static void ep_unregister_pollwait(struct eventpoll *ep, struct epitem *epi)
{
	struct list_head *lsthead = &epi->pwqlist;
	struct eppoll_entry *pwq;

	while (!list_empty(lsthead)) {
		pwq = list_first_entry(lsthead, struct eppoll_entry, llink);

		list_del(&pwq->llink);
		ep_remove_wait_queue(pwq);
		kmem_cache_free(pwq_cache, pwq);
	}
}