From owner-freebsd-fs@FreeBSD.ORG Thu Nov 23 22:37:20 2006 Return-Path: X-Original-To: freebsd-fs@freebsd.org Delivered-To: freebsd-fs@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 187D216A403; Thu, 23 Nov 2006 22:37:20 +0000 (UTC) (envelope-from killing@multiplay.co.uk) Received: from multiplay.co.uk (core6.multiplay.co.uk [85.236.96.23]) by mx1.FreeBSD.org (Postfix) with ESMTP id E42F343D49; Thu, 23 Nov 2006 22:36:41 +0000 (GMT) (envelope-from killing@multiplay.co.uk) Received: from vader ([212.135.219.179]) by multiplay.co.uk (multiplay.co.uk [85.236.96.23]) (MDaemon PRO v9.0.1) with ESMTP id md50003248036.msg; Thu, 23 Nov 2006 22:37:15 +0000 Message-ID: <076f01c70f4f$e6b96050$b3db87d4@multiplay.co.uk> From: "Steven Hartland" To: "Kostik Belousov" References: <447366AD.30203@rogers.com><20060701034922.GA37822@deviant.kiev.zoral.com.ua><027b01c70e6c$6c879470$b3db87d4@multiplay.co.uk> <20061123101246.GM1841@deviant.kiev.zoral.com.ua> Date: Thu, 23 Nov 2006 22:36:57 -0000 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2869 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2962 X-Spam-Processed: multiplay.co.uk, Thu, 23 Nov 2006 22:37:15 +0000 (not processed: message from valid local sender) X-MDRemoteIP: 212.135.219.179 X-Return-Path: killing@multiplay.co.uk X-MDAV-Processed: multiplay.co.uk, Thu, 23 Nov 2006 22:37:15 +0000 Cc: freebsd-fs@freebsd.org, Mike Jakubik , freebsd-stable@freebsd.org Subject: Re: md deadlocks on wdrain. Was: [Re: quota and snapshotsin6.1-RELEASE] X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 23 Nov 2006 22:37:20 -0000 Thanks for that, from our point of view its required as without the machine deadlocks without even trying. One real strange thing was that if I created a copy of the vnode file, this particular task ( installworld ) would succeed but given the nature of the bug ( timing critical ) that seem to make sence. With this still being a potential issue I think we have no choice but to migrate away from using any vnode backed jails. That said I thank you for this as it certainly help us. Steve ----- Original Message ----- From: "Kostik Belousov" This is not a fix, this is only a way to make the deadlock less frequent (I would not ever call it workaround). I have got a reports of deadlocks with this change applied, and I think that I understand the cause of it. Also, I have an idea of how to fix it, but not got around to even start coding. > ? sys/dev/md/.arch-ids > Index: sys/dev/md/md.c > =================================================================== > RCS file: /usr/local/arch/ncvs/src/sys/dev/md/md.c,v > retrieving revision 1.164 > diff -u -r1.164 md.c > --- sys/dev/md/md.c 28 Mar 2006 21:25:11 -0000 1.164 > +++ sys/dev/md/md.c 1 Jul 2006 03:48:41 -0000 > @@ -650,6 +650,8 @@ > mtx_lock_spin(&sched_lock); > sched_prio(curthread, PRIBIO); > mtx_unlock_spin(&sched_lock); > + if (sc->type == MD_VNODE) > + curthread->td_pflags |= TDP_NORUNNINGBUF; > > for (;;) { > mtx_lock(&sc->queue_mtx); ================================================ This e.mail is private and confidential between Multiplay (UK) Ltd. and the person or entity to whom it is addressed. In the event of misdirection, the recipient is prohibited from using, copying, printing or otherwise disseminating it or any information contained in it. In the event of misdirection, illegible or incomplete transmission please telephone +44 845 868 1337 or return the E.mail to postmaster@multiplay.co.uk.