From: David Gibson <david@gibson.dropbear.id.au>
To: Alexander Graf <agraf@suse.de>
Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [Qemu-ppc] [PATCH] ppc: Avoid decrementer related kvm exits
Date: Fri, 21 Oct 2011 12:13:29 +1100 [thread overview]
Message-ID: <20111021011329.GD3852@truffala.fritz.box> (raw)
In-Reply-To: <BE398372-7360-4F5C-B538-9D6A5F133D82@suse.de>
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 <anton@au1.ibm.com>
> > Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
>
> 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
prev parent reply other threads:[~2011-10-21 2:14 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-17 5:26 [Qemu-devel] [PATCH] ppc: Avoid decrementer related kvm exits David Gibson
2011-10-20 17:08 ` Alexander Graf
2011-10-21 1:13 ` David Gibson [this message]
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