From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <461186A7.2020803@google.com> Date: Mon, 02 Apr 2007 15:41:43 -0700 From: Martin Bligh MIME-Version: 1.0 Subject: Re: [PATCH 1/4] x86_64: Switch to SPARSE_VIRTUAL References: <20070401071024.23757.4113.sendpatchset@schroedinger.engr.sgi.com> <1175550968.22373.122.camel@localhost.localdomain> <200704030031.24898.ak@suse.de> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: Andi Kleen , Dave Hansen , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, KAMEZAWA Hiroyuki List-ID: Christoph Lameter wrote: > On Tue, 3 Apr 2007, Andi Kleen wrote: > >> If it works I would be inclined to replaced old sparsemem with Christoph's >> new one on x86-64. Perhaps that could cut down the bewildering sparsemem >> ifdef jungle that is there currently. >> >> But I presume it won't work on 32bit because of the limited address space? > > Not in general but it will work in non PAE mode. 4GB need 2^(32-21+4) = > 16MB pages. This would require the mapping on 4 4MB pages. IIRC NUMA isn't supported (or useful anyway) without PAE. > For 64GB you'd need 256M which would be a quarter of low mem. Probably > takes up too much of low mem. Yup. M. -- 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