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

John Bradford
2003-09-15T19:05:47Z

> > > In the model I'm proposing, the 386 kernel would be missing the Athlon
> > > workarounds.
> >
> > This is unworkable unless you also have all the existing models where
> > you have fixes for later processors too.
>
> I think John wants to have the default be that only code for the target
> CPU be included in the kernel when built for a given CPU.

Yes, that's what I meant.

> There's no
> reason why someone building for 386 would want code for other CPUs at all,
> vendors and people who want to run a single suboptimal kernel on multiple
> machines.
>
> My own suggestion is that the default could continue to be "include
> anything which doesn't break or drastically slow the target CPU," and then
> have a flag value to exclude fixups or enhancements for other CPUs. This
> allows existing code to be gradully marked for simplification by embedded
> users or those who just want to avoid overhead in their kernel.

Ah, OK, on reflection that's probably more realistic from a practical
viewpoint, (see my other post in this thread).

John.