Re: Improving scheduler for KVM

[Gleb Natapov <gleb@redhat.com>]

On Fri, Nov 01, 2013 at 02:51:28PM +0800, R wrote:
> Hi,
> 
> Another quick question.
> 
> Is there any benchmark that is used to measure the performance of a VM
> scheduler?
> 
I am not sure what do you mean by "performance of a VM scheduler". Since
you are the one who wants to improve scheduler I would have assumed that
you know what aspects of it you are going to improve and know how to
show current inefficiency.

> 
> 2013/10/30 R <19890121wr@gmail.com>:
> > Hi
> > Not only lock waiter preemption, but the scheduler may affect VMs' IO
> > throughput.
> > Experiments must be taken to figure out the reason.
> >
> > I am trying to use preempt_notifier and vmexit handler to build a more
> > efficient scheduler.
> > Something like priority boosting.
> >
> > 2013/10/29 Gleb Natapov <gleb@redhat.com>:
> >> On Tue, Oct 29, 2013 at 10:20:37AM +0800, R wrote:
> >>> Hi, everyone
> >>>
> >>> I am a graduate student. And now I have some spare time.
> >>> I notice that KVM uses kernel scheduler to schedule VCPUs.
> >>> But there exists many problem beyond the capability of current
> >>> scheduler. (e.g. Lock Waiter Preemption problem)
> >>>
> >>> And I don't want to reinvent the wheel. So I want to implement a
> >>> module which can be used by the scheduler to schedule VCPUs more
> >>> efficient.
> >>>
> >>> Is there any documentation about any problem that I should pay attention to?
> >>> Any comment is welcome.
> >>>
> >> If you are thinking about gang scheduler it was done before, but it will
> >> never be accepted upstream. And IIRC pvticketlock result was close if
> >> not better than gang scheduling. If you are thinking about something
> >> else then implement it in Linux scheduler directly. Linux scheduler is
> >> not pluggable, so you cannot change it from a module.
> >>
> >> --
> >>                         Gleb.
> >
> >
> >
> > --
> > Thanks
> > Rui Wu
> 
> 
> 
> -- 
> Thanks
> Rui Wu

--
			Gleb.