_synth_var_refs++] = var_ref;
+
+ hist_data->var_refs[hist_data->n_var_refs] = var_ref;
+ var_ref->var_ref_idx = hist_data->n_var_refs++;
+}
+
+static int check_synth_field(struct synth_event *event,
+ struct hist_field *hist_field,
+ unsigned int field_pos)
+{
+ struct synth_field *field;
+
+ if (field_pos >= event->n_fields)
+ return -EINVAL;
+
+ field = event->fields[field_pos];
+
+ if (strcmp(field->type, hist_field->type) != 0)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int parse_action_params(char *params, struct action_data *data)
+{
+ char *param, *saved_param;
+ int ret = 0;
+
+ while (params) {
+ if (data->n_params >= SYNTH_FIELDS_MAX)
+ goto out;
+
+ param = strsep(¶ms, ",");
+ if (!param) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ param = strstrip(param);
+ if (strlen(param) < 2) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ saved_param = kstrdup(param, GFP_KERNEL);
+ if (!saved_param) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ data->params[data->n_params++] = saved_param;
+ }
+ out:
+ return ret;
+}
+
+static struct hist_field *
+onmatch_find_var(struct hist_trigger_data *hist_data, struct action_data *data,
+ char *system, char *event, char *var)
+{
+ struct hist_field *hist_field;
+
+ var++; /* skip '$' */
+
+ hist_field = find_target_event_var(hist_data, system, event, var);
+ if (!hist_field) {
+ if (!system) {
+ system = data->onmatch.match_event_system;
+ event = data->onmatch.match_event;
+ }
+
+ hist_field = find_event_var(hist_data, system, event, var);
+ }
+
+ return hist_field;
+}
+
+static struct hist_field *
+onmatch_create_field_var(struct hist_trigger_data *hist_data,
+ struct action_data *data, char *system,
+ char *event, char *var)
+{
+ struct hist_field *hist_field = NULL;
+ struct field_var *field_var;
+
+ /*
+ * First try to create a field var on the target event (the
+ * currently being defined). This will create a variable for
+ * unqualified fields on the target event, or if qualified,
+ * target fields that have qualified names matching the target.
+ */
+ field_var = create_target_field_var(hist_data, system, event, var);
+
+ if (field_var && !IS_ERR(field_var)) {
+ save_field_var(hist_data, field_var);
+ hist_field = field_var->var;
+ } else {
+ field_var = NULL;
+ /*
+ * If no explicit system.event is specfied, default to
+ * looking for fields on the onmatch(system.event.xxx)
+ * event.
+ */
+ if (!system) {
+ system = data->onmatch.match_event_system;
+ event = data->onmatch.match_event;
+ }
+
+ /*
+ * At this point, we're looking at a field on another
+ * event. Because we can't modify a hist trigger on
+ * another event to add a variable for a field, we need
+ * to create a new trigger on that event and create the
+ * variable at the same time.
+ */
+ hist_field = create_field_var_hist(hist_data, system, event, var);
+ if (IS_ERR(hist_field))
+ goto free;
+ }
+ out:
+ return hist_field;
+ free:
+ destroy_field_var(field_var);
+ hist_field = NULL;
+ goto out;
+}
+
+static int onmatch_create(struct hist_trigger_data *hist_data,
+ struct trace_event_file *file,
+ struct action_data *data)
+{
+ char *event_name, *param, *system = NULL;
+ struct hist_field *hist_field, *var_ref;
+ unsigned int i, var_ref_idx;
+ unsigned int field_pos = 0;
+ struct synth_event *event;
+ int ret = 0;
+
+ mutex_lock(&synth_event_mutex);
+ event = find_synth_event(data->onmatch.synth_event_name);
+ if (!event) {
+ mutex_unlock(&synth_event_mutex);
+ return -EINVAL;
+ }
+ event->ref++;
+ mutex_unlock(&synth_event_mutex);
+
+ var_ref_idx = hist_data->n_var_refs;
+
+ for (i = 0; i < data->n_params; i++) {
+ char *p;
+
+ p = param = kstrdup(data->params[i], GFP_KERNEL);
+ if (!param) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ system = strsep(¶m, ".");
+ if (!param) {
+ param = (char *)system;
+ system = event_name = NULL;
+ } else {
+ event_name = strsep(¶m, ".");
+ if (!param) {
+ kfree(p);
+ ret = -EINVAL;
+ goto err;
+ }
+ }
+
+ if (param[0] == '$')
+ hist_field = onmatch_find_var(hist_data, data, system,
+ event_name, param);
+ else
+ hist_field = onmatch_create_field_var(hist_data, data,
+ system,
+ event_name,
+ param);
+
+ if (!hist_field) {
+ kfree(p);
+ ret = -EINVAL;
+ goto err;
+ }
+
+ if (check_synth_field(event, hist_field, field_pos) == 0) {
+ var_ref = create_var_ref(hist_field, system, event_name);
+ if (!var_ref) {
+ kfree(p);
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ save_synth_var_ref(hist_data, var_ref);
+ field_pos++;
+ kfree(p);
+ continue;
+ }
+
+ kfree(p);
+ ret = -EINVAL;
+ goto err;
+ }
+
+ if (field_pos != event->n_fields) {
+ ret = -EINVAL;
+ goto err;
+ }
+
+ data->fn = action_trace;
+ data->onmatch.synth_event = event;
+ data->onmatch.var_ref_idx = var_ref_idx;
+ out:
+ return ret;
+ err:
+ mutex_lock(&synth_event_mutex);
+ event->ref--;
+ mutex_unlock(&synth_event_mutex);
+
+ goto out;
+}
+
+static struct action_data *onmatch_parse(struct trace_array *tr, char *str)
+{
+ char *match_event, *match_event_system;
+ char *synth_event_name, *params;
+ struct action_data *data;
+ int ret = -EINVAL;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return ERR_PTR(-ENOMEM);
+
+ match_event = strsep(&str, ")");
+ if (!match_event || !str)
+ goto free;
+
+ match_event_system = strsep(&match_event, ".");
+ if (!match_event)
+ goto free;
+
+ if (IS_ERR(event_file(tr, match_event_system, match_event)))
+ goto free;
+
+ data->onmatch.match_event = kstrdup(match_event, GFP_KERNEL);
+ if (!data->onmatch.match_event) {
+ ret = -ENOMEM;
+ goto free;
+ }
+
+ data->onmatch.match_event_system = kstrdup(match_event_system, GFP_KERNEL);
+ if (!data->onmatch.match_event_system) {
+ ret = -ENOMEM;
+ goto free;
+ }
+
+ strsep(&str, ".");
+ if (!str)
+ goto free;
+
+ synth_event_name = strsep(&str, "(");
+ if (!synth_event_name || !str)
+ goto free;
+
+ data->onmatch.synth_event_name = kstrdup(synth_event_name, GFP_KERNEL);
+ if (!data->onmatch.synth_event_name) {
+ ret = -ENOMEM;
+ goto free;
+ }
+
+ params = strsep(&str, ")");
+ if (!params || !str || (str && strlen(str)))
+ goto free;
+
+ ret = parse_action_params(params, data);
+ if (ret)
+ goto free;
+ out:
+ return data;
+ free:
+ onmatch_destroy(data);
+ data = ERR_PTR(ret);
+ goto out;
+}
+
static int create_hitcount_val(struct hist_trigger_data *hist_data)
{
hist_data->fields[HITCOUNT_IDX] =
@@ -3395,18 +3794,39 @@ static void destroy_actions(struct hist_trigger_data *hist_data)
for (i = 0; i < hist_data->n_actions; i++) {
struct action_data *data = hist_data->actions[i];
- kfree(data);
+ if (data->fn == action_trace)
+ onmatch_destroy(data);
+ else
+ kfree(data);
}
}
static int parse_actions(struct hist_trigger_data *hist_data)
{
+ struct trace_array *tr = hist_data->event_file->tr;
+ struct action_data *data;
unsigned int i;
int ret = 0;
char *str;
for (i = 0; i < hist_data->attrs->n_actions; i++) {
str = hist_data->attrs->action_str[i];
+
+ if (strncmp(str, "onmatch(", strlen("onmatch(")) == 0) {
+ char *action_str = str + strlen("onmatch(");
+
+ data = onmatch_parse(tr, action_str);
+ if (IS_ERR(data)) {
+ ret = PTR_ERR(data);
+ break;
+ }
+ data->fn = action_trace;
+ } else {
+ ret = -EINVAL;
+ break;
+ }
+
+ hist_data->actions[hist_data->n_actions++] = data;
}
return ret;
@@ -3421,11 +3841,50 @@ static int create_actions(struct hist_trigger_data *hist_data,
for (i = 0; i < hist_data->attrs->n_actions; i++) {
data = hist_data->actions[i];
+
+ if (data->fn == action_trace) {
+ ret = onmatch_create(hist_data, file, data);
+ if (ret)
+ return ret;
+ }
}
return ret;
}
+static void print_onmatch_spec(struct seq_file *m,
+ struct hist_trigger_data *hist_data,
+ struct action_data *data)
+{
+ unsigned int i;
+
+ seq_printf(m, ":onmatch(%s.%s).", data->onmatch.match_event_system,
+ data->onmatch.match_event);
+
+ seq_printf(m, "%s(", data->onmatch.synth_event->name);
+
+ for (i = 0; i < data->n_params; i++) {
+ if (i)
+ seq_puts(m, ",");
+ seq_printf(m, "%s", data->params[i]);
+ }
+
+ seq_puts(m, ")");
+}
+
+static void print_actions_spec(struct seq_file *m,
+ struct hist_trigger_data *hist_data)
+{
+ unsigned int i;
+
+ for (i = 0; i < hist_data->n_actions; i++) {
+ struct action_data *data = hist_data->actions[i];
+
+ if (data->fn == action_trace)
+ print_onmatch_spec(m, hist_data, data);
+ }
+}
+
static void destroy_field_var_hists(struct hist_trigger_data *hist_data)
{
unsigned int i;
@@ -3448,6 +3907,7 @@ static void destroy_hist_data(struct hist_trigger_data *hist_data)
destroy_actions(hist_data);
destroy_field_vars(hist_data);
destroy_field_var_hists(hist_data);
+ destroy_synth_var_refs(hist_data);
kfree(hist_data);
}
@@ -4004,6 +4464,8 @@ static int event_hist_trigger_print(struct seq_file *m,
}
seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits));
+ print_actions_spec(m, hist_data);
+
if (data->filter_str)
seq_printf(m, " if %s", data->filter_str);
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 27/46] tracing: Add onmax hist trigger action support
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (25 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 26/46] tracing: Add onmatch hist trigger action support Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 28/46] tracing: Allow whitespace to surround hist trigger filter Steven Rostedt
` (18 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0027-tracing-Add-onmax-hist-trigger-action-support.patch --]
[-- Type: text/plain, Size: 13082 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 331 ++++++++++++++++++++++++++++++++++-----
1 file changed, 296 insertions(+), 35 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 9ac6089b7513..7bcc32a7e266 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -292,6 +292,10 @@ struct hist_trigger_data {
unsigned int n_field_var_str;
struct field_var_hist *field_var_hists[SYNTH_FIELDS_MAX];
unsigned int n_field_var_hists;
+
+ struct field_var *max_vars[SYNTH_FIELDS_MAX];
+ unsigned int n_max_vars;
+ unsigned int n_max_var_str;
};
struct synth_field {
@@ -334,6 +338,14 @@ struct action_data {
char *synth_event_name;
struct synth_event *synth_event;
} onmatch;
+
+ struct {
+ char *var_str;
+ char *fn_name;
+ unsigned int max_var_ref_idx;
+ struct hist_field *max_var;
+ struct hist_field *var;
+ } onmax;
};
};
@@ -1697,7 +1709,8 @@ static int parse_action(char *str, struct hist_trigger_attrs *attrs)
if (attrs->n_actions >= HIST_ACTIONS_MAX)
return ret;
- if ((strncmp(str, "onmatch(", strlen("onmatch(")) == 0)) {
+ if ((strncmp(str, "onmatch(", strlen("onmatch(")) == 0) ||
+ (strncmp(str, "onmax(", strlen("onmax(")) == 0)) {
attrs->action_str[attrs->n_actions] = kstrdup(str, GFP_KERNEL);
if (!attrs->action_str[attrs->n_actions]) {
ret = -ENOMEM;
@@ -1869,7 +1882,7 @@ static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt)
}
}
- n_str = hist_data->n_field_var_str;
+ n_str = hist_data->n_field_var_str + hist_data->n_max_var_str;
size = STR_VAR_LEN_MAX;
@@ -2894,6 +2907,15 @@ static void update_field_vars(struct hist_trigger_data *hist_data,
hist_data->n_field_vars, 0);
}
+static void update_max_vars(struct hist_trigger_data *hist_data,
+ struct tracing_map_elt *elt,
+ struct ring_buffer_event *rbe,
+ void *rec)
+{
+ __update_field_vars(elt, rbe, rec, hist_data->max_vars,
+ hist_data->n_max_vars, hist_data->n_field_var_str);
+}
+
static struct hist_field *create_var(struct hist_trigger_data *hist_data,
struct trace_event_file *file,
char *name, int size, const char *type)
@@ -3023,6 +3045,227 @@ create_target_field_var(struct hist_trigger_data *target_hist_data,
return create_field_var(target_hist_data, file, var_name);
}
+static void onmax_print(struct seq_file *m,
+ struct hist_trigger_data *hist_data,
+ struct tracing_map_elt *elt,
+ struct action_data *data)
+{
+ unsigned int i, save_var_idx, max_idx = data->onmax.max_var->var.idx;
+
+ seq_printf(m, "\n\tmax: %10llu", tracing_map_read_var(elt, max_idx));
+
+ for (i = 0; i < hist_data->n_max_vars; i++) {
+ struct hist_field *save_val = hist_data->max_vars[i]->val;
+ struct hist_field *save_var = hist_data->max_vars[i]->var;
+ u64 val;
+
+ save_var_idx = save_var->var.idx;
+
+ val = tracing_map_read_var(elt, save_var_idx);
+
+ if (save_val->flags & HIST_FIELD_FL_STRING) {
+ seq_printf(m, " %s: %-32s", save_var->var.name,
+ (char *)(uintptr_t)(val));
+ } else
+ seq_printf(m, " %s: %10llu", save_var->var.name, val);
+ }
+}
+
+static void onmax_save(struct hist_trigger_data *hist_data,
+ struct tracing_map_elt *elt, void *rec,
+ struct ring_buffer_event *rbe,
+ struct action_data *data, u64 *var_ref_vals)
+{
+ unsigned int max_idx = data->onmax.max_var->var.idx;
+ unsigned int max_var_ref_idx = data->onmax.max_var_ref_idx;
+
+ u64 var_val, max_val;
+
+ var_val = var_ref_vals[max_var_ref_idx];
+ max_val = tracing_map_read_var(elt, max_idx);
+
+ if (var_val <= max_val)
+ return;
+
+ tracing_map_set_var(elt, max_idx, var_val);
+
+ update_max_vars(hist_data, elt, rbe, rec);
+}
+
+static void onmax_destroy(struct action_data *data)
+{
+ unsigned int i;
+
+ destroy_hist_field(data->onmax.max_var, 0);
+ destroy_hist_field(data->onmax.var, 0);
+
+ kfree(data->onmax.var_str);
+ kfree(data->onmax.fn_name);
+
+ for (i = 0; i < data->n_params; i++)
+ kfree(data->params[i]);
+
+ kfree(data);
+}
+
+static int onmax_create(struct hist_trigger_data *hist_data,
+ struct action_data *data)
+{
+ struct trace_event_file *file = hist_data->event_file;
+ struct hist_field *var_field, *ref_field, *max_var;
+ unsigned int var_ref_idx = hist_data->n_var_refs;
+ struct field_var *field_var;
+ char *onmax_var_str, *param;
+ unsigned long flags;
+ unsigned int i;
+ int ret = 0;
+
+ onmax_var_str = data->onmax.var_str;
+ if (onmax_var_str[0] != '$')
+ return -EINVAL;
+ onmax_var_str++;
+
+ var_field = find_target_event_var(hist_data, NULL, NULL, onmax_var_str);
+ if (!var_field)
+ return -EINVAL;
+
+ flags = HIST_FIELD_FL_VAR_REF;
+ ref_field = create_hist_field(hist_data, NULL, flags, NULL);
+ if (!ref_field)
+ return -ENOMEM;
+
+ if (init_var_ref(ref_field, var_field, NULL, NULL)) {
+ destroy_hist_field(ref_field, 0);
+ ret = -ENOMEM;
+ goto out;
+ }
+ hist_data->var_refs[hist_data->n_var_refs] = ref_field;
+ ref_field->var_ref_idx = hist_data->n_var_refs++;
+ data->onmax.var = ref_field;
+
+ data->fn = onmax_save;
+ data->onmax.max_var_ref_idx = var_ref_idx;
+ max_var = create_var(hist_data, file, "max", sizeof(u64), "u64");
+ if (IS_ERR(max_var)) {
+ ret = PTR_ERR(max_var);
+ goto out;
+ }
+ data->onmax.max_var = max_var;
+
+ for (i = 0; i < data->n_params; i++) {
+ param = kstrdup(data->params[i], GFP_KERNEL);
+ if (!param) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ field_var = create_target_field_var(hist_data, NULL, NULL, param);
+ if (IS_ERR(field_var)) {
+ ret = PTR_ERR(field_var);
+ kfree(param);
+ goto out;
+ }
+
+ hist_data->max_vars[hist_data->n_max_vars++] = field_var;
+ if (field_var->val->flags & HIST_FIELD_FL_STRING)
+ hist_data->n_max_var_str++;
+
+ kfree(param);
+ }
+ out:
+ return ret;
+}
+
+static int parse_action_params(char *params, struct action_data *data)
+{
+ char *param, *saved_param;
+ int ret = 0;
+
+ while (params) {
+ if (data->n_params >= SYNTH_FIELDS_MAX)
+ goto out;
+
+ param = strsep(¶ms, ",");
+ if (!param) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ param = strstrip(param);
+ if (strlen(param) < 2) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ saved_param = kstrdup(param, GFP_KERNEL);
+ if (!saved_param) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ data->params[data->n_params++] = saved_param;
+ }
+ out:
+ return ret;
+}
+
+static struct action_data *onmax_parse(char *str)
+{
+ char *onmax_fn_name, *onmax_var_str;
+ struct action_data *data;
+ int ret = -EINVAL;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return ERR_PTR(-ENOMEM);
+
+ onmax_var_str = strsep(&str, ")");
+ if (!onmax_var_str || !str) {
+ ret = -EINVAL;
+ goto free;
+ }
+
+ data->onmax.var_str = kstrdup(onmax_var_str, GFP_KERNEL);
+ if (!data->onmax.var_str) {
+ ret = -ENOMEM;
+ goto free;
+ }
+
+ strsep(&str, ".");
+ if (!str)
+ goto free;
+
+ onmax_fn_name = strsep(&str, "(");
+ if (!onmax_fn_name || !str)
+ goto free;
+
+ if (strncmp(onmax_fn_name, "save", strlen("save")) == 0) {
+ char *params = strsep(&str, ")");
+
+ if (!params) {
+ ret = -EINVAL;
+ goto free;
+ }
+
+ ret = parse_action_params(params, data);
+ if (ret)
+ goto free;
+ } else
+ goto free;
+
+ data->onmax.fn_name = kstrdup(onmax_fn_name, GFP_KERNEL);
+ if (!data->onmax.fn_name) {
+ ret = -ENOMEM;
+ goto free;
+ }
+ out:
+ return data;
+ free:
+ onmax_destroy(data);
+ data = ERR_PTR(ret);
+ goto out;
+}
+
static void onmatch_destroy(struct action_data *data)
{
unsigned int i;
@@ -3107,39 +3350,6 @@ static int check_synth_field(struct synth_event *event,
return 0;
}
-static int parse_action_params(char *params, struct action_data *data)
-{
- char *param, *saved_param;
- int ret = 0;
-
- while (params) {
- if (data->n_params >= SYNTH_FIELDS_MAX)
- goto out;
-
- param = strsep(¶ms, ",");
- if (!param) {
- ret = -EINVAL;
- goto out;
- }
-
- param = strstrip(param);
- if (strlen(param) < 2) {
- ret = -EINVAL;
- goto out;
- }
-
- saved_param = kstrdup(param, GFP_KERNEL);
- if (!saved_param) {
- ret = -ENOMEM;
- goto out;
- }
-
- data->params[data->n_params++] = saved_param;
- }
- out:
- return ret;
-}
-
static struct hist_field *
onmatch_find_var(struct hist_trigger_data *hist_data, struct action_data *data,
char *system, char *event, char *var)
@@ -3796,6 +4006,8 @@ static void destroy_actions(struct hist_trigger_data *hist_data)
if (data->fn == action_trace)
onmatch_destroy(data);
+ else if (data->fn == onmax_save)
+ onmax_destroy(data);
else
kfree(data);
}
@@ -3821,6 +4033,15 @@ static int parse_actions(struct hist_trigger_data *hist_data)
break;
}
data->fn = action_trace;
+ } else if (strncmp(str, "onmax(", strlen("onmax(")) == 0) {
+ char *action_str = str + strlen("onmax(");
+
+ data = onmax_parse(action_str);
+ if (IS_ERR(data)) {
+ ret = PTR_ERR(data);
+ break;
+ }
+ data->fn = onmax_save;
} else {
ret = -EINVAL;
break;
@@ -3846,12 +4067,48 @@ static int create_actions(struct hist_trigger_data *hist_data,
ret = onmatch_create(hist_data, file, data);
if (ret)
return ret;
+ } else if (data->fn == onmax_save) {
+ ret = onmax_create(hist_data, data);
+ if (ret)
+ return ret;
}
}
return ret;
}
+static void print_actions(struct seq_file *m,
+ struct hist_trigger_data *hist_data,
+ struct tracing_map_elt *elt)
+{
+ unsigned int i;
+
+ for (i = 0; i < hist_data->n_actions; i++) {
+ struct action_data *data = hist_data->actions[i];
+
+ if (data->fn == onmax_save)
+ onmax_print(m, hist_data, elt, data);
+ }
+}
+
+static void print_onmax_spec(struct seq_file *m,
+ struct hist_trigger_data *hist_data,
+ struct action_data *data)
+{
+ unsigned int i;
+
+ seq_puts(m, ":onmax(");
+ seq_printf(m, "%s", data->onmax.var_str);
+ seq_printf(m, ").%s(", data->onmax.fn_name);
+
+ for (i = 0; i < hist_data->n_max_vars; i++) {
+ seq_printf(m, "%s", hist_data->max_vars[i]->var->var.name);
+ if (i < hist_data->n_max_vars - 1)
+ seq_puts(m, ",");
+ }
+ seq_puts(m, ")");
+}
+
static void print_onmatch_spec(struct seq_file *m,
struct hist_trigger_data *hist_data,
struct action_data *data)
@@ -3882,6 +4139,8 @@ static void print_actions_spec(struct seq_file *m,
if (data->fn == action_trace)
print_onmatch_spec(m, hist_data, data);
+ else if (data->fn == onmax_save)
+ print_onmax_spec(m, hist_data, data);
}
}
@@ -4263,6 +4522,8 @@ hist_trigger_entry_print(struct seq_file *m,
}
}
+ print_actions(m, hist_data, elt);
+
seq_puts(m, "\n");
}
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 28/46] tracing: Allow whitespace to surround hist trigger filter
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (26 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 27/46] tracing: Add onmax " Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 29/46] tracing: Add cpu field for hist triggers Steven Rostedt
` (17 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0028-tracing-Allow-whitespace-to-surround-hist-trigger-fi.patch --]
[-- Type: text/plain, Size: 2166 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
The existing code only allows for one space before and after the 'if'
specifying the filter for a hist trigger. Add code to make that more
permissive as far as whitespace goes. Specifically, we want to allow
spaces in the trigger itself now that we have additional syntax
(onmatch/onmax) where spaces are more natural e.g. spaces after commas
in param lists.
Link: http://lkml.kernel.org/r/1053090c3c308d4f431accdeb59dff4b511d4554.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 37 ++++++++++++++++++++++++++++++++-----
1 file changed, 32 insertions(+), 5 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 7bcc32a7e266..7e88daae85b6 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -5162,7 +5162,7 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
struct synth_event *se;
const char *se_name;
bool remove = false;
- char *trigger;
+ char *trigger, *p;
int ret = 0;
if (!param)
@@ -5171,10 +5171,37 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
if (glob[0] == '!')
remove = true;
- /* separate the trigger from the filter (k:v [if filter]) */
- trigger = strsep(¶m, " \t");
- if (!trigger)
- return -EINVAL;
+ /*
+ * separate the trigger from the filter (k:v [if filter])
+ * allowing for whitespace in the trigger
+ */
+ p = trigger = param;
+ do {
+ p = strstr(p, "if");
+ if (!p)
+ break;
+ if (p == param)
+ return -EINVAL;
+ if (*(p - 1) != ' ' && *(p - 1) != '\t') {
+ p++;
+ continue;
+ }
+ if (p >= param + strlen(param) - strlen("if") - 1)
+ return -EINVAL;
+ if (*(p + strlen("if")) != ' ' && *(p + strlen("if")) != '\t') {
+ p++;
+ continue;
+ }
+ break;
+ } while (p);
+
+ if (!p)
+ param = NULL;
+ else {
+ *(p - 1) = '\0';
+ param = strstrip(p);
+ trigger = strstrip(trigger);
+ }
attrs = parse_hist_trigger_attrs(trigger);
if (IS_ERR(attrs))
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 29/46] tracing: Add cpu field for hist triggers
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (27 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 28/46] tracing: Allow whitespace to surround hist trigger filter Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 30/46] tracing: Add hist trigger support for variable reference aliases Steven Rostedt
` (16 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0029-tracing-Add-cpu-field-for-hist-triggers.patch --]
[-- Type: text/plain, Size: 4173 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
A common key to use in a histogram is the cpuid - add a new cpu
'synthetic' field named 'cpu' for that purpose.
Link: http://lkml.kernel.org/r/89537645bfc957e0d76e2cacf5f0ada88691a6cc.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
Documentation/trace/histogram.txt | 15 +++++++++++++++
kernel/trace/trace_events_hist.c | 28 +++++++++++++++++++++++++++-
2 files changed, 42 insertions(+), 1 deletion(-)
diff --git a/Documentation/trace/histogram.txt b/Documentation/trace/histogram.txt
index 25c94730d3fe..be612ca79455 100644
--- a/Documentation/trace/histogram.txt
+++ b/Documentation/trace/histogram.txt
@@ -172,6 +172,21 @@
The examples below provide a more concrete illustration of the
concepts and typical usage patterns discussed above.
+ 'special' event fields
+ ------------------------
+
+ There are a number of 'special event fields' available for use as
+ keys or values in a hist trigger. These look like and behave as if
+ they were actual event fields, but aren't really part of the event's
+ field definition or format file. They are however available for any
+ event, and can be used anywhere an actual event field could be.
+ They are:
+
+ common_timestamp u64 - timestamp (from ring buffer) associated
+ with the event, in nanoseconds. May be
+ modified by .usecs to have timestamps
+ interpreted as microseconds.
+ cpu int - the cpu on which the event occurred.
6.2 'hist' trigger examples
---------------------------
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 7e88daae85b6..98be6ad883eb 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -227,6 +227,7 @@ enum hist_field_flags {
HIST_FIELD_FL_VAR = 1 << 12,
HIST_FIELD_FL_EXPR = 1 << 13,
HIST_FIELD_FL_VAR_REF = 1 << 14,
+ HIST_FIELD_FL_CPU = 1 << 15,
};
struct var_defs {
@@ -1164,6 +1165,16 @@ static u64 hist_field_timestamp(struct hist_field *hist_field,
return ts;
}
+static u64 hist_field_cpu(struct hist_field *hist_field,
+ struct tracing_map_elt *elt,
+ struct ring_buffer_event *rbe,
+ void *event)
+{
+ int cpu = smp_processor_id();
+
+ return cpu;
+}
+
static struct hist_field *
check_field_for_var_ref(struct hist_field *hist_field,
struct hist_trigger_data *var_data,
@@ -1602,6 +1613,8 @@ static const char *hist_field_name(struct hist_field *field,
field_name = hist_field_name(field->operands[0], ++level);
else if (field->flags & HIST_FIELD_FL_TIMESTAMP)
field_name = "common_timestamp";
+ else if (field->flags & HIST_FIELD_FL_CPU)
+ field_name = "cpu";
else if (field->flags & HIST_FIELD_FL_EXPR ||
field->flags & HIST_FIELD_FL_VAR_REF) {
if (field->system) {
@@ -2109,6 +2122,15 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
goto out;
}
+ if (flags & HIST_FIELD_FL_CPU) {
+ hist_field->fn = hist_field_cpu;
+ hist_field->size = sizeof(int);
+ hist_field->type = kstrdup("unsigned int", GFP_KERNEL);
+ if (!hist_field->type)
+ goto free;
+ goto out;
+ }
+
if (WARN_ON_ONCE(!field))
goto out;
@@ -2345,7 +2367,9 @@ parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file,
hist_data->enable_timestamps = true;
if (*flags & HIST_FIELD_FL_TIMESTAMP_USECS)
hist_data->attrs->ts_in_usecs = true;
- } else {
+ } else if (strcmp(field_name, "cpu") == 0)
+ *flags |= HIST_FIELD_FL_CPU;
+ else {
field = trace_find_event_field(file->event_call, field_name);
if (!field || !field->size) {
field = ERR_PTR(-EINVAL);
@@ -4619,6 +4643,8 @@ static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP)
seq_puts(m, "common_timestamp");
+ else if (hist_field->flags & HIST_FIELD_FL_CPU)
+ seq_puts(m, "cpu");
else if (field_name) {
if (hist_field->flags & HIST_FIELD_FL_VAR_REF)
seq_putc(m, '$');
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 30/46] tracing: Add hist trigger support for variable reference aliases
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (28 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 29/46] tracing: Add cpu field for hist triggers Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 31/46] tracing: Add last error error facility for hist triggers Steven Rostedt
` (15 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0030-tracing-Add-hist-trigger-support-for-variable-refere.patch --]
[-- Type: text/plain, Size: 5460 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Add support for alias=$somevar where alias can be used as
onmatch.xxx($alias).
Aliases are a way of creating a new name for an existing variable, for
flexibly in making naming more clear in certain cases. For example in
the below the user perhaps feels that using $new_lat in the synthetic
event invocation is opaque or doesn't fit well stylistically with
previous triggers, so creates an alias of $new_lat named $latency and
uses that in the call instead:
# echo 'hist:keys=next_pid:new_lat=common_timestamp.usecs' >
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
# echo 'hist:keys=pid:latency=$new_lat:
onmatch(sched.sched_switch).wake2($latency,pid)' >
/sys/kernel/debug/tracing/events/synthetic/wake1/trigger
Link: http://lkml.kernel.org/r/ef20a65d921af3a873a6f1e8c71407c926d5586f.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 74 ++++++++++++++++++++++++++++++++++++----
1 file changed, 67 insertions(+), 7 deletions(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 98be6ad883eb..32af523501bc 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -228,6 +228,7 @@ enum hist_field_flags {
HIST_FIELD_FL_EXPR = 1 << 13,
HIST_FIELD_FL_VAR_REF = 1 << 14,
HIST_FIELD_FL_CPU = 1 << 15,
+ HIST_FIELD_FL_ALIAS = 1 << 16,
};
struct var_defs {
@@ -1609,7 +1610,8 @@ static const char *hist_field_name(struct hist_field *field,
if (field->field)
field_name = field->field->name;
- else if (field->flags & HIST_FIELD_FL_LOG2)
+ else if (field->flags & HIST_FIELD_FL_LOG2 ||
+ field->flags & HIST_FIELD_FL_ALIAS)
field_name = hist_field_name(field->operands[0], ++level);
else if (field->flags & HIST_FIELD_FL_TIMESTAMP)
field_name = "common_timestamp";
@@ -2080,7 +2082,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
hist_field->hist_data = hist_data;
- if (flags & HIST_FIELD_FL_EXPR)
+ if (flags & HIST_FIELD_FL_EXPR || flags & HIST_FIELD_FL_ALIAS)
goto out; /* caller will populate */
if (flags & HIST_FIELD_FL_VAR_REF) {
@@ -2217,10 +2219,18 @@ static int init_var_ref(struct hist_field *ref_field,
}
}
- ref_field->name = kstrdup(var_field->var.name, GFP_KERNEL);
- if (!ref_field->name) {
- err = -ENOMEM;
- goto free;
+ if (var_field->var.name) {
+ ref_field->name = kstrdup(var_field->var.name, GFP_KERNEL);
+ if (!ref_field->name) {
+ err = -ENOMEM;
+ goto free;
+ }
+ } else if (var_field->name) {
+ ref_field->name = kstrdup(var_field->name, GFP_KERNEL);
+ if (!ref_field->name) {
+ err = -ENOMEM;
+ goto free;
+ }
}
ref_field->type = kstrdup(var_field->type, GFP_KERNEL);
@@ -2382,6 +2392,28 @@ parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file,
return field;
}
+static struct hist_field *create_alias(struct hist_trigger_data *hist_data,
+ struct hist_field *var_ref,
+ char *var_name)
+{
+ struct hist_field *alias = NULL;
+ unsigned long flags = HIST_FIELD_FL_ALIAS | HIST_FIELD_FL_VAR;
+
+ alias = create_hist_field(hist_data, NULL, flags, var_name);
+ if (!alias)
+ return NULL;
+
+ alias->fn = var_ref->fn;
+ alias->operands[0] = var_ref;
+
+ if (init_var_ref(alias, var_ref, var_ref->system, var_ref->event_name)) {
+ destroy_hist_field(alias, 0);
+ return NULL;
+ }
+
+ return alias;
+}
+
static struct hist_field *parse_atom(struct hist_trigger_data *hist_data,
struct trace_event_file *file, char *str,
unsigned long *flags, char *var_name)
@@ -2415,6 +2447,13 @@ static struct hist_field *parse_atom(struct hist_trigger_data *hist_data,
if (hist_field) {
hist_data->var_refs[hist_data->n_var_refs] = hist_field;
hist_field->var_ref_idx = hist_data->n_var_refs++;
+ if (var_name) {
+ hist_field = create_alias(hist_data, hist_field, var_name);
+ if (!hist_field) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
return hist_field;
}
} else
@@ -2515,6 +2554,26 @@ static int check_expr_operands(struct hist_field *operand1,
unsigned long operand1_flags = operand1->flags;
unsigned long operand2_flags = operand2->flags;
+ if ((operand1_flags & HIST_FIELD_FL_VAR_REF) ||
+ (operand1_flags & HIST_FIELD_FL_ALIAS)) {
+ struct hist_field *var;
+
+ var = find_var_field(operand1->var.hist_data, operand1->name);
+ if (!var)
+ return -EINVAL;
+ operand1_flags = var->flags;
+ }
+
+ if ((operand2_flags & HIST_FIELD_FL_VAR_REF) ||
+ (operand2_flags & HIST_FIELD_FL_ALIAS)) {
+ struct hist_field *var;
+
+ var = find_var_field(operand2->var.hist_data, operand2->name);
+ if (!var)
+ return -EINVAL;
+ operand2_flags = var->flags;
+ }
+
if ((operand1_flags & HIST_FIELD_FL_TIMESTAMP_USECS) !=
(operand2_flags & HIST_FIELD_FL_TIMESTAMP_USECS))
return -EINVAL;
@@ -4646,7 +4705,8 @@ static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
else if (hist_field->flags & HIST_FIELD_FL_CPU)
seq_puts(m, "cpu");
else if (field_name) {
- if (hist_field->flags & HIST_FIELD_FL_VAR_REF)
+ if (hist_field->flags & HIST_FIELD_FL_VAR_REF ||
+ hist_field->flags & HIST_FIELD_FL_ALIAS)
seq_putc(m, '$');
seq_printf(m, "%s", field_name);
}
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 31/46] tracing: Add last error error facility for hist triggers
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (29 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 30/46] tracing: Add hist trigger support for variable reference aliases Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 32/46] tracing: Add inter-event hist trigger Documentation Steven Rostedt
` (14 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0031-tracing-Add-last-error-error-facility-for-hist-trigg.patch --]
[-- Type: text/plain, Size: 15654 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
With the addition of variables and actions, it's become necessary to
provide more detailed error information to users about syntax errors.
Add a 'last error' facility accessible via the erroring event's 'hist'
file. Reading the hist file after an error will display more detailed
information about what went wrong, if information is available. This
extended error information will be available until the next hist
trigger command for that event.
# echo xxx > /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
echo: write error: Invalid argument
# cat /sys/kernel/debug/tracing/events/sched/sched_wakeup/hist
ERROR: Couldn't yyy: zzz
Last command: xxx
Also add specific error messages for variable and action errors.
Link: http://lkml.kernel.org/r/64e9c422fc8aeafcc2f7a3b4328c0cffe7969129.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
Documentation/trace/histogram.txt | 20 +++++
kernel/trace/trace_events_hist.c | 164 ++++++++++++++++++++++++++++++++++----
2 files changed, 170 insertions(+), 14 deletions(-)
diff --git a/Documentation/trace/histogram.txt b/Documentation/trace/histogram.txt
index be612ca79455..0aec2d8e166b 100644
--- a/Documentation/trace/histogram.txt
+++ b/Documentation/trace/histogram.txt
@@ -188,6 +188,26 @@
interpreted as microseconds.
cpu int - the cpu on which the event occurred.
+ Extended error information
+ --------------------------
+
+ For some error conditions encountered when invoking a hist trigger
+ command, extended error information is available via the
+ corresponding event's 'hist' file. Reading the hist file after an
+ error will display more detailed information about what went wrong,
+ if information is available. This extended error information will
+ be available until the next hist trigger command for that event.
+
+ If available for a given error condition, the extended error
+ information and usage takes the following form:
+
+ # echo xxx > /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
+ echo: write error: Invalid argument
+
+ # cat /sys/kernel/debug/tracing/events/sched/sched_wakeup/hist
+ ERROR: Couldn't yyy: zzz
+ Last command: xxx
+
6.2 'hist' trigger examples
---------------------------
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 32af523501bc..8719b0ea672f 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -351,6 +351,65 @@ struct action_data {
};
};
+
+static char last_hist_cmd[MAX_FILTER_STR_VAL];
+static char hist_err_str[MAX_FILTER_STR_VAL];
+
+static void last_cmd_set(char *str)
+{
+ if (!str)
+ return;
+
+ strncpy(last_hist_cmd, str, MAX_FILTER_STR_VAL - 1);
+}
+
+static void hist_err(char *str, char *var)
+{
+ int maxlen = MAX_FILTER_STR_VAL - 1;
+
+ if (!str)
+ return;
+
+ if (strlen(hist_err_str))
+ return;
+
+ if (!var)
+ var = "";
+
+ if (strlen(hist_err_str) + strlen(str) + strlen(var) > maxlen)
+ return;
+
+ strcat(hist_err_str, str);
+ strcat(hist_err_str, var);
+}
+
+static void hist_err_event(char *str, char *system, char *event, char *var)
+{
+ char err[MAX_FILTER_STR_VAL];
+
+ if (system && var)
+ snprintf(err, MAX_FILTER_STR_VAL, "%s.%s.%s", system, event, var);
+ else if (system)
+ snprintf(err, MAX_FILTER_STR_VAL, "%s.%s", system, event);
+ else
+ strncpy(err, var, MAX_FILTER_STR_VAL);
+
+ hist_err(str, err);
+}
+
+static void hist_err_clear(void)
+{
+ hist_err_str[0] = '\0';
+}
+
+static bool have_hist_err(void)
+{
+ if (strlen(hist_err_str))
+ return true;
+
+ return false;
+}
+
static LIST_HEAD(synth_event_list);
static DEFINE_MUTEX(synth_event_mutex);
@@ -1448,8 +1507,10 @@ static struct trace_event_file *find_var_file(struct trace_array *tr,
continue;
if (find_var_field(var_hist_data, var_name)) {
- if (found)
+ if (found) {
+ hist_err_event("Variable name not unique, need to use fully qualified name (subsys.event.var) for variable: ", system, event_name, var_name);
return NULL;
+ }
found = file;
}
@@ -1498,6 +1559,7 @@ find_match_var(struct hist_trigger_data *hist_data, char *var_name)
hist_field = find_file_var(file, var_name);
if (hist_field) {
if (found) {
+ hist_err_event("Variable name not unique, need to use fully qualified name (subsys.event.var) for variable: ", system, event_name, var_name);
return ERR_PTR(-EINVAL);
}
@@ -1781,6 +1843,7 @@ static int parse_assignment(char *str, struct hist_trigger_attrs *attrs)
char *assignment;
if (attrs->n_assignments == TRACING_MAP_VARS_MAX) {
+ hist_err("Too many variables defined: ", str);
ret = -EINVAL;
goto out;
}
@@ -2335,6 +2398,10 @@ static struct hist_field *parse_var_ref(struct hist_trigger_data *hist_data,
if (var_field)
ref_field = create_var_ref(var_field, system, event_name);
+ if (!ref_field)
+ hist_err_event("Couldn't find variable: $",
+ system, event_name, var_name);
+
return ref_field;
}
@@ -2494,6 +2561,7 @@ static struct hist_field *parse_unary(struct hist_trigger_data *hist_data,
/* we support only -(xxx) i.e. explicit parens required */
if (level > 3) {
+ hist_err("Too many subexpressions (3 max): ", str);
ret = -EINVAL;
goto free;
}
@@ -2575,8 +2643,10 @@ static int check_expr_operands(struct hist_field *operand1,
}
if ((operand1_flags & HIST_FIELD_FL_TIMESTAMP_USECS) !=
- (operand2_flags & HIST_FIELD_FL_TIMESTAMP_USECS))
+ (operand2_flags & HIST_FIELD_FL_TIMESTAMP_USECS)) {
+ hist_err("Timestamp units in expression don't match", NULL);
return -EINVAL;
+ }
return 0;
}
@@ -2591,8 +2661,10 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
int field_op, ret = -EINVAL;
char *sep, *operand1_str;
- if (level > 3)
+ if (level > 3) {
+ hist_err("Too many subexpressions (3 max): ", str);
return ERR_PTR(-EINVAL);
+ }
field_op = contains_operator(str);
@@ -2826,12 +2898,17 @@ create_field_var_hist(struct hist_trigger_data *target_hist_data,
char *cmd;
int ret;
- if (target_hist_data->n_field_var_hists >= SYNTH_FIELDS_MAX)
+ if (target_hist_data->n_field_var_hists >= SYNTH_FIELDS_MAX) {
+ hist_err_event("onmatch: Too many field variables defined: ",
+ subsys_name, event_name, field_name);
return ERR_PTR(-EINVAL);
+ }
file = event_file(tr, subsys_name, event_name);
if (IS_ERR(file)) {
+ hist_err_event("onmatch: Event file not found: ",
+ subsys_name, event_name, field_name);
ret = PTR_ERR(file);
return ERR_PTR(ret);
}
@@ -2843,8 +2920,11 @@ create_field_var_hist(struct hist_trigger_data *target_hist_data,
* yet a registered histogram so we can't use that.
*/
hist_data = find_compatible_hist(target_hist_data, file);
- if (!hist_data)
+ if (!hist_data) {
+ hist_err_event("onmatch: Matching event histogram not found: ",
+ subsys_name, event_name, field_name);
return ERR_PTR(-EINVAL);
+ }
/* See if a synthetic field variable has already been created */
event_var = find_synthetic_field_var(target_hist_data, subsys_name,
@@ -2903,6 +2983,8 @@ create_field_var_hist(struct hist_trigger_data *target_hist_data,
kfree(cmd);
kfree(var_hist->cmd);
kfree(var_hist);
+ hist_err_event("onmatch: Couldn't create histogram for field: ",
+ subsys_name, event_name, field_name);
return ERR_PTR(ret);
}
@@ -2914,6 +2996,8 @@ create_field_var_hist(struct hist_trigger_data *target_hist_data,
if (IS_ERR_OR_NULL(event_var)) {
kfree(var_hist->cmd);
kfree(var_hist);
+ hist_err_event("onmatch: Couldn't find synthetic variable: ",
+ subsys_name, event_name, field_name);
return ERR_PTR(-EINVAL);
}
@@ -3050,18 +3134,21 @@ static struct field_var *create_field_var(struct hist_trigger_data *hist_data,
int ret = 0;
if (hist_data->n_field_vars >= SYNTH_FIELDS_MAX) {
+ hist_err("Too many field variables defined: ", field_name);
ret = -EINVAL;
goto err;
}
val = parse_atom(hist_data, file, field_name, &flags, NULL);
if (IS_ERR(val)) {
+ hist_err("Couldn't parse field variable: ", field_name);
ret = PTR_ERR(val);
goto err;
}
var = create_var(hist_data, file, field_name, val->size, val->type);
if (IS_ERR(var)) {
+ hist_err("Couldn't create or find variable: ", field_name);
kfree(val);
ret = PTR_ERR(var);
goto err;
@@ -3204,13 +3291,17 @@ static int onmax_create(struct hist_trigger_data *hist_data,
int ret = 0;
onmax_var_str = data->onmax.var_str;
- if (onmax_var_str[0] != '$')
+ if (onmax_var_str[0] != '$') {
+ hist_err("onmax: For onmax(x), x must be a variable: ", onmax_var_str);
return -EINVAL;
+ }
onmax_var_str++;
var_field = find_target_event_var(hist_data, NULL, NULL, onmax_var_str);
- if (!var_field)
+ if (!var_field) {
+ hist_err("onmax: Couldn't find onmax variable: ", onmax_var_str);
return -EINVAL;
+ }
flags = HIST_FIELD_FL_VAR_REF;
ref_field = create_hist_field(hist_data, NULL, flags, NULL);
@@ -3230,6 +3321,7 @@ static int onmax_create(struct hist_trigger_data *hist_data,
data->onmax.max_var_ref_idx = var_ref_idx;
max_var = create_var(hist_data, file, "max", sizeof(u64), "u64");
if (IS_ERR(max_var)) {
+ hist_err("onmax: Couldn't create onmax variable: ", "max");
ret = PTR_ERR(max_var);
goto out;
}
@@ -3244,6 +3336,7 @@ static int onmax_create(struct hist_trigger_data *hist_data,
field_var = create_target_field_var(hist_data, NULL, NULL, param);
if (IS_ERR(field_var)) {
+ hist_err("onmax: Couldn't create field variable: ", param);
ret = PTR_ERR(field_var);
kfree(param);
goto out;
@@ -3276,6 +3369,7 @@ static int parse_action_params(char *params, struct action_data *data)
param = strstrip(param);
if (strlen(param) < 2) {
+ hist_err("Invalid action param: ", param);
ret = -EINVAL;
goto out;
}
@@ -3451,6 +3545,9 @@ onmatch_find_var(struct hist_trigger_data *hist_data, struct action_data *data,
hist_field = find_event_var(hist_data, system, event, var);
}
+ if (!hist_field)
+ hist_err_event("onmatch: Couldn't find onmatch param: $", system, event, var);
+
return hist_field;
}
@@ -3518,6 +3615,7 @@ static int onmatch_create(struct hist_trigger_data *hist_data,
mutex_lock(&synth_event_mutex);
event = find_synth_event(data->onmatch.synth_event_name);
if (!event) {
+ hist_err("onmatch: Couldn't find synthetic event: ", data->onmatch.synth_event_name);
mutex_unlock(&synth_event_mutex);
return -EINVAL;
}
@@ -3577,12 +3675,15 @@ static int onmatch_create(struct hist_trigger_data *hist_data,
continue;
}
+ hist_err_event("onmatch: Param type doesn't match synthetic event field type: ",
+ system, event_name, param);
kfree(p);
ret = -EINVAL;
goto err;
}
if (field_pos != event->n_fields) {
+ hist_err("onmatch: Param count doesn't match synthetic event field count: ", event->name);
ret = -EINVAL;
goto err;
}
@@ -3612,15 +3713,22 @@ static struct action_data *onmatch_parse(struct trace_array *tr, char *str)
return ERR_PTR(-ENOMEM);
match_event = strsep(&str, ")");
- if (!match_event || !str)
+ if (!match_event || !str) {
+ hist_err("onmatch: Missing closing paren: ", match_event);
goto free;
+ }
match_event_system = strsep(&match_event, ".");
- if (!match_event)
+ if (!match_event) {
+ hist_err("onmatch: Missing subsystem for match event: ", match_event_system);
goto free;
+ }
- if (IS_ERR(event_file(tr, match_event_system, match_event)))
+ if (IS_ERR(event_file(tr, match_event_system, match_event))) {
+ hist_err_event("onmatch: Invalid subsystem or event name: ",
+ match_event_system, match_event, NULL);
goto free;
+ }
data->onmatch.match_event = kstrdup(match_event, GFP_KERNEL);
if (!data->onmatch.match_event) {
@@ -3635,12 +3743,16 @@ static struct action_data *onmatch_parse(struct trace_array *tr, char *str)
}
strsep(&str, ".");
- if (!str)
+ if (!str) {
+ hist_err("onmatch: Missing . after onmatch(): ", str);
goto free;
+ }
synth_event_name = strsep(&str, "(");
- if (!synth_event_name || !str)
+ if (!synth_event_name || !str) {
+ hist_err("onmatch: Missing opening paramlist paren: ", synth_event_name);
goto free;
+ }
data->onmatch.synth_event_name = kstrdup(synth_event_name, GFP_KERNEL);
if (!data->onmatch.synth_event_name) {
@@ -3649,8 +3761,10 @@ static struct action_data *onmatch_parse(struct trace_array *tr, char *str)
}
params = strsep(&str, ")");
- if (!params || !str || (str && strlen(str)))
+ if (!params || !str || (str && strlen(str))) {
+ hist_err("onmatch: Missing closing paramlist paren: ", params);
goto free;
+ }
ret = parse_action_params(params, data);
if (ret)
@@ -3725,7 +3839,9 @@ static int create_var_field(struct hist_trigger_data *hist_data,
if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX))
return -EINVAL;
+
if (find_var(hist_data, file, var_name) && !hist_data->remove) {
+ hist_err("Variable already defined: ", var_name);
return -EINVAL;
}
@@ -3806,6 +3922,7 @@ static int create_key_field(struct hist_trigger_data *hist_data,
}
if (hist_field->flags & HIST_FIELD_FL_VAR_REF) {
+ hist_err("Using variable references as keys not supported: ", field_str);
destroy_hist_field(hist_field, 0);
ret = -EINVAL;
goto out;
@@ -3919,11 +4036,13 @@ static int parse_var_defs(struct hist_trigger_data *hist_data)
var_name = strsep(&field_str, "=");
if (!var_name || !field_str) {
+ hist_err("Malformed assignment: ", var_name);
ret = -EINVAL;
goto free;
}
if (n_vars == TRACING_MAP_VARS_MAX) {
+ hist_err("Too many variables defined: ", var_name);
ret = -EINVAL;
goto free;
}
@@ -4675,6 +4794,11 @@ static int hist_show(struct seq_file *m, void *v)
hist_trigger_show(m, data, n++);
}
+ if (have_hist_err()) {
+ seq_printf(m, "\nERROR: %s\n", hist_err_str);
+ seq_printf(m, " Last command: %s\n", last_hist_cmd);
+ }
+
out_unlock:
mutex_unlock(&event_mutex);
@@ -5039,6 +5163,7 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops,
if (named_data) {
if (!hist_trigger_match(data, named_data, named_data,
true)) {
+ hist_err("Named hist trigger doesn't match existing named trigger (includes variables): ", hist_data->attrs->name);
ret = -EINVAL;
goto out;
}
@@ -5058,13 +5183,16 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops,
test->paused = false;
else if (hist_data->attrs->clear)
hist_clear(test);
- else
+ else {
+ hist_err("Hist trigger already exists", NULL);
ret = -EEXIST;
+ }
goto out;
}
}
new:
if (hist_data->attrs->cont || hist_data->attrs->clear) {
+ hist_err("Can't clear or continue a nonexistent hist trigger", NULL);
ret = -ENOENT;
goto out;
}
@@ -5251,6 +5379,11 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
char *trigger, *p;
int ret = 0;
+ if (glob && strlen(glob)) {
+ last_cmd_set(param);
+ hist_err_clear();
+ }
+
if (!param)
return -EINVAL;
@@ -5389,6 +5522,9 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
/* Just return zero, not the number of registered triggers */
ret = 0;
out:
+ if (ret == 0)
+ hist_err_clear();
+
return ret;
out_unreg:
cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 32/46] tracing: Add inter-event hist trigger Documentation
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (30 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 31/46] tracing: Add last error error facility for hist triggers Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 33/46] tracing: Make tracing_set_clock() non-static Steven Rostedt
` (13 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi, Baohong Liu
[-- Attachment #1: 0032-tracing-Add-inter-event-hist-trigger-Documentation.patch --]
[-- Type: text/plain, Size: 18222 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Add background and details on inter-event hist triggers, including
hist variables, synthetic events, and actions.
Link: http://lkml.kernel.org/r/b0414efb66535aa52aa7411f58c3d56724027fce.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Baohong Liu <baohong.liu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
Documentation/trace/histogram.txt | 381 ++++++++++++++++++++++++++++++++++++++
1 file changed, 381 insertions(+)
diff --git a/Documentation/trace/histogram.txt b/Documentation/trace/histogram.txt
index 0aec2d8e166b..df08882d091c 100644
--- a/Documentation/trace/histogram.txt
+++ b/Documentation/trace/histogram.txt
@@ -1603,3 +1603,384 @@
Hits: 489
Entries: 7
Dropped: 0
+
+
+2.2 Inter-event hist triggers
+-----------------------------
+
+Inter-event hist triggers are hist triggers that combine values from
+one or more other events and create a histogram using that data. Data
+from an inter-event histogram can in turn become the source for
+further combined histograms, thus providing a chain of related
+histograms, which is important for some applications.
+
+The most important example of an inter-event quantity that can be used
+in this manner is latency, which is simply a difference in timestamps
+between two events. Although latency is the most important
+inter-event quantity, note that because the support is completely
+general across the trace event subsystem, any event field can be used
+in an inter-event quantity.
+
+An example of a histogram that combines data from other histograms
+into a useful chain would be a 'wakeupswitch latency' histogram that
+combines a 'wakeup latency' histogram and a 'switch latency'
+histogram.
+
+Normally, a hist trigger specification consists of a (possibly
+compound) key along with one or more numeric values, which are
+continually updated sums associated with that key. A histogram
+specification in this case consists of individual key and value
+specifications that refer to trace event fields associated with a
+single event type.
+
+The inter-event hist trigger extension allows fields from multiple
+events to be referenced and combined into a multi-event histogram
+specification. In support of this overall goal, a few enabling
+features have been added to the hist trigger support:
+
+ - In order to compute an inter-event quantity, a value from one
+ event needs to saved and then referenced from another event. This
+ requires the introduction of support for histogram 'variables'.
+
+ - The computation of inter-event quantities and their combination
+ require some minimal amount of support for applying simple
+ expressions to variables (+ and -).
+
+ - A histogram consisting of inter-event quantities isn't logically a
+ histogram on either event (so having the 'hist' file for either
+ event host the histogram output doesn't really make sense). To
+ address the idea that the histogram is associated with a
+ combination of events, support is added allowing the creation of
+ 'synthetic' events that are events derived from other events.
+ These synthetic events are full-fledged events just like any other
+ and can be used as such, as for instance to create the
+ 'combination' histograms mentioned previously.
+
+ - A set of 'actions' can be associated with histogram entries -
+ these can be used to generate the previously mentioned synthetic
+ events, but can also be used for other purposes, such as for
+ example saving context when a 'max' latency has been hit.
+
+ - Trace events don't have a 'timestamp' associated with them, but
+ there is an implicit timestamp saved along with an event in the
+ underlying ftrace ring buffer. This timestamp is now exposed as a
+ a synthetic field named 'common_timestamp' which can be used in
+ histograms as if it were any other event field; it isn't an actual
+ field in the trace format but rather is a synthesized value that
+ nonetheless can be used as if it were an actual field. By default
+ it is in units of nanoseconds; appending '.usecs' to a
+ common_timestamp field changes the units to microseconds.
+
+These features are decribed in more detail in the following sections.
+
+2.2.1 Histogram Variables
+-------------------------
+
+Variables are simply named locations used for saving and retrieving
+values between matching events. A 'matching' event is defined as an
+event that has a matching key - if a variable is saved for a histogram
+entry corresponding to that key, any subsequent event with a matching
+key can access that variable.
+
+A variable's value is normally available to any subsequent event until
+it is set to something else by a subsequent event. The one exception
+to that rule is that any variable used in an expression is essentially
+'read-once' - once it's used by an expression in a subsequent event,
+it's reset to its 'unset' state, which means it can't be used again
+unless it's set again. This ensures not only that an event doesn't
+use an uninitialized variable in a calculation, but that that variable
+is used only once and not for any unrelated subsequent match.
+
+The basic syntax for saving a variable is to simply prefix a unique
+variable name not corresponding to any keyword along with an '=' sign
+to any event field.
+
+Either keys or values can be saved and retrieved in this way. This
+creates a variable named 'ts0' for a histogram entry with the key
+'next_pid':
+
+ # echo 'hist:keys=next_pid:vals=$ts0:ts0=common_timestamp ... >> \
+ event/trigger
+
+The ts0 variable can be accessed by any subsequent event having the
+same pid as 'next_pid'.
+
+Variable references are formed by prepending the variable name with
+the '$' sign. Thus for example, the ts0 variable above would be
+referenced as '$ts0' in expressions.
+
+Because 'vals=' is used, the common_timestamp variable value above
+will also be summed as a normal histogram value would (though for a
+timestamp it makes little sense).
+
+The below shows that a key value can also be saved in the same way:
+
+ # echo 'hist:timer_pid=common_pid:key=timer_pid ...' >> event/trigger
+
+If a variable isn't a key variable or prefixed with 'vals=', the
+associated event field will be saved in a variable but won't be summed
+as a value:
+
+ # echo 'hist:keys=next_pid:ts1=common_timestamp ... >> event/trigger
+
+Multiple variables can be assigned at the same time. The below would
+result in both ts0 and b being created as variables, with both
+common_timestamp and field1 additionally being summed as values:
+
+ # echo 'hist:keys=pid:vals=$ts0,$b:ts0=common_timestamp,b=field1 ... >> \
+ event/trigger
+
+Note that variable assignments can appear either preceding or
+following their use. The command below behaves identically to the
+command above:
+
+ # echo 'hist:keys=pid:ts0=common_timestamp,b=field1:vals=$ts0,$b ... >> \
+ event/trigger
+
+Any number of variables not bound to a 'vals=' prefix can also be
+assigned by simply separating them with colons. Below is the same
+thing but without the values being summed in the histogram:
+
+ # echo 'hist:keys=pid:ts0=common_timestamp:b=field1 ... >> event/trigger
+
+Variables set as above can be referenced and used in expressions on
+another event.
+
+For example, here's how a latency can be calculated:
+
+ # echo 'hist:keys=pid,prio:ts0=common_timestamp ... >> event1/trigger
+ # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp-$ts0 ... >> event2/trigger
+
+In the first line above, the event's timetamp is saved into the
+variable ts0. In the next line, ts0 is subtracted from the second
+event's timestamp to produce the latency, which is then assigned into
+yet another variable, 'wakeup_lat'. The hist trigger below in turn
+makes use of the wakeup_lat variable to compute a combined latency
+using the same key and variable from yet another event:
+
+ # echo 'hist:key=pid:wakeupswitch_lat=$wakeup_lat+$switchtime_lat ... >> event3/trigger
+
+2.2.2 Synthetic Events
+----------------------
+
+Synthetic events are user-defined events generated from hist trigger
+variables or fields associated with one or more other events. Their
+purpose is to provide a mechanism for displaying data spanning
+multiple events consistent with the existing and already familiar
+usage for normal events.
+
+To define a synthetic event, the user writes a simple specification
+consisting of the name of the new event along with one or more
+variables and their types, which can be any valid field type,
+separated by semicolons, to the tracing/synthetic_events file.
+
+For instance, the following creates a new event named 'wakeup_latency'
+with 3 fields: lat, pid, and prio. Each of those fields is simply a
+variable reference to a variable on another event:
+
+ # echo 'wakeup_latency \
+ u64 lat; \
+ pid_t pid; \
+ int prio' >> \
+ /sys/kernel/debug/tracing/synthetic_events
+
+Reading the tracing/synthetic_events file lists all the currently
+defined synthetic events, in this case the event defined above:
+
+ # cat /sys/kernel/debug/tracing/synthetic_events
+ wakeup_latency u64 lat; pid_t pid; int prio
+
+An existing synthetic event definition can be removed by prepending
+the command that defined it with a '!':
+
+ # echo '!wakeup_latency u64 lat pid_t pid int prio' >> \
+ /sys/kernel/debug/tracing/synthetic_events
+
+At this point, there isn't yet an actual 'wakeup_latency' event
+instantiated in the event subsytem - for this to happen, a 'hist
+trigger action' needs to be instantiated and bound to actual fields
+and variables defined on other events (see Section 6.3.3 below).
+
+Once that is done, an event instance is created, and a histogram can
+be defined using it:
+
+ # echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
+ /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
+
+The new event is created under the tracing/events/synthetic/ directory
+and looks and behaves just like any other event:
+
+ # ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
+ enable filter format hist id trigger
+
+Like any other event, once a histogram is enabled for the event, the
+output can be displayed by reading the event's 'hist' file.
+
+2.2.3 Hist trigger 'actions'
+----------------------------
+
+A hist trigger 'action' is a function that's executed whenever a
+histogram entry is added or updated.
+
+The default 'action' if no special function is explicity specified is
+as it always has been, to simply update the set of values associated
+with an entry. Some applications, however, may want to perform
+additional actions at that point, such as generate another event, or
+compare and save a maximum.
+
+The following additional actions are available. To specify an action
+for a given event, simply specify the action between colons in the
+hist trigger specification.
+
+ - onmatch(matching.event).<synthetic_event_name>(param list)
+
+ The 'onmatch(matching.event).<synthetic_event_name>(params)' hist
+ trigger action is invoked whenever an event matches and the
+ histogram entry would be added or updated. It causes the named
+ synthetic event to be generated with the values given in the
+ 'param list'. The result is the generation of a synthetic event
+ that consists of the values contained in those variables at the
+ time the invoking event was hit.
+
+ The 'param list' consists of one or more parameters which may be
+ either variables or fields defined on either the 'matching.event'
+ or the target event. The variables or fields specified in the
+ param list may be either fully-qualified or unqualified. If a
+ variable is specified as unqualified, it must be unique between
+ the two events. A field name used as a param can be unqualified
+ if it refers to the target event, but must be fully qualified if
+ it refers to the matching event. A fully-qualified name is of the
+ form 'system.event_name.$var_name' or 'system.event_name.field'.
+
+ The 'matching.event' specification is simply the fully qualified
+ event name of the event that matches the target event for the
+ onmatch() functionality, in the form 'system.event_name'.
+
+ Finally, the number and type of variables/fields in the 'param
+ list' must match the number and types of the fields in the
+ synthetic event being generated.
+
+ As an example the below defines a simple synthetic event and uses
+ a variable defined on the sched_wakeup_new event as a parameter
+ when invoking the synthetic event. Here we define the synthetic
+ event:
+
+ # echo 'wakeup_new_test pid_t pid' >> \
+ /sys/kernel/debug/tracing/synthetic_events
+
+ # cat /sys/kernel/debug/tracing/synthetic_events
+ wakeup_new_test pid_t pid
+
+ The following hist trigger both defines the missing testpid
+ variable and specifies an onmatch() action that generates a
+ wakeup_new_test synthetic event whenever a sched_wakeup_new event
+ occurs, which because of the 'if comm == "cyclictest"' filter only
+ happens when the executable is cyclictest:
+
+ # echo 'hist:keys=$testpid:testpid=pid:onmatch(sched.sched_wakeup_new).\
+ wakeup_new_test($testpid) if comm=="cyclictest"' >> \
+ /sys/kernel/debug/tracing/events/sched/sched_wakeup_new/trigger
+
+ Creating and displaying a histogram based on those events is now
+ just a matter of using the fields and new synthetic event in the
+ tracing/events/synthetic directory, as usual:
+
+ # echo 'hist:keys=pid:sort=pid' >> \
+ /sys/kernel/debug/tracing/events/synthetic/wakeup_new_test/trigger
+
+ Running 'cyclictest' should cause wakeup_new events to generate
+ wakeup_new_test synthetic events which should result in histogram
+ output in the wakeup_new_test event's hist file:
+
+ # cat /sys/kernel/debug/tracing/events/synthetic/wakeup_new_test/hist
+
+ A more typical usage would be to use two events to calculate a
+ latency. The following example uses a set of hist triggers to
+ produce a 'wakeup_latency' histogram:
+
+ First, we define a 'wakeup_latency' synthetic event:
+
+ # echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
+ /sys/kernel/debug/tracing/synthetic_events
+
+ Next, we specify that whenever we see a sched_waking event for a
+ cyclictest thread, save the timestamp in a 'ts0' variable:
+
+ # echo 'hist:keys=$saved_pid:saved_pid=pid:ts0=common_timestamp.usecs \
+ if comm=="cyclictest"' >> \
+ /sys/kernel/debug/tracing/events/sched/sched_waking/trigger
+
+ Then, when the corresponding thread is actually scheduled onto the
+ CPU by a sched_switch event, calculate the latency and use that
+ along with another variable and an event field to generate a
+ wakeup_latency synthetic event:
+
+ # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:\
+ onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,\
+ $saved_pid,next_prio) if next_comm=="cyclictest"' >> \
+ /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
+
+ We also need to create a histogram on the wakeup_latency synthetic
+ event in order to aggregate the generated synthetic event data:
+
+ # echo 'hist:keys=pid,prio,lat:sort=pid,lat' >> \
+ /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
+
+ Finally, once we've run cyclictest to actually generate some
+ events, we can see the output by looking at the wakeup_latency
+ synthetic event's hist file:
+
+ # cat /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/hist
+
+ - onmax(var).save(field,.. .)
+
+ The 'onmax(var).save(field,...)' hist trigger action is invoked
+ whenever the value of 'var' associated with a histogram entry
+ exceeds the current maximum contained in that variable.
+
+ The end result is that the trace event fields specified as the
+ onmax.save() params will be saved if 'var' exceeds the current
+ maximum for that hist trigger entry. This allows context from the
+ event that exhibited the new maximum to be saved for later
+ reference. When the histogram is displayed, additional fields
+ displaying the saved values will be printed.
+
+ As an example the below defines a couple of hist triggers, one for
+ sched_waking and another for sched_switch, keyed on pid. Whenever
+ a sched_waking occurs, the timestamp is saved in the entry
+ corresponding to the current pid, and when the scheduler switches
+ back to that pid, the timestamp difference is calculated. If the
+ resulting latency, stored in wakeup_lat, exceeds the current
+ maximum latency, the values specified in the save() fields are
+ recoreded:
+
+ # echo 'hist:keys=pid:ts0=common_timestamp.usecs \
+ if comm=="cyclictest"' >> \
+ /sys/kernel/debug/tracing/events/sched/sched_waking/trigger
+
+ # echo 'hist:keys=next_pid:\
+ wakeup_lat=common_timestamp.usecs-$ts0:\
+ onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
+ if next_comm=="cyclictest"' >> \
+ /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
+
+ When the histogram is displayed, the max value and the saved
+ values corresponding to the max are displayed following the rest
+ of the fields:
+
+ # cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
+ { next_pid: 2255 } hitcount: 239
+ common_timestamp-ts0: 0
+ max: 27
+ next_comm: cyclictest
+ prev_pid: 0 prev_prio: 120 prev_comm: swapper/1
+
+ { next_pid: 2256 } hitcount: 2355
+ common_timestamp-ts0: 0
+ max: 49 next_comm: cyclictest
+ prev_pid: 0 prev_prio: 120 prev_comm: swapper/0
+
+ Totals:
+ Hits: 12970
+ Entries: 2
+ Dropped: 0
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 33/46] tracing: Make tracing_set_clock() non-static
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (31 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 32/46] tracing: Add inter-event hist trigger Documentation Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 34/46] tracing: Add a clock attribute for hist triggers Steven Rostedt
` (12 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0033-tracing-Make-tracing_set_clock-non-static.patch --]
[-- Type: text/plain, Size: 1543 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
Allow tracing code outside of trace.c to access tracing_set_clock().
Some applications may require a particular clock in order to function
properly, such as latency calculations.
Also, add an accessor returning the current clock string.
Link: http://lkml.kernel.org/r/6d1c53e9ee2163f54e1849f5376573f54f0e6009.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace.c | 2 +-
kernel/trace/trace.h | 1 +
2 files changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 68f8702af9fb..551a7cd0d705 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -6214,7 +6214,7 @@ static int tracing_clock_show(struct seq_file *m, void *v)
return 0;
}
-static int tracing_set_clock(struct trace_array *tr, const char *clockstr)
+int tracing_set_clock(struct trace_array *tr, const char *clockstr)
{
int i;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 99b7ee7ed127..9de3e2a2f042 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -289,6 +289,7 @@ extern int trace_array_get(struct trace_array *tr);
extern void trace_array_put(struct trace_array *tr);
extern int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs);
+extern int tracing_set_clock(struct trace_array *tr, const char *clockstr);
extern bool trace_clock_in_ns(struct trace_array *tr);
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 34/46] tracing: Add a clock attribute for hist triggers
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (32 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 33/46] tracing: Make tracing_set_clock() non-static Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 35/46] ring-buffer: Add nesting for adding events within events Steven Rostedt
` (11 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi, Rajvi Jingar
[-- Attachment #1: 0034-tracing-Add-a-clock-attribute-for-hist-triggers.patch --]
[-- Type: text/plain, Size: 4449 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
The default clock if timestamps are used in a histogram is "global".
If timestamps aren't used, the clock is irrelevant.
Use the "clock=" param only if you want to override the default
"global" clock for a histogram with timestamps.
Link: http://lkml.kernel.org/r/427bed1389c5d22aa40c3e0683e30cc3d151e260.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Rajvi Jingar <rajvi.jingar@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
Documentation/trace/histogram.txt | 11 +++++++++-
kernel/trace/trace_events_hist.c | 42 ++++++++++++++++++++++++++++++++++++---
2 files changed, 49 insertions(+), 4 deletions(-)
diff --git a/Documentation/trace/histogram.txt b/Documentation/trace/histogram.txt
index df08882d091c..6e05510afc28 100644
--- a/Documentation/trace/histogram.txt
+++ b/Documentation/trace/histogram.txt
@@ -1671,7 +1671,16 @@ features have been added to the hist trigger support:
it is in units of nanoseconds; appending '.usecs' to a
common_timestamp field changes the units to microseconds.
-These features are decribed in more detail in the following sections.
+A note on inter-event timestamps: If common_timestamp is used in a
+histogram, the trace buffer is automatically switched over to using
+absolute timestamps and the "global" trace clock, in order to avoid
+bogus timestamp differences with other clocks that aren't coherent
+across CPUs. This can be overridden by specifying one of the other
+trace clocks instead, using the "clock=XXX" hist trigger attribute,
+where XXX is any of the clocks listed in the tracing/trace_clock
+pseudo-file.
+
+These features are described in more detail in the following sections.
2.2.1 Histogram Variables
-------------------------
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 8719b0ea672f..f7d0da20c5c8 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -242,6 +242,7 @@ struct hist_trigger_attrs {
char *vals_str;
char *sort_key_str;
char *name;
+ char *clock;
bool pause;
bool cont;
bool clear;
@@ -1776,6 +1777,7 @@ static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs)
kfree(attrs->sort_key_str);
kfree(attrs->keys_str);
kfree(attrs->vals_str);
+ kfree(attrs->clock);
kfree(attrs);
}
@@ -1831,6 +1833,19 @@ static int parse_assignment(char *str, struct hist_trigger_attrs *attrs)
ret = -ENOMEM;
goto out;
}
+ } else if (strncmp(str, "clock=", strlen("clock=")) == 0) {
+ strsep(&str, "=");
+ if (!str) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ str = strstrip(str);
+ attrs->clock = kstrdup(str, GFP_KERNEL);
+ if (!attrs->clock) {
+ ret = -ENOMEM;
+ goto out;
+ }
} else if (strncmp(str, "size=", strlen("size=")) == 0) {
int map_bits = parse_map_size(str);
@@ -1895,6 +1910,14 @@ static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str)
goto free;
}
+ if (!attrs->clock) {
+ attrs->clock = kstrdup("global", GFP_KERNEL);
+ if (!attrs->clock) {
+ ret = -ENOMEM;
+ goto free;
+ }
+ }
+
return attrs;
free:
destroy_hist_trigger_attrs(attrs);
@@ -4934,6 +4957,8 @@ static int event_hist_trigger_print(struct seq_file *m,
seq_puts(m, ".descending");
}
seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits));
+ if (hist_data->enable_timestamps)
+ seq_printf(m, ":clock=%s", hist_data->attrs->clock);
print_actions_spec(m, hist_data);
@@ -5201,7 +5226,6 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops,
data->paused = true;
if (named_data) {
- destroy_hist_data(data->private_data);
data->private_data = named_data->private_data;
set_named_trigger_data(data, named_data);
data->ops = &event_hist_trigger_named_ops;
@@ -5213,10 +5237,22 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops,
goto out;
}
- ret++;
+ if (hist_data->enable_timestamps) {
+ char *clock = hist_data->attrs->clock;
+
+ ret = tracing_set_clock(file->tr, hist_data->attrs->clock);
+ if (ret) {
+ hist_err("Couldn't set trace_clock: ", clock);
+ goto out;
+ }
- if (hist_data->enable_timestamps)
tracing_set_time_stamp_abs(file->tr, true);
+ }
+
+ if (named_data)
+ destroy_hist_data(hist_data);
+
+ ret++;
out:
return ret;
}
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 35/46] ring-buffer: Add nesting for adding events within events
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (33 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 34/46] tracing: Add a clock attribute for hist triggers Steven Rostedt
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2018-03-21 2:21 ` [for-next][PATCH 36/46] tracing: Use the ring-buffer nesting to allow synthetic events to be traced Steven Rostedt
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45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton
[-- Attachment #1: 0035-ring-buffer-Add-nesting-for-adding-events-within-eve.patch --]
[-- Type: text/plain, Size: 4244 bytes --]
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
The ring-buffer code has recusion protection in case tracing ends up tracing
itself, the ring-buffer will detect that it was called at the same context
(normal, softirq, interrupt or NMI), and not continue to record the event.
With the histogram synthetic events, they are called while tracing another
event at the same context. The recusion protection triggers because it
detects tracing at the same context and stops it.
Add ring_buffer_nest_start() and ring_buffer_nest_end() that will notify the
ring buffer that a trace is about to happen within another trace and that it
is intended, and not to trigger the recursion blocking.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
include/linux/ring_buffer.h | 3 +++
kernel/trace/ring_buffer.c | 57 ++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 57 insertions(+), 3 deletions(-)
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index 7cb84774c20d..a0233edc0718 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -117,6 +117,9 @@ int ring_buffer_unlock_commit(struct ring_buffer *buffer,
int ring_buffer_write(struct ring_buffer *buffer,
unsigned long length, void *data);
+void ring_buffer_nest_start(struct ring_buffer *buffer);
+void ring_buffer_nest_end(struct ring_buffer *buffer);
+
struct ring_buffer_event *
ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts,
unsigned long *lost_events);
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 33073cdebb26..a2fd3893cc02 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -477,6 +477,7 @@ struct ring_buffer_per_cpu {
struct buffer_page *reader_page;
unsigned long lost_events;
unsigned long last_overrun;
+ unsigned long nest;
local_t entries_bytes;
local_t entries;
local_t overrun;
@@ -2624,10 +2625,10 @@ trace_recursive_lock(struct ring_buffer_per_cpu *cpu_buffer)
bit = pc & NMI_MASK ? RB_CTX_NMI :
pc & HARDIRQ_MASK ? RB_CTX_IRQ : RB_CTX_SOFTIRQ;
- if (unlikely(val & (1 << bit)))
+ if (unlikely(val & (1 << (bit + cpu_buffer->nest))))
return 1;
- val |= (1 << bit);
+ val |= (1 << (bit + cpu_buffer->nest));
cpu_buffer->current_context = val;
return 0;
@@ -2636,7 +2637,57 @@ trace_recursive_lock(struct ring_buffer_per_cpu *cpu_buffer)
static __always_inline void
trace_recursive_unlock(struct ring_buffer_per_cpu *cpu_buffer)
{
- cpu_buffer->current_context &= cpu_buffer->current_context - 1;
+ cpu_buffer->current_context &=
+ cpu_buffer->current_context - (1 << cpu_buffer->nest);
+}
+
+/* The recursive locking above uses 4 bits */
+#define NESTED_BITS 4
+
+/**
+ * ring_buffer_nest_start - Allow to trace while nested
+ * @buffer: The ring buffer to modify
+ *
+ * The ring buffer has a safty mechanism to prevent recursion.
+ * But there may be a case where a trace needs to be done while
+ * tracing something else. In this case, calling this function
+ * will allow this function to nest within a currently active
+ * ring_buffer_lock_reserve().
+ *
+ * Call this function before calling another ring_buffer_lock_reserve() and
+ * call ring_buffer_nest_end() after the nested ring_buffer_unlock_commit().
+ */
+void ring_buffer_nest_start(struct ring_buffer *buffer)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+ int cpu;
+
+ /* Enabled by ring_buffer_nest_end() */
+ preempt_disable_notrace();
+ cpu = raw_smp_processor_id();
+ cpu_buffer = buffer->buffers[cpu];
+ /* This is the shift value for the above recusive locking */
+ cpu_buffer->nest += NESTED_BITS;
+}
+
+/**
+ * ring_buffer_nest_end - Allow to trace while nested
+ * @buffer: The ring buffer to modify
+ *
+ * Must be called after ring_buffer_nest_start() and after the
+ * ring_buffer_unlock_commit().
+ */
+void ring_buffer_nest_end(struct ring_buffer *buffer)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+ int cpu;
+
+ /* disabled by ring_buffer_nest_start() */
+ cpu = raw_smp_processor_id();
+ cpu_buffer = buffer->buffers[cpu];
+ /* This is the shift value for the above recusive locking */
+ cpu_buffer->nest -= NESTED_BITS;
+ preempt_enable_notrace();
}
/**
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 36/46] tracing: Use the ring-buffer nesting to allow synthetic events to be traced
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (34 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 35/46] ring-buffer: Add nesting for adding events within events Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 37/46] tracing: Add inter-event blurb to HIST_TRIGGERS config option Steven Rostedt
` (9 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton
[-- Attachment #1: 0036-tracing-Use-the-ring-buffer-nesting-to-allow-synthet.patch --]
[-- Type: text/plain, Size: 1765 bytes --]
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Synthetic events can be done within the recording of other events. Notify
the ring buffer via ring_buffer_nest_start() and ring_buffer_nest_end() that
this is intended and not to block it due to its recursion protection.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_hist.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index f7d0da20c5c8..4f027642ceef 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -640,6 +640,7 @@ static notrace void trace_event_raw_event_synth(void *__data,
struct trace_event_file *trace_file = __data;
struct synth_trace_event *entry;
struct trace_event_buffer fbuffer;
+ struct ring_buffer *buffer;
struct synth_event *event;
unsigned int i, n_u64;
int fields_size = 0;
@@ -651,10 +652,17 @@ static notrace void trace_event_raw_event_synth(void *__data,
fields_size = event->n_u64 * sizeof(u64);
+ /*
+ * Avoid ring buffer recursion detection, as this event
+ * is being performed within another event.
+ */
+ buffer = trace_file->tr->trace_buffer.buffer;
+ ring_buffer_nest_start(buffer);
+
entry = trace_event_buffer_reserve(&fbuffer, trace_file,
sizeof(*entry) + fields_size);
if (!entry)
- return;
+ goto out;
for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
if (event->fields[i]->is_string) {
@@ -670,6 +678,8 @@ static notrace void trace_event_raw_event_synth(void *__data,
}
trace_event_buffer_commit(&fbuffer);
+out:
+ ring_buffer_nest_end(buffer);
}
static void free_synth_event_print_fmt(struct trace_event_call *call)
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 37/46] tracing: Add inter-event blurb to HIST_TRIGGERS config option
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (35 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 36/46] tracing: Use the ring-buffer nesting to allow synthetic events to be traced Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 38/46] selftests: ftrace: Add inter-event hist triggers testcases Steven Rostedt
` (8 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Tom Zanussi
[-- Attachment #1: 0037-tracing-Add-inter-event-blurb-to-HIST_TRIGGERS-confi.patch --]
[-- Type: text/plain, Size: 1062 bytes --]
From: Tom Zanussi <tom.zanussi@linux.intel.com>
So that users know that inter-event tracing is supported as part of
the HIST_TRIGGERS option, include text to that effect in the help
text.
Link: http://lkml.kernel.org/r/a38e24231d8d980be636b56d35814570acfd167a.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/Kconfig | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 0b249e2f0c3c..c4f0f2e4126e 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -606,7 +606,10 @@ config HIST_TRIGGERS
event activity as an initial guide for further investigation
using more advanced tools.
- See Documentation/trace/events.txt.
+ Inter-event tracing of quantities such as latencies is also
+ supported using hist triggers under this option.
+
+ See Documentation/trace/histogram.txt.
If in doubt, say N.
config MMIOTRACE_TEST
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 38/46] selftests: ftrace: Add inter-event hist triggers testcases
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (36 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 37/46] tracing: Add inter-event blurb to HIST_TRIGGERS config option Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 39/46] tracing: Remove BUG_ON() from append_filter_string() Steven Rostedt
` (7 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Rajvi Jingar, Tom Zanussi
[-- Attachment #1: 0038-selftests-ftrace-Add-inter-event-hist-triggers-testc.patch --]
[-- Type: text/plain, Size: 16072 bytes --]
From: Rajvi Jingar <rajvi.jingar@intel.com>
This adds inter-event hist triggers testcases which covers following:
- create/remove synthetic event
- disable histogram for synthetic event
- extended error support
- field variable support
- histogram variables
- histogram trigger onmatch action
- histogram trigger onmax action
- histogram trigger onmatch-onmax action
- simple expression support
- combined histogram
Here is the test result.
=== Ftrace unit tests ===
[1] event trigger - test extended error support [PASS]
[2] event trigger - test field variable support [PASS]
[3] event trigger - test inter-event combined histogram trigger [PASS]
[4] event trigger - test inter-event histogram trigger onmatch action [PASS]
[5] event trigger - test inter-event histogram trigger onmatch-onmax action [PASS]
[6] event trigger - test inter-event histogram trigger onmax action [PASS]
[7] event trigger - test synthetic event create remove [PASS]
Link: http://lkml.kernel.org/r/e07ef1e72f7bf0f84dc87c9b736d6dc91b4b0b49.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Rajvi Jingar <rajvi.jingar@intel.com>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
tools/testing/selftests/ftrace/test.d/functions | 7 +++
.../inter-event/trigger-extended-error-support.tc | 39 +++++++++++++++
.../inter-event/trigger-field-variable-support.tc | 54 ++++++++++++++++++++
.../trigger-inter-event-combined-hist.tc | 58 ++++++++++++++++++++++
.../inter-event/trigger-onmatch-action-hist.tc | 50 +++++++++++++++++++
.../trigger-onmatch-onmax-action-hist.tc | 50 +++++++++++++++++++
.../inter-event/trigger-onmax-action-hist.tc | 48 ++++++++++++++++++
.../trigger-synthetic-event-createremove.tc | 54 ++++++++++++++++++++
8 files changed, 360 insertions(+)
create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-extended-error-support.tc
create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-field-variable-support.tc
create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-inter-event-combined-hist.tc
create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmatch-action-hist.tc
create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmatch-onmax-action-hist.tc
create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmax-action-hist.tc
create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-createremove.tc
diff --git a/tools/testing/selftests/ftrace/test.d/functions b/tools/testing/selftests/ftrace/test.d/functions
index df3dd7fe5f9b..2a4f16fc9819 100644
--- a/tools/testing/selftests/ftrace/test.d/functions
+++ b/tools/testing/selftests/ftrace/test.d/functions
@@ -59,6 +59,13 @@ disable_events() {
echo 0 > events/enable
}
+clear_synthetic_events() { # reset all current synthetic events
+ grep -v ^# synthetic_events |
+ while read line; do
+ echo "!$line" >> synthetic_events
+ done
+}
+
initialize_ftrace() { # Reset ftrace to initial-state
# As the initial state, ftrace will be set to nop tracer,
# no events, no triggers, no filters, no function filters,
diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-extended-error-support.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-extended-error-support.tc
new file mode 100644
index 000000000000..786dce7e48be
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-extended-error-support.tc
@@ -0,0 +1,39 @@
+#!/bin/sh
+# description: event trigger - test extended error support
+
+
+do_reset() {
+ reset_trigger
+ echo > set_event
+ clear_trace
+}
+
+fail() { #msg
+ do_reset
+ echo $1
+ exit_fail
+}
+
+if [ ! -f set_event ]; then
+ echo "event tracing is not supported"
+ exit_unsupported
+fi
+
+if [ ! -f synthetic_events ]; then
+ echo "synthetic event is not supported"
+ exit_unsupported
+fi
+
+reset_tracer
+do_reset
+
+echo "Test extended error support"
+echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="ping"' > events/sched/sched_wakeup/trigger
+echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="ping"' >> events/sched/sched_wakeup/trigger &>/dev/null
+if ! grep -q "ERROR:" events/sched/sched_wakeup/hist; then
+ fail "Failed to generate extended error in histogram"
+fi
+
+do_reset
+
+exit 0
diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-field-variable-support.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-field-variable-support.tc
new file mode 100644
index 000000000000..7fd5b4a8f060
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-field-variable-support.tc
@@ -0,0 +1,54 @@
+#!/bin/sh
+# description: event trigger - test field variable support
+
+do_reset() {
+ reset_trigger
+ echo > set_event
+ clear_trace
+}
+
+fail() { #msg
+ do_reset
+ echo $1
+ exit_fail
+}
+
+if [ ! -f set_event ]; then
+ echo "event tracing is not supported"
+ exit_unsupported
+fi
+
+if [ ! -f synthetic_events ]; then
+ echo "synthetic event is not supported"
+ exit_unsupported
+fi
+
+clear_synthetic_events
+reset_tracer
+do_reset
+
+echo "Test field variable support"
+
+echo 'wakeup_latency u64 lat; pid_t pid; int prio; char comm[16]' > synthetic_events
+echo 'hist:keys=comm:ts0=common_timestamp.usecs if comm=="ping"' > events/sched/sched_waking/trigger
+echo 'hist:keys=next_comm:wakeup_lat=common_timestamp.usecs-$ts0:onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,sched.sched_waking.prio,next_comm) if next_comm=="ping"' > events/sched/sched_switch/trigger
+echo 'hist:keys=pid,prio,comm:vals=lat:sort=pid,prio' > events/synthetic/wakeup_latency/trigger
+
+ping localhost -c 3
+if ! grep -q "ping" events/synthetic/wakeup_latency/hist; then
+ fail "Failed to create inter-event histogram"
+fi
+
+if ! grep -q "synthetic_prio=prio" events/sched/sched_waking/hist; then
+ fail "Failed to create histogram with field variable"
+fi
+
+echo '!hist:keys=next_comm:wakeup_lat=common_timestamp.usecs-$ts0:onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,sched.sched_waking.prio,next_comm) if next_comm=="ping"' >> events/sched/sched_switch/trigger
+
+if grep -q "synthetic_prio=prio" events/sched/sched_waking/hist; then
+ fail "Failed to remove histogram with field variable"
+fi
+
+do_reset
+
+exit 0
diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-inter-event-combined-hist.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-inter-event-combined-hist.tc
new file mode 100644
index 000000000000..c93dbe38b5df
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-inter-event-combined-hist.tc
@@ -0,0 +1,58 @@
+#!/bin/sh
+# description: event trigger - test inter-event combined histogram trigger
+
+do_reset() {
+ reset_trigger
+ echo > set_event
+ clear_trace
+}
+
+fail() { #msg
+ do_reset
+ echo $1
+ exit_fail
+}
+
+if [ ! -f set_event ]; then
+ echo "event tracing is not supported"
+ exit_unsupported
+fi
+
+if [ ! -f synthetic_events ]; then
+ echo "synthetic event is not supported"
+ exit_unsupported
+fi
+
+reset_tracer
+do_reset
+clear_synthetic_events
+
+echo "Test create synthetic event"
+
+echo 'waking_latency u64 lat pid_t pid' > synthetic_events
+if [ ! -d events/synthetic/waking_latency ]; then
+ fail "Failed to create waking_latency synthetic event"
+fi
+
+echo "Test combined histogram"
+
+echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="ping"' > events/sched/sched_waking/trigger
+echo 'hist:keys=pid:waking_lat=common_timestamp.usecs-$ts0:onmatch(sched.sched_waking).waking_latency($waking_lat,pid) if comm=="ping"' > events/sched/sched_wakeup/trigger
+echo 'hist:keys=pid,lat:sort=pid,lat' > events/synthetic/waking_latency/trigger
+
+echo 'wakeup_latency u64 lat pid_t pid' >> synthetic_events
+echo 'hist:keys=pid:ts1=common_timestamp.usecs if comm=="ping"' >> events/sched/sched_wakeup/trigger
+echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts1:onmatch(sched.sched_wakeup).wakeup_latency($wakeup_lat,next_pid) if next_comm=="ping"' > events/sched/sched_switch/trigger
+
+echo 'waking+wakeup_latency u64 lat; pid_t pid' >> synthetic_events
+echo 'hist:keys=pid,lat:sort=pid,lat:ww_lat=$waking_lat+$wakeup_lat:onmatch(synthetic.wakeup_latency).waking+wakeup_latency($ww_lat,pid)' >> events/synthetic/wakeup_latency/trigger
+echo 'hist:keys=pid,lat:sort=pid,lat' >> events/synthetic/waking+wakeup_latency/trigger
+
+ping localhost -c 3
+if ! grep -q "pid:" events/synthetic/waking+wakeup_latency/hist; then
+ fail "Failed to create combined histogram"
+fi
+
+do_reset
+
+exit 0
diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmatch-action-hist.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmatch-action-hist.tc
new file mode 100644
index 000000000000..e84e7d048566
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmatch-action-hist.tc
@@ -0,0 +1,50 @@
+#!/bin/sh
+# description: event trigger - test inter-event histogram trigger onmatch action
+
+do_reset() {
+ reset_trigger
+ echo > set_event
+ clear_trace
+}
+
+fail() { #msg
+ do_reset
+ echo $1
+ exit_fail
+}
+
+if [ ! -f set_event ]; then
+ echo "event tracing is not supported"
+ exit_unsupported
+fi
+
+if [ ! -f synthetic_events ]; then
+ echo "synthetic event is not supported"
+ exit_unsupported
+fi
+
+clear_synthetic_events
+reset_tracer
+do_reset
+
+echo "Test create synthetic event"
+
+echo 'wakeup_latency u64 lat pid_t pid char comm[16]' > synthetic_events
+if [ ! -d events/synthetic/wakeup_latency ]; then
+ fail "Failed to create wakeup_latency synthetic event"
+fi
+
+echo "Test create histogram for synthetic event"
+echo "Test histogram variables,simple expression support and onmatch action"
+
+echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="ping"' > events/sched/sched_wakeup/trigger
+echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:onmatch(sched.sched_wakeup).wakeup_latency($wakeup_lat,next_pid,next_comm) if next_comm=="ping"' > events/sched/sched_switch/trigger
+echo 'hist:keys=comm,pid,lat:wakeup_lat=lat:sort=lat' > events/synthetic/wakeup_latency/trigger
+ping localhost -c 5
+if ! grep -q "ping" events/synthetic/wakeup_latency/hist; then
+ fail "Failed to create onmatch action inter-event histogram"
+fi
+
+do_reset
+
+exit 0
diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmatch-onmax-action-hist.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmatch-onmax-action-hist.tc
new file mode 100644
index 000000000000..7907d8aacde3
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmatch-onmax-action-hist.tc
@@ -0,0 +1,50 @@
+#!/bin/sh
+# description: event trigger - test inter-event histogram trigger onmatch-onmax action
+
+do_reset() {
+ reset_trigger
+ echo > set_event
+ clear_trace
+}
+
+fail() { #msg
+ do_reset
+ echo $1
+ exit_fail
+}
+
+if [ ! -f set_event ]; then
+ echo "event tracing is not supported"
+ exit_unsupported
+fi
+
+if [ ! -f synthetic_events ]; then
+ echo "synthetic event is not supported"
+ exit_unsupported
+fi
+
+clear_synthetic_events
+reset_tracer
+do_reset
+
+echo "Test create synthetic event"
+
+echo 'wakeup_latency u64 lat pid_t pid char comm[16]' > synthetic_events
+if [ ! -d events/synthetic/wakeup_latency ]; then
+ fail "Failed to create wakeup_latency synthetic event"
+fi
+
+echo "Test create histogram for synthetic event"
+echo "Test histogram variables,simple expression support and onmatch-onmax action"
+
+echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="ping"' > events/sched/sched_wakeup/trigger
+echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:onmatch(sched.sched_wakeup).wakeup_latency($wakeup_lat,next_pid,next_comm):onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) if next_comm=="ping"' >> events/sched/sched_switch/trigger
+echo 'hist:keys=comm,pid,lat:wakeup_lat=lat:sort=lat' > events/synthetic/wakeup_latency/trigger
+ping localhost -c 5
+if [ ! grep -q "ping" events/synthetic/wakeup_latency/hist -o ! grep -q "max:" events/sched/sched_switch/hist]; then
+ fail "Failed to create onmatch-onmax action inter-event histogram"
+fi
+
+do_reset
+
+exit 0
diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmax-action-hist.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmax-action-hist.tc
new file mode 100644
index 000000000000..38b7ed6242b2
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-onmax-action-hist.tc
@@ -0,0 +1,48 @@
+#!/bin/sh
+# description: event trigger - test inter-event histogram trigger onmax action
+
+do_reset() {
+ reset_trigger
+ echo > set_event
+ clear_trace
+}
+
+fail() { #msg
+ do_reset
+ echo $1
+ exit_fail
+}
+
+if [ ! -f set_event ]; then
+ echo "event tracing is not supported"
+ exit_unsupported
+fi
+
+if [ ! -f synthetic_events ]; then
+ echo "synthetic event is not supported"
+ exit_unsupported
+fi
+
+clear_synthetic_events
+reset_tracer
+do_reset
+
+echo "Test create synthetic event"
+
+echo 'wakeup_latency u64 lat pid_t pid char comm[16]' > synthetic_events
+if [ ! -d events/synthetic/wakeup_latency ]; then
+ fail "Failed to create wakeup_latency synthetic event"
+fi
+
+echo "Test onmax action"
+
+echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="ping"' >> events/sched/sched_waking/trigger
+echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) if next_comm=="ping"' >> events/sched/sched_switch/trigger
+ping localhost -c 3
+if ! grep -q "max:" events/sched/sched_switch/hist; then
+ fail "Failed to create onmax action inter-event histogram"
+fi
+
+do_reset
+
+exit 0
diff --git a/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-createremove.tc b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-createremove.tc
new file mode 100644
index 000000000000..cef11377dcbd
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/trigger/inter-event/trigger-synthetic-event-createremove.tc
@@ -0,0 +1,54 @@
+#!/bin/sh
+# description: event trigger - test synthetic event create remove
+do_reset() {
+ reset_trigger
+ echo > set_event
+ clear_trace
+}
+
+fail() { #msg
+ do_reset
+ echo $1
+ exit_fail
+}
+
+if [ ! -f set_event ]; then
+ echo "event tracing is not supported"
+ exit_unsupported
+fi
+
+if [ ! -f synthetic_events ]; then
+ echo "synthetic event is not supported"
+ exit_unsupported
+fi
+
+clear_synthetic_events
+reset_tracer
+do_reset
+
+echo "Test create synthetic event"
+
+echo 'wakeup_latency u64 lat pid_t pid char comm[16]' > synthetic_events
+if [ ! -d events/synthetic/wakeup_latency ]; then
+ fail "Failed to create wakeup_latency synthetic event"
+fi
+
+reset_trigger
+
+echo "Test create synthetic event with an error"
+echo 'wakeup_latency u64 lat pid_t pid char' > synthetic_events > /dev/null
+if [ -d events/synthetic/wakeup_latency ]; then
+ fail "Created wakeup_latency synthetic event with an invalid format"
+fi
+
+reset_trigger
+
+echo "Test remove synthetic event"
+echo '!wakeup_latency u64 lat pid_t pid char comm[16]' > synthetic_events
+if [ -d events/synthetic/wakeup_latency ]; then
+ fail "Failed to delete wakeup_latency synthetic event"
+fi
+
+do_reset
+
+exit 0
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 39/46] tracing: Remove BUG_ON() from append_filter_string()
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (37 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 38/46] selftests: ftrace: Add inter-event hist triggers testcases Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 40/46] tracing: Use trace_seq instead of open code string appending Steven Rostedt
` (6 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton
[-- Attachment #1: 0039-tracing-Remove-BUG_ON-from-append_filter_string.patch --]
[-- Type: text/plain, Size: 885 bytes --]
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
There's no reason to BUG if there's a bug in the filtering code. Simply do a
warning and return.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_filter.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index a764aec3c9a1..819a13c3e13c 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -681,7 +681,8 @@ static int append_filter_string(struct event_filter *filter,
int newlen;
char *new_filter_string;
- BUG_ON(!filter->filter_string);
+ if (WARN_ON(!filter->filter_string))
+ return -EINVAL;
newlen = strlen(filter->filter_string) + strlen(string) + 1;
new_filter_string = kmalloc(newlen, GFP_KERNEL);
if (!new_filter_string)
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 40/46] tracing: Use trace_seq instead of open code string appending
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (38 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 39/46] tracing: Remove BUG_ON() from append_filter_string() Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 41/46] tracing: Remove filter allocator helper Steven Rostedt
` (5 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton
[-- Attachment #1: 0040-tracing-Use-trace_seq-instead-of-open-code-string-ap.patch --]
[-- Type: text/plain, Size: 2414 bytes --]
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
The filter code does open code string appending to produce an error message.
Instead it can be simplified by using trace_seq function helpers.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_filter.c | 57 +++++++++++++++-----------------------
1 file changed, 23 insertions(+), 34 deletions(-)
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 819a13c3e13c..f42442cd423a 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -675,47 +675,36 @@ static int replace_filter_string(struct event_filter *filter,
return 0;
}
-static int append_filter_string(struct event_filter *filter,
- char *string)
-{
- int newlen;
- char *new_filter_string;
-
- if (WARN_ON(!filter->filter_string))
- return -EINVAL;
- newlen = strlen(filter->filter_string) + strlen(string) + 1;
- new_filter_string = kmalloc(newlen, GFP_KERNEL);
- if (!new_filter_string)
- return -ENOMEM;
-
- strcpy(new_filter_string, filter->filter_string);
- strcat(new_filter_string, string);
- kfree(filter->filter_string);
- filter->filter_string = new_filter_string;
-
- return 0;
-}
-
static void append_filter_err(struct filter_parse_state *ps,
struct event_filter *filter)
{
+ struct trace_seq *s;
int pos = ps->lasterr_pos;
- char *buf, *pbuf;
+ char *buf;
+ int len;
- buf = (char *)__get_free_page(GFP_KERNEL);
- if (!buf)
+ if (WARN_ON(!filter->filter_string))
return;
- append_filter_string(filter, "\n");
- memset(buf, ' ', PAGE_SIZE);
- if (pos > PAGE_SIZE - 128)
- pos = 0;
- buf[pos] = '^';
- pbuf = &buf[pos] + 1;
-
- sprintf(pbuf, "\nparse_error: %s\n", err_text[ps->lasterr]);
- append_filter_string(filter, buf);
- free_page((unsigned long) buf);
+ s = kmalloc(sizeof(*s), GFP_KERNEL);
+ if (!s)
+ return;
+ trace_seq_init(s);
+
+ len = strlen(filter->filter_string);
+ if (pos > len)
+ len = pos;
+
+ trace_seq_puts(s, filter->filter_string);
+ trace_seq_printf(s, "\n%*s", pos, "^");
+ trace_seq_printf(s, "\nparse_error: %s\n", err_text[ps->lasterr]);
+ trace_seq_putc(s, 0);
+ buf = kmemdup_nul(s->buffer, s->seq.len, GFP_KERNEL);
+ if (buf) {
+ kfree(filter->filter_string);
+ filter->filter_string = buf;
+ }
+ kfree(s);
}
static inline struct event_filter *event_filter(struct trace_event_file *file)
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 41/46] tracing: Remove filter allocator helper
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (39 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 40/46] tracing: Use trace_seq instead of open code string appending Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 42/46] tracing: Only add filter list when needed Steven Rostedt
` (4 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton
[-- Attachment #1: 0041-tracing-Remove-filter-allocator-helper.patch --]
[-- Type: text/plain, Size: 1601 bytes --]
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
The __alloc_filter() function does nothing more that allocate the filter.
There's no reason to have it as a helper function.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_filter.c | 12 ++----------
1 file changed, 2 insertions(+), 10 deletions(-)
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index f42442cd423a..3d60bbeb2ef1 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -866,14 +866,6 @@ void free_event_filter(struct event_filter *filter)
__free_filter(filter);
}
-static struct event_filter *__alloc_filter(void)
-{
- struct event_filter *filter;
-
- filter = kzalloc(sizeof(*filter), GFP_KERNEL);
- return filter;
-}
-
static int __alloc_preds(struct event_filter *filter, int n_preds)
{
struct filter_pred *pred;
@@ -1812,7 +1804,7 @@ static int replace_system_preds(struct trace_subsystem_dir *dir,
list_add_tail(&filter_item->list, &filter_list);
- filter_item->filter = __alloc_filter();
+ filter_item->filter = kzalloc(sizeof(*filter), GFP_KERNEL);
if (!filter_item->filter)
goto fail_mem;
filter = filter_item->filter;
@@ -1886,7 +1878,7 @@ static int create_filter_start(char *filter_str, bool set_str,
WARN_ON_ONCE(*psp || *filterp);
/* allocate everything, and if any fails, free all and fail */
- filter = __alloc_filter();
+ filter = kzalloc(sizeof(*filter), GFP_KERNEL);
if (filter && set_str)
err = replace_filter_string(filter, filter_str);
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 42/46] tracing: Only add filter list when needed
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (40 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 41/46] tracing: Remove filter allocator helper Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 43/46] tracing: Embed replace_filter_string() helper function Steven Rostedt
` (3 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton
[-- Attachment #1: 0042-tracing-Only-add-filter-list-when-needed.patch --]
[-- Type: text/plain, Size: 2736 bytes --]
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
replace_system_preds() creates a filter list to free even when it doesn't
really need to have it. Only save filters that require synchronize_sched()
in the filter list to free. This will allow the code to be updated a bit
easier in the future.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_filter.c | 27 ++++++++++++++-------------
1 file changed, 14 insertions(+), 13 deletions(-)
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 3d60bbeb2ef1..2401b7c727a3 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1769,6 +1769,7 @@ static int replace_system_preds(struct trace_subsystem_dir *dir,
{
struct trace_event_file *file;
struct filter_list *filter_item;
+ struct event_filter *filter = NULL;
struct filter_list *tmp;
LIST_HEAD(filter_list);
bool fail = true;
@@ -1790,7 +1791,6 @@ static int replace_system_preds(struct trace_subsystem_dir *dir,
}
list_for_each_entry(file, &tr->events, list) {
- struct event_filter *filter;
if (file->system != dir)
continue;
@@ -1798,16 +1798,9 @@ static int replace_system_preds(struct trace_subsystem_dir *dir,
if (event_no_set_filter_flag(file))
continue;
- filter_item = kzalloc(sizeof(*filter_item), GFP_KERNEL);
- if (!filter_item)
- goto fail_mem;
-
- list_add_tail(&filter_item->list, &filter_list);
-
- filter_item->filter = kzalloc(sizeof(*filter), GFP_KERNEL);
- if (!filter_item->filter)
+ filter = kzalloc(sizeof(*filter), GFP_KERNEL);
+ if (!filter)
goto fail_mem;
- filter = filter_item->filter;
/* Can only fail on no memory */
err = replace_filter_string(filter, filter_string);
@@ -1821,13 +1814,20 @@ static int replace_system_preds(struct trace_subsystem_dir *dir,
append_filter_err(ps, filter);
} else
event_set_filtered_flag(file);
+
+
+ filter_item = kzalloc(sizeof(*filter_item), GFP_KERNEL);
+ if (!filter_item)
+ goto fail_mem;
+
+ list_add_tail(&filter_item->list, &filter_list);
/*
* Regardless of if this returned an error, we still
* replace the filter for the call.
*/
- filter = event_filter(file);
- event_set_filter(file, filter_item->filter);
- filter_item->filter = filter;
+ filter_item->filter = event_filter(file);
+ event_set_filter(file, filter);
+ filter = NULL;
fail = false;
}
@@ -1856,6 +1856,7 @@ static int replace_system_preds(struct trace_subsystem_dir *dir,
parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
return -EINVAL;
fail_mem:
+ kfree(filter);
/* If any call succeeded, we still need to sync */
if (!fail)
synchronize_sched();
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 43/46] tracing: Embed replace_filter_string() helper function
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (41 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 42/46] tracing: Only add filter list when needed Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 44/46] tracing: Combine enum and arrays into single macro in filter code Steven Rostedt
` (2 subsequent siblings)
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton
[-- Attachment #1: 0043-tracing-Embed-replace_filter_string-helper-function.patch --]
[-- Type: text/plain, Size: 2927 bytes --]
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
The replace_filter_string() frees the current string and then copies a given
string. But in the two locations that it was used, the allocation happened
right after the filter was allocated (nothing to replace). There's no need
for this to be a helper function. Embedding the allocation in the two places
where it was called will make changing the code in the future easier.
Also make the variable consistent (always use "filter_string" as the name,
as it was used in one instance as "filter_str")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_filter.c | 27 +++++++++------------------
1 file changed, 9 insertions(+), 18 deletions(-)
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 2401b7c727a3..c3c6eee1e4df 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -664,17 +664,6 @@ static void remove_filter_string(struct event_filter *filter)
filter->filter_string = NULL;
}
-static int replace_filter_string(struct event_filter *filter,
- char *filter_string)
-{
- kfree(filter->filter_string);
- filter->filter_string = kstrdup(filter_string, GFP_KERNEL);
- if (!filter->filter_string)
- return -ENOMEM;
-
- return 0;
-}
-
static void append_filter_err(struct filter_parse_state *ps,
struct event_filter *filter)
{
@@ -1802,9 +1791,8 @@ static int replace_system_preds(struct trace_subsystem_dir *dir,
if (!filter)
goto fail_mem;
- /* Can only fail on no memory */
- err = replace_filter_string(filter, filter_string);
- if (err)
+ filter->filter_string = kstrdup(filter_string, GFP_KERNEL);
+ if (!filter->filter_string)
goto fail_mem;
err = replace_preds(file->event_call, filter, ps, false);
@@ -1868,7 +1856,7 @@ static int replace_system_preds(struct trace_subsystem_dir *dir,
return -ENOMEM;
}
-static int create_filter_start(char *filter_str, bool set_str,
+static int create_filter_start(char *filter_string, bool set_str,
struct filter_parse_state **psp,
struct event_filter **filterp)
{
@@ -1880,8 +1868,11 @@ static int create_filter_start(char *filter_str, bool set_str,
/* allocate everything, and if any fails, free all and fail */
filter = kzalloc(sizeof(*filter), GFP_KERNEL);
- if (filter && set_str)
- err = replace_filter_string(filter, filter_str);
+ if (filter && set_str) {
+ filter->filter_string = kstrdup(filter_string, GFP_KERNEL);
+ if (!filter->filter_string)
+ err = -ENOMEM;
+ }
ps = kzalloc(sizeof(*ps), GFP_KERNEL);
@@ -1895,7 +1886,7 @@ static int create_filter_start(char *filter_str, bool set_str,
*filterp = filter;
*psp = ps;
- parse_init(ps, filter_ops, filter_str);
+ parse_init(ps, filter_ops, filter_string);
err = filter_parse(ps);
if (err && set_str)
append_filter_err(ps, filter);
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 44/46] tracing: Combine enum and arrays into single macro in filter code
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (42 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 43/46] tracing: Embed replace_filter_string() helper function Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 45/46] tracing: Clean up and document pred_funcs_##type creation and use Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 46/46] tracing: Rewrite filter logic to be simpler and faster Steven Rostedt
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Masami Hiramatsu
[-- Attachment #1: 0044-tracing-Combine-enum-and-arrays-into-single-macro-in.patch --]
[-- Type: text/plain, Size: 4245 bytes --]
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Instead of having a separate enum that is the index into another array, like
a string array, make a single macro that combines them into a single list,
and then the two can not get out of sync. This makes it easier to add and
remove items.
The macro trick is:
#define DOGS \
C( JACK, "Jack Russell") \
C( ITALIAN, "Italian Greyhound") \
C( GERMAN, "German Shepherd")
#undef C
#define C(a, b) a
enum { DOGS };
#undef C
#define C(a, b) b
static char dogs[] = { DOGS };
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_filter.c | 112 ++++++++++++++++---------------------
1 file changed, 48 insertions(+), 64 deletions(-)
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index c3c6eee1e4df..a2ef393b3bb2 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -33,22 +33,26 @@
"# Only events with the given fields will be affected.\n" \
"# If no events are modified, an error message will be displayed here"
-enum filter_op_ids
-{
- OP_OR,
- OP_AND,
- OP_GLOB,
- OP_NE,
- OP_EQ,
- OP_LT,
- OP_LE,
- OP_GT,
- OP_GE,
- OP_BAND,
- OP_NOT,
- OP_NONE,
- OP_OPEN_PAREN,
-};
+#define OPS \
+ C( OP_OR, "||", 1 ), \
+ C( OP_AND, "&&", 2 ), \
+ C( OP_GLOB, "~", 4 ), \
+ C( OP_NE, "!=", 4 ), \
+ C( OP_EQ, "==", 4 ), \
+ C( OP_LT, "<", 5 ), \
+ C( OP_LE, "<=", 5 ), \
+ C( OP_GT, ">", 5 ), \
+ C( OP_GE, ">=", 5 ), \
+ C( OP_BAND, "&", 6 ), \
+ C( OP_NOT, "!", 6 ), \
+ C( OP_NONE, "OP_NONE", 0 ), \
+ C( OP_OPEN_PAREN, "(", 0 ), \
+ C( OP_MAX, NULL, 0 )
+
+#undef C
+#define C(a, b, c) a
+
+enum filter_op_ids { OPS };
struct filter_op {
int id;
@@ -56,56 +60,36 @@ struct filter_op {
int precedence;
};
-/* Order must be the same as enum filter_op_ids above */
-static struct filter_op filter_ops[] = {
- { OP_OR, "||", 1 },
- { OP_AND, "&&", 2 },
- { OP_GLOB, "~", 4 },
- { OP_NE, "!=", 4 },
- { OP_EQ, "==", 4 },
- { OP_LT, "<", 5 },
- { OP_LE, "<=", 5 },
- { OP_GT, ">", 5 },
- { OP_GE, ">=", 5 },
- { OP_BAND, "&", 6 },
- { OP_NOT, "!", 6 },
- { OP_NONE, "OP_NONE", 0 },
- { OP_OPEN_PAREN, "(", 0 },
-};
+#undef C
+#define C(a, b, c) { a, b, c }
-enum {
- FILT_ERR_NONE,
- FILT_ERR_INVALID_OP,
- FILT_ERR_UNBALANCED_PAREN,
- FILT_ERR_TOO_MANY_OPERANDS,
- FILT_ERR_OPERAND_TOO_LONG,
- FILT_ERR_FIELD_NOT_FOUND,
- FILT_ERR_ILLEGAL_FIELD_OP,
- FILT_ERR_ILLEGAL_INTVAL,
- FILT_ERR_BAD_SUBSYS_FILTER,
- FILT_ERR_TOO_MANY_PREDS,
- FILT_ERR_MISSING_FIELD,
- FILT_ERR_INVALID_FILTER,
- FILT_ERR_IP_FIELD_ONLY,
- FILT_ERR_ILLEGAL_NOT_OP,
-};
+static struct filter_op filter_ops[] = { OPS };
-static char *err_text[] = {
- "No error",
- "Invalid operator",
- "Unbalanced parens",
- "Too many operands",
- "Operand too long",
- "Field not found",
- "Illegal operation for field type",
- "Illegal integer value",
- "Couldn't find or set field in one of a subsystem's events",
- "Too many terms in predicate expression",
- "Missing field name and/or value",
- "Meaningless filter expression",
- "Only 'ip' field is supported for function trace",
- "Illegal use of '!'",
-};
+#define ERRORS \
+ C( NONE, "No error"), \
+ C( INVALID_OP, "Invalid operator"), \
+ C( UNBALANCED_PAREN, "Unbalanced parens"), \
+ C( TOO_MANY_OPERANDS, "Too many operands"), \
+ C( OPERAND_TOO_LONG, "Operand too long"), \
+ C( FIELD_NOT_FOUND, "Field not found"), \
+ C( ILLEGAL_FIELD_OP, "Illegal operation for field type"), \
+ C( ILLEGAL_INTVAL, "Illegal integer value"), \
+ C( BAD_SUBSYS_FILTER, "Couldn't find or set field in one of a subsystem's events"), \
+ C( TOO_MANY_PREDS, "Too many terms in predicate expression"), \
+ C( MISSING_FIELD, "Missing field name and/or value"), \
+ C( INVALID_FILTER, "Meaningless filter expression"), \
+ C( IP_FIELD_ONLY, "Only 'ip' field is supported for function trace"), \
+ C( ILLEGAL_NOT_OP, "Illegal use of '!'"),
+
+#undef C
+#define C(a, b) FILT_ERR_##a
+
+enum { ERRORS };
+
+#undef C
+#define C(a, b) b
+
+static char *err_text[] = { ERRORS };
struct opstack_op {
enum filter_op_ids op;
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 45/46] tracing: Clean up and document pred_funcs_##type creation and use
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (43 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 44/46] tracing: Combine enum and arrays into single macro in filter code Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
2018-03-21 2:21 ` [for-next][PATCH 46/46] tracing: Rewrite filter logic to be simpler and faster Steven Rostedt
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Masami Hiramatsu
[-- Attachment #1: 0045-tracing-Clean-up-and-document-pred_funcs_-type-creat.patch --]
[-- Type: text/plain, Size: 3674 bytes --]
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
The pred_funcs_##type arrays consist of five functions that are assigned
based on the ops. The array must be in the same order of the ops each
function represents. The PRED_FUNC_START macro denotes the op enum that
starts the op that maps to the pred_funcs_##type arrays. This is all very
subtle and prone to bugs if the code is changed.
Add comments describing how PRED_FUNC_START and pred_funcs_##type array is
used, and also a PRED_FUNC_MAX that is the maximum number of functions in
the arrays.
Clean up select_comparison_fn() that assigns the predicates to the
pred_funcs_##type array function as well as add protection in case an op is
passed in that does not map correctly to the array.
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_events_filter.c | 46 ++++++++++++++++++++++++++------------
1 file changed, 32 insertions(+), 14 deletions(-)
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index a2ef393b3bb2..9d383f4383dc 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -65,6 +65,13 @@ struct filter_op {
static struct filter_op filter_ops[] = { OPS };
+/*
+ * pred functions are OP_LT, OP_LE, OP_GT, OP_GE, and OP_BAND
+ * pred_funcs_##type below must match the order of them above.
+ */
+#define PRED_FUNC_START OP_LT
+#define PRED_FUNC_MAX (OP_BAND - PRED_FUNC_START)
+
#define ERRORS \
C( NONE, "No error"), \
C( INVALID_OP, "Invalid operator"), \
@@ -172,8 +179,6 @@ static const filter_pred_fn_t pred_funcs_##type[] = { \
filter_pred_BAND_##type, \
};
-#define PRED_FUNC_START OP_LT
-
#define DEFINE_EQUALITY_PRED(size) \
static int filter_pred_##size(struct filter_pred *pred, void *event) \
{ \
@@ -946,39 +951,52 @@ static filter_pred_fn_t select_comparison_fn(enum filter_op_ids op,
int field_size, int field_is_signed)
{
filter_pred_fn_t fn = NULL;
+ int pred_func_index = -1;
+
+ switch (op) {
+ case OP_EQ:
+ case OP_NE:
+ break;
+ default:
+ if (WARN_ON_ONCE(op < PRED_FUNC_START))
+ return NULL;
+ pred_func_index = op - PRED_FUNC_START;
+ if (WARN_ON_ONCE(pred_func_index > PRED_FUNC_MAX))
+ return NULL;
+ }
switch (field_size) {
case 8:
- if (op == OP_EQ || op == OP_NE)
+ if (pred_func_index < 0)
fn = filter_pred_64;
else if (field_is_signed)
- fn = pred_funcs_s64[op - PRED_FUNC_START];
+ fn = pred_funcs_s64[pred_func_index];
else
- fn = pred_funcs_u64[op - PRED_FUNC_START];
+ fn = pred_funcs_u64[pred_func_index];
break;
case 4:
- if (op == OP_EQ || op == OP_NE)
+ if (pred_func_index < 0)
fn = filter_pred_32;
else if (field_is_signed)
- fn = pred_funcs_s32[op - PRED_FUNC_START];
+ fn = pred_funcs_s32[pred_func_index];
else
- fn = pred_funcs_u32[op - PRED_FUNC_START];
+ fn = pred_funcs_u32[pred_func_index];
break;
case 2:
- if (op == OP_EQ || op == OP_NE)
+ if (pred_func_index < 0)
fn = filter_pred_16;
else if (field_is_signed)
- fn = pred_funcs_s16[op - PRED_FUNC_START];
+ fn = pred_funcs_s16[pred_func_index];
else
- fn = pred_funcs_u16[op - PRED_FUNC_START];
+ fn = pred_funcs_u16[pred_func_index];
break;
case 1:
- if (op == OP_EQ || op == OP_NE)
+ if (pred_func_index < 0)
fn = filter_pred_8;
else if (field_is_signed)
- fn = pred_funcs_s8[op - PRED_FUNC_START];
+ fn = pred_funcs_s8[pred_func_index];
else
- fn = pred_funcs_u8[op - PRED_FUNC_START];
+ fn = pred_funcs_u8[pred_func_index];
break;
}
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* [for-next][PATCH 46/46] tracing: Rewrite filter logic to be simpler and faster
2018-03-21 2:20 [for-next][PATCH 00/46] tracing: Updates for v4.17 Steven Rostedt
` (44 preceding siblings ...)
2018-03-21 2:21 ` [for-next][PATCH 45/46] tracing: Clean up and document pred_funcs_##type creation and use Steven Rostedt
@ 2018-03-21 2:21 ` Steven Rostedt
45 siblings, 0 replies; 47+ messages in thread
From: Steven Rostedt @ 2018-03-21 2:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Ingo Molnar, Andrew Morton, Al Viro
[-- Attachment #1: 0046-tracing-Rewrite-filter-logic-to-be-simpler-and-faste.patch --]
[-- Type: text/plain, Size: 73226 bytes --]
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Al Viro reviewed the filter logic of ftrace trace events and found it to be
very troubling. It creates a binary tree based on the logic operators and
walks it during tracing. He sent myself and Tom Zanussi a long explanation
(and formal proof) of how to do the string parsing better and end up with a
program array that can be simply iterated to come up with the correct
results.
I took his ideas and his pseudo code and rewrote the filter logic based on
them. In doing so, I was able to remove a lot of code, and have a much more
condensed filter logic in the process. I wrote a very long comment
describing the methadology that Al proposed in my own words. For more info
on how this works, read the comment above predicate_parse().
Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace.h | 15 +-
kernel/trace/trace_events_filter.c | 2311 ++++++++++++++++--------------------
2 files changed, 1054 insertions(+), 1272 deletions(-)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 9de3e2a2f042..6fb46a06c9dc 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1216,12 +1216,11 @@ struct ftrace_event_field {
int is_signed;
};
+struct prog_entry;
+
struct event_filter {
- int n_preds; /* Number assigned */
- int a_preds; /* allocated */
- struct filter_pred __rcu *preds;
- struct filter_pred __rcu *root;
- char *filter_string;
+ struct prog_entry __rcu *prog;
+ char *filter_string;
};
struct event_subsystem {
@@ -1413,12 +1412,8 @@ struct filter_pred {
unsigned short *ops;
struct ftrace_event_field *field;
int offset;
- int not;
+ int not;
int op;
- unsigned short index;
- unsigned short parent;
- unsigned short left;
- unsigned short right;
};
static inline bool is_string_field(struct ftrace_event_field *field)
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 9d383f4383dc..703a416aa5c2 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -33,60 +33,52 @@
"# Only events with the given fields will be affected.\n" \
"# If no events are modified, an error message will be displayed here"
+/* Due to token parsing '<=' must be before '<' and '>=' must be before '>' */
#define OPS \
- C( OP_OR, "||", 1 ), \
- C( OP_AND, "&&", 2 ), \
- C( OP_GLOB, "~", 4 ), \
- C( OP_NE, "!=", 4 ), \
- C( OP_EQ, "==", 4 ), \
- C( OP_LT, "<", 5 ), \
- C( OP_LE, "<=", 5 ), \
- C( OP_GT, ">", 5 ), \
- C( OP_GE, ">=", 5 ), \
- C( OP_BAND, "&", 6 ), \
- C( OP_NOT, "!", 6 ), \
- C( OP_NONE, "OP_NONE", 0 ), \
- C( OP_OPEN_PAREN, "(", 0 ), \
- C( OP_MAX, NULL, 0 )
+ C( OP_GLOB, "~" ), \
+ C( OP_NE, "!=" ), \
+ C( OP_EQ, "==" ), \
+ C( OP_LE, "<=" ), \
+ C( OP_LT, "<" ), \
+ C( OP_GE, ">=" ), \
+ C( OP_GT, ">" ), \
+ C( OP_BAND, "&" ), \
+ C( OP_MAX, NULL )
#undef C
-#define C(a, b, c) a
+#define C(a, b) a
enum filter_op_ids { OPS };
-struct filter_op {
- int id;
- char *string;
- int precedence;
-};
-
#undef C
-#define C(a, b, c) { a, b, c }
+#define C(a, b) b
-static struct filter_op filter_ops[] = { OPS };
+static const char * ops[] = { OPS };
/*
- * pred functions are OP_LT, OP_LE, OP_GT, OP_GE, and OP_BAND
+ * pred functions are OP_LE, OP_LT, OP_GE, OP_GT, and OP_BAND
* pred_funcs_##type below must match the order of them above.
*/
-#define PRED_FUNC_START OP_LT
+#define PRED_FUNC_START OP_LE
#define PRED_FUNC_MAX (OP_BAND - PRED_FUNC_START)
#define ERRORS \
- C( NONE, "No error"), \
- C( INVALID_OP, "Invalid operator"), \
- C( UNBALANCED_PAREN, "Unbalanced parens"), \
- C( TOO_MANY_OPERANDS, "Too many operands"), \
- C( OPERAND_TOO_LONG, "Operand too long"), \
- C( FIELD_NOT_FOUND, "Field not found"), \
- C( ILLEGAL_FIELD_OP, "Illegal operation for field type"), \
- C( ILLEGAL_INTVAL, "Illegal integer value"), \
- C( BAD_SUBSYS_FILTER, "Couldn't find or set field in one of a subsystem's events"), \
- C( TOO_MANY_PREDS, "Too many terms in predicate expression"), \
- C( MISSING_FIELD, "Missing field name and/or value"), \
- C( INVALID_FILTER, "Meaningless filter expression"), \
- C( IP_FIELD_ONLY, "Only 'ip' field is supported for function trace"), \
- C( ILLEGAL_NOT_OP, "Illegal use of '!'"),
+ C(NONE, "No error"), \
+ C(INVALID_OP, "Invalid operator"), \
+ C(TOO_MANY_OPEN, "Too many '('"), \
+ C(TOO_MANY_CLOSE, "Too few '('"), \
+ C(MISSING_QUOTE, "Missing matching quote"), \
+ C(OPERAND_TOO_LONG, "Operand too long"), \
+ C(EXPECT_STRING, "Expecting string field"), \
+ C(EXPECT_DIGIT, "Expecting numeric field"), \
+ C(ILLEGAL_FIELD_OP, "Illegal operation for field type"), \
+ C(FIELD_NOT_FOUND, "Field not found"), \
+ C(ILLEGAL_INTVAL, "Illegal integer value"), \
+ C(BAD_SUBSYS_FILTER, "Couldn't find or set field in one of a subsystem's events"), \
+ C(TOO_MANY_PREDS, "Too many terms in predicate expression"), \
+ C(INVALID_FILTER, "Meaningless filter expression"), \
+ C(IP_FIELD_ONLY, "Only 'ip' field is supported for function trace"), \
+ C(INVALID_VALUE, "Invalid value (did you forget quotes)?"),
#undef C
#define C(a, b) FILT_ERR_##a
@@ -98,84 +90,535 @@ enum { ERRORS };
static char *err_text[] = { ERRORS };
-struct opstack_op {
- enum filter_op_ids op;
- struct list_head list;
-};
+/* Called after a '!' character but "!=" and "!~" are not "not"s */
+static bool is_not(const char *str)
+{
+ switch (str[1]) {
+ case '=':
+ case '~':
+ return false;
+ }
+ return true;
+}
-struct postfix_elt {
- enum filter_op_ids op;
- char *operand;
- struct list_head list;
+/**
+ * prog_entry - a singe entry in the filter program
+ * @target: Index to jump to on a branch (actually one minus the index)
+ * @when_to_branch: The value of the result of the predicate to do a branch
+ * @pred: The predicate to execute.
+ */
+struct prog_entry {
+ int target;
+ int when_to_branch;
+ struct filter_pred *pred;
};
-struct filter_parse_state {
- struct filter_op *ops;
- struct list_head opstack;
- struct list_head postfix;
+/**
+ * update_preds- assign a program entry a label target
+ * @prog: The program array
+ * @N: The index of the current entry in @prog
+ * @when_to_branch: What to assign a program entry for its branch condition
+ *
+ * The program entry at @N has a target that points to the index of a program
+ * entry that can have its target and when_to_branch fields updated.
+ * Update the current program entry denoted by index @N target field to be
+ * that of the updated entry. This will denote the entry to update if
+ * we are processing an "||" after an "&&"
+ */
+static void update_preds(struct prog_entry *prog, int N, int invert)
+{
+ int t, s;
+
+ t = prog[N].target;
+ s = prog[t].target;
+ prog[t].when_to_branch = invert;
+ prog[t].target = N;
+ prog[N].target = s;
+}
+
+struct filter_parse_error {
int lasterr;
int lasterr_pos;
-
- struct {
- char *string;
- unsigned int cnt;
- unsigned int tail;
- } infix;
-
- struct {
- char string[MAX_FILTER_STR_VAL];
- int pos;
- unsigned int tail;
- } operand;
};
-struct pred_stack {
- struct filter_pred **preds;
- int index;
+static void parse_error(struct filter_parse_error *pe, int err, int pos)
+{
+ pe->lasterr = err;
+ pe->lasterr_pos = pos;
+}
+
+typedef int (*parse_pred_fn)(const char *str, void *data, int pos,
+ struct filter_parse_error *pe,
+ struct filter_pred **pred);
+
+enum {
+ INVERT = 1,
+ PROCESS_AND = 2,
+ PROCESS_OR = 4,
};
-/* If not of not match is equal to not of not, then it is a match */
+/*
+ * Without going into a formal proof, this explains the method that is used in
+ * parsing the logical expressions.
+ *
+ * For example, if we have: "a && !(!b || (c && g)) || d || e && !f"
+ * The first pass will convert it into the following program:
+ *
+ * n1: r=a; l1: if (!r) goto l4;
+ * n2: r=b; l2: if (!r) goto l4;
+ * n3: r=c; r=!r; l3: if (r) goto l4;
+ * n4: r=g; r=!r; l4: if (r) goto l5;
+ * n5: r=d; l5: if (r) goto T
+ * n6: r=e; l6: if (!r) goto l7;
+ * n7: r=f; r=!r; l7: if (!r) goto F
+ * T: return TRUE
+ * F: return FALSE
+ *
+ * To do this, we use a data structure to represent each of the above
+ * predicate and conditions that has:
+ *
+ * predicate, when_to_branch, invert, target
+ *
+ * The "predicate" will hold the function to determine the result "r".
+ * The "when_to_branch" denotes what "r" should be if a branch is to be taken
+ * "&&" would contain "!r" or (0) and "||" would contain "r" or (1).
+ * The "invert" holds whether the value should be reversed before testing.
+ * The "target" contains the label "l#" to jump to.
+ *
+ * A stack is created to hold values when parentheses are used.
+ *
+ * To simplify the logic, the labels will start at 0 and not 1.
+ *
+ * The possible invert values are 1 and 0. The number of "!"s that are in scope
+ * before the predicate determines the invert value, if the number is odd then
+ * the invert value is 1 and 0 otherwise. This means the invert value only
+ * needs to be toggled when a new "!" is introduced compared to what is stored
+ * on the stack, where parentheses were used.
+ *
+ * The top of the stack and "invert" are initialized to zero.
+ *
+ * ** FIRST PASS **
+ *
+ * #1 A loop through all the tokens is done:
+ *
+ * #2 If the token is an "(", the stack is push, and the current stack value
+ * gets the current invert value, and the loop continues to the next token.
+ * The top of the stack saves the "invert" value to keep track of what
+ * the current inversion is. As "!(a && !b || c)" would require all
+ * predicates being affected separately by the "!" before the parentheses.
+ * And that would end up being equivalent to "(!a || b) && !c"
+ *
+ * #3 If the token is an "!", the current "invert" value gets inverted, and
+ * the loop continues. Note, if the next token is a predicate, then
+ * this "invert" value is only valid for the current program entry,
+ * and does not affect other predicates later on.
+ *
+ * The only other acceptable token is the predicate string.
+ *
+ * #4 A new entry into the program is added saving: the predicate and the
+ * current value of "invert". The target is currently assigned to the
+ * previous program index (this will not be its final value).
+ *
+ * #5 We now enter another loop and look at the next token. The only valid
+ * tokens are ")", "&&", "||" or end of the input string "\0".
+ *
+ * #6 The invert variable is reset to the current value saved on the top of
+ * the stack.
+ *
+ * #7 The top of the stack holds not only the current invert value, but also
+ * if a "&&" or "||" needs to be processed. Note, the "&&" takes higher
+ * precedence than "||". That is "a && b || c && d" is equivalent to
+ * "(a && b) || (c && d)". Thus the first thing to do is to see if "&&" needs
+ * to be processed. This is the case if an "&&" was the last token. If it was
+ * then we call update_preds(). This takes the program, the current index in
+ * the program, and the current value of "invert". More will be described
+ * below about this function.
+ *
+ * #8 If the next token is "&&" then we set a flag in the top of the stack
+ * that denotes that "&&" needs to be processed, break out of this loop
+ * and continue with the outer loop.
+ *
+ * #9 Otherwise, if a "||" needs to be processed then update_preds() is called.
+ * This is called with the program, the current index in the program, but
+ * this time with an inverted value of "invert" (that is !invert). This is
+ * because the value taken will become the "when_to_branch" value of the
+ * program.
+ * Note, this is called when the next token is not an "&&". As stated before,
+ * "&&" takes higher precedence, and "||" should not be processed yet if the
+ * next logical operation is "&&".
+ *
+ * #10 If the next token is "||" then we set a flag in the top of the stack
+ * that denotes that "||" needs to be processed, break out of this loop
+ * and continue with the outer loop.
+ *
+ * #11 If this is the end of the input string "\0" then we break out of both
+ * loops.
+ *
+ * #12 Otherwise, the next token is ")", where we pop the stack and continue
+ * this inner loop.
+ *
+ * Now to discuss the update_pred() function, as that is key to the setting up
+ * of the program. Remember the "target" of the program is initialized to the
+ * previous index and not the "l" label. The target holds the index into the
+ * program that gets affected by the operand. Thus if we have something like
+ * "a || b && c", when we process "a" the target will be "-1" (undefined).
+ * When we process "b", its target is "0", which is the index of "a", as that's
+ * the predicate that is affected by "||". But because the next token after "b"
+ * is "&&" we don't call update_preds(). Instead continue to "c". As the
+ * next token after "c" is not "&&" but the end of input, we first process the
+ * "&&" by calling update_preds() for the "&&" then we process the "||" by
+ * callin updates_preds() with the values for processing "||".
+ *
+ * What does that mean? What update_preds() does is to first save the "target"
+ * of the program entry indexed by the current program entry's "target"
+ * (remember the "target" is initialized to previous program entry), and then
+ * sets that "target" to the current index which represents the label "l#".
+ * That entry's "when_to_branch" is set to the value passed in (the "invert"
+ * or "!invert"). Then it sets the current program entry's target to the saved
+ * "target" value (the old value of the program that had its "target" updated
+ * to the label).
+ *
+ * Looking back at "a || b && c", we have the following steps:
+ * "a" - prog[0] = { "a", X, -1 } // pred, when_to_branch, target
+ * "||" - flag that we need to process "||"; continue outer loop
+ * "b" - prog[1] = { "b", X, 0 }
+ * "&&" - flag that we need to process "&&"; continue outer loop
+ * (Notice we did not process "||")
+ * "c" - prog[2] = { "c", X, 1 }
+ * update_preds(prog, 2, 0); // invert = 0 as we are processing "&&"
+ * t = prog[2].target; // t = 1
+ * s = prog[t].target; // s = 0
+ * prog[t].target = 2; // Set target to "l2"
+ * prog[t].when_to_branch = 0;
+ * prog[2].target = s;
+ * update_preds(prog, 2, 1); // invert = 1 as we are now processing "||"
+ * t = prog[2].target; // t = 0
+ * s = prog[t].target; // s = -1
+ * prog[t].target = 2; // Set target to "l2"
+ * prog[t].when_to_branch = 1;
+ * prog[2].target = s;
+ *
+ * #13 Which brings us to the final step of the first pass, which is to set
+ * the last program entry's when_to_branch and target, which will be
+ * when_to_branch = 0; target = N; ( the label after the program entry after
+ * the last program entry processed above).
+ *
+ * If we denote "TRUE" to be the entry after the last program entry processed,
+ * and "FALSE" the program entry after that, we are now done with the first
+ * pass.
+ *
+ * Making the above "a || b && c" have a progam of:
+ * prog[0] = { "a", 1, 2 }
+ * prog[1] = { "b", 0, 2 }
+ * prog[2] = { "c", 0, 3 }
+ *
+ * Which translates into:
+ * n0: r = a; l0: if (r) goto l2;
+ * n1: r = b; l1: if (!r) goto l2;
+ * n2: r = c; l2: if (!r) goto l3; // Which is the same as "goto F;"
+ * T: return TRUE; l3:
+ * F: return FALSE
+ *
+ * Although, after the first pass, the program is correct, it is
+ * inefficient. The simple sample of "a || b && c" could be easily been
+ * converted into:
+ * n0: r = a; if (r) goto T
+ * n1: r = b; if (!r) goto F
+ * n2: r = c; if (!r) goto F
+ * T: return TRUE;
+ * F: return FALSE;
+ *
+ * The First Pass is over the input string. The next too passes are over
+ * the program itself.
+ *
+ * ** SECOND PASS **
+ *
+ * Which brings us to the second pass. If a jump to a label has the
+ * same condition as that label, it can instead jump to its target.
+ * The original example of "a && !(!b || (c && g)) || d || e && !f"
+ * where the first pass gives us:
+ *
+ * n1: r=a; l1: if (!r) goto l4;
+ * n2: r=b; l2: if (!r) goto l4;
+ * n3: r=c; r=!r; l3: if (r) goto l4;
+ * n4: r=g; r=!r; l4: if (r) goto l5;
+ * n5: r=d; l5: if (r) goto T
+ * n6: r=e; l6: if (!r) goto l7;
+ * n7: r=f; r=!r; l7: if (!r) goto F:
+ * T: return TRUE;
+ * F: return FALSE
+ *
+ * We can see that "l3: if (r) goto l4;" and at l4, we have "if (r) goto l5;".
+ * And "l5: if (r) goto T", we could optimize this by converting l3 and l4
+ * to go directly to T. To accomplish this, we start from the last
+ * entry in the program and work our way back. If the target of the entry
+ * has the same "when_to_branch" then we could use that entry's target.
+ * Doing this, the above would end up as:
+ *
+ * n1: r=a; l1: if (!r) goto l4;
+ * n2: r=b; l2: if (!r) goto l4;
+ * n3: r=c; r=!r; l3: if (r) goto T;
+ * n4: r=g; r=!r; l4: if (r) goto T;
+ * n5: r=d; l5: if (r) goto T;
+ * n6: r=e; l6: if (!r) goto F;
+ * n7: r=f; r=!r; l7: if (!r) goto F;
+ * T: return TRUE
+ * F: return FALSE
+ *
+ * In that same pass, if the "when_to_branch" doesn't match, we can simply
+ * go to the program entry after the label. That is, "l2: if (!r) goto l4;"
+ * where "l4: if (r) goto T;", then we can convert l2 to be:
+ * "l2: if (!r) goto n5;".
+ *
+ * This will have the second pass give us:
+ * n1: r=a; l1: if (!r) goto n5;
+ * n2: r=b; l2: if (!r) goto n5;
+ * n3: r=c; r=!r; l3: if (r) goto T;
+ * n4: r=g; r=!r; l4: if (r) goto T;
+ * n5: r=d; l5: if (r) goto T
+ * n6: r=e; l6: if (!r) goto F;
+ * n7: r=f; r=!r; l7: if (!r) goto F
+ * T: return TRUE
+ * F: return FALSE
+ *
+ * Notice, all the "l#" labels are no longer used, and they can now
+ * be discarded.
+ *
+ * ** THIRD PASS **
+ *
+ * For the third pass we deal with the inverts. As they simply just
+ * make the "when_to_branch" get inverted, a simple loop over the
+ * program to that does: "when_to_branch ^= invert;" will do the
+ * job, leaving us with:
+ * n1: r=a; if (!r) goto n5;
+ * n2: r=b; if (!r) goto n5;
+ * n3: r=c: if (!r) goto T;
+ * n4: r=g; if (!r) goto T;
+ * n5: r=d; if (r) goto T
+ * n6: r=e; if (!r) goto F;
+ * n7: r=f; if (r) goto F
+ * T: return TRUE
+ * F: return FALSE
+ *
+ * As "r = a; if (!r) goto n5;" is obviously the same as
+ * "if (!a) goto n5;" without doing anything we can interperate the
+ * program as:
+ * n1: if (!a) goto n5;
+ * n2: if (!b) goto n5;
+ * n3: if (!c) goto T;
+ * n4: if (!g) goto T;
+ * n5: if (d) goto T
+ * n6: if (!e) goto F;
+ * n7: if (f) goto F
+ * T: return TRUE
+ * F: return FALSE
+ *
+ * Since the inverts are discarded at the end, there's no reason to store
+ * them in the program array (and waste memory). A separate array to hold
+ * the inverts is used and freed at the end.
+ */
+static struct prog_entry *
+predicate_parse(const char *str, int nr_parens, int nr_preds,
+ parse_pred_fn parse_pred, void *data,
+ struct filter_parse_error *pe)
+{
+ struct prog_entry *prog_stack;
+ struct prog_entry *prog;
+ const char *ptr = str;
+ char *inverts = NULL;
+ int *op_stack;
+ int *top;
+ int invert = 0;
+ int ret = -ENOMEM;
+ int len;
+ int N = 0;
+ int i;
+
+ nr_preds += 2; /* For TRUE and FALSE */
+
+ op_stack = kmalloc(sizeof(*op_stack) * nr_parens, GFP_KERNEL);
+ if (!op_stack)
+ return ERR_PTR(-ENOMEM);
+ prog_stack = kmalloc(sizeof(*prog_stack) * nr_preds, GFP_KERNEL);
+ if (!prog_stack) {
+ parse_error(pe, -ENOMEM, 0);
+ goto out_free;
+ }
+ inverts = kmalloc(sizeof(*inverts) * nr_preds, GFP_KERNEL);
+ if (!inverts) {
+ parse_error(pe, -ENOMEM, 0);
+ goto out_free;
+ }
+
+ top = op_stack;
+ prog = prog_stack;
+ *top = 0;
+
+ /* First pass */
+ while (*ptr) { /* #1 */
+ const char *next = ptr++;
+
+ if (isspace(*next))
+ continue;
+
+ switch (*next) {
+ case '(': /* #2 */
+ if (top - op_stack > nr_parens)
+ return ERR_PTR(-EINVAL);
+ *(++top) = invert;
+ continue;
+ case '!': /* #3 */
+ if (!is_not(next))
+ break;
+ invert = !invert;
+ continue;
+ }
+
+ if (N >= nr_preds) {
+ parse_error(pe, FILT_ERR_TOO_MANY_PREDS, next - str);
+ goto out_free;
+ }
+
+ inverts[N] = invert; /* #4 */
+ prog[N].target = N-1;
+
+ len = parse_pred(next, data, ptr - str, pe, &prog[N].pred);
+ if (len < 0) {
+ ret = len;
+ goto out_free;
+ }
+ ptr = next + len;
+
+ N++;
+
+ ret = -1;
+ while (1) { /* #5 */
+ next = ptr++;
+ if (isspace(*next))
+ continue;
+
+ switch (*next) {
+ case ')':
+ case '\0':
+ break;
+ case '&':
+ case '|':
+ if (next[1] == next[0]) {
+ ptr++;
+ break;
+ }
+ default:
+ parse_error(pe, FILT_ERR_TOO_MANY_PREDS,
+ next - str);
+ goto out_free;
+ }
+
+ invert = *top & INVERT;
+
+ if (*top & PROCESS_AND) { /* #7 */
+ update_preds(prog, N - 1, invert);
+ *top &= ~PROCESS_AND;
+ }
+ if (*next == '&') { /* #8 */
+ *top |= PROCESS_AND;
+ break;
+ }
+ if (*top & PROCESS_OR) { /* #9 */
+ update_preds(prog, N - 1, !invert);
+ *top &= ~PROCESS_OR;
+ }
+ if (*next == '|') { /* #10 */
+ *top |= PROCESS_OR;
+ break;
+ }
+ if (!*next) /* #11 */
+ goto out;
+
+ if (top == op_stack) {
+ ret = -1;
+ /* Too few '(' */
+ parse_error(pe, FILT_ERR_TOO_MANY_CLOSE, ptr - str);
+ goto out_free;
+ }
+ top--; /* #12 */
+ }
+ }
+ out:
+ if (top != op_stack) {
+ /* Too many '(' */
+ parse_error(pe, FILT_ERR_TOO_MANY_OPEN, ptr - str);
+ goto out_free;
+ }
+
+ prog[N].pred = NULL; /* #13 */
+ prog[N].target = 1; /* TRUE */
+ prog[N+1].pred = NULL;
+ prog[N+1].target = 0; /* FALSE */
+ prog[N-1].target = N;
+ prog[N-1].when_to_branch = false;
+
+ /* Second Pass */
+ for (i = N-1 ; i--; ) {
+ int target = prog[i].target;
+ if (prog[i].when_to_branch == prog[target].when_to_branch)
+ prog[i].target = prog[target].target;
+ }
+
+ /* Third Pass */
+ for (i = 0; i < N; i++) {
+ invert = inverts[i] ^ prog[i].when_to_branch;
+ prog[i].when_to_branch = invert;
+ /* Make sure the program always moves forward */
+ if (WARN_ON(prog[i].target <= i)) {
+ ret = -EINVAL;
+ goto out_free;
+ }
+ }
+
+ return prog;
+out_free:
+ kfree(op_stack);
+ kfree(prog_stack);
+ kfree(inverts);
+ return ERR_PTR(ret);
+}
+
#define DEFINE_COMPARISON_PRED(type) \
static int filter_pred_LT_##type(struct filter_pred *pred, void *event) \
{ \
type *addr = (type *)(event + pred->offset); \
type val = (type)pred->val; \
- int match = (*addr < val); \
- return !!match == !pred->not; \
+ return *addr < val; \
} \
static int filter_pred_LE_##type(struct filter_pred *pred, void *event) \
{ \
type *addr = (type *)(event + pred->offset); \
type val = (type)pred->val; \
- int match = (*addr <= val); \
- return !!match == !pred->not; \
+ return *addr <= val; \
} \
static int filter_pred_GT_##type(struct filter_pred *pred, void *event) \
{ \
type *addr = (type *)(event + pred->offset); \
type val = (type)pred->val; \
- int match = (*addr > val); \
- return !!match == !pred->not; \
+ return *addr > val; \
} \
static int filter_pred_GE_##type(struct filter_pred *pred, void *event) \
{ \
type *addr = (type *)(event + pred->offset); \
type val = (type)pred->val; \
- int match = (*addr >= val); \
- return !!match == !pred->not; \
+ return *addr >= val; \
} \
static int filter_pred_BAND_##type(struct filter_pred *pred, void *event) \
{ \
type *addr = (type *)(event + pred->offset); \
type val = (type)pred->val; \
- int match = !!(*addr & val); \
- return match == !pred->not; \
+ return !!(*addr & val); \
} \
static const filter_pred_fn_t pred_funcs_##type[] = { \
- filter_pred_LT_##type, \
filter_pred_LE_##type, \
- filter_pred_GT_##type, \
+ filter_pred_LT_##type, \
filter_pred_GE_##type, \
+ filter_pred_GT_##type, \
filter_pred_BAND_##type, \
};
@@ -261,44 +704,36 @@ static int filter_pred_strloc(struct filter_pred *pred, void *event)
static int filter_pred_cpu(struct filter_pred *pred, void *event)
{
int cpu, cmp;
- int match = 0;
cpu = raw_smp_processor_id();
cmp = pred->val;
switch (pred->op) {
case OP_EQ:
- match = cpu == cmp;
- break;
+ return cpu == cmp;
+ case OP_NE:
+ return cpu != cmp;
case OP_LT:
- match = cpu < cmp;
- break;
+ return cpu < cmp;
case OP_LE:
- match = cpu <= cmp;
- break;
+ return cpu <= cmp;
case OP_GT:
- match = cpu > cmp;
- break;
+ return cpu > cmp;
case OP_GE:
- match = cpu >= cmp;
- break;
+ return cpu >= cmp;
default:
- break;
+ return 0;
}
-
- return !!match == !pred->not;
}
/* Filter predicate for COMM. */
static int filter_pred_comm(struct filter_pred *pred, void *event)
{
- int cmp, match;
+ int cmp;
cmp = pred->regex.match(current->comm, &pred->regex,
- pred->regex.field_len);
- match = cmp ^ pred->not;
-
- return match;
+ TASK_COMM_LEN);
+ return cmp ^ pred->not;
}
static int filter_pred_none(struct filter_pred *pred, void *event)
@@ -355,6 +790,7 @@ static int regex_match_glob(char *str, struct regex *r, int len __maybe_unused)
return 1;
return 0;
}
+
/**
* filter_parse_regex - parse a basic regex
* @buff: the raw regex
@@ -415,10 +851,9 @@ static void filter_build_regex(struct filter_pred *pred)
struct regex *r = &pred->regex;
char *search;
enum regex_type type = MATCH_FULL;
- int not = 0;
if (pred->op == OP_GLOB) {
- type = filter_parse_regex(r->pattern, r->len, &search, ¬);
+ type = filter_parse_regex(r->pattern, r->len, &search, &pred->not);
r->len = strlen(search);
memmove(r->pattern, search, r->len+1);
}
@@ -440,210 +875,32 @@ static void filter_build_regex(struct filter_pred *pred)
r->match = regex_match_glob;
break;
}
-
- pred->not ^= not;
-}
-
-enum move_type {
- MOVE_DOWN,
- MOVE_UP_FROM_LEFT,
- MOVE_UP_FROM_RIGHT
-};
-
-static struct filter_pred *
-get_pred_parent(struct filter_pred *pred, struct filter_pred *preds,
- int index, enum move_type *move)
-{
- if (pred->parent & FILTER_PRED_IS_RIGHT)
- *move = MOVE_UP_FROM_RIGHT;
- else
- *move = MOVE_UP_FROM_LEFT;
- pred = &preds[pred->parent & ~FILTER_PRED_IS_RIGHT];
-
- return pred;
-}
-
-enum walk_return {
- WALK_PRED_ABORT,
- WALK_PRED_PARENT,
- WALK_PRED_DEFAULT,
-};
-
-typedef int (*filter_pred_walkcb_t) (enum move_type move,
- struct filter_pred *pred,
- int *err, void *data);
-
-static int walk_pred_tree(struct filter_pred *preds,
- struct filter_pred *root,
- filter_pred_walkcb_t cb, void *data)
-{
- struct filter_pred *pred = root;
- enum move_type move = MOVE_DOWN;
- int done = 0;
-
- if (!preds)
- return -EINVAL;
-
- do {
- int err = 0, ret;
-
- ret = cb(move, pred, &err, data);
- if (ret == WALK_PRED_ABORT)
- return err;
- if (ret == WALK_PRED_PARENT)
- goto get_parent;
-
- switch (move) {
- case MOVE_DOWN:
- if (pred->left != FILTER_PRED_INVALID) {
- pred = &preds[pred->left];
- continue;
- }
- goto get_parent;
- case MOVE_UP_FROM_LEFT:
- pred = &preds[pred->right];
- move = MOVE_DOWN;
- continue;
- case MOVE_UP_FROM_RIGHT:
- get_parent:
- if (pred == root)
- break;
- pred = get_pred_parent(pred, preds,
- pred->parent,
- &move);
- continue;
- }
- done = 1;
- } while (!done);
-
- /* We are fine. */
- return 0;
-}
-
-/*
- * A series of AND or ORs where found together. Instead of
- * climbing up and down the tree branches, an array of the
- * ops were made in order of checks. We can just move across
- * the array and short circuit if needed.
- */
-static int process_ops(struct filter_pred *preds,
- struct filter_pred *op, void *rec)
-{
- struct filter_pred *pred;
- int match = 0;
- int type;
- int i;
-
- /*
- * Micro-optimization: We set type to true if op
- * is an OR and false otherwise (AND). Then we
- * just need to test if the match is equal to
- * the type, and if it is, we can short circuit the
- * rest of the checks:
- *
- * if ((match && op->op == OP_OR) ||
- * (!match && op->op == OP_AND))
- * return match;
- */
- type = op->op == OP_OR;
-
- for (i = 0; i < op->val; i++) {
- pred = &preds[op->ops[i]];
- if (!WARN_ON_ONCE(!pred->fn))
- match = pred->fn(pred, rec);
- if (!!match == type)
- break;
- }
- /* If not of not match is equal to not of not, then it is a match */
- return !!match == !op->not;
-}
-
-struct filter_match_preds_data {
- struct filter_pred *preds;
- int match;
- void *rec;
-};
-
-static int filter_match_preds_cb(enum move_type move, struct filter_pred *pred,
- int *err, void *data)
-{
- struct filter_match_preds_data *d = data;
-
- *err = 0;
- switch (move) {
- case MOVE_DOWN:
- /* only AND and OR have children */
- if (pred->left != FILTER_PRED_INVALID) {
- /* If ops is set, then it was folded. */
- if (!pred->ops)
- return WALK_PRED_DEFAULT;
- /* We can treat folded ops as a leaf node */
- d->match = process_ops(d->preds, pred, d->rec);
- } else {
- if (!WARN_ON_ONCE(!pred->fn))
- d->match = pred->fn(pred, d->rec);
- }
-
- return WALK_PRED_PARENT;
- case MOVE_UP_FROM_LEFT:
- /*
- * Check for short circuits.
- *
- * Optimization: !!match == (pred->op == OP_OR)
- * is the same as:
- * if ((match && pred->op == OP_OR) ||
- * (!match && pred->op == OP_AND))
- */
- if (!!d->match == (pred->op == OP_OR))
- return WALK_PRED_PARENT;
- break;
- case MOVE_UP_FROM_RIGHT:
- break;
- }
-
- return WALK_PRED_DEFAULT;
}
/* return 1 if event matches, 0 otherwise (discard) */
int filter_match_preds(struct event_filter *filter, void *rec)
{
- struct filter_pred *preds;
- struct filter_pred *root;
- struct filter_match_preds_data data = {
- /* match is currently meaningless */
- .match = -1,
- .rec = rec,
- };
- int n_preds, ret;
+ struct prog_entry *prog;
+ int i;
/* no filter is considered a match */
if (!filter)
return 1;
- n_preds = filter->n_preds;
- if (!n_preds)
+ prog = rcu_dereference_sched(filter->prog);
+ if (!prog)
return 1;
- /*
- * n_preds, root and filter->preds are protect with preemption disabled.
- */
- root = rcu_dereference_sched(filter->root);
- if (!root)
- return 1;
-
- data.preds = preds = rcu_dereference_sched(filter->preds);
- ret = walk_pred_tree(preds, root, filter_match_preds_cb, &data);
- WARN_ON(ret);
- return data.match;
+ for (i = 0; prog[i].pred; i++) {
+ struct filter_pred *pred = prog[i].pred;
+ int match = pred->fn(pred, rec);
+ if (match == prog[i].when_to_branch)
+ i = prog[i].target;
+ }
+ return prog[i].target;
}
EXPORT_SYMBOL_GPL(filter_match_preds);
-static void parse_error(struct filter_parse_state *ps, int err, int pos)
-{
- ps->lasterr = err;
- ps->lasterr_pos = pos;
-}
-
static void remove_filter_string(struct event_filter *filter)
{
if (!filter)
@@ -653,11 +910,11 @@ static void remove_filter_string(struct event_filter *filter)
filter->filter_string = NULL;
}
-static void append_filter_err(struct filter_parse_state *ps,
+static void append_filter_err(struct filter_parse_error *pe,
struct event_filter *filter)
{
struct trace_seq *s;
- int pos = ps->lasterr_pos;
+ int pos = pe->lasterr_pos;
char *buf;
int len;
@@ -671,11 +928,19 @@ static void append_filter_err(struct filter_parse_state *ps,
len = strlen(filter->filter_string);
if (pos > len)
- len = pos;
+ pos = len;
+
+ /* indexing is off by one */
+ if (pos)
+ pos++;
trace_seq_puts(s, filter->filter_string);
- trace_seq_printf(s, "\n%*s", pos, "^");
- trace_seq_printf(s, "\nparse_error: %s\n", err_text[ps->lasterr]);
+ if (pe->lasterr > 0) {
+ trace_seq_printf(s, "\n%*s", pos, "^");
+ trace_seq_printf(s, "\nparse_error: %s\n", err_text[pe->lasterr]);
+ } else {
+ trace_seq_printf(s, "\nError: (%d)\n", pe->lasterr);
+ }
trace_seq_putc(s, 0);
buf = kmemdup_nul(s->buffer, s->seq.len, GFP_KERNEL);
if (buf) {
@@ -715,108 +980,18 @@ void print_subsystem_event_filter(struct event_subsystem *system,
mutex_unlock(&event_mutex);
}
-static int __alloc_pred_stack(struct pred_stack *stack, int n_preds)
-{
- stack->preds = kcalloc(n_preds + 1, sizeof(*stack->preds), GFP_KERNEL);
- if (!stack->preds)
- return -ENOMEM;
- stack->index = n_preds;
- return 0;
-}
-
-static void __free_pred_stack(struct pred_stack *stack)
-{
- kfree(stack->preds);
- stack->index = 0;
-}
-
-static int __push_pred_stack(struct pred_stack *stack,
- struct filter_pred *pred)
-{
- int index = stack->index;
-
- if (WARN_ON(index == 0))
- return -ENOSPC;
-
- stack->preds[--index] = pred;
- stack->index = index;
- return 0;
-}
-
-static struct filter_pred *
-__pop_pred_stack(struct pred_stack *stack)
-{
- struct filter_pred *pred;
- int index = stack->index;
-
- pred = stack->preds[index++];
- if (!pred)
- return NULL;
-
- stack->index = index;
- return pred;
-}
-
-static int filter_set_pred(struct event_filter *filter,
- int idx,
- struct pred_stack *stack,
- struct filter_pred *src)
-{
- struct filter_pred *dest = &filter->preds[idx];
- struct filter_pred *left;
- struct filter_pred *right;
-
- *dest = *src;
- dest->index = idx;
-
- if (dest->op == OP_OR || dest->op == OP_AND) {
- right = __pop_pred_stack(stack);
- left = __pop_pred_stack(stack);
- if (!left || !right)
- return -EINVAL;
- /*
- * If both children can be folded
- * and they are the same op as this op or a leaf,
- * then this op can be folded.
- */
- if (left->index & FILTER_PRED_FOLD &&
- ((left->op == dest->op && !left->not) ||
- left->left == FILTER_PRED_INVALID) &&
- right->index & FILTER_PRED_FOLD &&
- ((right->op == dest->op && !right->not) ||
- right->left == FILTER_PRED_INVALID))
- dest->index |= FILTER_PRED_FOLD;
-
- dest->left = left->index & ~FILTER_PRED_FOLD;
- dest->right = right->index & ~FILTER_PRED_FOLD;
- left->parent = dest->index & ~FILTER_PRED_FOLD;
- right->parent = dest->index | FILTER_PRED_IS_RIGHT;
- } else {
- /*
- * Make dest->left invalid to be used as a quick
- * way to know this is a leaf node.
- */
- dest->left = FILTER_PRED_INVALID;
-
- /* All leafs allow folding the parent ops. */
- dest->index |= FILTER_PRED_FOLD;
- }
-
- return __push_pred_stack(stack, dest);
-}
-
-static void __free_preds(struct event_filter *filter)
+static void free_prog(struct event_filter *filter)
{
+ struct prog_entry *prog;
int i;
- if (filter->preds) {
- for (i = 0; i < filter->n_preds; i++)
- kfree(filter->preds[i].ops);
- kfree(filter->preds);
- filter->preds = NULL;
- }
- filter->a_preds = 0;
- filter->n_preds = 0;
+ prog = rcu_access_pointer(filter->prog);
+ if (!prog)
+ return;
+
+ for (i = 0; prog[i].pred; i++)
+ kfree(prog[i].pred);
+ kfree(prog);
}
static void filter_disable(struct trace_event_file *file)
@@ -834,7 +1009,7 @@ static void __free_filter(struct event_filter *filter)
if (!filter)
return;
- __free_preds(filter);
+ free_prog(filter);
kfree(filter->filter_string);
kfree(filter);
}
@@ -844,30 +1019,6 @@ void free_event_filter(struct event_filter *filter)
__free_filter(filter);
}
-static int __alloc_preds(struct event_filter *filter, int n_preds)
-{
- struct filter_pred *pred;
- int i;
-
- if (filter->preds)
- __free_preds(filter);
-
- filter->preds = kcalloc(n_preds, sizeof(*filter->preds), GFP_KERNEL);
-
- if (!filter->preds)
- return -ENOMEM;
-
- filter->a_preds = n_preds;
- filter->n_preds = 0;
-
- for (i = 0; i < n_preds; i++) {
- pred = &filter->preds[i];
- pred->fn = filter_pred_none;
- }
-
- return 0;
-}
-
static inline void __remove_filter(struct trace_event_file *file)
{
filter_disable(file);
@@ -898,812 +1049,466 @@ static void filter_free_subsystem_filters(struct trace_subsystem_dir *dir,
struct trace_event_file *file;
list_for_each_entry(file, &tr->events, list) {
- if (file->system != dir)
- continue;
- __free_subsystem_filter(file);
- }
-}
-
-static int filter_add_pred(struct filter_parse_state *ps,
- struct event_filter *filter,
- struct filter_pred *pred,
- struct pred_stack *stack)
-{
- int err;
-
- if (WARN_ON(filter->n_preds == filter->a_preds)) {
- parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
- return -ENOSPC;
- }
-
- err = filter_set_pred(filter, filter->n_preds, stack, pred);
- if (err)
- return err;
-
- filter->n_preds++;
-
- return 0;
-}
-
-int filter_assign_type(const char *type)
-{
- if (strstr(type, "__data_loc") && strstr(type, "char"))
- return FILTER_DYN_STRING;
-
- if (strchr(type, '[') && strstr(type, "char"))
- return FILTER_STATIC_STRING;
-
- return FILTER_OTHER;
-}
-
-static bool is_legal_op(struct ftrace_event_field *field, enum filter_op_ids op)
-{
- if (is_string_field(field) &&
- (op != OP_EQ && op != OP_NE && op != OP_GLOB))
- return false;
- if (!is_string_field(field) && op == OP_GLOB)
- return false;
-
- return true;
-}
-
-static filter_pred_fn_t select_comparison_fn(enum filter_op_ids op,
- int field_size, int field_is_signed)
-{
- filter_pred_fn_t fn = NULL;
- int pred_func_index = -1;
-
- switch (op) {
- case OP_EQ:
- case OP_NE:
- break;
- default:
- if (WARN_ON_ONCE(op < PRED_FUNC_START))
- return NULL;
- pred_func_index = op - PRED_FUNC_START;
- if (WARN_ON_ONCE(pred_func_index > PRED_FUNC_MAX))
- return NULL;
- }
-
- switch (field_size) {
- case 8:
- if (pred_func_index < 0)
- fn = filter_pred_64;
- else if (field_is_signed)
- fn = pred_funcs_s64[pred_func_index];
- else
- fn = pred_funcs_u64[pred_func_index];
- break;
- case 4:
- if (pred_func_index < 0)
- fn = filter_pred_32;
- else if (field_is_signed)
- fn = pred_funcs_s32[pred_func_index];
- else
- fn = pred_funcs_u32[pred_func_index];
- break;
- case 2:
- if (pred_func_index < 0)
- fn = filter_pred_16;
- else if (field_is_signed)
- fn = pred_funcs_s16[pred_func_index];
- else
- fn = pred_funcs_u16[pred_func_index];
- break;
- case 1:
- if (pred_func_index < 0)
- fn = filter_pred_8;
- else if (field_is_signed)
- fn = pred_funcs_s8[pred_func_index];
- else
- fn = pred_funcs_u8[pred_func_index];
- break;
- }
-
- return fn;
-}
-
-static int init_pred(struct filter_parse_state *ps,
- struct ftrace_event_field *field,
- struct filter_pred *pred)
-
-{
- filter_pred_fn_t fn = filter_pred_none;
- unsigned long long val;
- int ret;
-
- pred->offset = field->offset;
-
- if (!is_legal_op(field, pred->op)) {
- parse_error(ps, FILT_ERR_ILLEGAL_FIELD_OP, 0);
- return -EINVAL;
- }
-
- if (field->filter_type == FILTER_COMM) {
- filter_build_regex(pred);
- fn = filter_pred_comm;
- pred->regex.field_len = TASK_COMM_LEN;
- } else if (is_string_field(field)) {
- filter_build_regex(pred);
-
- if (field->filter_type == FILTER_STATIC_STRING) {
- fn = filter_pred_string;
- pred->regex.field_len = field->size;
- } else if (field->filter_type == FILTER_DYN_STRING)
- fn = filter_pred_strloc;
- else
- fn = filter_pred_pchar;
- } else if (is_function_field(field)) {
- if (strcmp(field->name, "ip")) {
- parse_error(ps, FILT_ERR_IP_FIELD_ONLY, 0);
- return -EINVAL;
- }
- } else {
- if (field->is_signed)
- ret = kstrtoll(pred->regex.pattern, 0, &val);
- else
- ret = kstrtoull(pred->regex.pattern, 0, &val);
- if (ret) {
- parse_error(ps, FILT_ERR_ILLEGAL_INTVAL, 0);
- return -EINVAL;
- }
- pred->val = val;
-
- if (field->filter_type == FILTER_CPU)
- fn = filter_pred_cpu;
- else
- fn = select_comparison_fn(pred->op, field->size,
- field->is_signed);
- if (!fn) {
- parse_error(ps, FILT_ERR_INVALID_OP, 0);
- return -EINVAL;
- }
- }
-
- if (pred->op == OP_NE)
- pred->not ^= 1;
-
- pred->fn = fn;
- return 0;
-}
-
-static void parse_init(struct filter_parse_state *ps,
- struct filter_op *ops,
- char *infix_string)
-{
- memset(ps, '\0', sizeof(*ps));
-
- ps->infix.string = infix_string;
- ps->infix.cnt = strlen(infix_string);
- ps->ops = ops;
-
- INIT_LIST_HEAD(&ps->opstack);
- INIT_LIST_HEAD(&ps->postfix);
-}
-
-static char infix_next(struct filter_parse_state *ps)
-{
- if (!ps->infix.cnt)
- return 0;
-
- ps->infix.cnt--;
-
- return ps->infix.string[ps->infix.tail++];
-}
-
-static char infix_peek(struct filter_parse_state *ps)
-{
- if (ps->infix.tail == strlen(ps->infix.string))
- return 0;
-
- return ps->infix.string[ps->infix.tail];
-}
-
-static void infix_advance(struct filter_parse_state *ps)
-{
- if (!ps->infix.cnt)
- return;
-
- ps->infix.cnt--;
- ps->infix.tail++;
-}
-
-static inline int is_precedence_lower(struct filter_parse_state *ps,
- int a, int b)
-{
- return ps->ops[a].precedence < ps->ops[b].precedence;
-}
-
-static inline int is_op_char(struct filter_parse_state *ps, char c)
-{
- int i;
-
- for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) {
- if (ps->ops[i].string[0] == c)
- return 1;
- }
-
- return 0;
-}
-
-static int infix_get_op(struct filter_parse_state *ps, char firstc)
-{
- char nextc = infix_peek(ps);
- char opstr[3];
- int i;
-
- opstr[0] = firstc;
- opstr[1] = nextc;
- opstr[2] = '\0';
-
- for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) {
- if (!strcmp(opstr, ps->ops[i].string)) {
- infix_advance(ps);
- return ps->ops[i].id;
- }
- }
-
- opstr[1] = '\0';
-
- for (i = 0; strcmp(ps->ops[i].string, "OP_NONE"); i++) {
- if (!strcmp(opstr, ps->ops[i].string))
- return ps->ops[i].id;
- }
-
- return OP_NONE;
-}
-
-static inline void clear_operand_string(struct filter_parse_state *ps)
-{
- memset(ps->operand.string, '\0', MAX_FILTER_STR_VAL);
- ps->operand.tail = 0;
-}
-
-static inline int append_operand_char(struct filter_parse_state *ps, char c)
-{
- if (ps->operand.tail == MAX_FILTER_STR_VAL - 1)
- return -EINVAL;
-
- ps->operand.string[ps->operand.tail++] = c;
-
- return 0;
-}
-
-static int filter_opstack_push(struct filter_parse_state *ps,
- enum filter_op_ids op)
-{
- struct opstack_op *opstack_op;
-
- opstack_op = kmalloc(sizeof(*opstack_op), GFP_KERNEL);
- if (!opstack_op)
- return -ENOMEM;
-
- opstack_op->op = op;
- list_add(&opstack_op->list, &ps->opstack);
-
- return 0;
-}
-
-static int filter_opstack_empty(struct filter_parse_state *ps)
-{
- return list_empty(&ps->opstack);
-}
-
-static int filter_opstack_top(struct filter_parse_state *ps)
-{
- struct opstack_op *opstack_op;
-
- if (filter_opstack_empty(ps))
- return OP_NONE;
-
- opstack_op = list_first_entry(&ps->opstack, struct opstack_op, list);
-
- return opstack_op->op;
-}
-
-static int filter_opstack_pop(struct filter_parse_state *ps)
-{
- struct opstack_op *opstack_op;
- enum filter_op_ids op;
-
- if (filter_opstack_empty(ps))
- return OP_NONE;
-
- opstack_op = list_first_entry(&ps->opstack, struct opstack_op, list);
- op = opstack_op->op;
- list_del(&opstack_op->list);
-
- kfree(opstack_op);
-
- return op;
-}
-
-static void filter_opstack_clear(struct filter_parse_state *ps)
-{
- while (!filter_opstack_empty(ps))
- filter_opstack_pop(ps);
-}
-
-static char *curr_operand(struct filter_parse_state *ps)
-{
- return ps->operand.string;
-}
-
-static int postfix_append_operand(struct filter_parse_state *ps, char *operand)
-{
- struct postfix_elt *elt;
-
- elt = kmalloc(sizeof(*elt), GFP_KERNEL);
- if (!elt)
- return -ENOMEM;
-
- elt->op = OP_NONE;
- elt->operand = kstrdup(operand, GFP_KERNEL);
- if (!elt->operand) {
- kfree(elt);
- return -ENOMEM;
- }
-
- list_add_tail(&elt->list, &ps->postfix);
-
- return 0;
-}
-
-static int postfix_append_op(struct filter_parse_state *ps, enum filter_op_ids op)
-{
- struct postfix_elt *elt;
-
- elt = kmalloc(sizeof(*elt), GFP_KERNEL);
- if (!elt)
- return -ENOMEM;
-
- elt->op = op;
- elt->operand = NULL;
-
- list_add_tail(&elt->list, &ps->postfix);
-
- return 0;
-}
-
-static void postfix_clear(struct filter_parse_state *ps)
-{
- struct postfix_elt *elt;
-
- while (!list_empty(&ps->postfix)) {
- elt = list_first_entry(&ps->postfix, struct postfix_elt, list);
- list_del(&elt->list);
- kfree(elt->operand);
- kfree(elt);
- }
-}
-
-static int filter_parse(struct filter_parse_state *ps)
-{
- enum filter_op_ids op, top_op;
- int in_string = 0;
- char ch;
-
- while ((ch = infix_next(ps))) {
- if (ch == '"') {
- in_string ^= 1;
- continue;
- }
-
- if (in_string)
- goto parse_operand;
-
- if (isspace(ch))
- continue;
-
- if (is_op_char(ps, ch)) {
- op = infix_get_op(ps, ch);
- if (op == OP_NONE) {
- parse_error(ps, FILT_ERR_INVALID_OP, 0);
- return -EINVAL;
- }
-
- if (strlen(curr_operand(ps))) {
- postfix_append_operand(ps, curr_operand(ps));
- clear_operand_string(ps);
- }
-
- while (!filter_opstack_empty(ps)) {
- top_op = filter_opstack_top(ps);
- if (!is_precedence_lower(ps, top_op, op)) {
- top_op = filter_opstack_pop(ps);
- postfix_append_op(ps, top_op);
- continue;
- }
- break;
- }
-
- filter_opstack_push(ps, op);
- continue;
- }
-
- if (ch == '(') {
- filter_opstack_push(ps, OP_OPEN_PAREN);
- continue;
- }
-
- if (ch == ')') {
- if (strlen(curr_operand(ps))) {
- postfix_append_operand(ps, curr_operand(ps));
- clear_operand_string(ps);
- }
-
- top_op = filter_opstack_pop(ps);
- while (top_op != OP_NONE) {
- if (top_op == OP_OPEN_PAREN)
- break;
- postfix_append_op(ps, top_op);
- top_op = filter_opstack_pop(ps);
- }
- if (top_op == OP_NONE) {
- parse_error(ps, FILT_ERR_UNBALANCED_PAREN, 0);
- return -EINVAL;
- }
+ if (file->system != dir)
continue;
- }
-parse_operand:
- if (append_operand_char(ps, ch)) {
- parse_error(ps, FILT_ERR_OPERAND_TOO_LONG, 0);
- return -EINVAL;
- }
+ __free_subsystem_filter(file);
}
+}
- if (strlen(curr_operand(ps)))
- postfix_append_operand(ps, curr_operand(ps));
+int filter_assign_type(const char *type)
+{
+ if (strstr(type, "__data_loc") && strstr(type, "char"))
+ return FILTER_DYN_STRING;
- while (!filter_opstack_empty(ps)) {
- top_op = filter_opstack_pop(ps);
- if (top_op == OP_NONE)
- break;
- if (top_op == OP_OPEN_PAREN) {
- parse_error(ps, FILT_ERR_UNBALANCED_PAREN, 0);
- return -EINVAL;
- }
- postfix_append_op(ps, top_op);
- }
+ if (strchr(type, '[') && strstr(type, "char"))
+ return FILTER_STATIC_STRING;
- return 0;
+ return FILTER_OTHER;
}
-static struct filter_pred *create_pred(struct filter_parse_state *ps,
- struct trace_event_call *call,
- enum filter_op_ids op,
- char *operand1, char *operand2)
+static filter_pred_fn_t select_comparison_fn(enum filter_op_ids op,
+ int field_size, int field_is_signed)
{
- struct ftrace_event_field *field;
- static struct filter_pred pred;
-
- memset(&pred, 0, sizeof(pred));
- pred.op = op;
-
- if (op == OP_AND || op == OP_OR)
- return &pred;
+ filter_pred_fn_t fn = NULL;
+ int pred_func_index = -1;
- if (!operand1 || !operand2) {
- parse_error(ps, FILT_ERR_MISSING_FIELD, 0);
- return NULL;
+ switch (op) {
+ case OP_EQ:
+ case OP_NE:
+ break;
+ default:
+ if (WARN_ON_ONCE(op < PRED_FUNC_START))
+ return NULL;
+ pred_func_index = op - PRED_FUNC_START;
+ if (WARN_ON_ONCE(pred_func_index > PRED_FUNC_MAX))
+ return NULL;
}
- field = trace_find_event_field(call, operand1);
- if (!field) {
- parse_error(ps, FILT_ERR_FIELD_NOT_FOUND, 0);
- return NULL;
+ switch (field_size) {
+ case 8:
+ if (pred_func_index < 0)
+ fn = filter_pred_64;
+ else if (field_is_signed)
+ fn = pred_funcs_s64[pred_func_index];
+ else
+ fn = pred_funcs_u64[pred_func_index];
+ break;
+ case 4:
+ if (pred_func_index < 0)
+ fn = filter_pred_32;
+ else if (field_is_signed)
+ fn = pred_funcs_s32[pred_func_index];
+ else
+ fn = pred_funcs_u32[pred_func_index];
+ break;
+ case 2:
+ if (pred_func_index < 0)
+ fn = filter_pred_16;
+ else if (field_is_signed)
+ fn = pred_funcs_s16[pred_func_index];
+ else
+ fn = pred_funcs_u16[pred_func_index];
+ break;
+ case 1:
+ if (pred_func_index < 0)
+ fn = filter_pred_8;
+ else if (field_is_signed)
+ fn = pred_funcs_s8[pred_func_index];
+ else
+ fn = pred_funcs_u8[pred_func_index];
+ break;
}
- strcpy(pred.regex.pattern, operand2);
- pred.regex.len = strlen(pred.regex.pattern);
- pred.field = field;
- return init_pred(ps, field, &pred) ? NULL : &pred;
+ return fn;
}
-static int check_preds(struct filter_parse_state *ps)
+/* Called when a predicate is encountered by predicate_parse() */
+static int parse_pred(const char *str, void *data,
+ int pos, struct filter_parse_error *pe,
+ struct filter_pred **pred_ptr)
{
- int n_normal_preds = 0, n_logical_preds = 0;
- struct postfix_elt *elt;
- int cnt = 0;
+ struct trace_event_call *call = data;
+ struct ftrace_event_field *field;
+ struct filter_pred *pred = NULL;
+ char num_buf[24]; /* Big enough to hold an address */
+ char *field_name;
+ char q;
+ u64 val;
+ int len;
+ int ret;
+ int op;
+ int s;
+ int i = 0;
- list_for_each_entry(elt, &ps->postfix, list) {
- if (elt->op == OP_NONE) {
- cnt++;
- continue;
- }
+ /* First find the field to associate to */
+ while (isspace(str[i]))
+ i++;
+ s = i;
- if (elt->op == OP_AND || elt->op == OP_OR) {
- n_logical_preds++;
- cnt--;
- continue;
- }
- if (elt->op != OP_NOT)
- cnt--;
- n_normal_preds++;
- /* all ops should have operands */
- if (cnt < 0)
- break;
- }
+ while (isalnum(str[i]) || str[i] == '_')
+ i++;
+
+ len = i - s;
+
+ if (!len)
+ return -1;
+
+ field_name = kmemdup_nul(str + s, len, GFP_KERNEL);
+ if (!field_name)
+ return -ENOMEM;
+
+ /* Make sure that the field exists */
- if (cnt != 1 || !n_normal_preds || n_logical_preds >= n_normal_preds) {
- parse_error(ps, FILT_ERR_INVALID_FILTER, 0);
+ field = trace_find_event_field(call, field_name);
+ kfree(field_name);
+ if (!field) {
+ parse_error(pe, FILT_ERR_FIELD_NOT_FOUND, pos + i);
return -EINVAL;
}
- return 0;
-}
+ while (isspace(str[i]))
+ i++;
-static int count_preds(struct filter_parse_state *ps)
-{
- struct postfix_elt *elt;
- int n_preds = 0;
+ /* Make sure this op is supported */
+ for (op = 0; ops[op]; op++) {
+ /* This is why '<=' must come before '<' in ops[] */
+ if (strncmp(str + i, ops[op], strlen(ops[op])) == 0)
+ break;
+ }
- list_for_each_entry(elt, &ps->postfix, list) {
- if (elt->op == OP_NONE)
- continue;
- n_preds++;
+ if (!ops[op]) {
+ parse_error(pe, FILT_ERR_INVALID_OP, pos + i);
+ goto err_free;
}
- return n_preds;
-}
+ i += strlen(ops[op]);
-struct check_pred_data {
- int count;
- int max;
-};
+ while (isspace(str[i]))
+ i++;
-static int check_pred_tree_cb(enum move_type move, struct filter_pred *pred,
- int *err, void *data)
-{
- struct check_pred_data *d = data;
+ s = i;
- if (WARN_ON(d->count++ > d->max)) {
- *err = -EINVAL;
- return WALK_PRED_ABORT;
- }
- return WALK_PRED_DEFAULT;
-}
+ pred = kzalloc(sizeof(*pred), GFP_KERNEL);
+ if (!pred)
+ return -ENOMEM;
-/*
- * The tree is walked at filtering of an event. If the tree is not correctly
- * built, it may cause an infinite loop. Check here that the tree does
- * indeed terminate.
- */
-static int check_pred_tree(struct event_filter *filter,
- struct filter_pred *root)
-{
- struct check_pred_data data = {
+ pred->field = field;
+ pred->offset = field->offset;
+ pred->op = op;
+
+ if (ftrace_event_is_function(call)) {
/*
- * The max that we can hit a node is three times.
- * Once going down, once coming up from left, and
- * once coming up from right. This is more than enough
- * since leafs are only hit a single time.
+ * Perf does things different with function events.
+ * It only allows an "ip" field, and expects a string.
+ * But the string does not need to be surrounded by quotes.
+ * If it is a string, the assigned function as a nop,
+ * (perf doesn't use it) and grab everything.
*/
- .max = 3 * filter->n_preds,
- .count = 0,
- };
+ if (strcmp(field->name, "ip") != 0) {
+ parse_error(pe, FILT_ERR_IP_FIELD_ONLY, pos + i);
+ goto err_free;
+ }
+ pred->fn = filter_pred_none;
+
+ /*
+ * Quotes are not required, but if they exist then we need
+ * to read them till we hit a matching one.
+ */
+ if (str[i] == '\'' || str[i] == '"')
+ q = str[i];
+ else
+ q = 0;
+
+ for (i++; str[i]; i++) {
+ if (q && str[i] == q)
+ break;
+ if (!q && (str[i] == ')' || str[i] == '&' ||
+ str[i] == '|'))
+ break;
+ }
+ /* Skip quotes */
+ if (q)
+ s++;
+ len = i - s;
+ if (len >= MAX_FILTER_STR_VAL) {
+ parse_error(pe, FILT_ERR_OPERAND_TOO_LONG, pos + i);
+ goto err_free;
+ }
- return walk_pred_tree(filter->preds, root,
- check_pred_tree_cb, &data);
-}
+ pred->regex.len = len;
+ strncpy(pred->regex.pattern, str + s, len);
+ pred->regex.pattern[len] = 0;
+
+ /* This is either a string, or an integer */
+ } else if (str[i] == '\'' || str[i] == '"') {
+ char q = str[i];
+
+ /* Make sure the op is OK for strings */
+ switch (op) {
+ case OP_NE:
+ pred->not = 1;
+ /* Fall through */
+ case OP_GLOB:
+ case OP_EQ:
+ break;
+ default:
+ parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i);
+ goto err_free;
+ }
-static int count_leafs_cb(enum move_type move, struct filter_pred *pred,
- int *err, void *data)
-{
- int *count = data;
+ /* Make sure the field is OK for strings */
+ if (!is_string_field(field)) {
+ parse_error(pe, FILT_ERR_EXPECT_DIGIT, pos + i);
+ goto err_free;
+ }
- if ((move == MOVE_DOWN) &&
- (pred->left == FILTER_PRED_INVALID))
- (*count)++;
+ for (i++; str[i]; i++) {
+ if (str[i] == q)
+ break;
+ }
+ if (!str[i]) {
+ parse_error(pe, FILT_ERR_MISSING_QUOTE, pos + i);
+ goto err_free;
+ }
- return WALK_PRED_DEFAULT;
-}
+ /* Skip quotes */
+ s++;
+ len = i - s;
+ if (len >= MAX_FILTER_STR_VAL) {
+ parse_error(pe, FILT_ERR_OPERAND_TOO_LONG, pos + i);
+ goto err_free;
+ }
-static int count_leafs(struct filter_pred *preds, struct filter_pred *root)
-{
- int count = 0, ret;
+ pred->regex.len = len;
+ strncpy(pred->regex.pattern, str + s, len);
+ pred->regex.pattern[len] = 0;
- ret = walk_pred_tree(preds, root, count_leafs_cb, &count);
- WARN_ON(ret);
- return count;
-}
+ filter_build_regex(pred);
-struct fold_pred_data {
- struct filter_pred *root;
- int count;
- int children;
-};
+ if (field->filter_type == FILTER_COMM) {
+ pred->fn = filter_pred_comm;
-static int fold_pred_cb(enum move_type move, struct filter_pred *pred,
- int *err, void *data)
-{
- struct fold_pred_data *d = data;
- struct filter_pred *root = d->root;
+ } else if (field->filter_type == FILTER_STATIC_STRING) {
+ pred->fn = filter_pred_string;
+ pred->regex.field_len = field->size;
- if (move != MOVE_DOWN)
- return WALK_PRED_DEFAULT;
- if (pred->left != FILTER_PRED_INVALID)
- return WALK_PRED_DEFAULT;
+ } else if (field->filter_type == FILTER_DYN_STRING)
+ pred->fn = filter_pred_strloc;
+ else
+ pred->fn = filter_pred_pchar;
+ /* go past the last quote */
+ i++;
- if (WARN_ON(d->count == d->children)) {
- *err = -EINVAL;
- return WALK_PRED_ABORT;
- }
+ } else if (isdigit(str[i])) {
- pred->index &= ~FILTER_PRED_FOLD;
- root->ops[d->count++] = pred->index;
- return WALK_PRED_DEFAULT;
-}
+ /* Make sure the field is not a string */
+ if (is_string_field(field)) {
+ parse_error(pe, FILT_ERR_EXPECT_STRING, pos + i);
+ goto err_free;
+ }
-static int fold_pred(struct filter_pred *preds, struct filter_pred *root)
-{
- struct fold_pred_data data = {
- .root = root,
- .count = 0,
- };
- int children;
+ if (op == OP_GLOB) {
+ parse_error(pe, FILT_ERR_ILLEGAL_FIELD_OP, pos + i);
+ goto err_free;
+ }
- /* No need to keep the fold flag */
- root->index &= ~FILTER_PRED_FOLD;
+ /* We allow 0xDEADBEEF */
+ while (isalnum(str[i]))
+ i++;
- /* If the root is a leaf then do nothing */
- if (root->left == FILTER_PRED_INVALID)
- return 0;
+ len = i - s;
+ /* 0xfeedfacedeadbeef is 18 chars max */
+ if (len >= sizeof(num_buf)) {
+ parse_error(pe, FILT_ERR_OPERAND_TOO_LONG, pos + i);
+ goto err_free;
+ }
- /* count the children */
- children = count_leafs(preds, &preds[root->left]);
- children += count_leafs(preds, &preds[root->right]);
+ strncpy(num_buf, str + s, len);
+ num_buf[len] = 0;
- root->ops = kcalloc(children, sizeof(*root->ops), GFP_KERNEL);
- if (!root->ops)
- return -ENOMEM;
+ /* Make sure it is a value */
+ if (field->is_signed)
+ ret = kstrtoll(num_buf, 0, &val);
+ else
+ ret = kstrtoull(num_buf, 0, &val);
+ if (ret) {
+ parse_error(pe, FILT_ERR_ILLEGAL_INTVAL, pos + s);
+ goto err_free;
+ }
- root->val = children;
- data.children = children;
- return walk_pred_tree(preds, root, fold_pred_cb, &data);
-}
+ pred->val = val;
-static int fold_pred_tree_cb(enum move_type move, struct filter_pred *pred,
- int *err, void *data)
-{
- struct filter_pred *preds = data;
+ if (field->filter_type == FILTER_CPU)
+ pred->fn = filter_pred_cpu;
+ else {
+ pred->fn = select_comparison_fn(pred->op, field->size,
+ field->is_signed);
+ if (pred->op == OP_NE)
+ pred->not = 1;
+ }
- if (move != MOVE_DOWN)
- return WALK_PRED_DEFAULT;
- if (!(pred->index & FILTER_PRED_FOLD))
- return WALK_PRED_DEFAULT;
+ } else {
+ parse_error(pe, FILT_ERR_INVALID_VALUE, pos + i);
+ goto err_free;
+ }
- *err = fold_pred(preds, pred);
- if (*err)
- return WALK_PRED_ABORT;
+ *pred_ptr = pred;
+ return i;
- /* eveyrhing below is folded, continue with parent */
- return WALK_PRED_PARENT;
+err_free:
+ kfree(pred);
+ return -EINVAL;
}
+enum {
+ TOO_MANY_CLOSE = -1,
+ TOO_MANY_OPEN = -2,
+ MISSING_QUOTE = -3,
+};
+
/*
- * To optimize the processing of the ops, if we have several "ors" or
- * "ands" together, we can put them in an array and process them all
- * together speeding up the filter logic.
+ * Read the filter string once to calculate the number of predicates
+ * as well as how deep the parentheses go.
+ *
+ * Returns:
+ * 0 - everything is fine (err is undefined)
+ * -1 - too many ')'
+ * -2 - too many '('
+ * -3 - No matching quote
*/
-static int fold_pred_tree(struct event_filter *filter,
- struct filter_pred *root)
-{
- return walk_pred_tree(filter->preds, root, fold_pred_tree_cb,
- filter->preds);
-}
-
-static int replace_preds(struct trace_event_call *call,
- struct event_filter *filter,
- struct filter_parse_state *ps,
- bool dry_run)
-{
- char *operand1 = NULL, *operand2 = NULL;
- struct filter_pred *pred;
- struct filter_pred *root;
- struct postfix_elt *elt;
- struct pred_stack stack = { }; /* init to NULL */
- int err;
- int n_preds = 0;
-
- n_preds = count_preds(ps);
- if (n_preds >= MAX_FILTER_PRED) {
- parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
- return -ENOSPC;
- }
-
- err = check_preds(ps);
- if (err)
- return err;
+static int calc_stack(const char *str, int *parens, int *preds, int *err)
+{
+ bool is_pred = false;
+ int nr_preds = 0;
+ int open = 1; /* Count the expression as "(E)" */
+ int last_quote = 0;
+ int max_open = 1;
+ int quote = 0;
+ int i;
- if (!dry_run) {
- err = __alloc_pred_stack(&stack, n_preds);
- if (err)
- return err;
- err = __alloc_preds(filter, n_preds);
- if (err)
- goto fail;
- }
+ *err = 0;
- n_preds = 0;
- list_for_each_entry(elt, &ps->postfix, list) {
- if (elt->op == OP_NONE) {
- if (!operand1)
- operand1 = elt->operand;
- else if (!operand2)
- operand2 = elt->operand;
- else {
- parse_error(ps, FILT_ERR_TOO_MANY_OPERANDS, 0);
- err = -EINVAL;
- goto fail;
- }
+ for (i = 0; str[i]; i++) {
+ if (isspace(str[i]))
+ continue;
+ if (quote) {
+ if (str[i] == quote)
+ quote = 0;
continue;
}
- if (elt->op == OP_NOT) {
- if (!n_preds || operand1 || operand2) {
- parse_error(ps, FILT_ERR_ILLEGAL_NOT_OP, 0);
- err = -EINVAL;
- goto fail;
+ switch (str[i]) {
+ case '\'':
+ case '"':
+ quote = str[i];
+ last_quote = i;
+ break;
+ case '|':
+ case '&':
+ if (str[i+1] != str[i])
+ break;
+ is_pred = false;
+ continue;
+ case '(':
+ is_pred = false;
+ open++;
+ if (open > max_open)
+ max_open = open;
+ continue;
+ case ')':
+ is_pred = false;
+ if (open == 1) {
+ *err = i;
+ return TOO_MANY_CLOSE;
}
- if (!dry_run)
- filter->preds[n_preds - 1].not ^= 1;
+ open--;
continue;
}
-
- if (WARN_ON(n_preds++ == MAX_FILTER_PRED)) {
- parse_error(ps, FILT_ERR_TOO_MANY_PREDS, 0);
- err = -ENOSPC;
- goto fail;
+ if (!is_pred) {
+ nr_preds++;
+ is_pred = true;
}
+ }
- pred = create_pred(ps, call, elt->op, operand1, operand2);
- if (!pred) {
- err = -EINVAL;
- goto fail;
- }
+ if (quote) {
+ *err = last_quote;
+ return MISSING_QUOTE;
+ }
- if (!dry_run) {
- err = filter_add_pred(ps, filter, pred, &stack);
- if (err)
- goto fail;
- }
+ if (open != 1) {
+ int level = open;
- operand1 = operand2 = NULL;
+ /* find the bad open */
+ for (i--; i; i--) {
+ if (quote) {
+ if (str[i] == quote)
+ quote = 0;
+ continue;
+ }
+ switch (str[i]) {
+ case '(':
+ if (level == open) {
+ *err = i;
+ return TOO_MANY_OPEN;
+ }
+ level--;
+ break;
+ case ')':
+ level++;
+ break;
+ case '\'':
+ case '"':
+ quote = str[i];
+ break;
+ }
+ }
+ /* First character is the '(' with missing ')' */
+ *err = 0;
+ return TOO_MANY_OPEN;
}
- if (!dry_run) {
- /* We should have one item left on the stack */
- pred = __pop_pred_stack(&stack);
- if (!pred)
- return -EINVAL;
- /* This item is where we start from in matching */
- root = pred;
- /* Make sure the stack is empty */
- pred = __pop_pred_stack(&stack);
- if (WARN_ON(pred)) {
- err = -EINVAL;
- filter->root = NULL;
- goto fail;
+ /* Set the size of the required stacks */
+ *parens = max_open;
+ *preds = nr_preds;
+ return 0;
+}
+
+static int process_preds(struct trace_event_call *call,
+ const char *filter_string,
+ struct event_filter *filter,
+ struct filter_parse_error *pe)
+{
+ struct prog_entry *prog;
+ int nr_parens;
+ int nr_preds;
+ int index;
+ int ret;
+
+ ret = calc_stack(filter_string, &nr_parens, &nr_preds, &index);
+ if (ret < 0) {
+ switch (ret) {
+ case MISSING_QUOTE:
+ parse_error(pe, FILT_ERR_MISSING_QUOTE, index);
+ break;
+ case TOO_MANY_OPEN:
+ parse_error(pe, FILT_ERR_TOO_MANY_OPEN, index);
+ break;
+ default:
+ parse_error(pe, FILT_ERR_TOO_MANY_CLOSE, index);
}
- err = check_pred_tree(filter, root);
- if (err)
- goto fail;
-
- /* Optimize the tree */
- err = fold_pred_tree(filter, root);
- if (err)
- goto fail;
-
- /* We don't set root until we know it works */
- barrier();
- filter->root = root;
+ return ret;
}
- err = 0;
-fail:
- __free_pred_stack(&stack);
- return err;
+ if (!nr_preds) {
+ prog = NULL;
+ } else {
+ prog = predicate_parse(filter_string, nr_parens, nr_preds,
+ parse_pred, call, pe);
+ if (IS_ERR(prog))
+ return PTR_ERR(prog);
+ }
+ rcu_assign_pointer(filter->prog, prog);
+ return 0;
}
static inline void event_set_filtered_flag(struct trace_event_file *file)
@@ -1753,9 +1558,9 @@ struct filter_list {
struct event_filter *filter;
};
-static int replace_system_preds(struct trace_subsystem_dir *dir,
+static int process_system_preds(struct trace_subsystem_dir *dir,
struct trace_array *tr,
- struct filter_parse_state *ps,
+ struct filter_parse_error *pe,
char *filter_string)
{
struct trace_event_file *file;
@@ -1766,29 +1571,11 @@ static int replace_system_preds(struct trace_subsystem_dir *dir,
bool fail = true;
int err;
- list_for_each_entry(file, &tr->events, list) {
- if (file->system != dir)
- continue;
-
- /*
- * Try to see if the filter can be applied
- * (filter arg is ignored on dry_run)
- */
- err = replace_preds(file->event_call, NULL, ps, true);
- if (err)
- event_set_no_set_filter_flag(file);
- else
- event_clear_no_set_filter_flag(file);
- }
-
list_for_each_entry(file, &tr->events, list) {
if (file->system != dir)
continue;
- if (event_no_set_filter_flag(file))
- continue;
-
filter = kzalloc(sizeof(*filter), GFP_KERNEL);
if (!filter)
goto fail_mem;
@@ -1797,11 +1584,11 @@ static int replace_system_preds(struct trace_subsystem_dir *dir,
if (!filter->filter_string)
goto fail_mem;
- err = replace_preds(file->event_call, filter, ps, false);
+ err = process_preds(file->event_call, filter_string, filter, pe);
if (err) {
filter_disable(file);
- parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
- append_filter_err(ps, filter);
+ parse_error(pe, FILT_ERR_BAD_SUBSYS_FILTER, 0);
+ append_filter_err(pe, filter);
} else
event_set_filtered_flag(file);
@@ -1843,7 +1630,7 @@ static int replace_system_preds(struct trace_subsystem_dir *dir,
list_del(&filter_item->list);
kfree(filter_item);
}
- parse_error(ps, FILT_ERR_BAD_SUBSYS_FILTER, 0);
+ parse_error(pe, FILT_ERR_BAD_SUBSYS_FILTER, 0);
return -EINVAL;
fail_mem:
kfree(filter);
@@ -1859,16 +1646,16 @@ static int replace_system_preds(struct trace_subsystem_dir *dir,
}
static int create_filter_start(char *filter_string, bool set_str,
- struct filter_parse_state **psp,
+ struct filter_parse_error **pse,
struct event_filter **filterp)
{
struct event_filter *filter;
- struct filter_parse_state *ps = NULL;
+ struct filter_parse_error *pe = NULL;
int err = 0;
- WARN_ON_ONCE(*psp || *filterp);
+ if (WARN_ON_ONCE(*pse || *filterp))
+ return -EINVAL;
- /* allocate everything, and if any fails, free all and fail */
filter = kzalloc(sizeof(*filter), GFP_KERNEL);
if (filter && set_str) {
filter->filter_string = kstrdup(filter_string, GFP_KERNEL);
@@ -1876,32 +1663,24 @@ static int create_filter_start(char *filter_string, bool set_str,
err = -ENOMEM;
}
- ps = kzalloc(sizeof(*ps), GFP_KERNEL);
+ pe = kzalloc(sizeof(*pe), GFP_KERNEL);
- if (!filter || !ps || err) {
- kfree(ps);
+ if (!filter || !pe || err) {
+ kfree(pe);
__free_filter(filter);
return -ENOMEM;
}
/* we're committed to creating a new filter */
*filterp = filter;
- *psp = ps;
+ *pse = pe;
- parse_init(ps, filter_ops, filter_string);
- err = filter_parse(ps);
- if (err && set_str)
- append_filter_err(ps, filter);
- return err;
+ return 0;
}
-static void create_filter_finish(struct filter_parse_state *ps)
+static void create_filter_finish(struct filter_parse_error *pe)
{
- if (ps) {
- filter_opstack_clear(ps);
- postfix_clear(ps);
- kfree(ps);
- }
+ kfree(pe);
}
/**
@@ -1921,24 +1700,20 @@ static void create_filter_finish(struct filter_parse_state *ps)
* freeing it.
*/
static int create_filter(struct trace_event_call *call,
- char *filter_str, bool set_str,
+ char *filter_string, bool set_str,
struct event_filter **filterp)
{
+ struct filter_parse_error *pe = NULL;
struct event_filter *filter = NULL;
- struct filter_parse_state *ps = NULL;
int err;
- err = create_filter_start(filter_str, set_str, &ps, &filter);
- if (!err) {
- err = replace_preds(call, filter, ps, false);
- if (err && set_str)
- append_filter_err(ps, filter);
- }
- if (err && !set_str) {
- free_event_filter(filter);
- filter = NULL;
- }
- create_filter_finish(ps);
+ err = create_filter_start(filter_string, set_str, &pe, &filter);
+ if (err)
+ return err;
+
+ err = process_preds(call, filter_string, filter, pe);
+ if (err && set_str)
+ append_filter_err(pe, filter);
*filterp = filter;
return err;
@@ -1965,21 +1740,21 @@ static int create_system_filter(struct trace_subsystem_dir *dir,
char *filter_str, struct event_filter **filterp)
{
struct event_filter *filter = NULL;
- struct filter_parse_state *ps = NULL;
+ struct filter_parse_error *pe = NULL;
int err;
- err = create_filter_start(filter_str, true, &ps, &filter);
+ err = create_filter_start(filter_str, true, &pe, &filter);
if (!err) {
- err = replace_system_preds(dir, tr, ps, filter_str);
+ err = process_system_preds(dir, tr, pe, filter_str);
if (!err) {
/* System filters just show a default message */
kfree(filter->filter_string);
filter->filter_string = NULL;
} else {
- append_filter_err(ps, filter);
+ append_filter_err(pe, filter);
}
}
- create_filter_finish(ps);
+ create_filter_finish(pe);
*filterp = filter;
return err;
@@ -2162,66 +1937,79 @@ static int __ftrace_function_set_filter(int filter, char *buf, int len,
return ret;
}
-static int ftrace_function_check_pred(struct filter_pred *pred, int leaf)
+static int ftrace_function_check_pred(struct filter_pred *pred)
{
struct ftrace_event_field *field = pred->field;
- if (leaf) {
- /*
- * Check the leaf predicate for function trace, verify:
- * - only '==' and '!=' is used
- * - the 'ip' field is used
- */
- if ((pred->op != OP_EQ) && (pred->op != OP_NE))
- return -EINVAL;
+ /*
+ * Check the predicate for function trace, verify:
+ * - only '==' and '!=' is used
+ * - the 'ip' field is used
+ */
+ if ((pred->op != OP_EQ) && (pred->op != OP_NE))
+ return -EINVAL;
- if (strcmp(field->name, "ip"))
- return -EINVAL;
- } else {
- /*
- * Check the non leaf predicate for function trace, verify:
- * - only '||' is used
- */
- if (pred->op != OP_OR)
- return -EINVAL;
- }
+ if (strcmp(field->name, "ip"))
+ return -EINVAL;
return 0;
}
-static int ftrace_function_set_filter_cb(enum move_type move,
- struct filter_pred *pred,
- int *err, void *data)
+static int ftrace_function_set_filter_pred(struct filter_pred *pred,
+ struct function_filter_data *data)
{
+ int ret;
+
/* Checking the node is valid for function trace. */
- if ((move != MOVE_DOWN) ||
- (pred->left != FILTER_PRED_INVALID)) {
- *err = ftrace_function_check_pred(pred, 0);
- } else {
- *err = ftrace_function_check_pred(pred, 1);
- if (*err)
- return WALK_PRED_ABORT;
-
- *err = __ftrace_function_set_filter(pred->op == OP_EQ,
- pred->regex.pattern,
- pred->regex.len,
- data);
- }
+ ret = ftrace_function_check_pred(pred);
+ if (ret)
+ return ret;
+
+ return __ftrace_function_set_filter(pred->op == OP_EQ,
+ pred->regex.pattern,
+ pred->regex.len,
+ data);
+}
+
+static bool is_or(struct prog_entry *prog, int i)
+{
+ int target;
- return (*err) ? WALK_PRED_ABORT : WALK_PRED_DEFAULT;
+ /*
+ * Only "||" is allowed for function events, thus,
+ * all true branches should jump to true, and any
+ * false branch should jump to false.
+ */
+ target = prog[i].target + 1;
+ /* True and false have NULL preds (all prog entries should jump to one */
+ if (prog[target].pred)
+ return false;
+
+ /* prog[target].target is 1 for TRUE, 0 for FALSE */
+ return prog[i].when_to_branch == prog[target].target;
}
static int ftrace_function_set_filter(struct perf_event *event,
struct event_filter *filter)
{
+ struct prog_entry *prog = filter->prog;
struct function_filter_data data = {
.first_filter = 1,
.first_notrace = 1,
.ops = &event->ftrace_ops,
};
+ int i;
+
+ for (i = 0; prog[i].pred; i++) {
+ struct filter_pred *pred = prog[i].pred;
+
+ if (!is_or(prog, i))
+ return -EINVAL;
- return walk_pred_tree(filter->preds, filter->root,
- ftrace_function_set_filter_cb, &data);
+ if (ftrace_function_set_filter_pred(pred, &data) < 0)
+ return -EINVAL;
+ }
+ return 0;
}
#else
static int ftrace_function_set_filter(struct perf_event *event,
@@ -2364,26 +2152,27 @@ static int test_pred_visited_fn(struct filter_pred *pred, void *event)
return 1;
}
-static int test_walk_pred_cb(enum move_type move, struct filter_pred *pred,
- int *err, void *data)
+static void update_pred_fn(struct event_filter *filter, char *fields)
{
- char *fields = data;
+ struct prog_entry *prog = filter->prog;
+ int i;
- if ((move == MOVE_DOWN) &&
- (pred->left == FILTER_PRED_INVALID)) {
+ for (i = 0; prog[i].pred; i++) {
+ struct filter_pred *pred = prog[i].pred;
struct ftrace_event_field *field = pred->field;
+ WARN_ON_ONCE(!pred->fn);
+
if (!field) {
- WARN(1, "all leafs should have field defined");
- return WALK_PRED_DEFAULT;
+ WARN_ONCE(1, "all leafs should have field defined %d", i);
+ continue;
}
+
if (!strchr(fields, *field->name))
- return WALK_PRED_DEFAULT;
+ continue;
- WARN_ON(!pred->fn);
pred->fn = test_pred_visited_fn;
}
- return WALK_PRED_DEFAULT;
}
static __init int ftrace_test_event_filter(void)
@@ -2413,9 +2202,7 @@ static __init int ftrace_test_event_filter(void)
*/
preempt_disable();
if (*d->not_visited)
- walk_pred_tree(filter->preds, filter->root,
- test_walk_pred_cb,
- d->not_visited);
+ update_pred_fn(filter, d->not_visited);
test_pred_visited = 0;
err = filter_match_preds(filter, &d->rec);
--
2.15.1
^ permalink raw reply related [flat|nested] 47+ messages in thread