diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index eae6ff69360477c8fb0f610fe016a017bf9203a8..c4e90b8cd60d460c77795e61cfc48004b9bbe633 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -1049,8 +1049,8 @@ static int perf_event_refresh(struct perf_event *event, int refresh)
 	return 0;
 }
 
-void __perf_event_sched_out(struct perf_event_context *ctx,
-			      struct perf_cpu_context *cpuctx)
+static void __perf_event_sched_out(struct perf_event_context *ctx,
+				   struct perf_cpu_context *cpuctx)
 {
 	struct perf_event *event;