Commit 3fcee5a6 authored Jul 06, 2020 by Pavel Begunkov Committed by Jens Axboe Jul 06, 2020

io_uring: briefly loose locks while reaping events



It's not nice to hold @uring_lock for too long io_iopoll_reap_events().
For instance, the lock is needed to publish requests to @poll_list, and
that locks out tasks doing that for no good reason. Loose it
occasionally.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent eba0a4dd

fs/io_uring.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -2069,8 +2069,13 @@ static void io_iopoll_reap_events(struct io_ring_ctx *ctx)
		/*
		* Ensure we allow local-to-the-cpu processing to take place,
		* in this case we need to ensure that we reap all events.
		* Also let task_work, etc. to progress by releasing the mutex
		*/
		if (need_resched()) {
		mutex_unlock(&ctx->uring_lock);
		cond_resched();
		mutex_lock(&ctx->uring_lock);
		}
		}
		mutex_unlock(&ctx->uring_lock);
		}