Messages in this thread | | | Date | Fri, 14 Jul 2023 15:44:40 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 1/1] perf test task_exit: No need for a cycles event to check if we get an PERF_RECORD_EXIT |
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Forgot to CC lkml :-\
Em Fri, Jul 14, 2023 at 03:39:22PM -0300, Arnaldo Carvalho de Melo escreveu: > The intent of this test is to check we get a PERF_RECORD_EXIT as asked > for by setting perf_event_attr.task=1. > > When the test was written we didn't have the "dummy" event so we went > with the default event, "cycles". > > There were reports of this test failing sometimes, one of these reports > was with a PREEMPT_RT_FULL kernel, but I noticed it failing sometimes > on an aarch64 Firefly board. > > In the kernel the call to perf_event_task_output(), that generates the > PERF_RECORD_EXIT may fail when there is not enough memory in the ring > buffer, if the ring buffer is paused, etc. > > So switch to using the "dummy" event to use the ring buffer just for > what the test was designed for, avoiding uneeded PERF_RECORD_SAMPLEs. > > Cc: Adrian Hunter <adrian.hunter@intel.com> > Cc: Ian Rogers <irogers@google.com> > Cc: Jiri Olsa <jolsa@kernel.org> > Cc: Juri Lelli <juri.lelli@redhat.com> > Cc: Namhyung Kim <namhyung@kernel.org> > Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> > --- > tools/perf/tests/task-exit.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/tools/perf/tests/task-exit.c b/tools/perf/tests/task-exit.c > index 25f075fa9125bd53..968dddde6ddaf0be 100644 > --- a/tools/perf/tests/task-exit.c > +++ b/tools/perf/tests/task-exit.c > @@ -58,9 +58,9 @@ static int test__task_exit(struct test_suite *test __maybe_unused, int subtest _ > > signal(SIGCHLD, sig_handler); > > - evlist = evlist__new_default(); > + evlist = evlist__new_dummy(); > if (evlist == NULL) { > - pr_debug("evlist__new_default\n"); > + pr_debug("evlist__new_dummy\n"); > return -1; > } > > -- > 2.37.1 >
--
- Arnaldo
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