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: 7b72d661f1 ("io_uring: gate iowait schedule on having pending requests")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2024-03-11 13:30:43 -06:00
parent 045395d86a
commit 6f0974eccb

View File

@ -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;
}