[libvirt] cgroup cpuset limited by default?

[Daniel P. Berrange]

On Mon, Apr 16, 2012 at 06:00:22PM +0200, Marc-André Lureau wrote:
> Hi
> 
> On Mon, Apr 16, 2012 at 2:32 PM, Srivatsa S. Bhat
> <srivatsa.bhat at linux.vnet.ibm.com> wrote:
> > On 04/16/2012 05:34 PM, Marc-André Lureau wrote:
> > Did you happen to perform a suspend/resume or a hibernation/restore
> > on your computer? (Or did you do CPU hotplug manually?)
> >
> > If yes, you might be seeing the problem reported at:
> > https://bugzilla.redhat.com/show_bug.cgi?id=714271
> 
> yep, thank you very much, that seems to be the reason

This problem has existed for ages now. I wonder if there's a way we get get
a userspace workaround implemented.

IIRC, pm-utils has the ability to run arbitrary shell scripts upon
restore from suspend/hibernate. We could put a temp hack in libvirt
which resets the CPU affinity in the top level libvirt cgroup. That
would at least make new VMs start with good affinity. To deal with
existing running VMs, we would need to record existing affinity
before suspend & re-store it fully afterwards which is more complicated


Daniel
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