Commit-ID: 95035c5e167ae6e740b1ddd30210ae0eaf39a5db Gitweb: https://git.kernel.org/tip/95035c5e167ae6e740b1ddd30210ae0eaf39a5db Author: Kan Liang <kan.li...@linux.intel.com> AuthorDate: Mon, 9 Jul 2018 07:15:22 -0700 Committer: Arnaldo Carvalho de Melo <a...@redhat.com> CommitDate: Tue, 31 Jul 2018 09:56:46 -0300
perf evlist: Fix error out while applying initial delay and LBR 'perf record' will error out if both --delay and LBR are applied. For example: # perf record -D 1000 -a -e cycles -j any -- sleep 2 Error: dummy:HG: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat' # A dummy event is added implicitly for initial delay, which has the same configurations as real sampling events. The dummy event is a software event. If LBR is configured, perf must error out. The dummy event will only be used to track PERF_RECORD_MMAP while perf waits for the initial delay to enable the real events. The BRANCH_STACK bit can be safely cleared for the dummy event. After applying the patch: # perf record -D 1000 -a -e cycles -j any -- sleep 2 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 1.054 MB perf.data (828 samples) ] # Reported-by: Sunil K Pandey <sunil.k.pan...@intel.com> Signed-off-by: Kan Liang <kan.li...@linux.intel.com> Acked-by: Jiri Olsa <jo...@kernel.org> Tested-by: Arnaldo Carvalho de Melo <a...@redhat.com> Cc: Andi Kleen <a...@linux.intel.com> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Peter Zijlstra <pet...@infradead.org> Link: http://lkml.kernel.org/r/1531145722-16404-1-git-send-email-kan.li...@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/util/evsel.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 5285da0417c5..ddf84b941abf 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -859,6 +859,12 @@ static void apply_config_terms(struct perf_evsel *evsel, } } +static bool is_dummy_event(struct perf_evsel *evsel) +{ + return (evsel->attr.type == PERF_TYPE_SOFTWARE) && + (evsel->attr.config == PERF_COUNT_SW_DUMMY); +} + /* * The enable_on_exec/disabled value strategy: * @@ -1097,6 +1103,14 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts, else perf_evsel__reset_sample_bit(evsel, PERIOD); } + + /* + * 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)) + perf_evsel__reset_sample_bit(evsel, BRANCH_STACK); } static int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
