Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751068AbXA2TaY (ORCPT ); Mon, 29 Jan 2007 14:30:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751401AbXA2TaY (ORCPT ); Mon, 29 Jan 2007 14:30:24 -0500 Received: from mail.screens.ru ([213.234.233.54]:34348 "EHLO mail.screens.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751068AbXA2TaX (ORCPT ); Mon, 29 Jan 2007 14:30:23 -0500 Date: Mon, 29 Jan 2007 22:29:57 +0300 From: Oleg Nesterov To: Christoph Lameter Cc: Ingo Molnar , Srivatsa Vaddagiri , "Pallipadi, Venkatesh" , Gautham shenoy , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: slab: start_cpu_timer/cache_reap CONFIG_HOTPLUG_CPU problems Message-ID: <20070129192957.GA233@tv-sign.ru> References: <20070129011301.GA844@tv-sign.ru> <20070129171923.GA138@tv-sign.ru> <20070129182742.GA158@tv-sign.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1598 Lines: 46 On 01/29, Christoph Lameter wrote: > > On Mon, 29 Jan 2007, Oleg Nesterov wrote: > > > > The slab would need a notification > > > that the workqueue for a processor was shutdown in order to set work.func > > > = NULL. > > > > The slab has a notification: CPU_XXX events. It should cancel a pending per > > cpu "reap_work timer". > > Ahh. Okay then the following patch would fix it? > > Shutdown cache_reaper when cpu goes down > > Shutdown the cache_reaper in slab.c if the cpu is brought down > and set the cache_reap.func to NULL. Otherwise hotplug shuts > down the reaper for good. > > Signed-off-by: Christoph Lameter > > Index: linux-2.6.20-rc6/mm/slab.c > =================================================================== > --- linux-2.6.20-rc6.orig/mm/slab.c 2007-01-24 20:19:28.000000000 -0600 > +++ linux-2.6.20-rc6/mm/slab.c 2007-01-29 13:08:05.773928988 -0600 > @@ -1269,6 +1269,10 @@ static int __cpuinit cpuup_callback(stru > break; > #ifdef CONFIG_HOTPLUG_CPU > case CPU_DOWN_PREPARE: > + /* Shutdown cache reaper */ > + cancel_rearming_delayed_work(&per_cpu(reap_work, cpu)); > + per_cpu(reap_work, cpu).work.func = NULL; > + > mutex_lock(&cache_chain_mutex); > break; > case CPU_DOWN_FAILED: Then CPU_DOWN_FAILED should do start_cpu_timer(cpu). Oleg. - 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/