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Re: [Xen-devel] [PATCH] Export Multicore information

On 12/12/06 7:27 pm, "Kamble, Nitin A" <nitin.a.kamble@xxxxxxxxx> wrote:

>    The most interesting field of the cacheinfo is "shared cpus map".
> Take an example of clowertown. It has 4 cores per socket. Basically
> there are 2 duel-core dies in the packages. So there are 2 pairs of
> cores in the packages which share the L2 caches among the pair itself,
> not across the package.
>    So with this information the end user/admin would have better
> selection when she decides to split the cores from a single package
> across multiple domains.

Hm.... Ok, so we can have cache hierarchies where a single cache is split
among *some* of the threads in a core, or *some* of the cores in a package?
So you end up needing the physical APIC id to be able to apply the CPUID
information and find out *which* siblings are sharing?

I'm still tempted just to provide that APICid info to the guest. Was my
earlier presumption that the cache hierarchy in practice will always be
symmetric correct? Because that could simplify things.

 -- Keir

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