From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265833AbUHVCSC (ORCPT ); Sat, 21 Aug 2004 22:18:02 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265789AbUHVCSA (ORCPT ); Sat, 21 Aug 2004 22:18:00 -0400 Received: from sccrmhc13.comcast.net ([204.127.202.64]:7313 "EHLO sccrmhc13.comcast.net") by vger.kernel.org with ESMTP id S265293AbUHVCPj (ORCPT ); Sat, 21 Aug 2004 22:15:39 -0400 Subject: 2.6.(8.1) clock drift with apic enabled From: Quel Qun Reply-To: linux-kernel@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: kelk1@comcast.net Content-Type: text/plain Date: Sat, 21 Aug 2004 19:15:34 -0700 Message-Id: <1093140934.4180.34.camel@dsktop.net.home> Mime-Version: 1.0 X-Mailer: Evolution 1.5.93-2kk1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, Maybe a follow-up to http://groups.google.com/groups?q=time+drift +group:fa.linux.kernel&hl=en&lr=&ie=UTF-8&group=fa.linux.kernel&selm=fa.kv2ep3o.6i053a%40ifi.uio.no&rnum=7 With 2.6 kernels (at least since 2.6.7), I observe a huge system time drift (~12s/h) if I boot with apic enabled. If I boot with noapic nolapic, the system time is stable. Of course, ntpd is stopped to get the following results. # cat /proc/cmdline BOOT_IMAGE=linux-2681-2kk1 ro root=345 noapic nolapic nodevfs pmdisk=/dev/hda6 splash=silent # while (true) ; do ntpdate -q gateway ; sleep 300 ; done Looking for host gateway and service ntp host found : gateway.home.net server 192.168.0.1, stratum 2, offset 0.000618, delay 0.02631 21 Aug 17:29:53 ntpdate[4636]: adjust time server 192.168.0.1 offset 0.000618 sec Looking for host gateway and service ntp host found : gateway.home.net server 192.168.0.1, stratum 2, offset 0.000717, delay 0.02631 21 Aug 17:34:53 ntpdate[4645]: adjust time server 192.168.0.1 offset 0.000717 sec Looking for host gateway and service ntp host found : gateway.home.net server 192.168.0.1, stratum 2, offset 0.000827, delay 0.02631 21 Aug 17:39:53 ntpdate[4654]: adjust time server 192.168.0.1 offset 0.000827 sec Looking for host gateway and service ntp host found : gateway.home.net server 192.168.0.1, stratum 2, offset 0.000775, delay 0.02632 21 Aug 17:44:53 ntpdate[4663]: adjust time server 192.168.0.1 offset 0.000775 sec Looking for host gateway and service ntp host found : gateway.home.net server 192.168.0.1, stratum 2, offset 0.000759, delay 0.02632 21 Aug 17:49:54 ntpdate[4672]: adjust time server 192.168.0.1 offset 0.000759 sec # cat /proc/cmdline BOOT_IMAGE=linux-2681-2kk1 ro root=345 nodevfs pmdisk=/dev/hda6 splash=silent # while (true) ; do ntpdate -q gateway ; sleep 300 ; done Looking for host gateway and service ntp host found : gateway.home.net server 192.168.0.1, stratum 2, offset -0.749909, delay 0.02631 21 Aug 17:59:27 ntpdate[4033]: step time server 192.168.0.1 offset -0.749909 secLooking for host gateway and service ntp host found : gateway.home.net server 192.168.0.1, stratum 2, offset -1.865757, delay 0.02629 21 Aug 18:04:27 ntpdate[4044]: step time server 192.168.0.1 offset -1.865757 secLooking for host gateway and service ntp host found : gateway.home.net server 192.168.0.1, stratum 2, offset -2.941571, delay 0.02631 21 Aug 18:09:27 ntpdate[4053]: step time server 192.168.0.1 offset -2.941571 secLooking for host gateway and service ntp host found : gateway.home.net server 192.168.0.1, stratum 2, offset -4.057391, delay 0.02631 21 Aug 18:14:27 ntpdate[4062]: step time server 192.168.0.1 offset -4.057391 secLooking for host gateway and service ntp host found : gateway.home.net server 192.168.0.1, stratum 2, offset -5.140378, delay 0.02631 21 Aug 18:19:27 ntpdate[4071]: step time server 192.168.0.1 offset -5.140378 sec At 12seconds/hour, the system is unusable. Hardware is an Asus A7N8X2 MB with an Athlon XP 2100+ Please cc me directly if you need more info as I am not subscribed to the list. Thank you, -- kk1