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io_uring: don't save/restore iowait state

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[ Upstream commit 6f0974eccbf78baead1735722c4f1ee3eb9422cd ]

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: 7b72d661f1f2 ("io_uring: gate iowait schedule on having pending requests")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Jens Axboe 2024-03-11 13:30:43 -06:00 committed by Sasha Levin
parent 2584d6bbc2
commit e627c433c8
1 changed files with 2 additions and 3 deletions
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5
io_uring/io_uring.c
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@ -2501,7 +2501,7 @@ 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;
@ -2519,7 +2519,6 @@ 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;
@ -2527,7 +2526,7 @@ 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;
}