From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from jade.spiritone.com (jade.aracnet.com [216.99.193.136]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 97038679E7 for ; Mon, 16 May 2005 08:43:59 +1000 (EST) Received: from [192.168.0.2] (216-99-213-225.dsl.aracnet.com [216.99.213.225]) (authenticated bits=0) by jade.spiritone.com (8.12.8/8.12.8) with ESMTP id j4FMb0Op017444 for ; Sun, 15 May 2005 15:37:01 -0700 Message-ID: <4287CF06.5000809@BitWagon.com> Date: Sun, 15 May 2005 15:36:54 -0700 From: John Reiser MIME-Version: 1.0 To: linuxppc-dev@ozlabs.org Content-Type: text/plain; charset=ISO-8859-1; format=flowed Subject: 2GB address space limit on 32-bit PowerPC Macintosh List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , The 2GB limit on TASK_SIZE for user address space on 32-bit PowerPC Apple Macintosh is getting in the way of database, filesystem maintenance, and scientific applications. In user mode, most i686 desktops can address 3GB. While 64-bit systems are becoming available, the vast majority of existing systems are still 32-bit. What can be done to get a larger address space for existing Macs? According to arch/ppc/syslib/prom_init.c, the first problem is that CONFIG_BOOTX_TEXT restricts CONFIG_TASK_SIZE to only 0x80000000. Is this an initialization-only restriction that just happens to persist beyond initialization? What would it take to remove this collision from affecting life after boot? How much of booting does CONFIG_BOOTX_TEXT affect? --