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

Pavel Machek
2003-09-10T14:18:53Z

Hi!

> > > 2. The CPU types are not a total order. Say I want a kernel
> > > that supports Athlons and a Centaur for my cluster. What
> > > CPU setting should I use? What CPU setting will give my the best
> > > performing kernel - and is that the same as the one for smallest
> > > kernel?
> >
> > You'd use two kernels. There is no sane other answer to that specific
> > case 8)
>
> Ehmm. In some cases, having multiple kernels is a pain in the @55.
>
> Having the option to make a generic kernel should remain. One that
> works on as much as possible CPUs. Even if it's a bit suboptimal on
> some CPUs.
>
> Also it would be nice if we can make the boot code run on anything
> until the point where the CPU is detected. Then we can give a nice
> message that the kernel was not compiled for this cpu instead of a
> blank-screen-hang. If we have to compile printk for 386 for this

Better yet do the check in i386/boot/setup.S; its assembly anyway... I
actually had check there (or somewhere near that :-) for x86-64. Not
sure where it is now.
Pavel
--
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]