From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261886AbVCQUR1 (ORCPT ); Thu, 17 Mar 2005 15:17:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261884AbVCQUR1 (ORCPT ); Thu, 17 Mar 2005 15:17:27 -0500 Received: from everest.2mbit.com ([24.123.221.2]:28817 "EHLO mail.sosdg.org") by vger.kernel.org with ESMTP id S261922AbVCQUNV (ORCPT ); Thu, 17 Mar 2005 15:13:21 -0500 Message-ID: <4239E4CC.7050007@lovecn.org> Date: Fri, 18 Mar 2005 04:13:00 +0800 From: Coywolf Qi Hunt User-Agent: Debian Thunderbird 1.0 (X11/20050116) X-Accept-Language: en-us, en MIME-Version: 1.0 To: linux-os@analogic.com CC: "Peter W. Morreale" , linux-kernel@vger.kernel.org References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Broken-Reverse-DNS: no host name for for IP address 221.201.199.142 X-Scan-Signature: 0c1945f502a06f7766c9348c347b6b03 X-SA-Exim-Connect-IP: 221.201.199.142 X-SA-Exim-Mail-From: coywolf@lovecn.org Subject: Re: Kernel memory limits? X-Spam-Report: * -4.9 BAYES_00 BODY: Bayesian spam probability is 0 to 1% * [score: 0.0000] * 4.0 RCVD_IN_AHBL_CNKR RBL: AHBL: sender is listed in the AHBL China/Korea blocks * [221.201.199.142 listed in cnkrbl.ahbl.org] X-SA-Exim-Version: 4.2 (built Sun, 13 Feb 2005 18:23:43 -0500) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org linux-os wrote: > On Thu, 17 Mar 2005, Peter W. Morreale wrote: > >> (I did not see this addressed in the FAQs...) >> >> How much physical memory can the 2.4.26 kernel address in kernel >> context on x86? >> > > All of it. > >> What about DMA memory? >> > > All of it, too. The old DMA controller(s) could only address 16 MB > because that's all the page-registers allowed. Bus-mastering DMA > off the PCI/Bus has no such limitation. Most have DMA controllers > that use scatter-lists so RAM doesn't even have to be contiguous, > only properly allocated (in pages) and nailed down with no caching. > Kernel Image itself resides at physical address 1M. Is this kernel image area a hole to the old DMA range? Thanks. Coywolf