Re: [PATCH 3/10] NTP: add ntp_update_frequency

From: Roman Zippel
Date: Thu Jan 12 2006 - 07:27:19 EST


Hi,

On Wed, 11 Jan 2006, john stultz wrote:

> > This introduces ntp_update_frequency and deinlines ntp_clear() (as it's
> > not performance critical).
> > It also changes how tick_nsec is calculated from tick_usec, instead of
> > scaling it using TICK_USEC_TO_NSEC it's simply shifted by the difference.
> > Since ntp doesn't change the tick value, the result in practice is the
> > same, but it's easier to change this into a clock parameter, which can
> > be calculated during boot.
> >
>
> One last thing, shouldn't this patch kill TICK_USEC_TO_NSEC ?

If it's the only user it could be removed, but jiffies.h can still be
cleaned up in a separate pass.

> > @@ -334,10 +334,11 @@ int do_adjtimex(struct timex *txc)
> > time_freq = max(time_freq, -time_tolerance);
> > } /* STA_PLL */
> > } /* txc->modes & ADJ_OFFSET */
> > - if (txc->modes & ADJ_TICK) {
> > + if (txc->modes & ADJ_TICK)
> > tick_usec = txc->tick;
> > - tick_nsec = TICK_USEC_TO_NSEC(tick_usec);
> > - }
> > +
> > + if (txc->modes & ADJ_TICK)
> > + ntp_update_frequency();
>
> Why the extra conditional instead of just adding ntp_update_frequency()
> inside the braces?

This changes in the next patch. :)

> > +void ntp_update_frequency(void)
> > +{
> > + tick_nsec = tick_usec * 1000;
> > + tick_nsec -= NSEC_PER_SEC / HZ - TICK_NSEC;
> > +}
>
> Could you add another "john is slow and forgetful" comment here?

Ok.

bye, Roman
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/