From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934014AbWKTIu0 (ORCPT ); Mon, 20 Nov 2006 03:50:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934015AbWKTIu0 (ORCPT ); Mon, 20 Nov 2006 03:50:26 -0500 Received: from mtagate2.de.ibm.com ([195.212.29.151]:26605 "EHLO mtagate2.de.ibm.com") by vger.kernel.org with ESMTP id S934013AbWKTIuZ (ORCPT ); Mon, 20 Nov 2006 03:50:25 -0500 Date: Mon, 20 Nov 2006 09:49:06 +0100 From: Heiko Carstens To: Alasdair G Kergon Cc: Ingo Molnar , linux-kernel@vger.kernel.org, dm-devel@redhat.com, Andrew Morton , Neil Brown Subject: Re: 2.6.19-rc6 -- dm: possible recursive locking detected Message-ID: <20061120084906.GB17447@osiris.boeblingen.de.ibm.com> References: <20061117153003.GB7131@osiris.boeblingen.de.ibm.com> <20061117194303.GB4409@agk.surrey.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061117194303.GB4409@agk.surrey.redhat.com> User-Agent: mutt-ng/devel-r804 (Linux) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 17, 2006 at 07:43:03PM +0000, Alasdair G Kergon wrote: > On Fri, Nov 17, 2006 at 04:30:03PM +0100, Heiko Carstens wrote: > > ============================================= > > [ INFO: possible recursive locking detected ] > > 2.6.19-rc6-g1b9bb3c1 #28 > > --------------------------------------------- > > kpartx/945 is trying to acquire lock: > > (&md->io_lock){----}, at: [<00000000001f8faa>] dm_request+0x42/0x24c > > > > but task is already holding lock: > > (&md->io_lock){----}, at: [<00000000001f8faa>] dm_request+0x42/0x24c > > Known problem - nobody's written a patch to fix it yet to my knowledge, > but I don't recall any reports of real world lock-ups related to this - just > several reports of the debug warning messages:-) > > Simply ignore the message for now - or submit a patch that fixes the > underlying problem:-) Ignoring would be good, but this problem renders lockdep useless since it stops working after it found the first possible bug. While we are at it: this one is sitting since ages in -mm and probably waiting for your approval: http://www.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.19-rc5/2.6.19-rc5-mm2/broken-out/md-dm-reduce-stack-usage-with-stacked-block-devices.patch