perf evlist: Add perf_evlist__parse_sample_timestamp function

Add perf_evlist__parse_sample_timestamp to retrieve the timestamp of the
sample.

The idea is to use this function instead of the full sample parsing
before we queue the sample. At that time only the timestamp is needed
and we parse the sample once again later on delivery.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-o7syqo8lipj4or7renpu8e8y@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 59 insertions, 6 deletions

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 03d7abcdc6b7..95853c51c0ca 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1962,6 +1962,20 @@ static inline bool overflow(const void *endp, u16 max_size, const void *offset,
 #define OVERFLOW_CHECK_u64(offset) \
 	OVERFLOW_CHECK(offset, sizeof(u64), sizeof(u64))
 
+static int
+perf_event__check_size(union perf_event *event, unsigned int sample_size)
+{
+	/*
+	 * The evsel's sample_size is based on PERF_SAMPLE_MASK which includes
+	 * up to PERF_SAMPLE_PERIOD.  After that overflow() must be used to
+	 * check the format does not go past the end of the event.
+	 */
+	if (sample_size + sizeof(event->header) > event->header.size)
+		return -EFAULT;
+
+	return 0;
+}
+
 int perf_evsel__parse_sample(struct perf_evsel *evsel, union perf_event *event,
 			     struct perf_sample *data)
 {
@@ -1994,12 +2008,7 @@ int perf_evsel__parse_sample(struct perf_evsel *evsel, union perf_event *event,
 
 	array = event->sample.array;
 
-	/*
-	 * The evsel's sample_size is based on PERF_SAMPLE_MASK which includes
-	 * up to PERF_SAMPLE_PERIOD.  After that overflow() must be used to
-	 * check the format does not go past the end of the event.
-	 */
-	if (evsel->sample_size + sizeof(event->header) > event->header.size)
+	if (perf_event__check_size(event, evsel->sample_size))
 		return -EFAULT;
 
 	if (type & PERF_SAMPLE_IDENTIFIER) {
@@ -2232,6 +2241,50 @@ int perf_evsel__parse_sample(struct perf_evsel *evsel, union perf_event *event,
 	return 0;
 }
 
+int perf_evsel__parse_sample_timestamp(struct perf_evsel *evsel,
+				       union perf_event *event,
+				       u64 *timestamp)
+{
+	u64 type = evsel->attr.sample_type;
+	const u64 *array;
+
+	if (!(type & PERF_SAMPLE_TIME))
+		return -1;
+
+	if (event->header.type != PERF_RECORD_SAMPLE) {
+		struct perf_sample data = {
+			.time = -1ULL,
+		};
+
+		if (!evsel->attr.sample_id_all)
+			return -1;
+		if (perf_evsel__parse_id_sample(evsel, event, &data))
+			return -1;
+
+		*timestamp = data.time;
+		return 0;
+	}
+
+	array = event->sample.array;
+
+	if (perf_event__check_size(event, evsel->sample_size))
+		return -EFAULT;
+
+	if (type & PERF_SAMPLE_IDENTIFIER)
+		array++;
+
+	if (type & PERF_SAMPLE_IP)
+		array++;
+
+	if (type & PERF_SAMPLE_TID)
+		array++;
+
+	if (type & PERF_SAMPLE_TIME)
+		*timestamp = *array;
+
+	return 0;
+}
+
 size_t perf_event__sample_event_size(const struct perf_sample *sample, u64 type,
 				     u64 read_format)
 {