aboutsummaryrefslogtreecommitdiff
path: root/Documentation/trace
diff options
context:
space:
mode:
authorLinus Torvalds2019-05-10 13:24:53 -0400
committerLinus Torvalds2019-05-10 13:24:53 -0400
commit1fb3b526df3bd7647e7854915ae6b22299408baf (patch)
treeb1fd6c9eaad0b1aff2b1df28ef1d5efcd6d7532a /Documentation/trace
parente290e6af1d22c3f5225c9d46faabdde80e27aef2 (diff)
parentafbd4d42470e91470bc59040094b89cd717530bd (diff)
Merge tag 'docs-5.2a' of git://git.lwn.net/linux
Pull more documentation updates from Jonathan Corbet: "Some late arriving documentation changes. In particular, this contains the conversion of the x86 docs to RST, which has been in the works for some time but needed a couple of final tweaks" * tag 'docs-5.2a' of git://git.lwn.net/linux: (29 commits) Documentation: x86: convert x86_64/machinecheck to reST Documentation: x86: convert x86_64/cpu-hotplug-spec to reST Documentation: x86: convert x86_64/fake-numa-for-cpusets to reST Documentation: x86: convert x86_64/5level-paging.txt to reST Documentation: x86: convert x86_64/mm.txt to reST Documentation: x86: convert x86_64/uefi.txt to reST Documentation: x86: convert x86_64/boot-options.txt to reST Documentation: x86: convert i386/IO-APIC.txt to reST Documentation: x86: convert usb-legacy-support.txt to reST Documentation: x86: convert orc-unwinder.txt to reST Documentation: x86: convert resctrl_ui.txt to reST Documentation: x86: convert microcode.txt to reST Documentation: x86: convert pti.txt to reST Documentation: x86: convert amd-memory-encryption.txt to reST Documentation: x86: convert intel_mpx.txt to reST Documentation: x86: convert protection-keys.txt to reST Documentation: x86: convert pat.txt to reST Documentation: x86: convert mtrr.txt to reST Documentation: x86: convert tlb.txt to reST Documentation: x86: convert zero-page.txt to reST ...
Diffstat (limited to 'Documentation/trace')
-rw-r--r--Documentation/trace/histogram.rst11
1 files changed, 7 insertions, 4 deletions
diff --git a/Documentation/trace/histogram.rst b/Documentation/trace/histogram.rst
index f95d94d19c22..ddbaffa530f9 100644
--- a/Documentation/trace/histogram.rst
+++ b/Documentation/trace/histogram.rst
@@ -1915,7 +1915,10 @@ The following commonly-used handler.action pairs are available:
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'.
+ onmatch() functionality, in the form 'system.event_name'. Histogram
+ keys of both events are compared to find if events match. In case
+ multiple histogram keys are used, they all must match in the specified
+ order.
Finally, the number and type of variables/fields in the 'param
list' must match the number and types of the fields in the
@@ -1978,9 +1981,9 @@ The following commonly-used handler.action pairs are available:
/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::
+ CPU by a sched_switch event (saved_pid matches next_pid), 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,\