[PATCH 1/8] perf stat record: Keep sample_type 0 for pipe session

From: Jiri Olsa
Date: Tue Jan 05 2016 - 16:11:38 EST


For pipe sessions we need to keep sample_type zero,
because script's perf_evsel__check_attr is triggered
by sample_type != 0, and the check would fail on
stat session.

I was tempted to keep it zero unconditionally, but the
pipe session is sufficient. In perf.data session we
are guarded by HEADER_STAT feature.

Link: http://lkml.kernel.org/n/tip-77k0kpd1c9beill47ceo8fp3@xxxxxxxxxxxxxx
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
tools/perf/builtin-stat.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 9805e03ab163..7f568244662b 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -184,11 +184,18 @@ static int create_perf_stat_counter(struct perf_evsel *evsel)
* like tracepoints. Clear it up for counting.
*/
attr->sample_period = 0;
+
/*
* But set sample_type to PERF_SAMPLE_IDENTIFIER, which should be harmless
* while avoiding that older tools show confusing messages.
+ *
+ * However for pipe sessions we need to keep it zero,
+ * because script's perf_evsel__check_attr is triggered
+ * by attr->sample_type != 0, and we can't run it on
+ * stat sessions.
*/
- attr->sample_type = PERF_SAMPLE_IDENTIFIER;
+ if (!(STAT_RECORD && perf_stat.file.is_pipe))
+ attr->sample_type = PERF_SAMPLE_IDENTIFIER;

/*
* Disabling all counters initially, they will be enabled
--
2.4.3

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