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| author | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2019-08-06 17:41:01 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2019-08-14 10:59:59 -0300 |
| commit | ce7b0e426ef359ee1d4a6126314ee3547a8eed87 (patch) | |
| tree | 6d8433c74638b13e9a262e58c7c4e4456fa1058c /tools/perf/Documentation | |
| parent | 73e5de70dca00344cb48e018131a4cadec0fabf0 (diff) | |
| download | linux-ce7b0e426ef359ee1d4a6126314ee3547a8eed87.tar.gz | |
perf record: Add an option to take an AUX snapshot on exit
It is sometimes useful to generate a snapshot when perf record exits; I've been using a wrapper script around the workload that would do a killall -USR2 perf when the workload exits. This patch makes it easier and also works when perf record is attached to a pre-existing task. A new snapshot option 'e' can be specified in -S to enable this behavior: root@elsewhere:~# perf record -e intel_pt// -Se sleep 1 [ perf record: Woken up 2 times to write data ] [ perf record: Captured and wrote 0.085 MB perf.data ] Co-developed-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20190806144101.62892-1-alexander.shishkin@linux.intel.com [ Fixed up !HAVE_AUXTRACE_SUPPORT build in builtin-record.c, adding 2 missing __maybe_unused ] 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 | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 15e0fa87241b..d5e58e0a2bca 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -422,9 +422,14 @@ CLOCK_BOOTTIME, CLOCK_REALTIME and CLOCK_TAI. -S:: --snapshot:: Select AUX area tracing Snapshot Mode. This option is valid only with an -AUX area tracing event. Optionally the number of bytes to capture per -snapshot can be specified. In Snapshot Mode, trace data is captured only when -signal SIGUSR2 is received. +AUX area tracing event. Optionally, certain snapshot capturing parameters +can be specified in a string that follows this option: + 'e': take one last snapshot on exit; guarantees that there is at least one + snapshot in the output file; + <size>: if the PMU supports this, specify the desired snapshot size. + +In Snapshot Mode trace data is captured only when signal SIGUSR2 is received +and on exit if the above 'e' option is given. --proc-map-timeout:: When processing pre-existing threads /proc/XXX/mmap, it may take a long time, |