Re: 2.6.12-mm1 boot failure on NUMA box.

[Ingo Molnar <mingo@elte.hu>]

* Martin J. Bligh <mbligh@mbligh.org> wrote:

> > -	/*
> > -	 * In the NUMA case we dont use the TSC as they are not
> > -	 * synchronized across all CPUs.
> > -	 */
> > -#ifndef CONFIG_NUMA
> > -	if (!use_tsc)
> > -#endif
> > +	if (!cpu_has_tsc)
> >  		/* no locking but a rare wrong value is not a big deal */
> >  		return jiffies_64 * (1000000000 / HZ);
> 
> Humpf. That does look dangerous on a NUMA-Q. The TSCs aren't synced, 
> and we can't use them .... have to use PIT, whether the CPUs have TSC 
> or not.

is the only problem the unsyncedness? That should be fine as far as the 
scheduler is concerned. (we compensate for per-CPU drifts)

	Ingo