Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932332AbXA2VtV (ORCPT ); Mon, 29 Jan 2007 16:49:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932472AbXA2VtV (ORCPT ); Mon, 29 Jan 2007 16:49:21 -0500 Received: from omx1-ext.sgi.com ([192.48.179.11]:48530 "EHLO omx1.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932332AbXA2VtU (ORCPT ); Mon, 29 Jan 2007 16:49:20 -0500 Date: Mon, 29 Jan 2007 13:48:48 -0800 (PST) From: Christoph Lameter To: Oleg Nesterov 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 In-Reply-To: <20070129210550.GA247@tv-sign.ru> Message-ID: References: <20070129011301.GA844@tv-sign.ru> <20070129171923.GA138@tv-sign.ru> <20070129182742.GA158@tv-sign.ru> <20070129194938.GB233@tv-sign.ru> <20070129210550.GA247@tv-sign.ru> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1527 Lines: 42 On Tue, 30 Jan 2007, Oleg Nesterov wrote: > Now we have 2 additional events, CPU_LOCK_ACQUIRE/CPU_LOCK_RELEASE, > so cpuup_callback() can use them to lock/unlock cache_chain_mutex, > but this is not related. Then we wont need to do the mutex_lock/unlock in CPU_DOWN_XX anymore, right? Which brings us to this form of the patch: 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-mm2/mm/slab.c =================================================================== --- linux-2.6.20-rc6-mm2.orig/mm/slab.c 2007-01-29 14:27:34.199229828 -0600 +++ linux-2.6.20-rc6-mm2/mm/slab.c 2007-01-29 15:47:18.293962726 -0600 @@ -1271,6 +1271,14 @@ static int __cpuinit cpuup_callback(stru start_cpu_timer(cpu); 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; + break; + case CPU_DOWN_FAILED: + start_cpu_timer(cpu); + break; case CPU_DEAD: /* * Even if all the cpus of a node are down, we don't free the - 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/