Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757335AbYHGWjt (ORCPT ); Thu, 7 Aug 2008 18:39:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753225AbYHGWjl (ORCPT ); Thu, 7 Aug 2008 18:39:41 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:42564 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751308AbYHGWjk (ORCPT ); Thu, 7 Aug 2008 18:39:40 -0400 Date: Thu, 7 Aug 2008 15:38:30 -0700 (PDT) From: Linus Torvalds To: "H. Peter Anvin" cc: Zachary Amsden , Alok Kataria , Ingo Molnar , the arch/x86 maintainers , LKML Subject: Re: [PATCH]Fix broken VMI in 2.6.27-rc.. In-Reply-To: <489B7470.5030408@kernel.org> Message-ID: References: <1218136365.23770.52.camel@alok-dev1> <489B6710.9000604@kernel.org> <1218144438.20178.336.camel@bodhitayantram.eng.vmware.com> <489B6A5C.8030400@kernel.org> <1218145344.20178.347.camel@bodhitayantram.eng.vmware.com> <489B6E83.7000202@kernel.org> <1218146154.20178.352.camel@bodhitayantram.eng.vmware.com> <489B7470.5030408@kernel.org> User-Agent: Alpine 1.10 (LFD 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1027 Lines: 26 On Thu, 7 Aug 2008, H. Peter Anvin wrote: > > The only way I can see around that, though, is to move the 1:1 mapping base up > by 2/4 MB (for PAE/no PAE, respectively) and put the fixmap area there. Kind > of sucks, but would be doable. So if the address isn't fixed, you'll end up with an indirect pointer, and it would likely be much better to just use a fixed direct pointer that is not at the top. And anything that is within the top 31 bits of the address space should generate the same good code, since the fixed offset is always going to be a 32-bit thing anyway. So moving the FIXMAP area down by 4MB sounds like a fine thing to do with no real downside, if it then means that we don't need to move the FIXMAP area at all. Hmm? Am I missing something? Linus -- 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/