Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759543AbXHJBoT (ORCPT ); Thu, 9 Aug 2007 21:44:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756116AbXHJBoJ (ORCPT ); Thu, 9 Aug 2007 21:44:09 -0400 Received: from netops-testserver-4-out.sgi.com ([192.48.171.29]:50048 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755795AbXHJBoH (ORCPT ); Thu, 9 Aug 2007 21:44:07 -0400 Date: Thu, 9 Aug 2007 18:44:07 -0700 (PDT) From: Christoph Lameter X-X-Sender: clameter@schroedinger.engr.sgi.com To: Mel Gorman cc: Lee.Schermerhorn@hp.com, ak@suse.de, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 3/4] Embed zone_id information within the zonelist->zones pointer In-Reply-To: <20070809233300.GA31644@skynet.ie> Message-ID: References: <20070809210616.14702.73376.sendpatchset@skynet.skynet.ie> <20070809210716.14702.43074.sendpatchset@skynet.skynet.ie> <20070809233300.GA31644@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 Content-Length: 801 Lines: 20 On Fri, 10 Aug 2007, Mel Gorman wrote: > > > +#if defined(CONFIG_SMP) && INTERNODE_CACHE_SHIFT > ZONES_SHIFT > > > > Is this necessary? ZONES_SHIFT is always <= 2 so it will work with > > any pointer. Why disable this for UP? > > > > Caution in case the number of zones increases. There was no guarantee of > zone alignment. It's the same reason I have a BUG_ON in the encode > function so that if we don't catch problems at compile-time, it'll go > BANG in a nice predictable fashion. Caution would lead to a BUG_ON but why the #if? Why exclude UP? - 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/