I checked my home FreeBSD 8.2 NTP server for the clk_jitter reads zero bug, and yes, I see it too when using PPS kernel discipline.
server 127.127.22.1 flag3 1 http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver22.html So, I need to understand what "Controls the kernel PPS discipline" means and what the differences in code are between disabled, (default), and enabled are. I also need to understand the importance of the clock jitter statistic; I notice that system jitter is still reported with kernel PPS discipline enabled. If system jitter is less --yet to be determined--with kernel PPS discipline enabled, wouldn't that imply that kernel PPS would be prefered, regardless of reported clock jitter? Again, I have been mostly concerned with the clock offset and the stability of the frequency. I need to understand the importance and differences in both clock jitter and system jitter? Regards, Ed > -----Original Message----- > From: Mischanko, Edward T > Sent: Wednesday, January 09, 2013 1:34 PM > To: 'David J Taylor' > Subject: RE: Raspberry Pi Linux distributions w/ NTP > > David, > > I'm glad I was able to suggest something that is helpful. As to > what it means.... I am guessing that something in the Linux > kernel is not quite right when it comes to NTP. What that > something is, I don't know. Is it possible to submit a bug to > the Linux community as to how they are implementing PPS support > in their kernel? > > Regards, > Ed > > > -----Original Message----- > > From: David J Taylor [mailto:david-tay...@blueyonder.co.uk] > > Sent: Wednesday, January 09, 2013 10:40 AM > > To: Mischanko, Edward T > > Subject: Re: Raspberry Pi Linux distributions w/ NTP > > > > OK, Ed. I changed RasPi-1 at 14:20 UTC, Please let me know > if > > you see any > > difference.... > > > > http://www.satsignal.eu/mrtg/performance_ntp.php > > > > Cheers, > > David > > ============================== > > > > Interestingly, clk_jitter is now being reported as 0.004 ms, > and > > the zero > > jitter in bug 2314 is not present in the loopstats. It seems > to > > be > > stabilising at 0.003815 ms. > > > > Cheers, > > David > > -- > > SatSignal Software - Quality software written to your > > requirements > > Web: http://www.satsignal.eu > > Email: david-tay...@blueyonder.co.uk _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions