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perf evsel: Dummy events never triggers, no need to ask for PERF_SAMPLE_BRANCH_STACK

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A dummy event never triggers any actual counter and therefore cannot be
used with branch_stack

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200422173615.59436-1-irogers@google.com
[ split from a larger patch ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Ian Rogers 2020-05-08 14:08:03 -03:00 committed by Arnaldo Carvalho de Melo
parent 8510895baf
commit 5885a202d0
1 changed files with 4 additions and 1 deletions
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5
tools/perf/util/evsel.c
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@ -1153,11 +1153,14 @@ void evsel__config(struct evsel *evsel, struct record_opts *opts,
}
/*
* A dummy event never triggers any actual counter and therefore
* cannot be used with branch_stack.
*
* For initial_delay, a dummy event is added implicitly.
* The software event will trigger -EOPNOTSUPP error out,
* if BRANCH_STACK bit is set.
*/
if (opts->initial_delay && is_dummy_event(evsel))
if (is_dummy_event(evsel))
evsel__reset_sample_bit(evsel, BRANCH_STACK);
}