Commit aaa9f0f4 authored May 16, 2021 by Pavel Begunkov Committed by Jens Axboe Jun 14, 2021

io_uring: improve sq_thread waiting check

If SQPOLL task finds a ring requesting it to continue running, no need
to set wake flag to rest of the rings as it will be cleared in a moment
anyway, so hide it in a single sqd->ctx_list loop.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/1ee5a696d9fd08645994c58ee147d149a8957d94.1621201931.git.asml.silence@gmail.com

Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent e4b6d902

fs/io_uring.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -6894,11 +6894,10 @@ static int io_sq_thread(void *data)

		prepare_to_wait(&sqd->wait, &wait, TASK_INTERRUPTIBLE);
		if (!io_sqd_events_pending(sqd)) {
		list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
		io_ring_set_wakeup_flag(ctx);

		needs_sched = true;
		list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) {
		io_ring_set_wakeup_flag(ctx);

		if ((ctx->flags & IORING_SETUP_IOPOLL) &&
		!list_empty_careful(&ctx->iopoll_list)) {
		needs_sched = false;