Re: KVM Processor cache size

Anthony Liguori
2010-08-02T22:23:25Z

On 08/02/2010 08:49 AM, Ulrich Drepper wrote:
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> On 08/02/2010 05:51 AM, Andre Przywara wrote:
>
>> Do you have a use case for the cache size or is this just out of curiosity?
>>
> glibc uses the cache size information returned by cpuid to perform
> optimizations. For instance, copy operations which would pollute too
> much of the cache because they are large will use non-temporal
> instructions. There are real performance benefits.

I imagine that there would be real performance problems from doing live
migration with -cpu host too if we don't guarantee these values remain
stable across migration...

Regards,

Anthony Liguori

> Even the synthetic
> CPU provided by qemu should have a more realistic value.
>
> - --
> ➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖
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