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.