From: Chegu Vinod <chegu_vinod@hp.com>
To: kvm@vger.kernel.org
Subject: Re: How to determine the backing host physical memory for a given guest ?
Date: Sat, 12 May 2012 02:50:19 +0000 (UTC) [thread overview]
Message-ID: <loom.20120512T044637-238@post.gmane.org> (raw)
In-Reply-To: loom.20120511T013646-106@post.gmane.org
Chegu Vinod <chegu_vinod <at> hp.com> writes:
>
> Andrew Theurer <habanero <at> linux.vnet.ibm.com> writes:
>
> Regarding the -numa option :
>
> I had earlier (about a ~month ago) tried the -numa option. The layout I
> specified didn't match the layout the guest saw. Haven't yet looked into the
> exact reason...but came to know that there was already an open issue:
>
> https://bugzilla.redhat.com/show_bug.cgi?id=816804
>
> Also remember noticing a warning message when the -numa option was used for a
> guest with more than 64VCPUs. (in my case with 80 VCPUs). Will be looking at
> the code soon to see if there is any limitation...
>
Just FYI...
Made some minor changes in qemu to allow for >64 cpus while using the -numa
option and was able to boot 80way guest with 8 numa nodes in them.
With NUMA in the guest I got much better performance for AIM7-high-systime
workload (pretty close to native!).
Given the nature of this system intensive workload and a small memory footprint
I didn't pin the VCPUs. Do expect to see a need for pinning the VCPUs while
running memory intensive workloads.
Still have to try out the experiments with the PV lock changes (instead
of the current temporary workarounds).
Thanks
Vinod
> >
> > -Andrew Theurer
> >
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>
prev parent reply other threads:[~2012-05-12 2:50 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-09 13:05 How to determine the backing host physical memory for a given guest ? Chegu Vinod
2012-05-09 13:46 ` Avi Kivity
2012-05-10 1:23 ` Chegu Vinod
2012-05-10 15:34 ` Andrew Theurer
2012-05-11 1:22 ` Chegu Vinod
2012-05-12 2:50 ` Chegu Vinod [this message]
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