Hi, After changing the clock source from kvm-clock to tsc, everything is OK. Probably it's the bug of kvm-clock. Maybe these bugs have been fixed in latest qemu. Thanks, Paul On Wed, Aug 24, 2011 at 8:47 PM, Paul <flypen@xxxxxxxxx> wrote: > > Hi, > > Sometimes this problem happened in one day, but sometimes it was very > difficult to reproduce it. > Previously the clock source of the guest was kvm-clock. Now I changed > it to tsc. The problem didn't occur until now. Is it related to the > clock source? I find that there are some bug fixes for kvm-clock > recently. (e.g., > http://www.spinics.net/lists/stable-commits/msg11942.html) Anyway, I > will update KVM later. > > Thanks, > Paul > > On Wed, Aug 24, 2011 at 6:24 PM, Stefan Hajnoczi <stefanha@xxxxxxxxx> wrote: > > > > On Wed, Aug 24, 2011 at 10:02 AM, Xiao Guangrong > > <xiaoguangrong@xxxxxxxxxxxxxx> wrote: > > > On 08/24/2011 04:40 PM, Paul wrote: > > >> Hi, > > >> > > >> I captured the output of pidstat when the problem was reproduced: > > >> > > >> bash-4.1# pidstat -p $PID 8966 > > >> Linux 2.6.32-71.el6.x86_64 (test) 07/24/11 _x86_64_ (4 CPU) > > >> > > >> 16:25:15 PID %usr %system %guest %CPU CPU Command > > >> 16:25:15 8966 0.14 55.04 115.41 170.59 1 qemu-kvm > > >> > > > > > > I have tried to reproduce it, but it was failed. I am using the > > > current KVM code. I suggest you to test it by the new code if possible. > > > > Yes, that's a good idea. The issue might already be fixed. But if > > this is hard to reproduce then perhaps keep the spinning guest around > > a bit longer so we can poke at it and figure out what is happening. > > > > The pidstat output shows us that it's the guest that is spinning, not > > qemu-kvm userspace. > > > > The system time (time spent in host kernel) is also quite high so > > running kvm_stat might show some interesting KVM events happening. > > > > Stefan -- 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
