From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262391AbVCQSfv (ORCPT ); Thu, 17 Mar 2005 13:35:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262382AbVCQSfu (ORCPT ); Thu, 17 Mar 2005 13:35:50 -0500 Received: from e2.ny.us.ibm.com ([32.97.182.142]:21691 "EHLO e2.ny.us.ibm.com") by vger.kernel.org with ESMTP id S262391AbVCQSff (ORCPT ); Thu, 17 Mar 2005 13:35:35 -0500 Subject: Re: Kernel memory limits? From: Dave Hansen To: "Peter W. Morreale" Cc: Linux Kernel Mailing List In-Reply-To: References: Content-Type: text/plain Date: Thu, 17 Mar 2005 10:34:48 -0800 Message-Id: <1111084488.4945.4.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.0.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2005-03-17 at 11:06 -0700, 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? 896 MB There are patches to move this around, though. > What about DMA memory? What kind of DMA? > Local rumor says ~1GB. But this makes little sense given a 32-bit address. > > Where in the source can I learn more about this? arch/i386 include/asm-i386 :) Check out MAXMEM in include/asm-i386/page.h (at least 2.6) -- Dave