cpu.shares are not affected by the number of vCPUs

[Vladik Romanovsky]

Currently, a default value of cpu_shares is being assigned to all guest instances, regardless of the number of vCPUs has been
configured for each guest.

As cpu_shares are specifying the weight to provide CPU time, this reduces the amount of time each
vCPU gets, as the amount of vCPUs, in the instance, increases.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/129690

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/129690
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=21a07f92e8d757c96528b0425064b297bb807637
Submitter: Jenkins
Branch: master

commit 21a07f92e8d757c96528b0425064b297bb807637
Author: Vladik Romanovsky <email address hidden>
Date: Fri Oct 17 17:53:17 2014 -0400

    libvirt: set guest cpu_shares value as a multiple of guest vCPUs

    Currently, a default value of cpu_shares is being assigned to all
    guest instances, regardless of the number of vCPUs has been
    configured for each guest. As cpu_shares are specifying the weight
    to provide CPU time, this reduces the amount of time each
    vCPU gets, for instances with a higher number of vCPUs.

    Setting the default value of guest cpu.shares to be a multiple of
    the number of guest vcpus.

    Closes-Bug: #1383377

    Change-Id: I3a669da3536061919e3673da88c102a868999902