diff options
| author | Kan Liang <kan.liang@intel.com> | 2015-08-04 10:30:19 +0200 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2015-08-05 17:50:52 +0200 |
| commit | 320677123905fd1dd122895cd5fb870ee9e1380b (patch) | |
| tree | 82b523328ec900684341656326ec6bf0a1e5e382 /tools/perf/Documentation | |
| parent | perf trace: Use vfs_getname syscall arg beautifier in more syscalls (diff) | |
| download | linux-320677123905fd1dd122895cd5fb870ee9e1380b.tar.xz linux-320677123905fd1dd122895cd5fb870ee9e1380b.zip | |
perf tools: Per-event time support
This patchkit adds the ability to turn off time stamps per event.
One usaful case for partial time is to work with per-event callgraph to
enable "PEBS threshold > 1" (https://lkml.org/lkml/2015/5/10/196), which
can significantly reduce the sampling overhead.
The event samples with time stamps off will not be ordered.
Signed-off-by: Kan Liang <kan.liang@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1438677022-34296-2-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation')
| -rw-r--r-- | tools/perf/Documentation/perf-record.txt | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index ac41350ca485..0d852d1bc90f 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -49,7 +49,9 @@ OPTIONS These params can be used to overload default config values per event. Here is a list of the params. - 'period': Set event sampling period - + - 'time': Disable/enable time stamping. Acceptable values are 1 for + enabling time stamping. 0 for disabling time stamping. + The default is 1. Note: If user explicitly sets options which conflict with the params, the value set by the params will be overridden. |