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

[Pavel Machek <pavel@ucw.cz>]

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?]