perf thread: Allow deletion of a thread with no map groups

It needs to be possible to call thread__delete() on a thread with no map
groups.

This is needed for a subsequent patch which deletes a thread on the
error path before map groups have been attached.

Cc: David Ahern <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Adrian Hunter <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 4 insertions, 2 deletions

diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
index 7a32f447a8e7..b9c36ef42d2f 100644
--- a/tools/perf/util/thread.c
+++ b/tools/perf/util/thread.c
@@ -60,8 +60,10 @@ void thread__delete(struct thread *thread)
 {
 	struct comm *comm, *tmp;
 
-	map_groups__put(thread->mg);
-	thread->mg = NULL;
+	if (thread->mg) {
+		map_groups__put(thread->mg);
+		thread->mg = NULL;
+	}
 	list_for_each_entry_safe(comm, tmp, &thread->comm_list, list) {
 		list_del(&comm->list);
 		comm__free(comm);