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: Mathieu Poirier mathieu.poirier@linaro.org --- tools/perf/util/cs-etm.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+)
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index 38034964da56..632237b54b81 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -1207,6 +1207,42 @@ 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, @@ -1247,6 +1283,8 @@ 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; }