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author | Takashi Iwai <tiwai@suse.de> | 2020-09-09 18:26:07 +0200 |
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committer | Takashi Iwai <tiwai@suse.de> | 2020-09-09 18:26:48 +0200 |
commit | 9ddb236f13594b34a12dacf69a5adca7a1aef35e (patch) | |
tree | 1dc1f6e54962a2e3ad3d56c894522cb4b1ddce93 /tools/lib/perf/Documentation/libperf-sampling.txt | |
parent | ALSA: vx: vx_pcm: remove redundant assignment (diff) | |
parent | ALSA: hda/realtek - The Mic on a RedmiBook doesn't work (diff) | |
download | linux-dev-9ddb236f13594b34a12dacf69a5adca7a1aef35e.tar.xz linux-dev-9ddb236f13594b34a12dacf69a5adca7a1aef35e.zip |
Merge branch 'for-linus' into for-next
Back-merge to apply the tasklet conversion patches that are based
on the already applied tasklet API changes on 5.9-rc4.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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: |