Date: Sun, 21 Feb 2010 14:29:28 -0500 From: David Magda <dmagda@ee.ryerson.ca> To: Peter Jeremy <peterjeremy@acm.org> Cc: FreeBSD Stable <freebsd-stable@freebsd.org> Subject: Re: ntpd struggling to keep up - how to fix? Message-ID: <F00C6A46-324F-43AA-BD0E-C1B978DF7739@ee.ryerson.ca> In-Reply-To: <20100221173619.2470aa85.torfinn.ingolfsen@broadpark.no> References: <20100212132947.eb2af3d0.torfinn.ingolfsen@broadpark.no> <20100212131117.GA51905@icarus.home.lan> <20100212174452.2140cd72.torfinn.ingolfsen@broadpark.no> <20100217194927.e3ec60ae.torfinn.ingolfsen@broadpark.no> <20100217200322.da66c9f8.torfinn.ingolfsen@broadpark.no> <20100218205458.GA78560@server.vk2pj.dyndns.org> <20100218231223.ec6b9fa8.torfinn.ingolfsen@broadpark.no> <20100219003844.acdaa866.torfinn.ingolfsen@broadpark.no> <20100220015351.GB81639@server.vk2pj.dyndns.org> <20100220223201.178e67dd.torfinn.ingolfsen@broadpark.no> <20100221050823.GB22670@server.vk2pj.dyndns.org> <20100221173619.2470aa85.torfinn.ingolfsen@broadpark.no>
next in thread | previous in thread | raw e-mail | index | archive | help
On Feb 21, 2010, at 11:36, Torfinn Ingolfsen wrote: > On Sun, 21 Feb 2010 16:08:23 +1100 Peter Jeremy > <peterjeremy@acm.org> wrote: > >> Having re-checked my maths, using both your "time reset" results, can >> you please try: >> sysctl machdep.acpi_timer_freq=3570847 >> That should result in a drift of close to zero (well within NTP's >> lock range of +/- 300ppm). > > And a few hours later: from /var/log/messages: > Feb 21 09:54:50 kg-f2 ntpd[55452]: ntpd 4.2.4p5-a (1) > Feb 21 09:59:10 kg-f2 ntpd[55453]: kernel time sync status change 2001 > > More info: > root@kg-f2# ntpq -p > remote refid st t when poll reach delay > offset jitter > ========================================================== > *kg-omni1.kg4.no 78.157.115.4 3 u 31 64 377 0.174 > -10.253 0.160 > root@kg-f2# ntpdc -c loopi -c sysi > offset: -0.010253 s > frequency: 6.744 ppm > poll adjust: -30 > watchdog timer: 47 s [...] For future reference, how does the math work? How do you go from taking a timer number: $ sysctl machdep.acpi_timer_freq machdep.acpi_timer_freq: 3577045 And the ntpd(8) time reset log entries to adjust the frequency? Or do you use the PPM output of the ntpdc(8) command? I'm not quite sure I understand what happened here. :)
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?F00C6A46-324F-43AA-BD0E-C1B978DF7739>