[libvirt] [PATCH RESEND RFC v4 1/6] Introduce the function virCgroupForVcpu

Daniel P. Berrange berrange at redhat.com
Thu Jul 21 10:09:26 UTC 2011


On Thu, Jul 21, 2011 at 10:08:03AM +0800, Wen Congyang wrote:
> Introduce the function virCgroupForVcpu() to create sub directory for each vcpu.

I'm far from convinced that this is a good idea. Setting policies on
individual VCPUs is giving the host admin a misleading illusion of
control over individual guest VCPUs. The problem is that QEMU has
many non-VCPU threads which consume non-trivial CPU time. CPU time
generated by a CPU in the guest, does not neccessarily map to a VCPU
thread in the host, but could instead go to a I/O thread or a display
thread, etc.

IMHO we should only be doing controls at the whole VM level here.

Daniel
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