2 files changed, 16 insertions, 0 deletions
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 53332da100e8..6ad629db63b7 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -3686,6 +3686,20 @@ int perf_session__write_header(struct perf_session *session,
 	return perf_session__do_write_header(session, evlist, fd, at_exit, NULL);
 }
 
+size_t perf_session__data_offset(const struct evlist *evlist)
+{
+	struct evsel *evsel;
+	size_t data_offset;
+
+	data_offset = sizeof(struct perf_file_header);
+	evlist__for_each_entry(evlist, evsel) {
+		data_offset += evsel->core.ids * sizeof(u64);
+	}
+	data_offset += evlist->core.nr_entries * sizeof(struct perf_file_attr);
+
+	return data_offset;
+}
+
 int perf_session__inject_header(struct perf_session *session,
 				struct evlist *evlist,
 				int fd,
diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h
index 08563c1f1bff..56916dabce7b 100644
--- a/tools/perf/util/header.h
+++ b/tools/perf/util/header.h
@@ -136,6 +136,8 @@ int perf_session__inject_header(struct perf_session *session,
 				int fd,
 				struct feat_copier *fc);
 
+size_t perf_session__data_offset(const struct evlist *evlist);
+
 void perf_header__set_feat(struct perf_header *header, int feat);
 void perf_header__clear_feat(struct perf_header *header, int feat);
 bool perf_header__has_feat(const struct perf_header *header, int feat);