Commit 23a65db8 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: improve same wq polling 



Move earlier the check for whether __io_queue_proc() tries to poll
already polled waitqueue, and do the same for the second poll entry, if
any. Shouldn't really matter, but at least it would have a more
predictable behaviour.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/8cb428cfe8ade0fd055859fabb878db8777d4c2f.1629228203.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 505657bc

fs/io_uring.c

+5 −3
Original line number Diff line number Diff line
@@ -5062,8 +5062,13 @@ static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt, 
	if (unlikely(pt->nr_entries)) {

		struct io_poll_iocb *poll_one = poll;



		/* double add on the same waitqueue head, ignore */

		if (poll_one->head == head)

			return;

		/* already have a 2nd entry, fail a third attempt */

		if (*poll_ptr) {

			if ((*poll_ptr)->head == head)

				return;

			pt->error = -EINVAL;

			return;

		}
@@ -5073,9 +5078,6 @@ static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt, 
		 */

		if (!(poll_one->events & EPOLLONESHOT))

			poll_one->events |= EPOLLONESHOT;

		/* double add on the same waitqueue head, ignore */

		if (poll_one->head == head)

			return;

		poll = kmalloc(sizeof(*poll), GFP_ATOMIC);

		if (!poll) {

			pt->error = -ENOMEM;