Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758266AbYFYTCH (ORCPT ); Wed, 25 Jun 2008 15:02:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753305AbYFYTB4 (ORCPT ); Wed, 25 Jun 2008 15:01:56 -0400 Received: from one.firstfloor.org ([213.235.205.2]:43605 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753128AbYFYTBz (ORCPT ); Wed, 25 Jun 2008 15:01:55 -0400 Date: Wed, 25 Jun 2008 21:13:15 +0200 From: Andi Kleen To: Keir Fraser Cc: Andi Kleen , Jeremy Fitzhardinge , Mark McLoughlin , xen-devel , Eduardo Habkost , LKML , Stephen Tweedie Subject: Re: [Xen-devel] Re: [PATCH 00 of 36] x86/paravirt: groundwork for 64-bit Xen support Message-ID: <20080625191315.GD6708@one.firstfloor.org> References: <87skv1r8ln.fsf@basil.nowhere.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 793 Lines: 20 > What does Linux expect to scale up to? Reserving 16 PML4 entries leaves the > kernel with 120TB of available 'negative' address space. Should be plenty, I > would think. There are already (ok non x86-64) systems shipping today with 10+TB of addressable memory. 100+TB is not that far away with typical growth rates. Besides there has to be much more in the negative address space than just direct mapping. So far we always that 64bit Linux can support upto 1/4*max VA memory. With your change that formula would be not true anymore. -Andi -- 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/