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io_uring: move POLLFREE handling to separate function

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We really don't care about this at all in terms of performance. Outside
of having it already be marked unlikely(), shove it into a separate
__cold function.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2022-06-21 14:34:15 -06:00
parent 795bbbc8a9
commit fe991a7688
1 changed files with 27 additions and 23 deletions
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50
io_uring/poll.c
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@ -325,6 +325,31 @@ static void io_poll_cancel_req(struct io_kiocb *req)
#define IO_ASYNC_POLL_COMMON (EPOLLONESHOT | EPOLLPRI)
static __cold int io_pollfree_wake(struct io_kiocb *req, struct io_poll *poll)
{
io_poll_mark_cancelled(req);
/* we have to kick tw in case it's not already */
io_poll_execute(req, 0);
/*
* If the waitqueue is being freed early but someone is already
* holds ownership over it, we have to tear down the request as
* best we can. That means immediately removing the request from
* its waitqueue and preventing all further accesses to the
* waitqueue via the request.
*/
list_del_init(&poll->wait.entry);
/*
* Careful: this *must* be the last step, since as soon
* as req->head is NULL'ed out, the request can be
* completed and freed, since aio_poll_complete_work()
* will no longer need to take the waitqueue lock.
*/
smp_store_release(&poll->head, NULL);
return 1;
}
static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
void *key)
{
@ -332,29 +357,8 @@ static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
struct io_poll *poll = container_of(wait, struct io_poll, wait);
__poll_t mask = key_to_poll(key);
if (unlikely(mask & POLLFREE)) {
io_poll_mark_cancelled(req);
/* we have to kick tw in case it's not already */
io_poll_execute(req, 0);
/*
* If the waitqueue is being freed early but someone is already
* holds ownership over it, we have to tear down the request as
* best we can. That means immediately removing the request from
* its waitqueue and preventing all further accesses to the
* waitqueue via the request.
*/
list_del_init(&poll->wait.entry);
/*
* Careful: this *must* be the last step, since as soon
* as req->head is NULL'ed out, the request can be
* completed and freed, since aio_poll_complete_work()
* will no longer need to take the waitqueue lock.
*/
smp_store_release(&poll->head, NULL);
return 1;
}
if (unlikely(mask & POLLFREE))
return io_pollfree_wake(req, poll);
/* for instances that support it check for an event match first */
if (mask && !(mask & (poll->events & ~IO_ASYNC_POLL_COMMON)))