From owner-freebsd-stable@FreeBSD.ORG Sun Feb 21 19:40:02 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id C96061065672 for ; Sun, 21 Feb 2010 19:40:02 +0000 (UTC) (envelope-from dmagda@ee.ryerson.ca) Received: from toq11-srv.bellnexxia.net (toq11.bellnexxia.net [209.226.175.118]) by mx1.freebsd.org (Postfix) with ESMTP id 71ABD8FC08 for ; Sun, 21 Feb 2010 19:40:02 +0000 (UTC) Received: from toip5.srvr.bell.ca ([209.226.175.88]) by tomts16-srv.bellnexxia.net (InterMail vM.5.01.06.13 201-253-122-130-113-20050324) with ESMTP id <20100221192929.DDVA11823.tomts16-srv.bellnexxia.net@toip5.srvr.bell.ca> for ; Sun, 21 Feb 2010 14:29:29 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ApEBACITgUtMQR9h/2dsb2JhbAAH1VWEawSDFQ Received: from bas1-toronto09-1279336289.dsl.bell.ca (HELO [192.168.1.103]) ([76.65.31.97]) by toip5.srvr.bell.ca with ESMTP; 21 Feb 2010 14:29:04 -0500 Message-Id: From: David Magda To: Peter Jeremy In-Reply-To: <20100221173619.2470aa85.torfinn.ingolfsen@broadpark.no> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v936) Date: Sun, 21 Feb 2010 14:29:28 -0500 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> X-Mailer: Apple Mail (2.936) Cc: FreeBSD Stable Subject: Re: ntpd struggling to keep up - how to fix? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 21 Feb 2010 19:40:02 -0000 On Feb 21, 2010, at 11:36, Torfinn Ingolfsen wrote: > On Sun, 21 Feb 2010 16:08:23 +1100 Peter Jeremy > 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. :)