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Subject: Re: [hwloc-devel] Cache size/sharing errors on 8x4 Opteron system
From: Brice Goglin (Brice.Goglin_at_[hidden])
Date: 2009-09-22 13:29:33


Samuel Thibault wrote:
> Samuel Thibault, le Tue 22 Sep 2009 16:44:11 +0200, a écrit :
>
>> I'm afraid the bug is most probably in the kernel,
>>
>
> BTW, I know that on x86 at least glibc and libgomp use the cpuid
> instruction themselves to discover the cpu topology. Such backend could
> be written to compensate for kernel bugs, but it's not necessarily clear
> whether it would be easy to decide at runtime which one between linux
> and such backend is right (because more up-to-date). It would however
> be useful for OSes which don't export this kind of information.
>

Well, the kernel also uses cpuid to discover the cpu topology.

Brice