Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932157AbWBXOYa (ORCPT ); Fri, 24 Feb 2006 09:24:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932158AbWBXOYa (ORCPT ); Fri, 24 Feb 2006 09:24:30 -0500 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:63908 "EHLO ebiederm.dsl.xmission.com") by vger.kernel.org with ESMTP id S932157AbWBXOY3 (ORCPT ); Fri, 24 Feb 2006 09:24:29 -0500 To: Rene Herman Cc: Linus Torvalds , Arjan van de Ven , Andi Kleen , linux-kernel@vger.kernel.org, akpm@osdl.org, mingo@elte.hu Subject: Re: Patch to reorder functions in the vmlinux to a defined order References: <1140700758.4672.51.camel@laptopd505.fenrus.org> <1140707358.4672.67.camel@laptopd505.fenrus.org> <200602231700.36333.ak@suse.de> <1140713001.4672.73.camel@laptopd505.fenrus.org> <43FE0B9A.40209@keyaccess.nl> <43FE1764.6000300@keyaccess.nl> <43FE4B00.8080205@keyaccess.nl> From: ebiederm@xmission.com (Eric W. Biederman) In-Reply-To: <43FE4B00.8080205@keyaccess.nl> (Rene Herman's message of "Fri, 24 Feb 2006 00:53:36 +0100") User-Agent: Gnus/5.1007 (Gnus v5.10.7) Emacs/21.4 (gnu/linux) Date: Fri, 24 Feb 2006 07:23:13 -0700 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1255 Lines: 29 Rene Herman writes: > Linus Torvalds wrote: > >> On Thu, 23 Feb 2006, Rene Herman wrote: > >>> Okay. I suppose the only other option is to make "physical_start" a variable >>> passed in by the bootloader so that it could make a runtime decision? Ie, >>> place us at min(top_of_mem, 4G) if it cared to. I just grepped for >>> PHYSICAL_START and this didn't look _too_ bad. >> No can do. You'd have to make the kernel relocatable, and do load-time >> fixups. Very invasive. > > Yes, that wasn't too smart. I believe in principe most of it _could_ be done via > some pagetable trickery though, with the kernel still at a fixed virtual > address? The page table trickery is actually the more invasive approach. I believe for 32 bit kernels the real problem is giving up the identity mapping of low memory. Short of the moving the kernel to end of the address space where vmalloc and the fixmaps are now I don't think there is a reasonable chunk of the address space we can use. Eric - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/