Commit 6f0974ec authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: don't save/restore iowait state 



This kind of state is per-syscall, and since we're doing the waiting off
entering the io_uring_enter(2) syscall, there's no way that iowait can
already be set for this case. Simplify it by setting it if we need to,
and always clearing it to 0 when done.

Fixes: 7b72d661 ("io_uring: gate iowait schedule on having pending requests")
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 045395d8

io_uring/io_uring.c

+2 −3
Original line number Diff line number Diff line
@@ -2539,7 +2539,7 @@ static bool current_pending_io(void) 
static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx,

					  struct io_wait_queue *iowq)

{

	int io_wait, ret;

	int ret;



	if (unlikely(READ_ONCE(ctx->check_cq)))

		return 1;
@@ -2557,7 +2557,6 @@ static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx, 
	 * can take into account that the task is waiting for IO - turns out

	 * to be important for low QD IO.

	 */

	io_wait = current->in_iowait;

	if (current_pending_io())

		current->in_iowait = 1;

	ret = 0;
@@ -2565,7 +2564,7 @@ static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx, 
		schedule();

	else if (!schedule_hrtimeout(&iowq->timeout, HRTIMER_MODE_ABS))

		ret = -ETIME;

	current->in_iowait = io_wait;

	current->in_iowait = 0;

	return ret;

}