Re: ppc: bogomips at 73 when CPU is at 1GHz

From: Sven Luther
Date: Tue May 16 2006 - 20:30:25 EST


On Wed, May 17, 2006 at 06:18:19AM +0900, Junichi Uekawa wrote:
> Hi,
>
> I've noticed the very log value on bogomips on self-compiled 2.6.16.16
> on iBook G4.
>
> [06:12:59]ibookg4:~> cat /proc/cpuinfo
> processor : 0
> cpu : 7447A, altivec supported
> clock : 1066.666000MHz
> revision : 0.1 (pvr 8003 0101)
> bogomips : 73.47
> timebase : 18432000
> machine : PowerBook6,5
> motherboard : PowerBook6,5 MacRISC3 Power Macintosh
> detected as : 287 (iBook G4)
> pmac flags : 0000001b
> L2 cache : 512K unified
> pmac-generation : NewWorld
>
>
> It was somewhat higher on 2.6.14.
>
>
> Apparently I'm not the only person who noticed something similar;
> but I can't really read spanish:
>
> https://listas.hispalinux.es/pipermail/linux-ppc-es/2006-May/000820.html
>
> Am I missing something or is everyone seeing this?

2.6.16 doesn't use the some kind of do-nothing loop anymore to set the
bogomips value, but some internal cpu counter or something such. I don't know
the details.

As such, the bogomips value changed radically, and what you see is normal.
bogomips values are bogus anyway, so this change should not have any other
major effect.

Friendly,

Sven Luther

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