Re: [PATCH v2 0/2] Optimise io_uring completion waiting

From: Jens Axboe
Date: Tue Sep 24 2019 - 06:09:42 EST


On 9/24/19 3:21 AM, Pavel Begunkov wrote:
> On 24/09/2019 11:02, Jens Axboe wrote:
>> On 9/24/19 1:06 AM, Pavel Begunkov wrote:
>>> On 24/09/2019 02:00, Jens Axboe wrote:
>>>>> 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.
>>>>
>>>> Totally untested, and sent out 5 min before departure... But something
>>>> like this.
>>> Hmm, reminds me my first version. Basically that's the same thing but
>>> with macroses inlined. I wanted to make it reusable and self-contained,
>>> though.
>>>
>>> If you don't think it could be useful in other places, sure, we could do
>>> something like that. Is that so?
>>
>> I totally agree it could be useful in other places. Maybe formalized and
>> used with wake_up_nr() instead of adding a new primitive? Haven't looked
>> into that, I may be talking nonsense.
>
> @nr there is about number of tasks to wake up. AFAIK doesn't solve the
> problem.

Ah right, embarassingly I'm actually the one that added that
functionality ages ago...

--
Jens Axboe