From owner-freebsd-stable@FreeBSD.ORG Fri Feb 12 19:46:06 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 3E725106568B for ; Fri, 12 Feb 2010 19:46:06 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from qmta01.emeryville.ca.mail.comcast.net (qmta01.emeryville.ca.mail.comcast.net [76.96.30.16]) by mx1.freebsd.org (Postfix) with ESMTP id 240318FC1D for ; Fri, 12 Feb 2010 19:46:05 +0000 (UTC) Received: from omta01.emeryville.ca.mail.comcast.net ([76.96.30.11]) by qmta01.emeryville.ca.mail.comcast.net with comcast id h2t61d00C0EPchoA17m6XF; Fri, 12 Feb 2010 19:46:06 +0000 Received: from koitsu.dyndns.org ([98.248.46.159]) by omta01.emeryville.ca.mail.comcast.net with comcast id h7m51d0093S48mS8M7m6jG; Fri, 12 Feb 2010 19:46:06 +0000 Received: by icarus.home.lan (Postfix, from userid 1000) id C00D81E301A; Fri, 12 Feb 2010 11:46:04 -0800 (PST) Date: Fri, 12 Feb 2010 11:46:04 -0800 From: Jeremy Chadwick To: Torfinn Ingolfsen Message-ID: <20100212194604.GA73961@icarus.home.lan> References: <20100211190652.6a66c618.torfinn.ingolfsen@broadpark.no> <20100211192515.GB13854@icarus.home.lan> <20100212132947.eb2af3d0.torfinn.ingolfsen@broadpark.no> <20100212131117.GA51905@icarus.home.lan> <20100212174452.2140cd72.torfinn.ingolfsen@broadpark.no> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100212174452.2140cd72.torfinn.ingolfsen@broadpark.no> User-Agent: Mutt/1.5.20 (2009-06-14) Cc: freebsd-stable@freebsd.org 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: Fri, 12 Feb 2010 19:46:06 -0000 On Fri, Feb 12, 2010 at 05:44:52PM +0100, Torfinn Ingolfsen wrote: > On Fri, 12 Feb 2010 05:11:17 -0800 > Jeremy Chadwick wrote: > > > Please try doing this: > > > > - stop ntpd > > - rm /var/db/ntpd.drift > > - sysctl kern.timecounter.hardware=ACPI-safe > > - start ntpd > > Thanks, I'm currently testing that. Results in 72 hours (or less) :-) Something else came to mind: some BIOSes let you disable/enable HPET. Often labelled as "High Performance Event Timer" or "Multimedia Timer", you could disable this option then check kern.timecounter.choice to see if HPET is gone from the list. If it is, FreeBSD will very likely choose ACPI-safe as the default timecounter (again, check kern.timecounter.hardware to see what the kernel chose itself. Remember that your sysctl.conf entry will override this though! :-) ), which -- assuming it works -- should solve your problem. Technical footnote: I wish I understood 1) the difference between ACPI-safe and ACPI-fast, and 2) how the system or OS "ranks" the timecounters (the higher the value in parenthesis, supposedly the more accurate/preferred it is). Xin, do you happen to know how this works? -- | Jeremy Chadwick jdc@parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |