amd64/127484: [timecounters] Drift problem with FreeBSD 7.0 and 7.1 PRERELEASE

[Paul van Berlo]

The following reply was made to PR amd64/127484; it has been noted by GNATS.

From: "Paul van Berlo" <pvanberlo at fastmail.fm>
To: bug-followup at FreeBSD.org, tg.at.swox.com at FreeBSD.org
Cc:  
Subject: Re: amd64/127484: [timecounters] Drift problem with FreeBSD 7.0 and 7.1
 PRERELEASE
Date: Sat, 27 Sep 2008 09:52:00 +0200

 Hello,
 
 I'm experiencing the exact same issue on 7.0/amd64. I have an Asrock
 A780FullDisplayPort mainboard (with an AMD Athlon64 X2 CPU, CnQ
 disabled, so the CPU doesn't throttle and always runs at 2.0Ghz, tested
 with both ACPI HPET enabled and disabled in bios), and looking at NTP it
 appears my clock is between 1-3 seconds slow each time it synchronizes.
 
 kern.timecounter.choice: TSC(-100) HPET(900) ACPI-safe(850) i8254(0)
 dummy(-1000000)
 
 I tried setting kern.timecounter.hardware to HPET (default), ACPI-safe
 and i8254. Neither of these solved the issue. I also set kern.hz=100
 which didn't solve the issue either.
 
 27 Sep 08:52:07 ntpd[761]: ntpd exiting on signal 15
 27 Sep 08:53:25 ntpd[761]: synchronized to 194.171.167.130, stratum=1
 27 Sep 08:53:27 ntpd[761]: time reset +1.365546 s
 27 Sep 08:54:38 ntpd[761]: synchronized to 194.171.167.130, stratum=1
 27 Sep 09:08:46 ntpd[761]: synchronized to 194.109.153.91, stratum=3
 27 Sep 09:08:48 ntpd[761]: synchronized to 194.171.167.130, stratum=1
 27 Sep 09:16:20 ntpd[761]: time reset +2.359489 s
 27 Sep 09:16:20 ntpd[761]: kernel time sync enabled 2001
 27 Sep 09:17:32 ntpd[761]: synchronized to 194.109.153.91, stratum=3
 27 Sep 09:17:32 ntpd[761]: synchronized to 194.171.167.130, stratum=1
 27 Sep 09:30:40 ntpd[761]: synchronized to 194.171.167.130, stratum=1
 27 Sep 09:38:10 ntpd[761]: time reset +2.907558 s
 27 Sep 09:39:21 ntpd[761]: synchronized to 194.171.167.130, stratum=1
 
 Best regards,
 
 Paul van Berlo