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From: Christoph Hellwig <hch@infradead.org>
To: Matthew Wilcox <willy@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>,
	Jeremy Bongio <bongiojp@gmail.com>, Ted Tso <tytso@mit.edu>,
	"Darrick J . Wong" <djwong@kernel.org>,
	Allison Henderson <allison.henderson@oracle.com>,
	linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-xfs@vger.kernel.org
Subject: Re: [PATCH 0/1] iomap regression for aio dio 4k writes
Date: Wed, 21 Jun 2023 21:08:03 -0700	[thread overview]
Message-ID: <ZJPJI1t/wdj/L1W2@infradead.org> (raw)
In-Reply-To: <ZJO4OAYhJlXOBXMf@casper.infradead.org>

On Thu, Jun 22, 2023 at 03:55:52AM +0100, Matthew Wilcox wrote:
> Latency is important for reads, but why is it important for writes?
> There's such a thing as a dependent read, but writes are usually buffered
> and we can wait as long as we like for a write to complete.

That was exactly my reasoning on why I did always defer the write
completions in the initial iomap direct I/O code, and until now no
one has complained.

I could see why people care either about synchronous writes, or polled
io_uring writes, for which we might be able to do the work in the
completion thread context, but for aio writes this feels a bit odd.

  reply	other threads:[~2023-06-22  4:08 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-21 17:29 [PATCH 0/1] iomap regression for aio dio 4k writes Jeremy Bongio
2023-06-21 17:29 ` [PATCH 1/1] For DIO writes with no mapped pages for inode, skip deferring completion Jeremy Bongio
2023-06-21 18:55   ` Matthew Wilcox
2023-06-22  0:04   ` Dave Chinner
2023-06-21 23:59 ` [PATCH 0/1] iomap regression for aio dio 4k writes Dave Chinner
2023-06-22  1:55   ` Dave Chinner
2023-06-22  2:55     ` Matthew Wilcox
2023-06-22  4:08       ` Christoph Hellwig [this message]
2023-06-22  4:47       ` Dave Chinner
2023-06-23  2:32   ` Theodore Ts'o
2023-06-23  3:02     ` Dave Chinner
2023-06-22 23:22 ` Allison Henderson

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