From: Jens Axboe <axboe@kernel.dk>
To: Pavel Begunkov <asml.silence@gmail.com>, Ingo Molnar <mingo@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 0/2] Optimise io_uring completion waiting
Date: Mon, 23 Sep 2019 14:48:40 -0600 [thread overview]
Message-ID: <731b2087-7786-5374-68ff-8cba42f0cd68@kernel.dk> (raw)
In-Reply-To: <df612e90-8999-0085-d2d6-4418e044e429@gmail.com>
On 9/23/19 10:32 AM, Pavel Begunkov wrote:
> Sorry, mixed the threads.
>
>>>
>>> I'm not sure an extension is needed for such a special interface, why not
>>> just put a ->threshold value next to the ctx->wait field and use either
>>> the regular wait_event() APIs with the proper condition, or
>>> wait_event_cmd() style APIs if you absolutely need something more complex
>>> to happen inside?
> Ingo,
> io_uring works well without this patch just using wait_event_*() with
> proper condition, but there are performance issues with spurious
> wakeups. Detailed description in the previous mail.
> Am I missing something?
I think we can do the same thing, just wrapping the waitqueue in a
structure with a count in it, on the stack. Got some flight time
coming up later today, let me try and cook up a patch.
--
Jens Axboe
next prev parent reply other threads:[~2019-09-23 20:48 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-22 8:08 [PATCH v2 0/2] Optimise io_uring completion waiting Pavel Begunkov (Silence)
2019-09-22 8:08 ` [PATCH v2 1/2] sched/wait: Add wait_threshold Pavel Begunkov (Silence)
2019-09-23 7:19 ` Peter Zijlstra
2019-09-23 16:37 ` Pavel Begunkov
2019-09-23 19:27 ` Peter Zijlstra
2019-09-23 20:23 ` Peter Zijlstra
2019-09-24 6:44 ` Pavel Begunkov
2019-09-22 8:08 ` [PATCH v2 2/2] io_uring: Optimise cq waiting with wait_threshold Pavel Begunkov (Silence)
2019-09-22 15:51 ` [PATCH v2 0/2] Optimise io_uring completion waiting Jens Axboe
2019-09-23 8:35 ` Ingo Molnar
2019-09-23 16:21 ` Pavel Begunkov
2019-09-23 16:32 ` Pavel Begunkov
2019-09-23 20:48 ` Jens Axboe [this message]
2019-09-23 23:00 ` Jens Axboe
2019-09-24 7:06 ` Pavel Begunkov
2019-09-24 8:02 ` Jens Axboe
2019-09-24 8:27 ` Jens Axboe
2019-09-24 8:36 ` Jens Axboe
2019-09-24 9:33 ` Pavel Begunkov
2019-09-24 10:11 ` Jens Axboe
2019-09-24 9:49 ` Peter Zijlstra
2019-09-24 10:13 ` Jens Axboe
2019-09-24 10:34 ` Jens Axboe
2019-09-24 11:11 ` Pavel Begunkov
2019-09-24 11:15 ` Jens Axboe
2019-09-24 11:23 ` Pavel Begunkov
2019-09-24 13:13 ` Jens Axboe
2019-09-24 17:33 ` Pavel Begunkov
2019-09-24 17:46 ` Jens Axboe
2019-09-24 18:28 ` Pavel Begunkov
2019-09-24 19:32 ` Jens Axboe
2019-09-24 11:43 ` Peter Zijlstra
2019-09-24 12:57 ` Jens Axboe
2019-09-24 11:33 ` Peter Zijlstra
2019-09-24 9:20 ` Pavel Begunkov
2019-09-24 10:09 ` Jens Axboe
2019-09-24 9:21 ` Pavel Begunkov
2019-09-24 10:09 ` Jens Axboe
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