From owner-freebsd-xen@FreeBSD.ORG Sat Nov 20 08:14:55 2010 Return-Path: Delivered-To: freebsd-xen@freebsd.org Received: from mx2.freebsd.org (mx2.freebsd.org [IPv6:2001:4f8:fff6::35]) by hub.freebsd.org (Postfix) with ESMTP id C0B98106566C for ; Sat, 20 Nov 2010 08:14:55 +0000 (UTC) (envelope-from cperciva@freebsd.org) Received: from xps.daemonology.net (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx2.freebsd.org (Postfix) with SMTP id 4E3E4151CB9 for ; Sat, 20 Nov 2010 08:14:55 +0000 (UTC) Received: (qmail 32771 invoked from network); 20 Nov 2010 08:14:54 -0000 Received: from unknown (HELO xps.daemonology.net) (127.0.0.1) by localhost with SMTP; 20 Nov 2010 08:14:54 -0000 Message-ID: <4CE7837E.3030901@freebsd.org> Date: Sat, 20 Nov 2010 00:14:54 -0800 From: Colin Percival User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.1.11) Gecko/20100803 Thunderbird/3.0.6 MIME-Version: 1.0 To: Adrian Chadd References: <4CE68CD7.10804@freebsd.org> <1290191413.1758.16.camel@localhost> <4CE77AE7.3010106@freebsd.org> In-Reply-To: X-Enigmail-Version: 1.0.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "freebsd-xen@freebsd.org" Subject: Re: system stalls when wallclock/TOD nudged X-BeenThere: freebsd-xen@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion of the freebsd port to xen - implementation and usage List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 20 Nov 2010 08:14:55 -0000 On 11/19/10 23:40, Adrian Chadd wrote: > I bet if you did some slicing of -head versions, you'll find an > earlier version that doesn't do that. :-) Sure, all I need to do is go back a couple of days, and I find a FreeBSD Xen kernel which doesn't do this... because it panics before the clock gets nudged. :-) > On 20 November 2010 15:38, Colin Percival wrote: >> It seems that this bug is related somehow to the idle thread sleeping -- when >> I comment out the call to idle_block from cpu_idle_hlt in i386/machdep.c the >> stalling goes away. >> >>> On Fri, 2010-11-19 at 06:42 -0800, Colin Percival wrote: >>>> During the boot process, in the middle of running rc.d scripts, my FreeBSD/Xen >>>> instance stalls. It does nothing until I send a shutdown signal, at which point >>>>> [XEN] hypervisor wallclock nudged; nudging TOD. >>>> and a couple buffered lines of rc.d script output are printed. From there the >>>> rc.shutdown script starts running, but it too stalls after a short time; then I >>>> see >>>>> [XEN] hypervisor wallclock nudged; nudging TOD. >>>>> Nov 19 14:08:33 init: timeout expired for /bin/sh on /etc/rc.shutdown: Interrupted system call; going to single user mode >>>> printed, suggesting that the shutdown watchdog timer at least managed to not get >>>> stuck even though everything else did. -- Colin Percival Security Officer, FreeBSD | freebsd.org | The power to serve Founder / author, Tarsnap | tarsnap.com | Online backups for the truly paranoid