From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755533AbXGAWCi (ORCPT ); Sun, 1 Jul 2007 18:02:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751309AbXGAWC3 (ORCPT ); Sun, 1 Jul 2007 18:02:29 -0400 Received: from mx2.suse.de ([195.135.220.15]:43130 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751115AbXGAWC3 (ORCPT ); Sun, 1 Jul 2007 18:02:29 -0400 From: Andreas Schwab To: "Ahmed S. Darwish" Cc: linux-kernel@vger.kernel.org Subject: Re: [i386] Questions regarding provisional page tables initialization References: <20070701203833.GA3498@Ahmed> X-Yow: Hello, GORRY-O!! I'm a GENIUS from HARVARD!! Date: Mon, 02 Jul 2007 00:02:27 +0200 In-Reply-To: <20070701203833.GA3498@Ahmed> (Ahmed S. Darwish's message of "Sun\, 1 Jul 2007 23\:38\:33 +0300") Message-ID: User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/22.0.97 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org "Ahmed S. Darwish" writes: > page_pde_offset = (__PAGE_OFFSET >> 20) > movl %ecx,(%edx) /* Store identity PDE entry */ > movl %ecx,page_pde_offset(%edx) /* Store kernel PDE entry */ > > Why the pde_offset is PAGE_OFFSET >> 20 instead of PAGE_OFFSET >> 22 ? > * 22 to right shift the whole page_shift (12) and pgdir_shift (10) bits. 4 is the element size. Andreas. -- Andreas Schwab, SuSE Labs, schwab@suse.de SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany PGP key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different."