Re: Clocksource tsc unstable (delta = -8589361717 ns) in current git

Thomas Gleixner
2010-10-26T15:46:48Z

On Tue, 26 Oct 2010, Peter Zijlstra wrote:

> On Tue, 2010-10-26 at 15:58 +0200, Markus Trippelsdorf wrote:
> > >
> > > This is strange, tsc is actually stable on your F10h revC.
> >
> > Yes. constant_tsc is among the CPU flags.
>
> constant_tsc only means the TSC is not affected by cpu freq changes.
>
> It has zero relevance to cross-cpu sync of the TSC. The clocksource
> stuff requires your TSC to be synchronous over all your CPUs.

That and not affected by C-States either.

Thanks,

tglx