Re: [ANNOUNCE] v5.14-rc4-rt4

On 2021-08-04 08:23:55 [-0600], Jens Axboe wrote:

quoted

Totally untested, but I think the principle is sound. I'll run it through
some testing.

This is needed:

diff --git a/fs/io-wq.c b/fs/io-wq.c
index 1192ee2abd982..77ec6896edaa5 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c

@@ -428,9 +428,9 @@ static struct io_wq_work *io_get_next_work(struct io_wqe *wqe)
 	}
 
 	if (stall_hash != -1U) {
-		raw_spin_unlock(&wqe->lock);
+		raw_spin_unlock_irq(&wqe->lock);
 		io_wait_on_hash(wqe, stall_hash);
-		raw_spin_lock(&wqe->lock);
+		raw_spin_lock_irq(&wqe->lock);
 	}
 
 	return NULL;

otherwise the spinlock_t lock in io_wait_on_hash() is acquired with
disabled interrupts which is a no-no on -RT.
With that it all looks good as far as I can tell.
Thank you.