From: "Theodore Ts'o" <tytso@mit.edu>
To: Zhang Yi <yi.zhang@huaweicloud.com>
Cc: "D, Suneeth" <Suneeth.D@amd.com>,
linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, willy@infradead.org,
adilger.kernel@dilger.ca, jack@suse.cz, yi.zhang@huawei.com,
libaokun1@huawei.com, yukuai3@huawei.com, yangerkun@huawei.com
Subject: Re: [PATCH v2 8/8] ext4: enable large folio for regular file
Date: Thu, 26 Jun 2025 10:56:47 -0400 [thread overview]
Message-ID: <20250626145647.GA217371@mit.edu> (raw)
In-Reply-To: <94de227e-23c1-4089-b99c-e8fc0beae5da@huaweicloud.com>
On Thu, Jun 26, 2025 at 09:26:41PM +0800, Zhang Yi wrote:
>
> Thanks for the report, I will try to reproduce this performance regression on
> my machine and find out what caused this regression.
I took a quick look at this, and I *think* it's because lmbench is
measuring the latency of mmap read's --- I'm going to guess 4k random
page faults, but I'm not sure. If that's the case, this may just be a
natural result of using large folios, and the tradeoff of optimizing
for large reads versus small page faults.
But if you could take a closer look, that would be great, thanks!
- Ted
next prev parent reply other threads:[~2025-06-26 14:57 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-12 6:33 [PATCH v2 0/8] ext4: enable large folio for regular files Zhang Yi
2025-05-12 6:33 ` [PATCH v2 1/8] ext4: make ext4_mpage_readpages() support large folios Zhang Yi
2025-05-20 10:41 ` Ojaswin Mujoo
2025-05-12 6:33 ` [PATCH v2 2/8] ext4: make regular file's buffered write path " Zhang Yi
2025-05-12 6:33 ` [PATCH v2 3/8] ext4: make __ext4_block_zero_page_range() support large folio Zhang Yi
2025-05-20 10:41 ` Ojaswin Mujoo
2025-05-12 6:33 ` [PATCH v2 4/8] ext4/jbd2: convert jbd2_journal_blocks_per_page() to " Zhang Yi
2025-05-19 20:16 ` Jan Kara
2025-05-20 12:46 ` Zhang Yi
2025-05-21 10:31 ` Jan Kara
2025-05-12 6:33 ` [PATCH v2 5/8] ext4: correct the journal credits calculations of allocating blocks Zhang Yi
2025-05-19 2:48 ` Zhang Yi
2025-05-19 15:48 ` Theodore Ts'o
2025-05-20 13:04 ` Zhang Yi
2025-05-19 20:24 ` Jan Kara
2025-05-20 12:53 ` Zhang Yi
2025-05-12 6:33 ` [PATCH v2 6/8] ext4: make the writeback path support large folios Zhang Yi
2025-05-20 10:42 ` Ojaswin Mujoo
2025-05-12 6:33 ` [PATCH v2 7/8] ext4: make online defragmentation " Zhang Yi
2025-05-12 6:33 ` [PATCH v2 8/8] ext4: enable large folio for regular file Zhang Yi
2025-05-16 9:05 ` kernel test robot
2025-05-20 10:48 ` Ojaswin Mujoo
2025-06-25 8:14 ` Lai, Yi
2025-06-25 13:15 ` Theodore Ts'o
2025-06-26 3:35 ` Lai, Yi
2025-06-26 11:29 ` D, Suneeth
2025-06-26 13:26 ` Zhang Yi
2025-06-26 14:56 ` Theodore Ts'o [this message]
2025-07-03 14:13 ` Zhang Yi
2025-05-16 11:48 ` [PATCH v2 0/8] ext4: enable large folio for regular files Ojaswin Mujoo
2025-05-19 1:19 ` Zhang Yi
2025-05-19 11:02 ` Ojaswin Mujoo
2025-05-19 20:33 ` Jan Kara
2025-05-20 13:09 ` Zhang Yi
2025-05-20 10:37 ` Ojaswin Mujoo
2025-05-20 13:41 ` Zhang Yi
2025-05-20 14:40 ` Theodore Ts'o
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