From 5885a202d04482427bc4079981680b30e3e5bbab Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Fri, 8 May 2020 14:08:03 -0300 Subject: [PATCH] perf evsel: Dummy events never triggers, no need to ask for PERF_SAMPLE_BRANCH_STACK A dummy event never triggers any actual counter and therefore cannot be used with branch_stack Signed-off-by: Ian Rogers Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200422173615.59436-1-irogers@google.com [ split from a larger patch ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/evsel.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 28683b0eb738..a2397ca4d57a 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -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); }