From: Peter Zijlstra <peterz@infradead.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jens Axboe <axboe@kernel.dk>, Ingo Molnar <mingo@redhat.com>,
Will Deacon <will@kernel.org>,
Christian Brauner <brauner@kernel.org>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
Mark Rutland <mark.rutland@arm.com>
Subject: Re: [GIT PULL] pipe: nonblocking rw for io_uring
Date: Tue, 25 Apr 2023 21:49:10 +0200 [thread overview]
Message-ID: <20230425194910.GA1350354@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <CAHk-=wjSuGTLrmygUSNh==u81iWUtVzJ5GNSz0A-jbr4WGoZyw@mail.gmail.com>
On Tue, Apr 25, 2023 at 10:20:31AM -0700, Linus Torvalds wrote:
> But the more I look at it, the more I'm convinced that our pattern of
>
> old = READ_ONCE(rq->fence.error);
> do {
> if (fatal_error(old))
> return false;
> } while (!try_cmpxchg(&rq->fence.error, &old, error));
>
> (to pick one random user) is simply horribly wrong.
The last time this came up I shared your view however Mark argued for
the READ_ONCE() thusly:
https://lore.kernel.org/all/Y71LoCIl+IFdy9D8@FVFF77S0Q05N/T/#u
next prev parent reply other threads:[~2023-04-25 19:49 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-21 14:01 [GIT PULL] pipe: nonblocking rw for io_uring Christian Brauner
2023-04-24 21:05 ` Linus Torvalds
2023-04-24 21:22 ` Jens Axboe
2023-04-24 21:37 ` Linus Torvalds
2023-04-24 21:55 ` Jens Axboe
2023-04-24 22:00 ` Linus Torvalds
2023-04-24 22:05 ` Jens Axboe
2023-04-24 22:03 ` Jens Axboe
2023-04-24 21:58 ` Linus Torvalds
2023-04-24 22:07 ` Jens Axboe
2023-04-24 22:44 ` Jens Axboe
2023-04-25 3:16 ` Linus Torvalds
2023-04-25 13:46 ` Jens Axboe
2023-04-25 17:20 ` Linus Torvalds
2023-04-25 19:49 ` Peter Zijlstra [this message]
2023-04-25 19:58 ` Linus Torvalds
2023-04-25 20:10 ` Jens Axboe
2023-04-25 20:29 ` Linus Torvalds
[not found] ` <978690c4-1d25-46e8-3375-45940ec1ea51@huaweicloud.com>
2023-05-08 8:39 ` Peter Zijlstra
2023-05-08 10:16 ` David Laight
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=20230425194910.GA1350354@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=axboe@kernel.dk \
--cc=brauner@kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=mingo@redhat.com \
--cc=torvalds@linux-foundation.org \
--cc=will@kernel.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