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a=openpgp; fpr=701B806FDCA5D3A58FFB8F7D7C276C64A5E44A1D Content-Transfer-Encoding: 8bit Section numbering in subsections of "Histogram Trigger Command" sections is inconsistent in order. In particular, "'hist' trigger examples" is erroneously numbered as 6.2, which is a leftover from b8df4a3634e08a ("tracing: Move hist trigger Documentation to histogram.txt"). Fix the order. Reviewed-by: Tom Zanussi Reviewed-by: Masami Hiramatsu (Google) Signed-off-by: Bagas Sanjaya --- Documentation/trace/histogram.rst | 34 +++++++++++++++---------------- 1 file changed, 17 insertions(+), 17 deletions(-) diff --git a/Documentation/trace/histogram.rst b/Documentation/trace/histogram.rst index af6d2e15568ebd..d158dadaa42447 100644 --- a/Documentation/trace/histogram.rst +++ b/Documentation/trace/histogram.rst @@ -186,8 +186,8 @@ Documentation written by Tom Zanussi The examples below provide a more concrete illustration of the concepts and typical usage patterns discussed above. -'special' event fields ------------------------- +2.1. '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 @@ -204,16 +204,16 @@ Documentation written by Tom Zanussi common_cpu int the cpu on which the event occurred. ====================== ==== ======================================= -Extended error information --------------------------- +2.2. Extended error information +------------------------------- For some error conditions encountered when invoking a hist trigger command, extended error information is available via the tracing/error_log file. See Error Conditions in :file:`Documentation/trace/ftrace.rst` for details. -6.2 'hist' trigger examples ---------------------------- +2.3. '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 @@ -1608,8 +1608,8 @@ Extended error information Entries: 7 Dropped: 0 -2.2 Inter-event hist triggers ------------------------------ +2.4. 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 @@ -1685,8 +1685,8 @@ pseudo-file. These features are described in more detail in the following sections. -2.2.1 Histogram Variables -------------------------- +2.5. Histogram Variables +------------------------ Variables are simply named locations used for saving and retrieving values between matching events. A 'matching' event is defined as an @@ -1789,8 +1789,8 @@ or assigned to a variable and referenced in a subsequent expression:: Variables can even hold stacktraces, which are useful with synthetic events. -2.2.2 Synthetic Events ----------------------- +2.6. Synthetic Events +--------------------- Synthetic events are user-defined events generated from hist trigger variables or fields associated with one or more other events. Their @@ -1846,7 +1846,7 @@ the command that defined it with a '!':: At this point, there isn't yet an actual 'wakeup_latency' event instantiated in the event subsystem - 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 2.2.3 below on +and variables defined on other events (see Section 2.7. below on how that is done using hist trigger 'onmatch' action). Once that is done, the 'wakeup_latency' synthetic event instance is created. @@ -2094,8 +2094,8 @@ histogram:: Entries: 7 Dropped: 0 -2.2.3 Hist trigger 'handlers' and 'actions' -------------------------------------------- +2.7. Hist trigger 'handlers' and 'actions' +------------------------------------------ A hist trigger 'action' is a function that's executed (in most cases conditionally) whenever a histogram entry is added or updated. @@ -2526,8 +2526,8 @@ The following commonly-used handler.action pairs are available: kworker/3:2-135 [003] d..3 49.823123: sched_switch: prev_comm=kworker/3:2 prev_pid=135 prev_prio=120 prev_state=T ==> next_comm=swapper/3 next_pid=0 next_prio=120 -0 [004] ..s7 49.823798: tcp_probe: src=10.0.0.10:54326 dest=23.215.104.193:80 mark=0x0 length=32 snd_nxt=0xe3ae2ff5 snd_una=0xe3ae2ecd snd_cwnd=10 ssthresh=2147483647 snd_wnd=28960 srtt=19604 rcv_wnd=29312 -3. User space creating a trigger --------------------------------- +2.8. User space creating a trigger +---------------------------------- Writing into /sys/kernel/tracing/trace_marker writes into the ftrace ring buffer. This can also act like an event, by writing into the trigger -- An old man doll... just what I always wanted! - Clara