Re: [PATCH RFC 0/7] blk-mq: improve tag fair sharing

Yu Kuai
2023-07-05T03:18:01Z

Hi,

在 2023/07/04 2:08, Bart Van Assche 写道:
> On 7/3/23 06:29, Yu Kuai wrote:
>> 在 2023/06/20 23:20, Bart Van Assche 写道:
>>> On 6/18/23 09:07, Yu Kuai wrote:
>>>> This is not a formal version and not fully tested, I send this RFC
>>>> because I want to make sure if people think doing this is meaningful,
>>>> before I spend too much time on this.
>>> The approach looks good to me but I'd like to hear from Jens and
>>> Christoph what their opinion is about the approach of this patch
>>> series before doing an in-depth review.
>>>
>> Any suggestions on this topic? It'll be great to hear that if anyone
>> thinks it's meaningful to refactor tag fair sharing.
>
> The cover letter of this patch series says "This is not a formal version
> and not fully tested". If a fully tested version will be posted, I will
> help with an in-depth review.

Thanks for taking time on this patchset, do you think I need to do
following for the formal version, or these improvements can be done
later?

- current algorithm to borrow tags in patch 7 is very easy and
straightforward, it should work fine on simple caces like the case you
reported for ufs, but this algorithm should be improved for more
complicated cases.
- currently borrowed tags will never be returned untill queue is idle,
I should figure out a way to return borrowed tags if this queue is not
busy, so that other queues can borrow tag from this queue.

Thanks,
Kuai

>
> Thanks,
>
> Bart.
>
>
> .
>