[libvirt] [PATCH 5/6] qemu: Implement hypervisor's period and quota tunable XML configuration and parsing

[KAMEZAWA Hiroyuki]

(2012/05/17 14:25), Wen Congyang wrote:

> At 05/17/2012 01:09 PM, KAMEZAWA Hiroyuki Wrote:
>> (2012/05/17 14:07), Wen Congyang wrote:
>>
>>> At 05/17/2012 12:46 PM, KAMEZAWA Hiroyuki Wrote:
>>>> (2012/05/17 12:54), Wen Congyang wrote:
>>
>>>>> So, if we donot limit the hypervisor, the behavior shoule not be
>>>>> changed. So we should limit the whole vm. If the hypervisor threads
>>>>> are limited, there is no need to limit the whole vm.
>>>>>
>>>>
>>>>
>>>> need to tune hypervisor quota to limit vcpu-only quota ?
>>>> Sounds strange to me.
>>>
>>> No, current implemetion is:
>>> 1. limit vcpu and hypervisor: vm is not limited
>>> 2. limit vcpu only: vm is limited
>>> 3. limit hypervisor: vm is not limited
>>> 4. vcpu and hypervisor are not limited: vm is not limited.
>>>
>>
>>
>> In 2.
>>
>>    vm               ----- quota_is_limited
>>     |- hypervisor   ----- quota is unlimited
>>     |- vcpu[0...x]  ----- quota is limited
>>
>> Hm...vm is limited. It seems user need to tune vm's quota...can user
>> makes vm's quota to be unlimited and limit *only* vpcus as Xen ?
> 
> Without this patchset, the vm will be limited if the vcpu is limited.
> We cannot know whether the hypervisor is unlimited or the user does not
> set it. If the user does not set it, we should not change the behavior.
> So I donot find an easy way to limit only vcpus.
> 

That just comes from your new XML rule..

If I was you..... I'll add an optional attribute to quota/period as

  <quota target='all|vcpu'>   </quota> # all is default and limit the whole vm.
                                       # vcpu is just limit vcpus. hypervisor is unlimited.
  <period> .... </period>              # period is shared in all settings.

If hypervisor should be limited.

  <quota target='hypervisor'> ...</quota>

should work.

Thanks,
-Kame