On Tue, Apr 17, 2012 at 11:09:33AM +0530, Srivatsa S. Bhat wrote: > On 04/16/2012 09:43 PM, Daniel P. Berrange wrote: > > > 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@xxxxxxxxxxxxxxxxxx> 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 > > > Thanks for the confirmation. The script below might work as a > temporary workaround. > > > > > 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 > > > > > I don't think that would be all that complicated.. Below is a script > that should do the trick, for all cases, including existing running VMs. > > This script is not at all specific to libvirt by the way (as the problem > itself is not at all libvirt specific). It saves the cpuset configuration > before suspend and restores it after resume, for all cpusets (not only > the ones controlled by libvirt). Of course, it hooks onto the pm-utils > mechanism, as you mentioned. Thanks for taking the time to write this. I have opened a BZ against systemd to see if they are willing to ship this script as a standard workaround for the kernel bug, since they are responsible for mounting the cpuset cgroups in Fedora 16 and later https://bugzilla.redhat.com/show_bug.cgi?id=813228 Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list