Re: kvm linux guest hanging for minutes at a time

Thomas Fjellstrom
2011-08-09T14:46:20Z

On August 9, 2011, Avi Kivity wrote:
> On 08/09/2011 05:31 PM, Thomas Fjellstrom wrote:
> > On August 9, 2011, Avi Kivity wrote:
> > > On 08/09/2011 03:03 PM, Thomas Fjellstrom wrote:
> > > > > 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_clocksou
> > > > > rce and
> > > > > /sys/devices/system/clocksource/clocksource0/current_clocksour
> > > > > ce (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
> > >
> > > Yikes. Please trace such a hang according to
> > > http://www.linux-kvm.org/page/Tracing.
> >
> > Does it matter that I have several vms running? Is there a way to limit
> > it to tracing the single kvm process that's been locking up?
>
> You can use "trace-cmd record -F ... qemu ..." but that misses out on
> events the run from workqueues.
>
> Best to stop those other guests.

I would prefer not to do that, those other guests are my web server, mail
server, and database server. I have no idea if I can reproduce the problem in
a reasonable time frame.