Re: [Qemu-devel] [Patch]KVM: enabling per domain PLE

[Hu, Xuekun]

> 
> The problem with this is that it requires an administrator to understand the
> workload, not only of the guest, but also of other guests on the machine.
> With low overcommit, a high PLE window reduces unneeded exits, but with
> high overcommit we need those exits to reduce spinning.
> 
> In addition, most kvm hosts don't have an administrator.  They are controlled
> by a management system, which means we'll need some algorithm in
> userspace to control the PLE window.  Taking the two together, we need a
> dynamic (for changing workloads) algorithm.
> 
> There are threads discussing this dynamic algorithm, we are making slow
> progress because it's such a difficult problem, but I think this is much more
> useful than anything requiring user intervention.

Avi, agreed that dynamic adaptive ple should be the best solution. However
currently it is a difficult problem like you said. Our solution just gives user
a choice who know how to set the two PLE values. So the solution is a compromise
solution, which should be better than nothing, for now? :-)

Your comments?