[libvirt] [PATCH] qemu: Create or remove cgroup when doing vcpu (un)hotpluging

[Peter Krempa]

On 10/09/12 18:08, Osier Yang wrote:
> Various APIs use cgroup to either set or get the statistics of
> host or guest. Hotplug or unhotplug new vcpus without creating
> or removing the cgroup for the vcpus could cause problems for
> those APIs. E.g.
>
> % virsh vcpucount dom
> maximum      config        10
> maximum      live          10
> current      config         1
> current      live           1
>
> % virsh setvcpu dom 2
>
> % virsh schedinfo dom --set vcpu_quota=1000
> Scheduler      : posix
> error: Unable to find vcpu cgroup for rhel6.2(vcpu: 1): No such file or
> directory
>
> This patch fixes the problem by creating cgroups for each of the
> onlined vcpus, and destroying cgroups for each of the offlined
> vcpus.
> ---
>   src/qemu/qemu_driver.c |   53 ++++++++++++++++++++++++++++++++++++++++++++++++
>   1 files changed, 53 insertions(+), 0 deletions(-)
>

s/unhotplug/hotunplug/g in your patch

The code looks fine, so Martin's ACK stands.

Peter