From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934686Ab0CLWdz (ORCPT ); Fri, 12 Mar 2010 17:33:55 -0500 Received: from mga10.intel.com ([192.55.52.92]:28833 "EHLO fmsmga102.fm.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S934667Ab0CLWdy (ORCPT ); Fri, 12 Mar 2010 17:33:54 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.49,628,1262592000"; d="scan'208";a="548618807" Message-ID: <4B9AC149.1010507@linux.intel.com> Date: Fri, 12 Mar 2010 14:33:45 -0800 From: Andi Kleen User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: Suresh Siddha CC: Jan Engelhardt , Linux Kernel Mailing List , "hpa@zytor.com" , Nick Piggin Subject: Re: page_to_nid not linked in on PAE References: <1268423424.2793.21.camel@sbs-t61.sc.intel.com> In-Reply-To: <1268423424.2793.21.camel@sbs-t61.sc.intel.com> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Jan, Even with out using the PG_head, PG_tail, PG_uncached and > PG_hwpoison, by allowing the NODES_SHIFT to have a maximum value of 9 on > 32bit kernel, can still result in the page flags to runout and result in > this problem. Best solution for now is to limit the NODES_SHIFT to 5. I > don't know of any platforms that have> 32nodes and where we care about > 32bit linux kernel. So it should be ok as a fix. If someone in future > cares about> 32 nodes for 32bit kernel, then we can think of a better > solution. Do you agree? I copied Andi/Nick for their eyes aswell on > this. Seems like the right approach to me. Although it might be better to use 1 3 or 1..4 or so, just in case someone else adds more page bits later (I'm sure it'll happen again). Even 8 nodes should be plenty for 32bit. Acked-by: Andi Kleen -Andi