Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1946024AbWLVKuW (ORCPT ); Fri, 22 Dec 2006 05:50:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1946034AbWLVKuW (ORCPT ); Fri, 22 Dec 2006 05:50:22 -0500 Received: from smtp.osdl.org ([65.172.181.25]:36662 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1946024AbWLVKuV (ORCPT ); Fri, 22 Dec 2006 05:50:21 -0500 Date: Fri, 22 Dec 2006 02:44:58 -0800 From: Andrew Morton To: ego@in.ibm.com, Oleg Nesterov Cc: Mathieu Desnoyers , linux-kernel@vger.kernel.org, David Wilder , Tom Zanussi , Ingo Molnar , Greg Kroah-Hartman , Christoph Hellwig , ltt-dev@shafik.org, systemtap@sources.redhat.com, Douglas Niehaus , "Martin J. Bligh" , Thomas Gleixner , kiran@scalex86.org, venkatesh.pallipadi@intel.com, dipankar@in.ibm.com, vatsa@in.ibm.com, torvalds@osdl.org, davej@redhat.com Subject: Re: [PATCH] Relay CPU Hotplug support Message-Id: <20061222024458.322adffd.akpm@osdl.org> In-Reply-To: <20061222103724.GA29348@in.ibm.com> References: <20061221003101.GA28643@Krystal> <20061220232350.eb4b6a46.akpm@osdl.org> <20061222103724.GA29348@in.ibm.com> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 968 Lines: 23 On Fri, 22 Dec 2006 16:07:24 +0530 Gautham R Shenoy wrote: > While we are at this per-subsystem cpuhotplug "locking", here's a > proposal that might put an end to the workqueue deadlock woes. Oleg is working on some patches which will permit us to cancel or wait upon a particular work_struct, rather than upon all pending work_structs. This will fix the problem where we accidentlly wait upon some unrelated work_struct which takes a lock which is related to one which we already hold. I hope. It'll be a bit tricky to implement: if some foreign work_struct is running right now, we cannot wait upon it - we must non-blockingly dequeue the work_struct which we want to kill before it gets to run. - 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/