Re: [PATCH 1/2] x86/tsc: Allow quick PIT calibration despite interruptions

[Jan H. SchÃnherr]

Am 12.02.19 um 12:57 schrieb Thomas Gleixner:
> On Tue, 29 Jan 2019, Thomas Gleixner wrote:
> > On Tue, 29 Jan 2019, Jan H. SchÃnherr wrote:
> >
> > > Am 29.01.2019 um 11:23 schrieb Jan H. SchÃnherr:
> > > > +calibrate:
> > > > +	/*
> > > > +	 * Extrapolate the error and fail fast if the error will
> > > > +	 * never be below 500 ppm.
> > > > +	 */
> > > > +	if (d1 + d1 >= (delta * MAX_QUICK_PIT_ITERATIONS) >> 11) {
> > > > +		pr_info("Fast TSC calibration failed (wouldn't work)\n");
> > > > +		return 0;
> > > > +	}
> > >
> > > I messed this check up. "delta" is not the actual tsc delta between the
> > > first two successful reads at this point.
> > >
> > > (If it were, it might also correspond to more than one iteration; not
> > > sure if we care about that aspect, though.)
> >
> > I rather go for correct and if only for the reason that me/you/whoelse
> > doesn't have to scratch the head for an hour when looking at this half a
> > year from now.
>
> Any update on this?

Second version is out.

Regards
Jan