From: Christoph Hellwig <hch@lst.de>
To: Daniel Gomez <da.gomez@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
linux-block@vger.kernel.org, lsf-pc@lists.linux-foundation.org,
david@fromorbit.com, leon@kernel.org, hch@lst.de,
kbusch@kernel.org, sagi@grimberg.me, axboe@kernel.dk,
joro@8bytes.org, brauner@kernel.org, hare@suse.de,
willy@infradead.org, djwong@kernel.org, john.g.garry@oracle.com,
ritesh.list@gmail.com, p.raghav@samsung.com,
gost.dev@samsung.com, da.gomez@samsung.com
Subject: Re: [LSF/MM/BPF TOPIC] breaking the 512 KiB IO boundary on x86_64
Date: Thu, 20 Mar 2025 15:54:49 +0100 [thread overview]
Message-ID: <20250320145449.GA14191@lst.de> (raw)
In-Reply-To: <ijpsvpc5xgd52r3uu3ibkjcyqzl6edke6fbotj7zf2wbw5vrqb@zzr274ln4tjd>
On Thu, Mar 20, 2025 at 02:47:22PM +0100, Daniel Gomez wrote:
> On Thu, Mar 20, 2025 at 04:41:11AM +0100, Luis Chamberlain wrote:
> > We've been constrained to a max single 512 KiB IO for a while now on x86_64.
> > This is due to the number of DMA segments and the segment size. With LBS the
> > segments can be much bigger without using huge pages, and so on a 64 KiB
> > block size filesystem you can now see 2 MiB IOs when using buffered IO.
>
> Actually up to 8 MiB I/O with 64k filesystem block size with buffered I/O
> as we can describe up to 128 segments at 64k size.
Block layer segments are in no way limited to the logical block size.
next prev parent reply other threads:[~2025-03-20 14:54 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-20 11:41 Luis Chamberlain
2025-03-20 12:11 ` Matthew Wilcox
2025-03-20 13:29 ` Daniel Gomez
2025-03-20 14:31 ` Matthew Wilcox
2025-03-20 13:47 ` Daniel Gomez
2025-03-20 14:54 ` Christoph Hellwig [this message]
2025-03-21 9:14 ` Daniel Gomez
2025-03-20 14:18 ` Christoph Hellwig
2025-03-20 15:37 ` Bart Van Assche
2025-03-20 15:58 ` Keith Busch
2025-03-20 16:13 ` Kanchan Joshi
2025-03-20 16:38 ` Christoph Hellwig
2025-03-20 21:50 ` Luis Chamberlain
2025-03-20 21:46 ` Luis Chamberlain
2025-03-20 21:40 ` Luis Chamberlain
2025-03-20 18:46 ` Ritesh Harjani
2025-03-20 21:30 ` Darrick J. Wong
2025-03-21 2:13 ` Ritesh Harjani
2025-03-21 3:05 ` Darrick J. Wong
2025-03-21 4:56 ` Theodore Ts'o
2025-03-21 5:00 ` Christoph Hellwig
2025-03-21 18:39 ` Ritesh Harjani
2025-03-21 16:38 ` Keith Busch
2025-03-21 17:21 ` Ritesh Harjani
2025-03-21 18:55 ` Keith Busch
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