From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753397AbXE3EOe (ORCPT ); Wed, 30 May 2007 00:14:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751493AbXE3EO1 (ORCPT ); Wed, 30 May 2007 00:14:27 -0400 Received: from netops-testserver-3-out.sgi.com ([192.48.171.28]:56215 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751483AbXE3EO0 (ORCPT ); Wed, 30 May 2007 00:14:26 -0400 Date: Tue, 29 May 2007 21:14:23 -0700 (PDT) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: Mel Gorman cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kamezawa.hiroyu@jp.fujitsu.com Subject: Re: [PATCH 7/7] Add /proc/sys/vm/compact_node for the explicit compaction of a node In-Reply-To: <20070529173830.1570.91184.sendpatchset@skynet.skynet.ie> Message-ID: References: <20070529173609.1570.4686.sendpatchset@skynet.skynet.ie> <20070529173830.1570.91184.sendpatchset@skynet.skynet.ie> 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 On Tue, 29 May 2007, Mel Gorman wrote: > + if (nodeid < 0) > + return -EINVAL; > + > + pgdat = NODE_DATA(nodeid); > + if (!pgdat || pgdat->node_id != nodeid) > + return -EINVAL; You cannot pass an arbitrary number to node data since NODE_DATA may do a simple array lookup. Check for node < nr_node_ids first. pgdat->node_id != nodeid? Sounds like something you should BUG() on. IA64's NODE_DATA is struct ia64_node_data { short active_cpu_count; short node; struct pglist_data *pg_data_ptrs[MAX_NUMNODES]; }; /* * Given a node id, return a pointer to the pg_data_t for the node. * * NODE_DATA - should be used in all code not related to system * initialization. It uses pernode data structures to minimize * offnode memory references. However, these structure are not * present during boot. This macro can be used once cpu_init * completes. */ #define NODE_DATA(nid) (local_node_data->pg_data_ptrs[nid]) x86_64 also does #define NODE_DATA(nid) (node_data[nid])