Re: Time precision, adjtime(x) vs. gettimeofday

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

> I repeat the question: what are the values of drift on the machines
> that encounter the problem ? Is this drift stable or unstable?

So far, there is no problem. The problem that was happening
was a via_calibrate_decr() bug with HZ != 100, but when
investigating, I figured out that we had a potential problem
there, that's all and that's why I want people like you who
know those problems well to state if it's worth bothering ;)
> >
> > On all cases, those will drift some way from what the NTP server will
> > give, either a lot or not, it will. So we may end up adjusting our
> > kernel rate and thus opening a window for the problem.
> 
> The worst variations of drift I've seen are a few ppm for a given
> machine, barring the occasional boot-time calibration problems that
> I have encountered.

OK.