diff --git a/tools/perf/util/data.c b/tools/perf/util/data.c
index 5d0f26aef77f1..b71c441cafbb2 100644
--- a/tools/perf/util/data.c
+++ b/tools/perf/util/data.c
@@ -393,3 +393,20 @@ int perf_data__switch(struct perf_data *data,
 	free(new_filepath);
 	return ret;
 }
+
+unsigned long perf_data__size(struct perf_data *data)
+{
+	u64 size = data->file.size;
+	int i;
+
+	if (!data->is_dir)
+		return size;
+
+	for (i = 0; i < data->dir.nr; i++) {
+		struct perf_data_file *file = &data->dir.files[i];
+
+		size += file->size;
+	}
+
+	return size;
+}
diff --git a/tools/perf/util/data.h b/tools/perf/util/data.h
index 0deeb1af9f543..d342469bdfda0 100644
--- a/tools/perf/util/data.h
+++ b/tools/perf/util/data.h
@@ -54,11 +54,6 @@ static inline int perf_data__fd(struct perf_data *data)
 	return data->file.fd;
 }
 
-static inline unsigned long perf_data__size(struct perf_data *data)
-{
-	return data->file.size;
-}
-
 int perf_data__open(struct perf_data *data);
 void perf_data__close(struct perf_data *data);
 ssize_t perf_data__write(struct perf_data *data,
@@ -80,4 +75,5 @@ int perf_data__create_dir(struct perf_data *data, int nr);
 int perf_data__open_dir(struct perf_data *data);
 void perf_data__close_dir(struct perf_data *data);
 int perf_data__update_dir(struct perf_data *data);
+unsigned long perf_data__size(struct perf_data *data);
 #endif /* __PERF_DATA_H */