From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756029AbYDII6q (ORCPT ); Wed, 9 Apr 2008 04:58:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752974AbYDII6i (ORCPT ); Wed, 9 Apr 2008 04:58:38 -0400 Received: from one.firstfloor.org ([213.235.205.2]:57552 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753079AbYDII6h (ORCPT ); Wed, 9 Apr 2008 04:58:37 -0400 Date: Wed, 9 Apr 2008 11:03:06 +0200 From: Andi Kleen To: Ingo Molnar Cc: Matti Aarnio , Zhao Forrest , Andi Kleen , discuss@x86-64.org, linux-kernel@vger.kernel.org, yhlu.kernel@gmail.com, ak@suse.de Subject: Re: Does Linux have plan to support memory hole remapping? Message-ID: <20080409090306.GF19010@one.firstfloor.org> References: <87iqyro3rc.fsf@basil.nowhere.org> <20080409083700.GU3700@mea-ext.zmailer.org> <20080409085440.GB32466@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080409085440.GB32466@elte.hu> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > having said that - but we'll still consider sane looking patches that > allow the remapping of otherwise inactive RAM. I doubt there is any way to do this sanely in the kernel. Usually you would need to move either the PCI hole (which is hard or impossible) or all RAM beyond it (potentially breaking SMM assumptions and causing other problems). Normally the memory controllers don't have a way to just remap pieces because that would need much hardware in critical paths. The only half way sane way to attack this without vendor support would be LinuxBIOS imho. -Andi