From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759667AbZAORKy (ORCPT ); Thu, 15 Jan 2009 12:10:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753545AbZAORKp (ORCPT ); Thu, 15 Jan 2009 12:10:45 -0500 Received: from terminus.zytor.com ([198.137.202.10]:54174 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753102AbZAORKp (ORCPT ); Thu, 15 Jan 2009 12:10:45 -0500 Message-ID: <496F6DFC.90006@zytor.com> Date: Thu, 15 Jan 2009 09:10:20 -0800 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Ingo Molnar CC: Jan Beulich , tglx@linutronix.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86: simplify HIGHMEM-related Kconfig entries References: <496DE927.76E4.0078.0@novell.com> <496E3F7D.2060908@zytor.com> <496F0796.76E4.0078.0@novell.com> <20090115085728.GA28607@elte.hu> In-Reply-To: <20090115085728.GA28607@elte.hu> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ingo Molnar wrote: >>> >>> No highmem - No highmem, no PAE >>> HIGHMEM4G - Highmem, no PAE >>> HIGHMEM64G - Highmem, PAE >>> >>> So X86_PAE and HIGHMEM4G is a bit of a contradiction. I haven't looked >>> at the logic in detail, or remember offhand if there have been any >>> weakening of the definitions above; e.g. someone could have implemented >>> a way to do PAE without highmem, to get access to the NX bits. >> Exactly - .23 made PAE an independently selectable option (in >> particular, the no-highmem+PAE combination is now valid), but I can't >> see why it added the !HIGHMEM4G dependency. > > There's no deep reason, it just has never really been tested that way. I > think we should try it. If so, what would be the difference between HIGHMEM4G and HIGHMEM64G in that case at all? -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.