[libvirt] [PATCH 06/10] vcpubandwidth: introduce two new libvirt APIs

Nikunj A. Dadhania nikunj at linux.vnet.ibm.com
Wed Jul 6 05:10:47 UTC 2011


On Wed, 6 Jul 2011 10:18:05 +0900, Taku Izumi <izumi.taku at jp.fujitsu.com> wrote:
> 
> > Nikunj is correct here.  We only need to ensure that the bandwidth is
> > distributed equally between all of the cpus.  This can be accomplished
> > internally by creating a cgroup for each vcpu and ensuring that
> > 'cpu.share' is the same for each vcpu cgroup.
> 
> 
> When taken together, virsh I/F and domain XML schema 
> are the following:
> 
> #virsh schedinfo VM --set cpuperiod=100000 --config
> #virsh schedinfo VM --set cpuquota=50000 --config
> 
> ..
> <vcpu>4</vcpu>
> <cputune>
>   <period>100000</period>
>   <quota>50000</quota>
> </cputune>
> 
> When specified above, the qemu driver creates cgroup for
> each vcpus and specified as follows:
> 
> The quota value is divided by the number of vcpus.
>  vcpu#: (quota/period) 
>  vcpu0: 12500/100000 
>  vcpu1: 12500/100000
>  vcpu2: 12500/100000
>  vcpu3: 12500/100000
>
I am with you till this point. This is what I was visualizing the
interface as, thanks for putting it.
   
> But, these values cannot be confirmed form the domain 
> XML file.
Do not understand what do you mean here.

Regards,
Nikunj




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