From: Pavel Begunkov <asml.silence@gmail.com>
To: Jens Axboe <axboe@kernel.dk>, io-uring@vger.kernel.org
Cc: stable@vger.kernel.org
Subject: Re: [PATCH 1/2] io_uring: wait potential ->release() on resurrect
Date: Sat, 20 Feb 2021 03:47:05 +0000 [thread overview]
Message-ID: <217745e7-0e2b-0faa-8fa9-8e4757515128@gmail.com> (raw)
In-Reply-To: <914848f1-f30e-4d3a-ab40-9db78e1321b7@kernel.dk>
On 20/02/2021 03:40, Jens Axboe wrote:
> On 2/19/21 6:39 PM, Pavel Begunkov wrote:
>> There is a short window where percpu_refs are already turned zero, but
>> we try to do resurrect(). Play nicer and wait for all users to leave RCU
>> section.
>
> We need to do something better than synchronize_rcu() here, that can
> take a long time on a loaded box. I'll try and think about this one.
It only happens when it can't be drained and there are task_works or
signals. I have another patch, doing it via tryget, but it's uglier and
I'd rather prefer synchronize_rcu for stable.
Want me to send it tomorrow (on top or not)?
--
Pavel Begunkov
next prev parent reply other threads:[~2021-02-20 3:51 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-20 1:39 [PATCH 0/2] random fixes Pavel Begunkov
2021-02-20 1:39 ` [PATCH 1/2] io_uring: wait potential ->release() on resurrect Pavel Begunkov
2021-02-20 3:40 ` Jens Axboe
2021-02-20 3:47 ` Pavel Begunkov [this message]
2021-02-20 3:53 ` Jens Axboe
2021-02-20 1:39 ` [PATCH 2/2] io_uring: fix leaving invalid req->flags Pavel Begunkov
2021-02-20 4:17 ` Jens Axboe
-- strict thread matches above, loose matches on Subject: below --
2021-02-20 17:21 [PATCH 0/2] resurrect Pavel Begunkov
2021-02-20 17:21 ` [PATCH 1/2] io_uring: wait potential ->release() on resurrect Pavel Begunkov
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