Re: CPU-freq and bogomips

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Mon, 2006-03-06 at 00:53 +0100, Elimar Riesebieter wrote:
> On Mon, 06 Mar 2006 the mental interface of
> Yves-Alexis Perez told:
> 
> > On Sun, 2006-03-05 at 23:42 +0100, Sven Luther wrote:
> > > bogomips are bogus :)
> > 
> > processor       : 0
> > cpu             : 7447A, altivec supported
> > clock           : 749.999000MHz
> > revision        : 0.2 (pvr 8003 0102)
> > bogomips        : 36.73
> > timebase        : 18432000
> > machine         : PowerBook5,6
> > motherboard     : PowerBook5,6 MacRISC3 Power Macintosh
> > detected as     : 287 (PowerBook G4 15")
> > pmac flags      : 0000001b
> > L2 cache        : 512K unified
> > pmac-generation : NewWorld
> > 
> > 
> > 36.73, woohoo :)

With recent kernels, when build with ARCH=powerpc, we now use the
hardware timebase instead of bogus processor loops for short timings.
Thus our bogomips value is no longer the speed at which the processor
runs empty loops, but the actual processor timebase value as obtained
after calibration at boot.

Ben.