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

From: Adrian Hunter
Date: Thu Jul 12 2018 - 02:19:21 EST


On 11/07/18 19:35, Ming Lei wrote:
> On Wed, Jul 11, 2018 at 4:31 PM, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
>> On 11/07/18 05:52, Martin K. Petersen wrote:
>>>
>>> Johannes,
>>>
>>>> It has been more than one year since we tried to change the default
>>>> from legacy to multi queue in SCSI with commit c279bd9e406 ("scsi:
>>>> default to scsi-mq"). But due to issues with suspend/resume and
>>>> performance problems it had been reverted again with commit
>>>> cbe7dfa26eee ("Revert "scsi: default to scsi-mq"").
>>>>
>>>> In the meantime there have been a substantial amount of performance
>>>> improvements and suspend/resume got fixed as well, thus we can
>>>> re-enable scsi-mq without a significant performance penalty.
>>>
>>> Applied to 4.19/scsi-queue, thanks!
>>>
>>
>> But there is no runtime pm support, is there? I tried enabling runtime PM
>> for UFS SCSI devices with scsi-mq and it didn't work, which is a regression.
>
> I just posted one RFC patchset for supporting runtime PM on scsi_mq, and
> looks it works in my test on usb-storage.
>
> https://marc.info/?l=linux-block&m=153132657922233&w=2

Cool, please cc me on the next revision of your patch set.