On August 9, 2011, Avi Kivity wrote: > On 08/07/2011 05:06 PM, Thomas Fjellstrom wrote: > > Occasionally when there's heavy cpu and/or io load, a kvm guest will lock > > up for minutes at a time, last occurrence was for about 12 minutes or > > so, and the guest itself reported: > > > > [1992982.639514] Clocksource tsc unstable (delta = -747307707123 ns) > > > > in dmesg after it came back. The only other hint as to what is going on > > is that the irq count for "local timer requests", virtio-input and > > virtio- requests spikes rather high. Also one of the cpu cores on the > > host was pegged the entire time. > > > > The last thing to cause a hang was an "aptitude upgrade" in the guest, > > which was a bit behind, so it had to update over 300 packages. > > > > The host is running 2.6.38-1-amd64 (2.6.38+32) from debian, qemu-kvm > > 0.14.0, and the guest was running 2.6.38-2-amd64 (not sure on the + > > number). > > > > Is this a known problem, thats hopefully fixed in newer kernels and > > qemu/kvm packages? > > Your guest isn't using kvmclock for some reason. Is it compiled in the > guest kernel? What are the contents of > /sys/devices/system/clocksource/clocksource0/available_clocksource and > /sys/devices/system/clocksource/clocksource0/current_clocksource (in the > guest filesystem)? Hi, it seems it is using kvm-clock: $ cat /sys/devices/system/clocksource/clocksource0/available_clocksource kvm-clock hpet acpi_pm $ cat /sys/devices/system/clocksource/clocksource0/current_clocksource kvm-clock -- Thomas Fjellstrom thomas@xxxxxxxxxxxxx -- 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
