Re: [BUG] cpufreq: constant cpu_khz

Alok Kataria
2008-08-25T17:34:52Z

On Mon, 2008-08-25 at 05:39 -0700, Ingo Molnar wrote:
> * Peter Zijlstra <peterz@infradead.org> wrote:
>
> > > I noticed that my sched_clock() was slow on a number of machine, so
> > > I started looking at cpufreq.
> >
> > The below seems to fix the problem for me, but I don't have enough
> > clue to know if its the correct fix, please advise.
>
> > - set_cyc2ns_scale(tsc_khz_ref, freq->cpu);
> > + set_cyc2ns_scale(tsc_khz, freq->cpu);
>
> hm, that too is due to the tsc.c unification - Alok Cc:-ed. Applied your
> fix to x86/urgent.
>

Yes the fix is correct, tsc_khz can change in the loop above.
Looking at tsc_64.c before the integration, that too had this bug but
32bit was good. So this is the right fix.

Thanks,
Alok

> Ingo