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| author | Mark Brown <broonie@kernel.org> | 2020-08-25 11:01:46 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2020-08-25 11:01:46 +0100 |
| commit | 3bec5b6aae830355e786e204b20a7cea38c3a8ed (patch) | |
| tree | fd597b87faf55ceb2a207ee94f4feca6276696db /tools/lib/perf/Documentation/libperf-sampling.txt | |
| parent | a577f3456c0a2fac3dee037c483753e6e68f3e49 (diff) | |
| parent | d012a7190fc1fd72ed48911e77ca97ba4521bccd (diff) | |
Merge tag 'v5.9-rc2' into regulator-5.9
Linux 5.9-rc2
Diffstat (limited to 'tools/lib/perf/Documentation/libperf-sampling.txt')
| -rw-r--r-- | tools/lib/perf/Documentation/libperf-sampling.txt | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/tools/lib/perf/Documentation/libperf-sampling.txt b/tools/lib/perf/Documentation/libperf-sampling.txt index d71a7b4fcf5f..d6ca24f6ef78 100644 --- a/tools/lib/perf/Documentation/libperf-sampling.txt +++ b/tools/lib/perf/Documentation/libperf-sampling.txt @@ -8,13 +8,13 @@ libperf-sampling - sampling interface DESCRIPTION ----------- -The sampling interface provides API to meassure and get count for specific perf events. +The sampling interface provides API to measure and get count for specific perf events. The following test tries to explain count on `sampling.c` example. It is by no means complete guide to sampling, but shows libperf basic API for sampling. -The `sampling.c` comes with libbperf package and can be compiled and run like: +The `sampling.c` comes with libperf package and can be compiled and run like: [source,bash] -- @@ -33,7 +33,8 @@ cpu 0, pid 4465, tid 4470, ip 7f84fe0ebebf, period 176 It requires root access, because it uses hardware cycles event. -The `sampling.c` example profiles/samples all CPUs with hardware cycles, in a nutshel it: +The `sampling.c` example profiles/samples all CPUs with hardware cycles, in a +nutshell it: - creates events - adds them to the event list @@ -90,7 +91,7 @@ Once the setup is complete we start by defining cycles event using the `struct p 36 }; -- -Next step is to prepare cpus map. +Next step is to prepare CPUs map. In this case we will monitor all the available CPUs: @@ -152,7 +153,7 @@ Once the events list is open, we can create memory maps AKA perf ring buffers: -- The event is created as disabled (note the `disabled = 1` assignment above), -so we need to enable the events list explicitely. +so we need to enable the events list explicitly. From this moment the cycles event is sampling. @@ -212,7 +213,7 @@ Each sample needs to get parsed: 106 cpu, pid, tid, ip, period); -- -And finaly cleanup. +And finally cleanup. We close the whole events list (both events) and remove it together with the threads map: |