From: Christoph Hellwig <hch@infradead.org>
To: Suren Baghdasaryan <surenb@google.com>
Cc: Christoph Hellwig <hch@infradead.org>,
Sooyong Suk <s.suk@samsung.com>,
Jaewon Kim <jaewon31.kim@gmail.com>,
viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org,
akpm@linux-foundation.org, linux-mm@kvack.org, spssyr@gmail.com,
axboe@kernel.dk, linux-block@vger.kernel.org, dhavale@google.com
Subject: Re: [RFC PATCH] block, fs: use FOLL_LONGTERM as gup_flags for direct IO
Date: Wed, 12 Mar 2025 08:25:05 -0700 [thread overview]
Message-ID: <Z9GnUaUD-iaFre_i@infradead.org> (raw)
In-Reply-To: <CAJuCfpGa43OQHG9BmnvxROX1AneCvkuLxFwM+TdxAdR1v9kWSg@mail.gmail.com>
On Wed, Mar 12, 2025 at 08:20:36AM -0700, Suren Baghdasaryan wrote:
> > Direct I/O pages are not unmovable. They are temporarily pinned for
> > the duration of the direct I/O.
>
> Yes but even temporarily pinned pages can cause CMA allocation
> failure. My point is that if we know beforehand that the pages will be
> pinned we could avoid using CMA and these failures would go away.
Direct I/O (and other users of pin_user_pages) are designed to work
on all anonymous and file backed pages, which is kinda the point.
If you CMA user can't wait for the time of an I/O something is wrong
with that caller and it really should not use CMA.
next prev parent reply other threads:[~2025-03-12 15:25 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20250306074101epcas1p4b24ac546f93df2c7fe3176607b20e47f@epcas1p4.samsung.com>
2025-03-06 7:40 ` Sooyong Suk
2025-03-06 15:26 ` Christoph Hellwig
2025-03-06 23:28 ` Jaewon Kim
2025-03-07 2:07 ` Sooyong Suk
2025-03-07 2:28 ` Suren Baghdasaryan
2025-03-07 6:38 ` Sooyong Suk
2025-03-12 15:17 ` Christoph Hellwig
2025-03-12 15:20 ` Suren Baghdasaryan
2025-03-12 15:25 ` Christoph Hellwig [this message]
2025-03-12 15:38 ` Suren Baghdasaryan
2025-03-12 15:52 ` Christoph Hellwig
2025-03-12 16:03 ` Bart Van Assche
2025-03-12 16:06 ` Suren Baghdasaryan
2025-03-12 16:21 ` Christoph Hellwig
2025-03-07 20:23 ` Matthew Wilcox
2025-03-07 21:37 ` Suren Baghdasaryan
2025-03-12 15:21 ` Christoph Hellwig
2025-03-13 22:49 ` David Hildenbrand
2025-03-15 1:04 ` John Hubbard
2025-03-15 23:00 ` David Hildenbrand
2025-03-15 23:09 ` Zi Yan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Z9GnUaUD-iaFre_i@infradead.org \
--to=hch@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=axboe@kernel.dk \
--cc=dhavale@google.com \
--cc=jaewon31.kim@gmail.com \
--cc=linux-block@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=s.suk@samsung.com \
--cc=spssyr@gmail.com \
--cc=surenb@google.com \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox