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From: Bart Van Assche <bvanassche@acm.org>
To: Theodore Tso <tytso@mit.edu>, Jaegeuk Kim <jaegeuk@kernel.org>
Cc: linux-api@vger.kernel.org, linux-kernel@vger.kernel.org,
	Matthew Wilcox <willy@infradead.org>,
	linux-f2fs-devel@lists.sourceforge.net,
	Christoph Hellwig <hch@infradead.org>,
	linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
	Akilesh Kailash <akailash@google.com>,
	Christian Brauner <christian@brauner.io>
Subject: Re: [f2fs-dev] [PATCH v2] f2fs: another way to set large folio by remembering inode number
Date: Tue, 26 May 2026 09:14:52 -0700	[thread overview]
Message-ID: <f4e521ac-2381-49ca-8dcc-3cb3cf3ffaea@acm.org> (raw)
In-Reply-To: <ybmbjekuvzmaw4hmlxd7nxs546dqtwmxqxwyali74d6m3u7tat@b4q3japqnhrl>

On 5/26/26 6:42 AM, Theodore Tso wrote:
> It seems... surprising that the additional I/O operations are actually
> throttloing UFS device bandwidth by 2x (4GB/s vs 2GB/s).  Have you dug
> into why this is happening, and whether there is anything that can be
> optimized below the file system?
The layers below the filesystem (block, SCSI, UFS) is what I'm
responsible for in the Pixel team and I can assure you that these are
highly optimized.

Since the transfer size used in Jaegeuk's tests is much larger than 4
KiB, how many CPU cycles are used per IO by the layers below the
filesystem is not limiting the transfer bandwidth.

Bart.

  reply	other threads:[~2026-05-26 16:15 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20260409134538.3692605-1-jaegeuk@kernel.org>
     [not found] ` <adhPZxtbZxgU-37v@google.com>
2026-04-14  8:02   ` [PATCH v2] f2fs: another way to set large folio by remembering inode number Christoph Hellwig
2026-04-15 16:44     ` Jaegeuk Kim
2026-04-15 17:15       ` Matthew Wilcox
2026-04-15 22:02         ` Jaegeuk Kim
2026-04-15 23:49           ` Darrick J. Wong
2026-04-16  1:19             ` Jaegeuk Kim
2026-05-21  8:51         ` Christoph Hellwig
2026-05-21 15:57           ` Theodore Tso
2026-05-21 17:42             ` Matthew Wilcox
2026-05-22  3:59               ` Jaegeuk Kim
2026-05-22 12:55                 ` Matthew Wilcox
2026-05-22 14:04                   ` [f2fs-dev] " Jaegeuk Kim
2026-05-25  5:34                     ` Christoph Hellwig
2026-05-26  1:21                       ` Jaegeuk Kim
2026-05-26  2:31                         ` Matthew Wilcox
2026-05-26  3:47                           ` Jaegeuk Kim
2026-05-25  5:34               ` Christoph Hellwig
2026-05-22  3:32             ` [f2fs-dev] " Jaegeuk Kim
2026-05-22  3:53               ` Eric Biggers
2026-05-22  4:02                 ` Jaegeuk Kim
2026-05-22 10:01                 ` Christian Brauner
2026-05-22 14:11               ` Theodore Tso
2026-05-22 17:08                 ` Jaegeuk Kim
2026-05-22 22:41                   ` Theodore Tso
2026-05-26  1:10                     ` Jaegeuk Kim
2026-05-26  2:35                       ` Matthew Wilcox
2026-05-26  3:34                         ` Jaegeuk Kim
2026-05-26  3:35                       ` Randy Dunlap
2026-05-26  4:12                         ` Jaegeuk Kim
2026-05-26 13:42                       ` Theodore Tso
2026-05-26 16:14                         ` Bart Van Assche [this message]
2026-05-26 21:52                         ` Jaegeuk Kim
2026-05-25  5:37               ` Christoph Hellwig
2026-05-22  9:59             ` Christian Brauner
2026-04-15 16:41   ` Jaegeuk Kim

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