On 2011-7-6 16:56, Nikunj A. Dadhania wrote: > On Wed, 06 Jul 2011 14:56:27 +0800, Gui Jianfeng <guijianfeng@xxxxxxxxxxxxxx> wrote: >> On 2011-7-5 16:41, Nikunj A. Dadhania wrote: >>> On Tue, 05 Jul 2011 15:06:06 +0800, Wen Congyang <wency@xxxxxxxxxxxxxx> wrote: >>>> At 07/04/2011 07:19 PM, Nikunj A. Dadhania Write: >>>>> On Thu, 30 Jun 2011 11:13:18 +0800, Wen Congyang <wency@xxxxxxxxxxxxxx> wrote: >>>>>> We want to control bandwidth for each vcpu, so we can not use the >>>>>> API virDomainSetSchedulerParameters(). Introduce two new APIs to >>>>>> change and query bandwidth for each vcpu. >>>>>> >>>>> Will we have different cpu bandwidth for different vcpus? >>>>> >>>>> Something like this: >>>>> >>>>> vcpu1: 1000000/250000 >>>>> vcpu2: 1000000/500000 >>>>> vcpu3: 1000000/300000 >>>>> vcpu4: 1000000/400000 >>>>> >>>>> IMO, that is not required, we can have a top level bandwitdh for the VM >>>>> and then redistribute it among vcpus equally, without user knowing about >>>>> it. >>>>> >>>>> Something like this: >>>>> >>>>> VM1(4vcpu) has to be throttled at 1CPU bandwidth using SetSchedParamters. >>>>> >>>>> Internally libvirt splits it equally: >>>>> vcpu1: 1000000/250000 >>>>> vcpu2: 1000000/250000 >>>>> vcpu3: 1000000/250000 >>>>> vcpu4: 1000000/250000 >>>>> >>>>> So why introduce VCPU level apis? >>>> >>>> Adam Litke said IBM's performance team nead to control cpu bandwidth for each >>>> vcpu. >>> Right, but we do not export that as a User API, that was my suggestion. >>> We can internally control each vcpu's bandwidth, i.e. divide equally. >> >> Hmm, I heard that some server could run CPUs at different speed. >> May be this patch can simulate this behavior. > That happens on my laptop as well, depending on the machine load CPU > frequency is changed but it is done transparently. I means explicitly CPU speed configuring. ;) > > I am not sure if we are trying to simulate that here. So why not leave the flexible interface here, and let users make the decision? Thanks, Gui > > Regards > Nikunj > > -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list