Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261331AbVBVXTQ (ORCPT ); Tue, 22 Feb 2005 18:19:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261330AbVBVXTP (ORCPT ); Tue, 22 Feb 2005 18:19:15 -0500 Received: from zcars04f.nortelnetworks.com ([47.129.242.57]:11909 "EHLO zcars04f.nortelnetworks.com") by vger.kernel.org with ESMTP id S261331AbVBVXRW (ORCPT ); Tue, 22 Feb 2005 18:17:22 -0500 Message-ID: <421BBD75.6040504@nortel.com> Date: Tue, 22 Feb 2005 17:17:09 -0600 X-Sybari-Space: 00000000 00000000 00000000 00000000 From: Chris Friesen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040115 X-Accept-Language: en-us, en MIME-Version: 1.0 To: linux-os@analogic.com CC: Horst von Brand , Anthony DiSante , linux-kernel Subject: Re: uninterruptible sleep lockups References: <421A3414.2020508@nodivisions.com> <200502211945.j1LJjgbZ029643@turing-police.cc.vt.edu> <421A4375.9040108@nodivisions.com> <421B12DB.70603@aitel.hist.no> <421B14A8.3000501@nodivisions.com> <421B9018.7020007@nodivisions.com> <200502222024.j1MKOtlZ007512@laptop11.inf.utfsm.cl> <421B9C86.8090800@nortel.com> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 928 Lines: 21 linux-os wrote: > Now, somebody needs a resource. It executes down(&semaphore); > once it gets control again, it has that resource. It attempts > to use that resource through a driver. The driver waits forever. > The resource is now permanently dorked --forever because its > driver is waiting forever. The user code never returns from > the driver so it can never execute up(&semaphore). What about something like a "robust mutex" (in OSDL terminology)? The guy holding it too long gets killed, and the mutex gets marked as dirty. The next guy to aquire the mutex is responsable for re-initializing the resource (resetting the device to a known state, for instance). Chris - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/