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Re: [Qemu-devel] [Qemu-ppc] [PATCH] ppc: Avoid decrementer related kvm e
From: |
David Gibson |
Subject: |
Re: [Qemu-devel] [Qemu-ppc] [PATCH] ppc: Avoid decrementer related kvm exits |
Date: |
Fri, 21 Oct 2011 12:13:29 +1100 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Thu, Oct 20, 2011 at 10:08:36AM -0700, Alexander Graf wrote:
>
> On 16.10.2011, at 22:26, David Gibson wrote:
>
> > In __cpu_ppc_store_decr(), we set up a regular timer used to trigger
> > decrementer interrupts. This is necessary to implement the decrementer
> > properly under TCG, but is unnecessary under KVM (true for both Book3S-PR
> > and Book3S-HV KVM variants), because the kernel handles generating and
> > delivering decrementer exceptions.
> >
> > Under kvm, in fact, the timer causes expensive and unnecessary exits from
> > kvm to qemu. This patch, therefore, disables setting the timer when kvm
> > is in use.
> >
> > Signed-off-by: Anton Blanchard <address@hidden>
> > Signed-off-by: David Gibson <address@hidden>
>
> Thanks, applied to ppc-next.
I think you've forgotten to push out the new ppc-next again..
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson