diff --git a/net/core/netclassid_cgroup.c b/net/core/netclassid_cgroup.c
index d6a70aeaa503..d22f0919821e 100644
--- a/net/core/netclassid_cgroup.c
+++ b/net/core/netclassid_cgroup.c
@@ -88,6 +88,12 @@ static void update_classid_task(struct task_struct *p, u32 classid)
 	};
 	unsigned int fd = 0;
 
+	/* Only update the leader task, when many threads in this task,
+	 * so it can avoid the useless traversal.
+	 */
+	if (p != p->group_leader)
+		return;
+
 	do {
 		task_lock(p);
 		fd = iterate_fd(p->files, fd, update_classid_sock, &ctx);