From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760613AbZEGO3U (ORCPT ); Thu, 7 May 2009 10:29:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753391AbZEGO3G (ORCPT ); Thu, 7 May 2009 10:29:06 -0400 Received: from terminus.zytor.com ([198.137.202.10]:42787 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754163AbZEGO3F (ORCPT ); Thu, 7 May 2009 10:29:05 -0400 Message-ID: <4A02EFD2.40707@zytor.com> Date: Thu, 07 May 2009 07:27:30 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Ingo Molnar CC: Pavel Machek , Rik van Riel , "linux-kernel@vger.kernel.org" , linux-mm@kvack.org, mingo@redhat.com, akpm@linux-foundation.org Subject: Re: [PATCH] x86: 46 bit PAE support References: <20090505172856.6820db22@cuia.bos.redhat.com> <4A00ED83.1030700@zytor.com> <4A0180AB.20108@redhat.com> <20090507120103.GA1497@ucw.cz> <20090507141642.GJ481@elte.hu> In-Reply-To: <20090507141642.GJ481@elte.hu> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ingo Molnar wrote: > > Yes, struct page is ~64 bytes, and 64*64 == 4096. > > Alas, it's not a problem: my suggestion wasnt to simulate 64 TB of > RAM. My suggestion was to create a sparse physical memory map (in a > virtual machine) that spreads ~1GB of RAM all around the 64 TB > physical address space. That will test whether the kernel is able to > map and work with such physical addresses. (which will cover most of > the issues) > > A good look at /debug/x86/dump_pagetables with such a system booted > up would be nice as well - to make sure every virtual memory range > is in its proper area, and that there's enough free space around > them. > We're working on simulating this at Intel. We should hopefully be able to test this next week. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.