static int ep_loop_check(struct eventpoll *ep, struct file *file)
{
	int ret;
	struct eventpoll *ep_cur, *ep_next;

	ret = ep_call_nested(&poll_loop_ncalls,
			      ep_loop_check_proc, file, ep, current);
	/* clear visited list */
	list_for_each_entry_safe(ep_cur, ep_next, &visited_list,
							visited_list_link) {
		ep_cur->visited = 0;
		list_del(&ep_cur->visited_list_link);
	}
	return ret;
}