Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758331AbXKFUCW (ORCPT ); Tue, 6 Nov 2007 15:02:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756927AbXKFTxv (ORCPT ); Tue, 6 Nov 2007 14:53:51 -0500 Received: from 1wt.eu ([62.212.114.60]:3737 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757584AbXKFTxs (ORCPT ); Tue, 6 Nov 2007 14:53:48 -0500 Date: Tue, 6 Nov 2007 20:53:05 +0100 From: Willy Tarreau To: "H. Peter Anvin" Cc: Andi Kleen , Ray Lee , Bo =?iso-8859-1?Q?Brant=E9n?= , Andrew Morton , Jesse Barnes , linux-kernel@vger.kernel.org Subject: Re: x86_64 ten times slower than i386 Message-ID: <20071106195305.GE1045@1wt.eu> References: <20071103162640.GS17536@waste.org> <2c0942db0711050832t5207ea8bib1f75e59e071ade2@mail.gmail.com> <20071106002647.GA27182@one.firstfloor.org> <472FC130.40605@zytor.com> <20071106194009.GC1045@1wt.eu> <4730C575.2020007@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4730C575.2020007@zytor.com> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 779 Lines: 20 On Tue, Nov 06, 2007 at 11:50:13AM -0800, H. Peter Anvin wrote: > Willy Tarreau wrote: > >Just out of curiosity, what would be the problem if the MTRRs covered more > >than the memory size ? For instance, instead of having 512 MB at 4G, why > >not have 1G at 4G ? > > That's fine, *as long as* you don't have any I/O devices there, > including things like UMA graphics devices or memory areas used by SMM. > In theory, those should be marked reserved in e820. In practice... OK, thanks Peter for the explanation. Cheers, Willy - 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/