Commit 7d189cad authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo
Browse files

perf intel-pt: Track sideband system-wide when needed 



User space tasks can migrate between CPUs, so when tracing selected CPUs,
sideband for all CPUs is still needed. This is in preparation for allowing
system-wide events on all CPUs while the user requested events are on only
user requested CPUs.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Acked-by: default avatarIan Rogers <irogers@google.com>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Link: https://lore.kernel.org/r/20220524075436.29144-9-adrian.hunter@intel.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent e665c82a

tools/perf/arch/x86/util/intel-pt.c

+10 −8
Original line number Diff line number Diff line
@@ -864,20 +864,22 @@ static int intel_pt_recording_options(struct auxtrace_record *itr, 


	/* Add dummy event to keep tracking */

	if (opts->full_auxtrace) {

		bool need_system_wide_tracking;

		struct evsel *tracking_evsel;



		err = parse_events(evlist, "dummy:u", NULL);

		if (err)

			return err;

		/*

		 * User space tasks can migrate between CPUs, so when tracing

		 * selected CPUs, sideband for all CPUs is still needed.

		 */

		need_system_wide_tracking = evlist->core.has_user_cpus &&

					    !intel_pt_evsel->core.attr.exclude_user;



		tracking_evsel = evlist__last(evlist);

		tracking_evsel = evlist__add_aux_dummy(evlist, need_system_wide_tracking);

		if (!tracking_evsel)

			return -ENOMEM;



		evlist__set_tracking_event(evlist, tracking_evsel);



		tracking_evsel->core.attr.freq = 0;

		tracking_evsel->core.attr.sample_period = 1;



		tracking_evsel->no_aux_samples = true;

		if (need_immediate)

			tracking_evsel->immediate = true;