2 files changed, 9 insertions, 0 deletions

diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 1757b0ffeaa9..2477270c1d3f 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -713,6 +713,7 @@ int event__parse_sample(event_t *event, u64 type, struct sample_data *data)
                 array++;
         }
 
+        data->id = -1ULL;
         if (type & PERF_SAMPLE_ID) {
                 data->id = *array;
                 array++;
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 2b9f898efea6..8847bec64c54 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -922,6 +922,14 @@ perf_header__find_attr(u64 id, struct perf_header *header)
 {
         int i;
 
+        /*
+         * We set id to -1 if the data file doesn't contain sample
+         * ids. Check for this and avoid walking through the entire
+         * list of ids which may be large.
+         */
+        if (id == -1ULL)
+                return NULL;
+
         for (i = 0; i < header->attrs; i++) {
                 struct perf_header_attr *attr = header->attr[i];
                 int j;