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

Adrian Bunk
2003-09-15T20:55:37Z

On Mon, Sep 15, 2003 at 07:32:49AM +0100, John Bradford wrote:
>...
> It should be possible, and straightforward, to compile a kernel which:
>
> 1. Supports, (I.E. has workarounds for), any combination of CPUs.
> E.G. a kernel which supports 386s, and Athlons _only_ would not
> need the F00F bug workaround. Currently '386' kernels include it,
> because '386' means 'support 386 and above processors'.
>
> 2. Has compiler optimisations for one particular CPU.
> E.G. the 386 and Athlon supporting kernel above could have
> alignment optimised for either 386 or Athlon.
>...

That's the point where even I consider such a system to be too complex.

If you want maximum performance compile a kernel specific for your
system.

Compiling a kernel that supports more than one CPU is for people that
can even live with let's say a 10% performance penalty.

If you want to run a kernel on both a 386 and an Athlon it's most likely
non-optimal for both of them.

> John.

cu
Adrian

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