From owner-freebsd-current@FreeBSD.ORG Thu Feb 3 21:27:11 2005 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id E7ED616A4CE for ; Thu, 3 Feb 2005 21:27:11 +0000 (GMT) Received: from mail28.sea5.speakeasy.net (mail28.sea5.speakeasy.net [69.17.117.30]) by mx1.FreeBSD.org (Postfix) with ESMTP id 9FB2C43D49 for ; Thu, 3 Feb 2005 21:27:11 +0000 (GMT) (envelope-from jhb@FreeBSD.org) Received: (qmail 3946 invoked from network); 3 Feb 2005 21:27:11 -0000 Received: from server.baldwin.cx ([216.27.160.63]) (envelope-sender )AES256-SHA encrypted SMTP for ; 3 Feb 2005 21:27:11 -0000 Received: from [10.50.40.202] (gw1.twc.weather.com [216.133.140.1]) (authenticated bits=0) by server.baldwin.cx (8.13.1/8.13.1) with ESMTP id j13LQs9H056817; Thu, 3 Feb 2005 16:26:56 -0500 (EST) (envelope-from jhb@FreeBSD.org) From: John Baldwin To: freebsd-current@FreeBSD.org Date: Thu, 3 Feb 2005 12:47:21 -0500 User-Agent: KMail/1.6.2 References: <79659.1106645826@critter.freebsd.dk> In-Reply-To: <79659.1106645826@critter.freebsd.dk> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200502031247.22241.jhb@FreeBSD.org> X-Spam-Status: No, score=-102.8 required=4.2 tests=ALL_TRUSTED, USER_IN_WHITELIST autolearn=failed version=3.0.2 X-Spam-Checker-Version: SpamAssassin 3.0.2 (2004-11-16) on server.baldwin.cx cc: Poul-Henning Kamp cc: Jeremie Le Hen Subject: Re: cvs commit: src/sys/dev/md md.c X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 03 Feb 2005 21:27:12 -0000 On Tuesday 25 January 2005 04:37 am, Poul-Henning Kamp wrote: > In message <20050124134546.GB59685@obiwan.tataz.chchile.org>, Jeremie Le Hen writes: > >While talking about WITNESS, I checked my kernel config and remembered > >that FULL_PREEMPTION is on. The panic disappeared when I turned off > >the latter : I managed to create up to about 16 md(4) devices. I know > >this should not be enabled for users, but I'm interested in "exposing > >race conditions" as said in the comment. > > Well, you clearly did :-) > > I suggest you send a summary of what you have found to jhb@freebsd.org, > he's working on the FULL_PREEMPTION stuff. FULL_PREEMPTION just preempts more often is all. It's still probably a locking bug of some sort. -- John Baldwin <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org