Messages in this thread | | | Subject | Re: [RFC -v3 PATCH 0/3] directed yield for Pause Loop Exiting | From | Mike Galbraith <> | Date | Tue, 04 Jan 2011 11:32:14 +0100 |
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On Tue, 2011-01-04 at 11:09 +0200, Avi Kivity wrote: > On 01/04/2011 08:42 AM, Mike Galbraith wrote:
> > If I were to, say, run a 256 CPU VM on my quad, would this help me get > > more hackbench or whatever oomph from my (256X80386/20:) box? > > First of all, you can't run 256 guests on x86 kvm.
I didn't want 256 guests. Just one great big dog slow virtual playpen :)
> > > Both Intel and AMD CPUs have a feature that detects when a virtual > > > CPU is spinning on a lock and will trap to the host. > > > > Does an Intel Q6600 have this trap gizmo (iow will this do anything at > > all for my little box if I were to try it out). > > Likely not. Run > http://git.kernel.org/?p=virt/kvm/qemu-kvm.git;a=blob_plain;f=kvm/scripts/vmxcap;hb=HEAD, > look for 'PAUSE-loop exiting'. I think the first processors to include > them were the Nehalem-EXs, and Westmeres have them as well.
Oh darn, need new box to get all the toys. Thanks.
-Mike
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