[tip:perf/core] perf stat record: Keep sample_type 0 for pipe session

[tip-bot for Jiri Olsa <tipbot@zytor.com>]

Commit-ID:  6db1a5c190d6abe416ea36aa28a6c53e0b3bbd5e
Gitweb:     http://git.kernel.org/tip/6db1a5c190d6abe416ea36aa28a6c53e0b3bbd5e
Author:     Jiri Olsa <jolsa@kernel.org>
AuthorDate: Tue, 5 Jan 2016 22:09:05 +0100
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Wed, 6 Jan 2016 20:11:14 -0300

perf stat record: Keep sample_type 0 for pipe session

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.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1452028152-26762-2-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 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 9805e03..7f56824 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