From: Pavel Begunkov <asml.silence@gmail.com>
To: Joseph Qi <jiangqi903@gmail.com>, Jens Axboe <axboe@kernel.dk>,
io-uring@vger.kernel.org
Subject: Re: [PATCH 0/3] files cancellation cleanup
Date: Mon, 25 Jan 2021 10:48:58 +0000 [thread overview]
Message-ID: <09aec3c5-bf2a-92cd-4388-2403ba9f4bd3@gmail.com> (raw)
In-Reply-To: <4ddd9aa4-bbdd-9730-f1b9-7a26ccaaf842@gmail.com>
On 25/01/2021 02:14, Joseph Qi wrote:
> On 1/23/21 5:49 AM, Pavel Begunkov wrote:
>> On 22/01/2021 09:45, Joseph Qi wrote:
>>> Seems this series can also resolve a possible deadlock case I'm looking
>>> into.
>>
>> It removes dead code, I believe your issue is solved by
>> ("io_uring: get rid of intermediate IORING_OP_CLOSE stage")
>> https://git.kernel.dk/cgit/linux-block/commit/?h=for-5.12/io_uring&id=7be8ba3b656cb4e0158b2c859b949f34a96aa94f
>>
> I've tested the above commit and the mentioned possible deadlock still
> exists.
I pasted a wrong patch, apparently had something else on my mind...
The intention was to point to a Jens' patch that made mentioned in
your report __io_uring_files_cancel() unreachable, though it was
dropped for unrelated reasons. So... the bug is still here at the
moment.
Anyway, thanks a lot for testing! Your reports are very helpful
>> Did you try this series in particular, or tested for-5.12/io_uring
>> and see that the issue is gone there?
>>
> I don't have this tree locally and it takes too long to clone it down.
> Will check once it is ready.
>
> Thanks,
> Joseph
>
>>> CPU0:
>>> ...
>>> io_kill_linked_timeout // &ctx->completion_lock
>>> io_commit_cqring
>>> __io_queue_deferred
>>> __io_queue_async_work
>>> io_wq_enqueue
>>> io_wqe_enqueue // &wqe->lock
>>>
>>> CPU1:
>>> ...
>>> __io_uring_files_cancel
>>> io_wq_cancel_cb
>>> io_wqe_cancel_pending_work // &wqe->lock
>>> io_cancel_task_cb // &ctx->completion_lock
>>>
--
Pavel Begunkov
prev parent reply other threads:[~2021-01-25 11:02 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-20 2:32 [PATCH 0/3] files cancellation cleanup Pavel Begunkov
2021-01-20 2:32 ` [PATCH 1/3] io_uring: remove cancel_files and inflight tracking Pavel Begunkov
2021-01-20 2:32 ` [PATCH 2/3] io_uring: cleanup iowq cancellation files matching Pavel Begunkov
2021-01-20 2:32 ` [PATCH 3/3] io_uring: don't pass files for cancellation Pavel Begunkov
2021-01-20 3:13 ` [PATCH 0/3] files cancellation cleanup Jens Axboe
2021-01-22 9:45 ` Joseph Qi
2021-01-22 21:49 ` Pavel Begunkov
2021-01-25 2:14 ` Joseph Qi
2021-01-25 10:48 ` Pavel Begunkov [this message]
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