BogoMIPS no longer supported on PowerPC?

Li Yang LeoLi at
Thu Aug 24 02:46:09 EST 2006

On 8/24/06, Tim Bird <tim.bird at> wrote:
> Johannes Berg wrote:
> > On Wed, 2006-08-23 at 18:25 +0800, Li Yang-r58472 wrote:
> >  > I noticed a recent modification to __delay has changed from using empty
> >  > loops to reading timebase.  Thus, breaks the calculation of bogomips,
> >  > and makes it terribly low.  Is the bogomips no longer being supported on
> >  > powerpc arch?
> >
> > What's there to be 'supported'? The only purpose of bogomips is
> > calibrating the delay loop, and that has changed now by using timebase,
> > hence bogomips no longer have a purpose. There was even a patch to
> > remove it from /proc/cpuinfo but I'm not sure whether that got applied
> > or not.
> I missed the patch for this, but I have a related question.
> What is the status of the calibration code now for PPC?
> Is it just skipped?

The calibration is still used.

> I assume that the ability to set a preset loops_per_jiffy
> is no longer relevant?

However, loop is no longer true loop now.  It should be called
timebase_change_per_jiffy. :)

- Leo

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