From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753130Ab1ATSCV (ORCPT ); Thu, 20 Jan 2011 13:02:21 -0500 Received: from caramon.arm.linux.org.uk ([78.32.30.218]:50277 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752791Ab1ATSCU (ORCPT ); Thu, 20 Jan 2011 13:02:20 -0500 Date: Thu, 20 Jan 2011 18:01:46 +0000 From: Russell King - ARM Linux To: Dave Hansen Cc: KyongHo Cho , Kukjin Kim , KeyYoung Park , linux-kernel@vger.kernel.org, Ilho Lee , linux-mm@kvack.org, linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] ARM: mm: Regarding section when dealing with meminfo Message-ID: <20110120180146.GH6335@n2100.arm.linux.org.uk> References: <1295516739-9839-1-git-send-email-pullip.cho@samsung.com> <1295544047.9039.609.camel@nimitz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1295544047.9039.609.camel@nimitz> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 20, 2011 at 09:20:47AM -0800, Dave Hansen wrote: > This problem actually exists without sparsemem, too. Discontigmem (at > least) does it as well. We don't expect banks to cross sparsemem boundaries, or the older discontigmem nodes (esp. as we used to store the node number.) Discontigmem support has been removed now so that doesn't apply anymore. > The x86 version of show_mem() actually manages to do this without any > #ifdefs, and works for a ton of configuration options. It uses > pfn_valid() to tell whether it can touch a given pfn. x86 memory layout tends to be very simple as it expects memory to start at the beginning of every region described by a pgdat and extend in one contiguous block. I wish ARM was that simple.