On 14 Feb 2006 at 14:21, Roman Zippel wrote:
> Hi,
>
> On Tue, 14 Feb 2006, Ulrich Windl wrote:
>
> > 15_time_offset and 18_time_freq change some well-known constants (like MAXPHASE)
> > by three orders of magnitude.
--- linux-2.6-mm.orig/include/linux/timex.h 2005-12-21 12:12:00.000000000 +0100
+++ linux-2.6-mm/include/linux/timex.h 2005-12-21 12:12:08.000000000 +0100
@@ -95,11 +95,11 @@
#define SHIFT_USEC 16 /* frequency offset scale (shift) */
#define FINENSEC (1L << SHIFT_SCALE) /* ~1 ns in phase units */
-#define MAXPHASE 512000L /* max phase error (us) */
+#define MAXPHASE 500000000L /* max phase error (ns) */
#define MAXFREQ (512L << SHIFT_USEC) /* max frequency error (ppm) */
#define MINSEC 16L /* min interval between updates (s) */
#define MAXSEC 1200L /* max interval between updates (s) */
-#define NTP_PHASE_LIMIT (MAXPHASE << 5) /* beyond max. dispersion */
+#define NTP_PHASE_LIMIT ((MAXPHASE / 1000) << 5) /* beyond max. dispersion */
> >
> > the new adjtime() (16_time_adjust, 12_time_adj) changes the semantics: Since about
> > Linux 0.99, adjtime() had the adjtime_is_accurate property, i.e. on the long term
> > it behaved like an addition.
>
> I disagree, could you please explain how you come to this conclusion?
+ tick_nsec_curr += time_adjust * 1000 / HZ;
Assuming 1024Hz interrupt frequency:
(1µs * 1000) / 1024 == 0ns; 0 * 1024 == 0µs, not 1µs
(2µs * 1000) / 1024 == 1ns; 1 * 1024 == 1.024µs, not 2µs
> The patches don't change the behaviour beyond that they increase
> resolution and precision. Only the final patch changes the ntp code to
> match the behaviour of ntp reference code without including all its mess.
It's quite hard to tell: The code is very different what I've ever seen.
Regards,
Ulrich
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