Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932405AbWBXR4j (ORCPT ); Fri, 24 Feb 2006 12:56:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932406AbWBXR4j (ORCPT ); Fri, 24 Feb 2006 12:56:39 -0500 Received: from smtpq2.tilbu1.nb.home.nl ([213.51.146.201]:12517 "EHLO smtpq2.tilbu1.nb.home.nl") by vger.kernel.org with ESMTP id S932405AbWBXR4i (ORCPT ); Fri, 24 Feb 2006 12:56:38 -0500 Message-ID: <43FF48F2.70508@keyaccess.nl> Date: Fri, 24 Feb 2006 18:57:06 +0100 From: Rene Herman User-Agent: Thunderbird 1.5 (X11/20051201) MIME-Version: 1.0 To: Linus Torvalds CC: "Eric W. Biederman" , 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> <43FF26A8.9070600@keyaccess.nl> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-AtHome-MailScanner-Information: Neem contact op met support@home.nl voor meer informatie X-AtHome-MailScanner: Found to be clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1147 Lines: 28 Linus Torvalds wrote: > The real issue is the _physical_ address. Nothing else matters. > > If the TLB splitting on the fixed MTRRs is an issue, it depends entirely > on what physical address the kernel resides in, and the virtual address is > totally inconsequential. > > So playing games with virtual mapping has absolutely no upsides, and it > definitely has downsides. The notion was that having a fixed virtual mapping of the kernel would allow it to be loaded anywhere physically without needing to do actual address fixups. The bootloader could then for example at runtime decide to load the kernel at 16MB if the machine had enough memory available, to free up ZONE_DMA. Or not do that if running on a <= 16MB machine. Or the kdump "host" kernel would make that decission, as it seems the want is shared with them. Eric Biederman said that fixups aren't that bad though... Rene. - 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/