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| author | Jiri Olsa <jolsa@kernel.org> | 2017-01-09 10:51:58 +0100 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2017-01-11 16:48:02 -0300 |
| commit | dc0c6127c231d4d264570497a916fa19740c915b (patch) | |
| tree | 9638b3798e736fd79aed45f45876a3f5c67e2677 /tools/perf/Documentation | |
| parent | cb4e1ebb6a398ff5b0067034b0d16566af4d78e8 (diff) | |
| download | op-kernel-dev-dc0c6127c231d4d264570497a916fa19740c915b.zip op-kernel-dev-dc0c6127c231d4d264570497a916fa19740c915b.tar.gz | |
perf record: Add switch-output size option argument
It's now possible to specify the threshold size for perf.data like:
$ perf record --switch-output=2G ...
Once it's reached, the current data are dumped in to the
perf.data.<timestamp> file and session does on.
$ perf record --switch-output=2G ...
[ perf record: dump data: Woken up 7244 times ]
[ perf record: Dump perf.data.2017010214093746 ]
...
The size is expected to be a number with appended unit character -
B/K/M/G.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1483955520-29063-5-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-record.txt | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 5054d91..3d55d2f 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -421,9 +421,17 @@ Configure all used events to run in user space. --timestamp-filename Append timestamp to output file name. ---switch-output:: +--switch-output[=mode]:: Generate multiple perf.data files, timestamp prefixed, switching to a new one -when receiving a SIGUSR2. +based on 'mode' value: + "signal" - when receiving a SIGUSR2 (default value) or + <size> - when reaching the size threshold, size is expected to + be a number with appended unit character - B/K/M/G + + Note: the precision of the size threshold hugely depends + on your configuration - the number and size of your ring + buffers (-m). It is generally more precise for higher sizes + (like >5M), for lower values expect different sizes. A possible use case is to, given an external event, slice the perf.data file that gets then processed, possibly via a perf script, to decide if that |
