On Tue, Dec 29, 2015 at 10:43:26PM -0800, Andy Lutomirski wrote: > [add cc's] > > Hi scheduler people: > > This is relatively easy for me to reproduce. Any hints for debugging > it? Could we really have a bug in which processes that are > schedulable as a result of mutex unlock aren't always reliably > scheduled? I would expect that to cause wide-spread fail, then again, virt is known to tickle timing issues that are improbable on actual hardware so anything is possible. Does it reproduce with DEBUG_MUTEXES set? (I'm not seeing a .config here). If its really easy you could start by tracing events/sched/sched_switch events/sched/sched_wakeup, those would be the actual scheduling events. Without DEBUG_MUTEXES there's the MUTEX_SPIN_ON_OWNER code that could still confuse things, but that's mutex internal and not scheduler related. If it ends up being the SPIN_ON_OWNER bits we'll have to cook up some extra debug patches. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
