NTP on amd74 + powernow issues

[Guido van Rooij]

I've got a amd64 system where I;m using powernow. I am using th i8254
timecounter. I keep getting time resets from ntp:

Apr  4 01:13:27 gvr ntpd[96120]: kernel time sync enabled 6001
Apr  4 01:30:21 gvr ntpd[96120]: kernel time sync enabled 2001
Apr  4 03:28:25 gvr ntpd[96120]: time reset -10.587614 s
Apr  4 03:49:52 gvr ntpd[96120]: time reset +0.308086 s
Apr  4 04:22:08 gvr ntpd[96120]: time reset -0.973635 s
Apr  4 04:43:37 gvr ntpd[96120]: time reset +0.240889 s
Apr  4 05:59:46 gvr ntpd[96120]: time reset -0.315836 s
Apr  4 06:25:37 gvr ntpd[96120]: time reset +0.212031 s
Apr  4 07:04:14 gvr ntpd[96120]: time reset +0.281665 s
Apr  4 07:38:26 gvr ntpd[96120]: time reset -0.350271 s
Apr  4 08:13:57 gvr ntpd[96120]: time reset +0.402641 s
Apr  4 08:35:25 gvr ntpd[96120]: time reset -0.323047 s
Apr  4 09:44:12 gvr ntpd[96120]: time reset -0.170829 s
Apr  4 11:03:24 gvr ntpd[96120]: time reset +0.315831 s
Apr  4 11:44:06 gvr ntpd[96120]: time reset -0.843654 s
Apr  4 12:16:26 gvr ntpd[96120]: time reset +0.158634 s
Apr  4 13:51:38 gvr ntpd[96120]: time reset -0.539251 s
Apr  4 15:22:40 gvr ntpd[96120]: time reset +0.190155 s
Apr  4 16:32:20 gvr ntpd[96120]: time reset +0.210177 s
Apr  4 16:53:44 gvr ntpd[96120]: time reset -0.175892 s
Apr  4 17:09:50 gvr ntpd[96120]: time reset -0.506791 s
Apr  4 17:31:13 gvr ntpd[96120]: time reset +0.257775 s
Apr  4 19:15:18 gvr ntpd[96120]: time reset +0.341047 s
Apr  4 19:34:31 gvr ntpd[96120]: time reset -0.232655 s

ntpd uses the following peers:
ntpq> peers
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
+pruts.nl        193.79.237.14    2 u   34   64   37   10.648  -94.402  21.692
+muso.komputilo. 130.88.200.98    3 u   31  512   37   11.775  -86.616  15.943
-enterprise.sono 158.43.128.66    3 u   30  512   37   10.948  -111.01  20.576
+steghoefer.eu   87.239.10.190    3 u   28  512   37   11.670  -80.331  16.798
*ntp0.nl.uu.net  .GPS.            1 u   30   64   37   17.938  -101.39  27.102
+clepsydra.dec.c .GPS.            1 u   27  512   37  175.971  -77.023  16.738
+swisstime.ee.et 129.132.2.22     2 u   33   64   37   33.010  -76.135  18.209
ntpq> 

Especially the largers resets (+10 seconds) are annoying as e.g. dovecot
bails out.

Any clue on how this could be fixed?

-Guido