* [PATCH] tracing/histogram: Wrap remaining shell snippets in code blocks
[not found] <202301290253.LU5yIxcJ-lkp@intel.com>
@ 2023-01-29 3:14 ` Bagas Sanjaya
2023-02-02 18:14 ` Jonathan Corbet
0 siblings, 1 reply; 4+ messages in thread
From: Bagas Sanjaya @ 2023-01-29 3:14 UTC (permalink / raw)
To: linux-kernel, linux-trace-kernel, linux-doc, oe-kbuild-all
Cc: Steven Rostedt, Masami Hiramatsu, Jonathan Corbet, Bagas Sanjaya,
kernel test robot
Most shell command snippets (echo/cat) and their output are already in
literal code blocks. However a few still isn't wrapped, in which the
htmldocs output is ugly.
Wrap the remaining unwrapped snippets, while also fix recent kernel test
robot warnings.
Link: https://lore.kernel.org/linux-doc/202301290253.LU5yIxcJ-lkp@intel.com/
Fixes: 88238513bb2671 ("tracing/histogram: Document variable stacktrace")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
---
Documentation/trace/histogram.rst | 93 ++++++++++++++++---------------
1 file changed, 47 insertions(+), 46 deletions(-)
diff --git a/Documentation/trace/histogram.rst b/Documentation/trace/histogram.rst
index 5c391328b9bb41..8e95295e39b65c 100644
--- a/Documentation/trace/histogram.rst
+++ b/Documentation/trace/histogram.rst
@@ -1864,7 +1864,7 @@ A histogram can now be defined for the new synthetic event::
The above shows the latency "lat" in a power of 2 grouping.
Like any other event, once a histogram is enabled for the event, the
-output can be displayed by reading the event's 'hist' file.
+output can be displayed by reading the event's 'hist' file::
# cat /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/hist
@@ -1911,7 +1911,7 @@ output can be displayed by reading the event's 'hist' file.
The latency values can also be grouped linearly by a given size with
-the ".buckets" modifier and specify a size (in this case groups of 10).
+the ".buckets" modifier and specify a size (in this case groups of 10)::
# echo 'hist:keys=pid,prio,lat.buckets=10:sort=lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
@@ -1945,7 +1945,7 @@ the ".buckets" modifier and specify a size (in this case groups of 10).
To save stacktraces, create a synthetic event with a field of type "unsigned long[]"
or even just "long[]". For example, to see how long a task is blocked in an
-uninterruptible state:
+uninterruptible state::
# cd /sys/kernel/tracing
# echo 's:block_lat pid_t pid; u64 delta; unsigned long[] stack;' > dynamic_events
@@ -1990,7 +1990,8 @@ uninterruptible state:
=> kthread+0xe9/0x110
=> ret_from_fork+0x2c/0x50
-A synthetic event that has a stacktrace field may use it as a key in histogram:
+A synthetic event that has a stacktrace field may use it as a key in
+histogram::
# echo 'hist:delta.buckets=100,stack.stacktrace:sort=delta' > events/synthetic/block_lat/trigger
# cat events/synthetic/block_lat/hist
@@ -2183,11 +2184,11 @@ The following commonly-used handler.action pairs are available:
wakeup_new_test($testpid) if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup_new/trigger
- Or, equivalently, using the 'trace' keyword syntax:
+ Or, equivalently, using the 'trace' keyword syntax::
- # echo 'hist:keys=$testpid:testpid=pid:onmatch(sched.sched_wakeup_new).\
- trace(wakeup_new_test,$testpid) if comm=="cyclictest"' >> \
- /sys/kernel/debug/tracing/events/sched/sched_wakeup_new/trigger
+ # echo 'hist:keys=$testpid:testpid=pid:onmatch(sched.sched_wakeup_new).\
+ trace(wakeup_new_test,$testpid) if comm=="cyclictest"' >> \
+ /sys/kernel/debug/tracing/events/sched/sched_wakeup_new/trigger
Creating and displaying a histogram based on those events is now
just a matter of using the fields and new synthetic event in the
@@ -2320,48 +2321,48 @@ The following commonly-used handler.action pairs are available:
resulting latency, stored in wakeup_lat, exceeds the current
maximum latency, a snapshot is taken. As part of the setup, all
the scheduler events are also enabled, which are the events that
- will show up in the snapshot when it is taken at some point:
+ will show up in the snapshot when it is taken at some point::
- # echo 1 > /sys/kernel/debug/tracing/events/sched/enable
+ # echo 1 > /sys/kernel/debug/tracing/events/sched/enable
- # echo 'hist:keys=pid:ts0=common_timestamp.usecs \
- if comm=="cyclictest"' >> \
- /sys/kernel/debug/tracing/events/sched/sched_waking/trigger
+ # echo 'hist:keys=pid:ts0=common_timestamp.usecs \
+ if comm=="cyclictest"' >> \
+ /sys/kernel/debug/tracing/events/sched/sched_waking/trigger
- # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0: \
- onmax($wakeup_lat).save(next_prio,next_comm,prev_pid,prev_prio, \
- prev_comm):onmax($wakeup_lat).snapshot() \
- if next_comm=="cyclictest"' >> \
- /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
+ # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0: \
+ onmax($wakeup_lat).save(next_prio,next_comm,prev_pid,prev_prio, \
+ prev_comm):onmax($wakeup_lat).snapshot() \
+ if next_comm=="cyclictest"' >> \
+ /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, for each bucket the max value
and the saved values corresponding to the max are displayed
following the rest of the fields.
If a snapshot was taken, there is also a message indicating that,
- along with the value and event that triggered the global maximum:
+ along with the value and event that triggered the global maximum::
- # cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
- { next_pid: 2101 } hitcount: 200
- max: 52 next_prio: 120 next_comm: cyclictest \
- prev_pid: 0 prev_prio: 120 prev_comm: swapper/6
+ # cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
+ { next_pid: 2101 } hitcount: 200
+ max: 52 next_prio: 120 next_comm: cyclictest \
+ prev_pid: 0 prev_prio: 120 prev_comm: swapper/6
- { next_pid: 2103 } hitcount: 1326
- max: 572 next_prio: 19 next_comm: cyclictest \
- prev_pid: 0 prev_prio: 120 prev_comm: swapper/1
+ { next_pid: 2103 } hitcount: 1326
+ max: 572 next_prio: 19 next_comm: cyclictest \
+ prev_pid: 0 prev_prio: 120 prev_comm: swapper/1
- { next_pid: 2102 } hitcount: 1982 \
- max: 74 next_prio: 19 next_comm: cyclictest \
- prev_pid: 0 prev_prio: 120 prev_comm: swapper/5
+ { next_pid: 2102 } hitcount: 1982 \
+ max: 74 next_prio: 19 next_comm: cyclictest \
+ prev_pid: 0 prev_prio: 120 prev_comm: swapper/5
- Snapshot taken (see tracing/snapshot). Details:
- triggering value { onmax($wakeup_lat) }: 572 \
- triggered by event with key: { next_pid: 2103 }
+ Snapshot taken (see tracing/snapshot). Details:
+ triggering value { onmax($wakeup_lat) }: 572 \
+ triggered by event with key: { next_pid: 2103 }
- Totals:
- Hits: 3508
- Entries: 3
- Dropped: 0
+ Totals:
+ Hits: 3508
+ Entries: 3
+ Dropped: 0
In the above case, the event that triggered the global maximum has
the key with next_pid == 2103. If you look at the bucket that has
@@ -2439,15 +2440,15 @@ The following commonly-used handler.action pairs are available:
$cwnd variable. If the value has changed, a snapshot is taken.
As part of the setup, all the scheduler and tcp events are also
enabled, which are the events that will show up in the snapshot
- when it is taken at some point:
+ when it is taken at some point::
- # echo 1 > /sys/kernel/debug/tracing/events/sched/enable
- # echo 1 > /sys/kernel/debug/tracing/events/tcp/enable
+ # echo 1 > /sys/kernel/debug/tracing/events/sched/enable
+ # echo 1 > /sys/kernel/debug/tracing/events/tcp/enable
- # echo 'hist:keys=dport:cwnd=snd_cwnd: \
- onchange($cwnd).save(snd_wnd,srtt,rcv_wnd): \
- onchange($cwnd).snapshot()' >> \
- /sys/kernel/debug/tracing/events/tcp/tcp_probe/trigger
+ # echo 'hist:keys=dport:cwnd=snd_cwnd: \
+ onchange($cwnd).save(snd_wnd,srtt,rcv_wnd): \
+ onchange($cwnd).snapshot()' >> \
+ /sys/kernel/debug/tracing/events/tcp/tcp_probe/trigger
When the histogram is displayed, for each bucket the tracked value
and the saved values corresponding to that value are displayed
@@ -2470,10 +2471,10 @@ The following commonly-used handler.action pairs are available:
{ dport: 443 } hitcount: 211
changed: 10 snd_wnd: 26960 srtt: 17379 rcv_wnd: 28800
- Snapshot taken (see tracing/snapshot). Details::
+ Snapshot taken (see tracing/snapshot). Details:
- triggering value { onchange($cwnd) }: 10
- triggered by event with key: { dport: 80 }
+ triggering value { onchange($cwnd) }: 10
+ triggered by event with key: { dport: 80 }
Totals:
Hits: 414
base-commit: 9f712417e1fc7d3db042941524e59573e02a55c7
--
An old man doll... just what I always wanted! - Clara
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