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From: "Theodore Ts'o" <tytso@mit.edu>
To: Jan Kara <jack@suse.cz>
Cc: Hao Sun <sunhao.th@gmail.com>,
	jack@suse.com, linux-ext4@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: KCSAN: data-race in __jbd2_journal_file_buffer / jbd2_journal_dirty_metadata
Date: Tue, 6 Apr 2021 11:01:39 -0400	[thread overview]
Message-ID: <YGx308zQXxOjmwNZ@mit.edu> (raw)
In-Reply-To: <20210406123232.GD19407@quack2.suse.cz>

On Tue, Apr 06, 2021 at 02:32:33PM +0200, Jan Kara wrote:
> And the comment explains, why we do this unreliable check. Again, if we
> wanted to silence KCSAN, we could use data_race() macro but AFAIU Ted isn't
> very fond of that annotation.

I'm not fond of the data_race macro, but I like bogus KCSAN reports
even less.  My main complaint is if we're going to have to put the
data_race() macro in place, we're going to need to annotate each
location with an explanation of why it's there (suppress a KCSAN false
positive), and why's it's safe.  If it's only one or two places, it'll
probably be fine.  If it's dozens, then I would say that KCSAN is
becoming a net negative in terms of making the Linux kernel code
maintainable.

						- Ted

  parent reply	other threads:[~2021-04-06 15:02 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-04  9:40 KCSAN: data-race in __jbd2_journal_file_buffer / jbd2_journal_dirty_metadata Hao Sun
2021-04-06 12:32 ` Jan Kara
2021-04-06 13:27   ` Hao Sun
2021-04-06 14:05     ` Jan Kara
2021-04-06 15:01   ` Theodore Ts'o [this message]
2021-04-06 16:12     ` Jan Kara
2021-04-12 18:20     ` Marco Elver

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