Re: [PATCH] 2.6 workaround for Athlon/Opteron prefetch errata

Jeff Garzik
2003-09-11T15:06:29Z

Andi Kleen wrote:
> On Thu, 11 Sep 2003 10:34:36 -0400
> Jeff Garzik <jgarzik@pobox.com> wrote:
>
>
>>>X86_GENERIC is merely an optimization hint (currently it only changes the cache
>>>line size hint) It does not change anything related to correctness. Everything
>>>that handles correctness is checked unconditionally.
>>
>>When, building non-Pentium4-related code when CONFIG_MPENTIUM4 &&
>>!CONFIG_X86_GENERIC, it's OK that the code is incorrect for (picking
>>example) AMD processors.
>
>
> No 2.6 changed that. On 2.6 you can exchange the kernels.
>
> [that was mainly done for distributions, but helps other users too]

If distributions are not building with CONFIG_X86_GENERIC, then they're
broken. So it was rather pointless for 2.6 to "change that."

Luckily, CONFIG_X86_GENERIC allows us the opportunity to be _less_
generic when it's not defined, regardless of what you originally
intended ;-)

Jeff