[tip:perf/core] perf session: Don't report zero period samples for slave events

[tip-bot for Jiri Olsa]

Commit-ID:  529c1a9e18c3b470d2eff7879923eda40b1431db
Gitweb:     https://git.kernel.org/tip/529c1a9e18c3b470d2eff7879923eda40b1431db
Author:     Jiri Olsa <jolsa@xxxxxxxxxx>
AuthorDate: Wed, 20 Feb 2019 13:27:55 +0100
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 20 Feb 2019 16:07:51 -0300

perf session: Don't report zero period samples for slave events

There's no reason to deliver a sample with zero period.  It means there
was no value for slave event since its last group leader sample.

Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20190220122800.864-2-jolsa@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/session.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 18fb9c8cbf9c..c764bbc91009 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1202,6 +1202,13 @@ static int deliver_sample_value(struct perf_evlist *evlist,
 		return 0;
 	}
 
+	/*
+	 * There's no reason to deliver sample
+	 * for zero period, bail out.
+	 */
+	if (!sample->period)
+		return 0;
+
 	return tool->sample(tool, event, sample, sid->evsel, machine);
 }