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authorMathieu Poirier <mathieu.poirier@linaro.org>2018-04-27 14:05:02 -0600
committerMathieu Poirier <mathieu.poirier@linaro.org>2019-04-03 04:17:30 -0600
commitbfab6de86f6604dfe1f1287957905b61e6220747 (patch)
tree9121eb5427d0a0866bf63d5b933a506eeca261d5
parent13772ff5826f99c824f02df0ec48c9bc77104900 (diff)
perf tools: 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: Mathieu Poirier <mathieu.poirier@linaro.org>
-rw-r--r--tools/perf/util/cs-etm.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index c58a6b87a376..b6fb389adcc3 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -1686,6 +1686,42 @@ 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,
@@ -1725,6 +1761,8 @@ 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;
}