Re: [PATCH v4 0/3] KVM: Introduce dedicated vCPUs hint KVM_HINTS_DEDICATED
From: Eduardo Valentin
Date: Tue Mar 06 2018 - 09:44:35 EST
Folks,
On Tue, Feb 13, 2018 at 09:05:39AM +0800, Wanpeng Li wrote:
> This patchset introduces dedicated vCPUs(vCPU pinning, and there is no
> vCPU over-commitment) hint KVM_HINTS_DEDICATED, it has two users now:
>
> 1) Waiman Long mentioned that:
>
> Generally speaking, unfair lock performs well for VMs with a small
> number of vCPUs. Native qspinlock may perform better than pvqspinlock
> if there is vCPU pinning and there is no vCPU over-commitment.
>
> 2) vCPUs are very unlikely to get preempted when they are the only task
> running on a CPU. PV TLB flush is slower that the native flush in that
> case.
>
> v3 -> v4:
> * update feature bit document
> v2 -> v3:
> * a separate table for CPUID[0x40000001].EDX bits
> * a new kvm_hint_has_feature macro
> v1 -> v2:
> * update to KVM_HINTS_DEDICATED
Great to see this has finally moved forward! Thanks for picking it up Wanpeng.
I would just request to next time at least reference the original thread and
copy the original authors of the patch/idea.
Thanks a lot.
--
All the best,
Eduardo Valentin