From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750762AbWEIQbo (ORCPT ); Tue, 9 May 2006 12:31:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750732AbWEIQbo (ORCPT ); Tue, 9 May 2006 12:31:44 -0400 Received: from hellhawk.shadowen.org ([80.68.90.175]:35847 "EHLO hellhawk.shadowen.org") by vger.kernel.org with ESMTP id S1750762AbWEIQbm (ORCPT ); Tue, 9 May 2006 12:31:42 -0400 Message-ID: <4460C3D5.1060905@shadowen.org> Date: Tue, 09 May 2006 17:31:17 +0100 From: Andy Whitcroft User-Agent: Debian Thunderbird 1.0.7 (X11/20051017) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Dave Hansen CC: Michael Ellerman , Andrew Morton , linux-kernel@vger.kernel.org, kravetz@us.ibm.com Subject: Re: [PATCH] SPARSEMEM + NUMA can't handle unaligned memory regions? References: <20060509070343.57853679F2@ozlabs.org> <44609A7B.7010103@shadowen.org> <4460A6F3.5060303@shadowen.org> <1147192006.23893.6.camel@localhost.localdomain> In-Reply-To: <1147192006.23893.6.camel@localhost.localdomain> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Dave Hansen wrote: > On Tue, 2006-05-09 at 15:28 +0100, Andy Whitcroft wrote: > >>+/* >>+ * During early boot we need to record the nid from which we will >>+ * later allocate the section mem_map. Encode this into the section >>+ * pointer. Overload the section_mem_map with this information. >>+ */ > > > Andy, this all looks pretty good. Although, it might be nice to > document this a bit more. > > First, can you update the mem_section definition comment? It has a nice > explanation of how we use section_mem_map, and it would be a shame to > miss this use. > > Also, your comment says when we _record_ the nid information, but not > that it is only _used_ during early boot. I think this is what Mike K. > missed, and it might be good to clarify. > > How about something like this: > > /* > * During early boot, before section_mem_map is used for an actual > * mem_map, we use section_mem_map to store the section's NUMA > * node. This keeps us from having to use another data structure. The > * node information is cleared just before we store the real mem_map. > */ Yep sounds very sane. Will update and resend -- best wait and see if it fixes Michael find its works for him too :). Thanks. -apw