Re: General protection fault with use_blk_mq=1.

["Zephaniah E. Loss-Cutler-Hull" <warp@aehallh.com>]

On 03/29/2018 02:12 AM, Zephaniah E. Loss-Cutler-Hull wrote:
> On 03/28/2018 10:13 PM, Paolo Valente wrote:
>> In addition, the outcome of your attempt without
>> CONFIG_DEBUG_BLK_CGROUP would give us useful bisection information:
>> - if no failure occurs, then the issue is likely to be confined in
>> that debugging code (which, on the bright side, is likely to be of
>> occasional interest, for only a handful of developers)
>> - if the issue still shows up, then we may have new hints on this odd
>> failure
>>
>> Finally, consider that this issue has been reported to disappear from
>> 4.16 [1], and, as a plus, that the service quality of BFQ had a
>> further boost exactly from 4.16.
> 
> I look forward to that either way then.
>>
>> Looking forward to your feedback, in case you try BFQ without
>> CONFIG_DEBUG_BLK_CGROUP,
> 
> I'm running that now, judging from the past if it survives until
> tomorrow evening then we're good, so I should hopefully know in the next
> day.

Alright, I now have an uptime of over 20 hours, with
scsi_mod.use_blk_mq=1 dm_mod.use_blk_mq=1

I did upgrade from 4.15.13 to 4.15.14 in the process, but a quick look
at the changes doesn't have anything jump out at me as impacting this.

So I'm reasonably comfortable stating that disabling
CONFIG_DEBUG_BLK_CGROUP was sufficient to render this stable.

Regards,
Zephaniah E. Loss-Cutler-Hull.