Re: [PATCH] block: check more requests for multiple_queues in blk_attempt_plug_merge

[Larkin Lowrey <llowrey@nuclearwinter.com>]

Thank you for investigating and resolving this issue. Your effort is 
very much appreciated.

I am interested in when this patch will end up in a release. Is it going 
to make it into a 5.17.x release or will it not come until 5.18?

--Larkin

On 3/11/2022 11:59 AM, Song Liu wrote:
> Hi Jens,
>
> On Fri, Mar 11, 2022 at 6:16 AM Jens Axboe <axboe@kernel.dk> wrote:
>> On 3/10/22 5:07 PM, Jens Axboe wrote:
>>> In any case, just doing larger reads would likely help quite a bit, but
>>> would still be nice to get to the bottom of why we're not seeing the
>>> level of merging we expect.
>> Song, can you try this one? It'll do the dispatch in a somewhat saner
>> fashion, bundling identical queues. And we'll keep iterating the plug
>> list for a merge if we have multiple disks, until we've seen a queue
>> match and checked.
> This one works great! We are seeing 99% read request merge and
> 500kB+ average read size. The original patch in this thread only got
> 88% and 34kB for these two metrics.
>
> Thanks,
> Song
>
> [...]