Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757287AbXJCPAb (ORCPT ); Wed, 3 Oct 2007 11:00:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754763AbXJCPAX (ORCPT ); Wed, 3 Oct 2007 11:00:23 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:38785 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754246AbXJCPAW (ORCPT ); Wed, 3 Oct 2007 11:00:22 -0400 Date: Wed, 03 Oct 2007 23:59:23 +0900 From: Yasunori Goto To: Christoph Lameter Subject: Re: [Patch / 002](memory hotplug) Callback function to create kmem_cache_node. Cc: Andrew Morton , Linux Kernel ML , linux-mm In-Reply-To: References: <20071002105422.2790.Y-GOTO@jp.fujitsu.com> X-Mailer-Plugin: BkASPil for Becky!2 Ver.2.068 Message-Id: <20071003234201.B5F9.Y-GOTO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.27 [ja] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1211 Lines: 41 > On Tue, 2 Oct 2007, Yasunori Goto wrote: > > > Do you mean that just nr_slabs should be checked like followings? > > I'm not sure this is enough. > > > > : > > if (s->node[nid]) { > > n = get_node(s, nid); > > if (!atomic_read(&n->nr_slabs)) { > > s->node[nid] = NULL; > > kmem_cache_free(kmalloc_caches, n); > > } > > } > > : > > : > > That would work. But it would be better to shrink the cache first. The > first 2 slabs on a node may be empty and the shrinking will remove those. > If you do not shrink then the code may falsely assume that there are > objects on the node. I'm sorry, but I don't think I understand what you mean... :-( Could you explain more? Which slabs should be shrinked? kmem_cache_node and kmem_cache_cpu? I think kmem_cache_cpu should be disabled by cpu hotplug, not memory/node hotplug. Basically, cpu should be offlined before memory offline on the node. Sorry, I'm confusing now... -- Yasunori Goto - 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/