From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264056AbUEEIhe (ORCPT ); Wed, 5 May 2004 04:37:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264340AbUEEIhe (ORCPT ); Wed, 5 May 2004 04:37:34 -0400 Received: from ozlabs.org ([203.10.76.45]:1206 "EHLO ozlabs.org") by vger.kernel.org with ESMTP id S264056AbUEEIhb (ORCPT ); Wed, 5 May 2004 04:37:31 -0400 Subject: Re: [PATCH] Fix deadlock in __create_workqueue From: Rusty Russell To: Srivatsa Vaddagiri Cc: Andrew Morton , Ingo Molnar , lkml - Kernel Mailing List In-Reply-To: <20040503122316.GA7143@in.ibm.com> References: <20040430113751.GA18296@in.ibm.com> <20040430192712.2e085895.akpm@osdl.org> <20040503122316.GA7143@in.ibm.com> Content-Type: text/plain Message-Id: <1083746224.14112.7.camel@bach> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Wed, 05 May 2004 18:37:04 +1000 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2004-05-03 at 22:23, Srivatsa Vaddagiri wrote: > On Fri, Apr 30, 2004 at 07:27:12PM -0700, Andrew Morton wrote: > > Can we not simply do: > > > > > > diff -puN kernel/workqueue.c~a kernel/workqueue.c > > --- 25/kernel/workqueue.c~a 2004-04-30 19:26:32.003303600 -0700 > > +++ 25-akpm/kernel/workqueue.c 2004-04-30 19:26:44.492404968 -0700 > > @@ -334,6 +334,7 @@ struct workqueue_struct *__create_workqu > > destroy = 1; > > } > > } > > + unlock_cpu_hotplug(); > > > > /* > > * Was there any error during startup? If yes then clean up: > > @@ -342,7 +343,6 @@ struct workqueue_struct *__create_workqu > > destroy_workqueue(wq); > > wq = NULL; > > } > > - unlock_cpu_hotplug(); > > return wq; > > } > > I didn't do this because I introduced a break at the first instance > when create_workqueue_thread failed. Breaking out of the loop > like that appeared to be more efficient rather than going back and > trying to create threads for rest of the online cpus, because most > likely thread creation will fail for other cpus also and anyway > the workqueue will be destroyed down the line. The logic was not the way I would have done it, but it *is* neater. I prefer the akpm fix I think. Rusty. -- Anyone who quotes me in their signature is an idiot -- Rusty Russell