Commit 364f374f authored by Al Viro's avatar Al Viro
Browse files

epoll: get rid of epitem->nwait 



we use it only to indicate allocation failures within queueing
callback back to ep_insert().  Might as well use epq.epi for that
reporting...

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 80285b75

fs/eventpoll.c

+20 −26
Original line number Diff line number Diff line
@@ -172,9 +172,6 @@ struct epitem { 
	/* The file descriptor information this item refers to */

	struct epoll_filefd ffd;



	/* Number of active wait queue attached to poll operations */

	int nwait;



	/* List containing poll wait queues */

	struct eppoll_entry *pwqlist;
@@ -351,12 +348,6 @@ static inline struct epitem *ep_item_from_wait(wait_queue_entry_t *p) 
	return container_of(p, struct eppoll_entry, wait)->base;

}



/* Get the "struct epitem" from an epoll queue wrapper */

static inline struct epitem *ep_item_from_epqueue(poll_table *p)

{

	return container_of(p, struct ep_pqueue, pt)->epi;

}



/* Initialize the poll safe wake up structure */

static void ep_nested_calls_init(struct nested_calls *ncalls)

{
@@ -1307,10 +1298,19 @@ static int ep_poll_callback(wait_queue_entry_t *wait, unsigned mode, int sync, v 
static void ep_ptable_queue_proc(struct file *file, wait_queue_head_t *whead,

				 poll_table *pt)

{

	struct epitem *epi = ep_item_from_epqueue(pt);

	struct ep_pqueue *epq = container_of(pt, struct ep_pqueue, pt);

	struct epitem *epi = epq->epi;

	struct eppoll_entry *pwq;



	if (epi->nwait >= 0 && (pwq = kmem_cache_alloc(pwq_cache, GFP_KERNEL))) {

	if (unlikely(!epi))	// an earlier allocation has failed

		return;



	pwq = kmem_cache_alloc(pwq_cache, GFP_KERNEL);

	if (unlikely(!pwq)) {

		epq->epi = NULL;

		return;

	}



	init_waitqueue_func_entry(&pwq->wait, ep_poll_callback);

	pwq->whead = whead;

	pwq->base = epi;
@@ -1320,11 +1320,6 @@ static void ep_ptable_queue_proc(struct file *file, wait_queue_head_t *whead, 
		add_wait_queue(whead, &pwq->wait);

	pwq->next = epi->pwqlist;

	epi->pwqlist = pwq;

		epi->nwait++;

	} else {

		/* We have to signal that an error occurred */

		epi->nwait = -1;

	}

}



static void ep_rbtree_insert(struct eventpoll *ep, struct epitem *epi)
@@ -1510,7 +1505,6 @@ static int ep_insert(struct eventpoll *ep, const struct epoll_event *event, 
	epi->ep = ep;

	ep_set_ffd(&epi->ffd, tfile, fd);

	epi->event = *event;

	epi->nwait = 0;

	epi->next = EP_UNACTIVE_PTR;

	if (epi->event.events & EPOLLWAKEUP) {

		error = ep_create_wakeup_source(epi);
@@ -1555,7 +1549,7 @@ static int ep_insert(struct eventpoll *ep, const struct epoll_event *event, 
	 * high memory pressure.

	 */

	error = -ENOMEM;

	if (epi->nwait < 0)

	if (!epq.epi)

		goto error_unregister;



	/* We have to drop the new item inside our item list to keep track of it */