Commit eba0a4dd authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: fix stopping iopoll'ing too early 



Nobody adjusts *nr_events (number of completed requests) before calling
io_iopoll_getevents(), so the passed @min shouldn't be adjusted as well.
Othewise it can return less than initially asked @min without hitting
need_resched().

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 3aadc23e

fs/io_uring.c

+2 −7
Original line number Diff line number Diff line
@@ -2044,7 +2044,7 @@ static int io_iopoll_getevents(struct io_ring_ctx *ctx, unsigned int *nr_events, 
		ret = io_do_iopoll(ctx, nr_events, min);

		if (ret < 0)

			return ret;

		if (!min || *nr_events >= min)

		if (*nr_events >= min)

			return 0;

	}
@@ -2087,8 +2087,6 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events, 
	 */

	mutex_lock(&ctx->uring_lock);

	do {

		int tmin = 0;



		/*

		 * Don't enter poll loop if we already have events pending.

		 * If we do, we can potentially be spinning for commands that
@@ -2113,10 +2111,7 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events, 
			mutex_lock(&ctx->uring_lock);

		}



		if (*nr_events < min)

			tmin = min - *nr_events;



		ret = io_iopoll_getevents(ctx, nr_events, tmin);

		ret = io_iopoll_getevents(ctx, nr_events, min);

		if (ret <= 0)

			break;

		ret = 0;