From: Qian Cai <cai@lca.pw>
To: Jan Kara <jack@suse.cz>
Cc: David Hildenbrand <david@redhat.com>,
akpm@linux-foundation.org, jhubbard@nvidia.com,
ira.weiny@intel.com, dan.j.williams@intel.com, elver@google.com,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: fix a data race in put_page()
Date: Thu, 6 Feb 2020 10:23:31 -0500 [thread overview]
Message-ID: <D022CBB0-C8EC-4F5A-A0B0-893AA7A014AA@lca.pw> (raw)
In-Reply-To: <20200206145501.GD26114@quack2.suse.cz>
> On Feb 6, 2020, at 9:55 AM, Jan Kara <jack@suse.cz> wrote:
>
> I don't think the problem is real. The question is how to make KCSAN happy
> in a way that doesn't silence other possibly useful things it can find and
> also which makes it most obvious to the reader what's going on... IMHO
> using READ_ONCE() fulfills these targets nicely - it is free
> performance-wise in this case, it silences the checker without impacting
> other races on page->flags, its kind of obvious we don't want the load torn
> in this case so it makes sense to the reader (although a comment may be
> nice).
Actually, use the data_race() macro there fulfilling the same purpose too, i.e, silence the splat here but still keep searching for other races.
next prev parent reply other threads:[~2020-02-06 15:23 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-06 13:17 Qian Cai
2020-02-06 13:33 ` David Hildenbrand
2020-02-06 13:51 ` Qian Cai
2020-02-06 14:55 ` Jan Kara
2020-02-06 14:59 ` David Hildenbrand
2020-02-06 15:23 ` Qian Cai [this message]
2020-02-06 23:34 ` John Hubbard
2020-02-06 23:36 ` John Hubbard
2020-02-06 23:55 ` Qian Cai
2020-02-07 0:18 ` Qian Cai
2020-02-07 0:27 ` John Hubbard
2020-02-07 0:55 ` Qian Cai
2020-02-07 13:17 ` Marco Elver
2020-02-09 1:44 ` John Hubbard
2020-02-09 3:10 ` Qian Cai
2020-02-09 7:12 ` John Hubbard
2020-02-10 7:48 ` Marco Elver
2020-02-10 12:16 ` Qian Cai
2020-02-10 12:58 ` Marco Elver
2020-02-10 13:36 ` Qian Cai
2020-02-10 13:38 ` Marco Elver
2020-02-10 13:55 ` Qian Cai
2020-02-10 14:12 ` Marco Elver
2020-02-10 14:31 ` Qian Cai
2020-02-10 16:23 ` Qian Cai
2020-02-10 16:33 ` Marco Elver
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=D022CBB0-C8EC-4F5A-A0B0-893AA7A014AA@lca.pw \
--to=cai@lca.pw \
--cc=akpm@linux-foundation.org \
--cc=dan.j.williams@intel.com \
--cc=david@redhat.com \
--cc=elver@google.com \
--cc=ira.weiny@intel.com \
--cc=jack@suse.cz \
--cc=jhubbard@nvidia.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
/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