From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from az33egw01.freescale.net (az33egw01.freescale.net [192.88.158.102]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "az33egw01.freescale.net", Issuer "Thawte Premium Server CA" (verified OK)) by ozlabs.org (Postfix) with ESMTP id 838DCDDF49 for ; Thu, 6 Dec 2007 04:50:33 +1100 (EST) Message-ID: <4756E4F0.8050906@freescale.com> Date: Wed, 05 Dec 2007 11:50:40 -0600 From: Scott Wood MIME-Version: 1.0 To: michael.firth@bt.com Subject: Re: Maximum ioremap size for ppc arch? References: <36D7B34A3A79F84F82FA0C154F299F2506080F6F@E03MVX1-UKDY.domain1.systemhost.net> <4756E3E8.8090102@freescale.com> In-Reply-To: <4756E3E8.8090102@freescale.com> Content-Type: text/plain; charset=UTF-8; format=flowed Cc: linuxppc-embedded@ozlabs.org List-Id: Linux on Embedded PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Scott Wood wrote: > michael.firth@bt.com wrote: >> This seems to leave only 1GB of addressing space for all the >> physically addressable memory (RAM + ioremapped + registers), while >> reserving 3GB of space for user processes. The 3GB is presumably >> mostly unusable on a system without a large amount of swap, as the >> 1GB limit on memory will prevent much more than that being available >> for user space. > > Well, it's also useful for sparse mappings, but I agree that the 3/1 > split is probably suboptimal for most workloads. Oh, and the 3G user is also useful for accessing highmem, of course. -Scott