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authorAdrian Hunter <adrian.hunter@intel.com>2020-09-01 12:37:57 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2020-09-04 14:38:15 -0300
commitd20aff1512f013fab79b8740427b7574569a9a2e (patch)
tree43c5261c26024130049b82902d24a0972baca09d /tools/perf/Documentation
parenta8fcbd269b4340c36dbf99b4453bcbfe128d93fb (diff)
perf record: Add 'snapshot' control command
Add 'snapshot' control command to create an AUX area tracing snapshot the same as if sending SIGUSR2. The advantage of the FIFO is that access is governed by access to the FIFO. Example: $ mkfifo perf.control $ mkfifo perf.ack $ cat perf.ack & [1] 15235 $ sudo ~/bin/perf record --control fifo:perf.control,perf.ack -S -e intel_pt//u -- sleep 60 & [2] 15243 $ ps -e | grep perf 15244 pts/1 00:00:00 perf $ kill -USR2 15244 bash: kill: (15244) - Operation not permitted $ echo snapshot > perf.control ack $ Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Alexey Budankov <alexey.budankov@linux.intel.com> Acked-by: Jiri Olsa <jolsa@redhat.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lore.kernel.org/lkml/20200901093758.32293-6-adrian.hunter@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.txt8
1 files changed, 4 insertions, 4 deletions
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index c1f44633abed..768888b9326a 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -635,10 +635,10 @@ endif::HAVE_LIBPFM[]
--control=fd:ctl-fd[,ack-fd]::
ctl-fifo / ack-fifo are opened and used as ctl-fd / ack-fd as follows.
Listen on ctl-fd descriptor for command to control measurement ('enable': enable events,
-'disable': disable events). Measurements can be started with events disabled using
---delay=-1 option. Optionally send control command completion ('ack\n') to ack-fd descriptor
-to synchronize with the controlling process. Example of bash shell script to enable and
-disable events during measurements:
+'disable': disable events, 'snapshot': AUX area tracing snapshot). Measurements can be
+started with events disabled using --delay=-1 option. Optionally send control command
+completion ('ack\n') to ack-fd descriptor to synchronize with the controlling process.
+Example of bash shell script to enable and disable events during measurements:
#!/bin/bash