From owner-freebsd-hackers@FreeBSD.ORG Sat Nov 19 19:16:05 2005 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 6059016A41F; Sat, 19 Nov 2005 19:16:05 +0000 (GMT) (envelope-from gemini@geminix.org) Received: from gen129.n001.c02.escapebox.net (gen129.n001.c02.escapebox.net [213.73.91.129]) by mx1.FreeBSD.org (Postfix) with ESMTP id E587643D45; Sat, 19 Nov 2005 19:16:04 +0000 (GMT) (envelope-from gemini@geminix.org) Message-ID: <437F79F1.5040706@geminix.org> Date: Sat, 19 Nov 2005 20:16:01 +0100 From: Uwe Doering Organization: Private UNIX Site User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.7.12) Gecko/20051117 X-Accept-Language: en-us, en MIME-Version: 1.0 To: John Baldwin References: <200511182215.04399.jhb@freebsd.org> In-Reply-To: <200511182215.04399.jhb@freebsd.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Received: from gemini by geminix.org with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.54 (FreeBSD)) id 1EdYBu-0008EP-IS; Sat, 19 Nov 2005 20:16:02 +0100 Cc: freebsd-hackers@freebsd.org, Charles Sprickman Subject: Re: 4.8 "Alternate system clock has died" error X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 19 Nov 2005 19:16:05 -0000 John Baldwin wrote: > On Friday 18 November 2005 10:05 pm, Charles Sprickman wrote: > >>I tried this query on -stable, hoping someone here can help me further >>understand and troubleshoot this. >> >>Reference: >>http://thread.gmane.org/gmane.os.freebsd.stable/32837 >> >>In short, top, ps report 0% CPU on all processes as of a few weeks ago. >>"systat -vmstat" hands out the "Alternate system clock has died" error. >> >>Box is running 4.8-p24 and has been up 425 days. Nothing out of the >>ordinary except for the above symptoms. In searching the various >>lists/newsgroups, it seems that the other folks with this problem have >>fixed it in various ways: >> >>-early 4.x users referenced a PR that was committed before 4.8 >>-some 5.3 users reported this with unknown resolution/cause >>-sending init a HUP was suggested (tried it, no luck) >>-setting kern.timecounter.method: 1 (tried it, no luck) >>-one user seemed to actually have a dead timer > > Actually, there was a patch that was committed in 5.4 and 6.0 for this issue. > You can see the diff here: > > http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/i386/isa/clock.c.diff?r1=1.213&r2=1.214&f=h > > That patch would probably backport to 4.x fairly easily. I just looked at RELENG_4, and yes, backporting should be easy. Though I haven't tried it yet on our machines. I wonder, however, what's writing to the RTC on a running server. Could this event perhaps have been triggered by the recent Daylight Saving Time switch? Uwe -- Uwe Doering | EscapeBox - Managed On-Demand UNIX Servers gemini@geminix.org | http://www.escapebox.net