io_uring: use cond_resched() in sqthread

If preempt isn't enabled in the kernel, we can run into hang issues with
sqthread submissions. Use cond_resched() to play nice instead of
cpu_relax(), if we end up starting the loop and not having any events
pending for submissions.

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

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 854dedd..05a299e 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2438,7 +2438,7 @@ static int io_sq_thread(void *data)
                         * to sleep.
                         */
                        if (inflight || !time_after(jiffies, timeout)) {
-                               cpu_relax();
+                               cond_resched();
                                continue;
                        }