From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id 4978B6B003D for ; Thu, 7 May 2009 10:27:15 -0400 (EDT) Message-ID: <4A02EFD2.40707@zytor.com> Date: Thu, 07 May 2009 07:27:30 -0700 From: "H. Peter Anvin" MIME-Version: 1.0 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: owner-linux-mm@kvack.org 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 List-ID: 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. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org