Re: [RFC] scsi: switch to scsi-mq by default

[John Garry]

On 04/07/2018 00:21, Bart Van Assche wrote:
> On Tue, 2018-07-03 at 08:54 +0200, Johannes Thumshirn wrote:
> > It has been more than one year since we tried to change the default
> > from legacy to multi queue in SCSI. Back then we had to retract the
> > change because of performance issues with rotating disks.
> >
> > In the meantime there have been a substantial amount of performance
> > improvements, thus we can re-enable scsi-mq without a significant
> > performance penalty.
>
> Hello Johannes,
>
> Please include references to commits cbe7dfa26eee ("Revert "scsi:
> default to scsi-mq"") and 5c279bd9e406 ("scsi: default to scsi-mq").
> I think it's a good idea to mention that suspend/resume now works
> with scsi-mq.
>
> Bart.

We were seeing performance drops previously for hisi_sas when originally 
enabled by default, but results on 4.18 seem almost identical with and 
without MQ default.

FWIW,

Acked-by: John Garry <john.garry@xxxxxxxxxx>

>