From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 28 May 2002 10:15:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 28 May 2002 10:15:15 -0400 Received: from sark.cc.gatech.edu ([130.207.7.23]:20882 "EHLO sark.cc.gatech.edu") by vger.kernel.org with ESMTP id ; Tue, 28 May 2002 10:15:14 -0400 Date: Tue, 28 May 2002 10:15:15 -0400 From: Josh Fryman To: linux-kernel@vger.kernel.org Subject: changing __PAGE_OFFSET on x86? Message-Id: <20020528101515.56785de1.fryman@cc.gatech.edu> X-Mailer: Sylpheed version 0.7.4 (GTK+ 1.2.8; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org hi, i posted a query last week about a problem we're having with some PCI devices. we have a P4 system with 512M of RAM and two PCI cards, each having another 256MB of RAM. we want our device driver to expose the entire memory region for the pci cards. when adding all this up, we're exceeding the 3G/1G split of the linux kernel. as dan maas pointed out, there should be a way to fix this in the kernel... so, after some grepping and code browsing, my new question is: to fix this, if we change the __PAGE_OFFSET in include/asm-i386/page.h from 0xc0000000 to 0xb000000, are there any hidden dependencies? is there anything else we need to worry about? (does the __PAGE_OFFSET need to lie on a 1G boundary?) i haven't seen any, but them i'm not willing to say i understand all the implications from chaging such a fundamental #define .... thanks, josh