From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965004AbWDMXTf (ORCPT ); Thu, 13 Apr 2006 19:19:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965029AbWDMXTe (ORCPT ); Thu, 13 Apr 2006 19:19:34 -0400 Received: from xenotime.net ([66.160.160.81]:38565 "HELO xenotime.net") by vger.kernel.org with SMTP id S965004AbWDMXTd (ORCPT ); Thu, 13 Apr 2006 19:19:33 -0400 Date: Thu, 13 Apr 2006 16:21:59 -0700 From: "Randy.Dunlap" To: Jan Engelhardt Cc: linux-kernel@vger.kernel.org Subject: Re: Flexible mem= parameter Message-Id: <20060413162159.5fd64b5e.rdunlap@xenotime.net> In-Reply-To: References: Organization: YPO4 X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.3; x86_64-unknown-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 On Fri, 14 Apr 2006 00:49:12 +0200 (MEST) Jan Engelhardt wrote: > Hello, > > mem= can be used to limit the amount of physical memory Linux uses. I > presume that when specifying mem=256M only the memory from 0x0 to > 0x10000000 is used. Is there a way to tune mem= so that it will use > 0x70000000 to 0x80000000? (A compile-time change would suffice.) > > > Background: I am trying to track down a nondeterministic (but > reproducible) segfault while building big projects like gcc or glibc. I do > not think it's a memory problem since it only showed up since I changed to > gcc 4.1.0 and tweaked it to use -mcpu=ultrasparc (rather than -mcpu=v7) by > default. I had been building gcc4 before with gcc3 a number of times w/o > problems. I did ran a userspace memtester for approx 20 hours (`memtest` > from debian). I've never tried it, but Documentation/kernel-parameters.txt suggests using mem= along with memmap= to specify an exact memmap. memmap=nn[KMG]@ss[KMG] [KNL] Force usage of a specific region of memory Region of memory to be used, from ss to ss+nn. Is this on a sparc system or are you just building sparc tools? I don't know if memmap= works on sparc arch. --- ~Randy