Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1162145AbWKPBOM (ORCPT ); Wed, 15 Nov 2006 20:14:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1162147AbWKPBOM (ORCPT ); Wed, 15 Nov 2006 20:14:12 -0500 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:26795 "EHLO fgwmail7.fujitsu.co.jp") by vger.kernel.org with ESMTP id S1162145AbWKPBOK (ORCPT ); Wed, 15 Nov 2006 20:14:10 -0500 Date: Thu, 16 Nov 2006 10:17:29 +0900 From: KAMEZAWA Hiroyuki To: Christoph Lameter Cc: mbligh@mbligh.org, steiner@sgi.com, krafft@de.ibm.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [patch 2/2] enables booting a NUMA system where some nodes have no memory Message-Id: <20061116101729.41257355.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: References: <20061115193049.3457b44c@localhost> <20061115193437.25cdc371@localhost> <20061115215845.GB20526@sgi.com> <455B9825.3030403@mbligh.org> <20061116095429.0e6109a7.kamezawa.hiroyu@jp.fujitsu.com> Organization: Fujitsu X-Mailer: Sylpheed version 2.2.0 (GTK+ 2.6.10; i686-pc-mingw32) 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: 1159 Lines: 29 On Wed, 15 Nov 2006 16:57:56 -0800 (PST) Christoph Lameter wrote: > numa_node_id() points to this and we always get allocations redirected to > other nodes. The slab duplicates its per node structures on the fallback > node. > > > The zonelist[] donen't contain empty-zone. > > So we will never encounter that zone except when going to the > pglist_data struct through numa_node_id()? > Some pgdat/zone scanning code will access it. See: for_each_zone() and populated_zone(). AFAIK, in 2.6.9 age(means RHEL4), cpus on memory-less-node are moved to the nearest node. And there were no useless pgdat. Now, there are memory-less-node. Cpus on memory-less-node are on a pgdat with empty-zone. I think this is very simple way rather than remapping. And I think cpus on memory-less-node are sharing something (FSB,switch,etc..) Tieing cpus to a memory-less-node may have some benefit. -Kame - 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/