[PATCH 24/56] perf tools: Introduce stat feature

[Jiri Olsa <jolsa@kernel.org>]

Introducing stat feature to mark perf.data as created by
perf stat record command. It contains no data.

It's needed for report tools (report/script) to differentiate
sampling data from stat data, because they need to be treated
in a different way.

In future it might be used to store version of the stat
storage system we used.

Link: http://lkml.kernel.org/n/tip-56xpt7m6au4d8u39nffoqgx1@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/builtin-record.c |  2 ++
 tools/perf/util/header.c    | 14 ++++++++++++++
 tools/perf/util/header.h    |  1 +
 3 files changed, 17 insertions(+)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 24ace2f318c1..99b690b51bff 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -451,6 +451,8 @@ static void record__init_features(struct record *rec)
 
 	if (!rec->opts.full_auxtrace)
 		perf_header__clear_feat(&session->header, HEADER_AUXTRACE);
+
+	perf_header__clear_feat(&session->header, HEADER_STAT);
 }
 
 static volatile int workload_exec_errno;
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index f35e8355cb1f..09baecf79036 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -868,6 +868,13 @@ static int write_auxtrace(int fd, struct perf_header *h,
 	return err;
 }
 
+static int write_stat(int fd __maybe_unused,
+		      struct perf_header *h __maybe_unused,
+		      struct perf_evlist *evlist __maybe_unused)
+{
+	return 0;
+}
+
 static void print_hostname(struct perf_header *ph, int fd __maybe_unused,
 			   FILE *fp)
 {
@@ -1159,6 +1166,12 @@ static void print_auxtrace(struct perf_header *ph __maybe_unused,
 	fprintf(fp, "# contains AUX area data (e.g. instruction trace)\n");
 }
 
+static void print_stat(struct perf_header *ph __maybe_unused,
+		       int fd __maybe_unused, FILE *fp)
+{
+	fprintf(fp, "# contains stat data\n");
+}
+
 static void print_pmu_mappings(struct perf_header *ph, int fd __maybe_unused,
 			       FILE *fp)
 {
@@ -1948,6 +1961,7 @@ static const struct feature_ops feat_ops[HEADER_LAST_FEATURE] = {
 	FEAT_OPP(HEADER_PMU_MAPPINGS,	pmu_mappings),
 	FEAT_OPP(HEADER_GROUP_DESC,	group_desc),
 	FEAT_OPP(HEADER_AUXTRACE,	auxtrace),
+	FEAT_OPA(HEADER_STAT,		stat),
 };
 
 struct header_print_data {
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index d39fd61db4c0..51b8f6c2ee6f 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -31,6 +31,7 @@ enum {
 	HEADER_PMU_MAPPINGS,
 	HEADER_GROUP_DESC,
 	HEADER_AUXTRACE,
+	HEADER_STAT,
 	HEADER_LAST_FEATURE,
 	HEADER_FEAT_BITS	= 256,
 };
-- 
2.4.3