diff mbox series

[22/23] io_uring: don't wait on CQ exclusively

Message ID d2e5339476d3cd9c5b738196e8771868ac3c3208.1621424513.git.asml.silence@gmail.com (mailing list archive)
State Changes Requested
Delegated to: BPF
Headers show
Series io_uring BPF requests | expand

Checks

Context Check Description
netdev/tree_selection success Not a local patch

Commit Message

Pavel Begunkov May 19, 2021, 2:13 p.m. UTC 
It doesn't make much sense for several tasks to wait on a single CQ, it
would be racy and involve rather strange code flow with synchronisation,
so we don't really care optimising this case.

Don't do exclusive CQ waiting and wake up everyone in the queue, it will
be handy for implementing waiting non-default CQs.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 fs/io_uring.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/fs/io_uring.c b/fs/io_uring.c
index c4682146afa4..805c10be7ea4 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7085,7 +7085,7 @@  static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode,
 	 */
 	if (io_should_wake(iowq) || test_bit(0, &iowq->ctx->cq_check_overflow))
 		return autoremove_wake_function(curr, mode, wake_flags, key);
-	return -1;
+	return 0;
 }
 
 static int io_run_task_work_sig(void)
@@ -7176,8 +7176,7 @@  static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
 			ret = -EBUSY;
 			break;
 		}
-		prepare_to_wait_exclusive(&ctx->wait, &iowq.wq,
-						TASK_INTERRUPTIBLE);
+		prepare_to_wait(&ctx->wait, &iowq.wq, TASK_INTERRUPTIBLE);
 		ret = io_cqring_wait_schedule(ctx, &iowq, &timeout);
 		finish_wait(&ctx->wait, &iowq.wq);
 		cond_resched();