Re: [PATCH] iomap: allocate s_dio_done_wq for async reads as well

Christoph Hellwig
2025-11-25T06:35:08Z

On Tue, Nov 25, 2025 at 08:45:00AM +1100, Dave Chinner wrote:
> But I can't help but wonder about putting this in the fast path....
>
> i.e. on the first io_uring/AIO DIO read or write, we will need
> allocate this work queue. I think that's getting quite common in
> applications and utilities these days, so filesystems are
> increasingly likely to need this wq.
>
> Maybe we should make this wq init unconditional and move it to fs
> superblock initialisation? That would remove this "only needed once
> for init" check that is made on every call through the the IO fast
> path....

I agree, and I originally did that, and it caused a long bikeshed.
So not feeling like reopening that can of worms right now even if I
agree with the sentiment.