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Date: Tue, 25 Nov 2025 07:35:06 +0100
From: Christoph Hellwig <hch@lst.de>
To: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@lst.de>, brauner@kernel.org, djwong@kernel.org,
	linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	syzbot+a2b9a4ed0d61b1efb3f5@syzkaller.appspotmail.com
Subject: Re: [PATCH] iomap: allocate s_dio_done_wq for async reads as well
Message-ID: <20251125063506.GA14851@lst.de>
References: <20251124140013.902853-1-hch@lst.de> <aSTR3GHyAZKdRCqo@dread.disaster.area>
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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.