Re: RFC: [2.6 patch] better i386 CPU selection

David Lang
2003-09-14T00:13:55Z

On Sun, 14 Sep 2003, Andi Kleen wrote:

> Adrian Bunk <bunk@fs.tum.de> writes:
> >
> > I don't like the current user interface that says "if you want to
> > support both an Athlon and a Pentium 4 in your kernel use the Pentium III
> > option. And for better optimization, also check the "generic" option".
>
> The big issue with your ifdefing of workarounds is that it causes subtle
> support problems. A lot of settings for specific CPUs boot and work
> fine on other CPUs (possibly with small performance impact, but they're
> rarely noticeable without explicit benchmarking). Just when you don't
> include the workarounds for the bugs on these other CPUs it will boot and
> even run, but fail mysteriously once a month. And that would be a support
> nightmare.
>

it sounds like a nessasary part of this patch would be to detect the CPU
type and complain VERY loudly if it's not one supported by the build.

This is probably a good idea anyway.

David Lang