This could be an unintended regression, I'm not finding much related at all in recent history in the traces. I'd say reproduce and get a sysrq+w captured. Most of the traces are actually from rdiff-backup, but the first one is a kworker. So something happens and then due to the ensuing congestion it all just gets worse. Maybe it would have eventually recovered but once it's this congested it might have taken a really long time. I would then also try to reproduce with 4.2.8 or 4.3.3 because those have ~ 25% backports than made it to 4.1.15, so there's an off chance it's fixed there. But even better to just go straight to 4.4.rc6 if you can, because an unintended regression that's not known will likely happen in 4.4 and would need to be fixed now before it'd get backported anyway. *shrug* Chris Murphy -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
