diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 928cd74..5ad4440 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -492,6 +492,8 @@
 	 * overflow on 32 bits):
 	 */
 	delta_exec = (unsigned long)(now - curr->exec_start);
+	if (!delta_exec)
+		return;
 
 	__update_curr(cfs_rq, curr, delta_exec);
 	curr->exec_start = now;