Re: [patch 2/2] x86 amd fix cmpxchg read acquire barrier

From: Mathieu Desnoyers
Date: Wed Apr 22 2009 - 19:26:49 EST


* Alan Cox (alan@xxxxxxxxxxxxxxxxxxx) wrote:
> > Good point. I should probably configure this as "nothing" unless
> >
> > #ifdef CONFIG_X86_64
> > #if (defined(CONFIG_GENERIC_CPU) || defined(CONFIG_MK8))
> > ...
> > #endif
> > #endif
>
> Is the erratum only present in 64bit mode ?
>

Hrm, from the info I gathered in the web pages linked in the patch
header (refering to Google and Solaris), nothing said it was limited to
64bit mode. You are right.

> Really this needs someone with knowledge of the erratum to characterise
> it accurately and the workarounds.

Yep, but all I can hear from AMD so far is... *crickets*

The last revision of their errata I can find has been updated in
February 2008, and does not talk about this issue.

http://support.amd.com/us/Processor_TechDocs/25759.pdf

Thanks,

Mathieu

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Mathieu Desnoyers
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