Re: [PATCH] Re: Discrepancies between /proc/cpuinfo and Dave J's

H. Peter Anvin (hpa@zytor.com)
9 Oct 2001 18:38:39 -0700


Followup to: <p05100361b77232f67994@[207.213.214.37]>
By author: Jonathan Lundell <jlundell@pobox.com>
In newsgroup: linux.dev.kernel
>
> At 4:28 PM +0200 2001-07-11, Dave Jones wrote:
> >On Wed, 11 Jul 2001, Hugh Dickins wrote:
> >
> >> Am I paranoid?
> >
> >Probably :)
> >The Intel CPUs with PSN I've seen simply drop 1 level.
> >What other CPUs support this feature? ISTR Transmeta had it?
> >Do they behave the same?
> >
> >> I feel nervous about "c->cpuid_level--" inferring
> >> what we expect to happen to it, would prefer to check it (below).
> >> + c->cpuid_level = cpuid_eax(0);
> >
> >No biggie, either solution is fine with me.
>
> HD's version has the advantage of not having to make assumptions
> about how future CPUs might handle the level, and leaves open the
> alternative possibility of leaving the level at 3 (or some future 4)
> and just turning off the serial-number capability.
>

cpuid_level-- is wrong on at least one existing processor (Crusoe),
which doesn't have CPUID level 2 and therefore goes from 3 to 1.

-hpa

-- 
<hpa@transmeta.com> at work, <hpa@zytor.com> in private!
"Unix gives you enough rope to shoot yourself in the foot."
http://www.zytor.com/~hpa/puzzle.txt	<amsp@zytor.com>
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