On Fri, 2011-06-03 at 09:34 +0200, Ingo Molnar wrote: > * Sasha Levin <levinsasha928@xxxxxxxxx> wrote: > > > > with no apparent progress being made. > > > > Since it's something that worked in 2.6.37, I've looked into it to > > find what might have caused this issue. > > > > I've bisected guest kernels and found that the problem starts with: > > > > a26ac2455ffcf3be5c6ef92bc6df7182700f2114 is the first bad commit > > commit a26ac2455ffcf3be5c6ef92bc6df7182700f2114 > > Author: Paul E. McKenney <paul.mckenney@xxxxxxxxxx> > > Date: Wed Jan 12 14:10:23 2011 -0800 > > > > rcu: move TREE_RCU from softirq to kthread > > > > Ingo, could you confirm that the problem goes away for you when you > > use an earlier commit? > > testing will have to wait, but there's a recent upstream fix: > > d72bce0e67e8: rcu: Cure load woes > > That *might* perhaps address this problem too. > I've re-tested with Linus's current git, the problem is still there. > If not then this appears to be some sort of RCU related livelock with > brutally overcommitted vcpus. On native this would show up too, in a > less drastic form, as a spurious bootup delay. I don't think it was overcommited by *that* much. With that commit it usually hangs at 20-40 vcpus, while without it I can go up to 255. -- Sasha. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
