Re: [PATCH v5 00/14] blk-mq: Reduce static requests memory footprint for shared sbitmap

[John Garry]

On 08/10/2021 04:11, Bart Van Assche wrote:

+

> On 10/7/21 13:31, Kashyap Desai wrote:
> > I tested this patchset on 5.15-rc4 (master) -
> > https://github.com/torvalds/linux.git
> >
> > #1 I noticed some performance regression @mq-deadline scheduler which 
> > is not
> > related to this series. I will bisect and get more detail about this 
> > issue
> > separately.
>
> Please test this patch series on top of Jens' for-next branch 
> (git://git.kernel.dk/linux-block). The mq-deadline performance on Jens' 
> for-next branch should match that of kernel v5.13.

Kashyap did also mention earlier that he say the drop from v5.11 -> v5.12.

The only thing I saw possibly related there was Jan's work in 
https://lore.kernel.org/linux-block/20210111164717.21937-1-jack@xxxxxxx/
to fix a performance regression witnessed on megaraid sas for slower media.

But I quite doubtful that this is the issue.

Thanks,
John