diff options
| author | Jiri Olsa <jolsa@kernel.org> | 2015-10-05 20:06:05 +0200 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2015-10-05 16:21:11 -0300 |
| commit | 7f94af7a489fada17d28cc60e8f4409ce216bd6d (patch) | |
| tree | b01ac1104e90dab6b9e8d657658d68dac4b873b7 /tools/perf/Documentation | |
| parent | 45cf6c33f95448752dd3d5531388429c3a5012d0 (diff) | |
perf tools: Introduce 'P' modifier to request max precision
The 'P' will cause the event to get maximum possible detected precise
level.
Following record:
$ perf record -e cycles:P ...
will detect maximum precise level for 'cycles' event and use it.
Commiter note:
Testing it:
$ perf record -e cycles:P usleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.013 MB perf.data (9 samples) ]
$ perf evlist
cycles:P
$ perf evlist -v
cycles:P: size: 112, { sample_period, sample_freq }: 4000, sample_type:
IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1,
enable_on_exec: 1, task: 1, precise_ip: 2, sample_id_all: 1, mmap2: 1,
comm_exec: 1
$
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1444068369-20978-6-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation')
| -rw-r--r-- | tools/perf/Documentation/perf-list.txt | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-list.txt b/tools/perf/Documentation/perf-list.txt index ad60c6ea1997..79483f40e991 100644 --- a/tools/perf/Documentation/perf-list.txt +++ b/tools/perf/Documentation/perf-list.txt @@ -30,6 +30,7 @@ counted. The following modifiers exist: G - guest counting (in KVM guests) H - host counting (not in KVM guests) p - precise level + P - use maximum detected precise level S - read sample value (PERF_SAMPLE_READ) D - pin the event to the PMU |