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Commit e0d170fa authored by Mathieu Poirier's avatar Mathieu Poirier Committed by Arnaldo Carvalho de Melo
Browse files

perf cs-etm: Add handling of switch-CPU-wide events 



Add handling of SWITCH-CPU-WIDE events in order to add the tid/pid of
the incoming process to the perf tools machine infrastructure.  This
information is later retrieved when a contextID packet is found in the
trace stream.

Signed-off-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Tested-by: default avatarLeo Yan <leo.yan@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20190524173508.29044-6-mathieu.poirier@linaro.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent a465f3c3

tools/perf/util/cs-etm.c

+38 −0
Original line number Diff line number Diff line
@@ -1680,6 +1680,42 @@ static int cs_etm__process_itrace_start(struct cs_etm_auxtrace *etm, 
	return 0;

}



static int cs_etm__process_switch_cpu_wide(struct cs_etm_auxtrace *etm,

					   union perf_event *event)

{

	struct thread *th;

	bool out = event->header.misc & PERF_RECORD_MISC_SWITCH_OUT;



	/*

	 * Context switch in per-thread mode are irrelevant since perf

	 * will start/stop tracing as the process is scheduled.

	 */

	if (etm->timeless_decoding)

		return 0;



	/*

	 * SWITCH_IN events carry the next process to be switched out while

	 * SWITCH_OUT events carry the process to be switched in.  As such

	 * we don't care about IN events.

	 */

	if (!out)

		return 0;



	/*

	 * Add the tid/pid to the log so that we can get a match when

	 * we get a contextID from the decoder.

	 */

	th = machine__findnew_thread(etm->machine,

				     event->context_switch.next_prev_pid,

				     event->context_switch.next_prev_tid);

	if (!th)

		return -ENOMEM;



	thread__put(th);



	return 0;

}



static int cs_etm__process_event(struct perf_session *session,

				 union perf_event *event,

				 struct perf_sample *sample,
@@ -1719,6 +1755,8 @@ static int cs_etm__process_event(struct perf_session *session, 


	if (event->header.type == PERF_RECORD_ITRACE_START)

		return cs_etm__process_itrace_start(etm, event);

	else if (event->header.type == PERF_RECORD_SWITCH_CPU_WIDE)

		return cs_etm__process_switch_cpu_wide(etm, event);



	return 0;

}