architecture kernel problems

[Mike Chalmers]

On 12/11/06, Matthew Saltzman <mjs at ces.clemson.edu> wrote:
> On Mon, 11 Dec 2006, James Wilkinson wrote:
>
> > Les wrote:
> >> I don't know what you are working on Mike, but if it helps, I installed
> >> to a 433Mhz celeron with the i386 package and when I ran that command I
> >> got:
> >> kernel-2.6.18-1.2798.fc6.i586
> >> kernel-2.6.18-1.2849.fc6.i586
> >> kernel-devel-2.6.18-1.2798.fc6.i586
> >> kernel-devel-2.6.18-1.2849.fc6.i586
> >> kernel-headers-2.6.18-1.2849.fc6.i386
> >>
> >> I was sort of expecting them all to say i386???  Maybe someone can help
> >> us understand what's happening.
> >
> > i586 will work, but an i686 kernel will work slightly better on a
> > Celeron.
> >
> > The basic 32 bit set of instructions that x86 Linux uses were introduced
> > with the Intel i386 back in 1986. Later Intel processors added extra
> > instructions to help in specific cases. (Later on, various "multimedia"
> > instructions were also added, but that's a separate discussion.)
> >
> > Most user-space programs don't actually need or gain from those extra
> > instructions. So Fedora compiles most programs using only i386
> > instructions -- hence the "i386" in most package names.
> >
> > Some packages (the kernel and glibc, for example) *can* make use of the
> > extra instructions. So Fedora provides an i686 version of those
> > packages, which do use the extra instructions. Unfortunately, there are
> > still some processors which don't support the i686 level of instructions
> > (Via only recently started supporting them, and AMD K6s are still used).
> > For these processors, Fedora provides an i586 version. (i586
> > instructions are still better than just the i386 instruction set in
> > these cases).
> >
> > i586 programs will work on later processors, but i586 processors don't
> > know how to handle i686 instructions. (If they did, they'd be i686
> > processors).
> >
> > I'm not sure whether the kernel headers actually contain *any*
> > instructions -- if they do, they'd be tiny portions of assembler. They
> > don't use processor-specific instructions, so count as i386.
> >
> > Hope this helps,
>
> IIRC, the i586 was peculiar to original Pentium and Pentium MMS.  I recall
> some discussion that optimal instruction ordering was different enough on
> i586 and i686 that running i586 kernels on i686 chips would result in more
> or less significant performance issues.
>
> >
> > James.
> >
> >
>
> --
>                 Matthew Saltzman
>
> Clemson University Math Sciences
> mjs AT clemson DOT edu
> http://www.math.clemson.edu/~mjs
>
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>

Is everything right with my system now that it says i686 instead of i586?

Kind Regards,
Mike