Commit 9c655058 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'io_uring-6.5-2023-07-28' of git://git.kernel.dk/linux 

Pull io_uring fix from Jens Axboe:
 "Just a single tweak to a patch from last week, to avoid having idle
  cqring waits be attributed as iowait"

* tag 'io_uring-6.5-2023-07-28' of git://git.kernel.dk/linux:
  io_uring: gate iowait schedule on having pending requests
parents 0299a13a 7b72d661

io_uring/io_uring.c

+17 −6
Original line number Diff line number Diff line
@@ -2493,11 +2493,20 @@ int io_run_task_work_sig(struct io_ring_ctx *ctx) 
	return 0;

}



static bool current_pending_io(void)

{

	struct io_uring_task *tctx = current->io_uring;



	if (!tctx)

		return false;

	return percpu_counter_read_positive(&tctx->inflight);

}



/* when returns >0, the caller should retry */

static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx,

					  struct io_wait_queue *iowq)

{

	int token, ret;

	int io_wait, ret;



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

		return 1;
@@ -2511,17 +2520,19 @@ static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx, 
		return 0;



	/*

	 * Use io_schedule_prepare/finish, so cpufreq can take into account

	 * that the task is waiting for IO - turns out to be important for low

	 * QD IO.

	 * Mark us as being in io_wait if we have pending requests, so cpufreq

	 * can take into account that the task is waiting for IO - turns out

	 * to be important for low QD IO.

	 */

	token = io_schedule_prepare();

	io_wait = current->in_iowait;

	if (current_pending_io())

		current->in_iowait = 1;

	ret = 0;

	if (iowq->timeout == KTIME_MAX)

		schedule();

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

		ret = -ETIME;

	io_schedule_finish(token);

	current->in_iowait = io_wait;

	return ret;

}