Date: Thu, 18 Feb 2010 23:12:23 +0100 From: Torfinn Ingolfsen <torfinn.ingolfsen@broadpark.no> To: freebsd-stable@freebsd.org Subject: Re: ntpd struggling to keep up - how to fix? Message-ID: <20100218231223.ec6b9fa8.torfinn.ingolfsen@broadpark.no> In-Reply-To: <20100218205458.GA78560@server.vk2pj.dyndns.org> 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> <20100217194927.e3ec60ae.torfinn.ingolfsen@broadpark.no> <20100217200322.da66c9f8.torfinn.ingolfsen@broadpark.no> <20100218205458.GA78560@server.vk2pj.dyndns.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, 19 Feb 2010 07:54:58 +1100 Peter Jeremy <peterjeremy@acm.org> wrote: > On 2010-Feb-17 20:03:22 +0100, Torfinn Ingolfsen <torfinn.ingolfsen@broadpark.no> wrote: > Did you delete /etc/ntp.drift between timecounter changes? I sure did, I used the instructions given. > There's ntptime(8) but it doesn't have a "self-calibrate mode". Ok, good to know. > Based on the messages log you gave, and assuming the ntpd PLL is sane, > your acpi-safe clock is about 2500ppm slow (the steps reflect about > 2000ppm and the ntpd PLL should be compensating for a further 500ppm) > - this is really bad, even for consumer-grade stuff. Are you running > non-standard clock speeds or multipliers? No, everything at default values here (ie. I haven't changed anything in either BIOS or FreeBSD), except from changing timer from HPET to ACPI-safe. > If there's nothing obvious, I'd follow John Hay's suggesion and > force set either your TSC or ACPI frequency in sysctl.conf (you > can't override the HPET frequency). > > Take either the TSC or ACPI frequency reported by "sysctl machdep", > reduce it by 2500ppm and set that in /etc/sysctl.conf. Assuming > a "standard" (3.58MHz) ACPI, the latter would look like: > > machdep.acpi_timer_freq=3570596 This one is root@kg-f2# sysctl machdep.acpi_timer_freq machdep.acpi_timer_freq: 3579545 So I should change that to 3577045, right? Like so: root@kg-f2# sysctl machdep.acpi_timer_freq=3579545 machdep.acpi_timer_freq: 3579545 -> 3579545 and I put it into /etc/sysctl.conf as well (in case the machine reboots again). > kern.timecounter.hardware=ACPI-safe Yes, this is already in /etc/sysctl.conf > The stop ntpd, delete /var/db/ntp.drift and either reboot or > manually set the above sysctl's and restart ntpd. Done. We'll see if it works or not. > [I think I've got the adjustment direction correct in the above, if > I've stuffed up, you need to adjust in the other direction] Ok. Thanks to all for helping out. -- Torfinn
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20100218231223.ec6b9fa8.torfinn.ingolfsen>