* Mike Galbraith | 2014-05-10 06:15:03 [+0200]: >On Fri, 2014-05-09 at 20:12 +0200, Sebastian Andrzej Siewior wrote: > >> Known issues: >> >> - bcache is disabled. >> >> - lazy preempt on x86_64 leads to a crash with some load. > >That is only with NO_HZ_FUL enabled here. Box blows the stack during >task exit, eyeballing hasn't spotted the why. Even if I disable NO_HZ_FULL it explodes as soon as hackbench starts. >> - CPU hotplug works in general. Steven's test script however >> deadlocks usually on the second invocation. > >My 64 core box runs for up to 14 hours, and never deadlocks.. it >explodes in what looks like it should be an impossible manner instead. It deadlocks here and I haven't figured the exact root cause. From what it looks like is that the irq thread blocks on something during startup (migrate_disable() or so). One of the blocked irq thrad is disk driver. The userland tasks then block on ext4 in order to complete the requests. I also noticed that the frequent cpu up/down fails at some point and my kvm guest has just 7 out 8 CPUs. That one CPU remains dead and can't get back online. Once that happens, the deadlock is comming in a few minutes :) >-Mike Sebastian -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
