From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261216AbTD1RYe (ORCPT ); Mon, 28 Apr 2003 13:24:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261218AbTD1RYe (ORCPT ); Mon, 28 Apr 2003 13:24:34 -0400 Received: from imap.gmx.net ([213.165.64.20]:26912 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S261216AbTD1RX7 (ORCPT ); Mon, 28 Apr 2003 13:23:59 -0400 Message-ID: <3EAD6688.7060809@gmx.net> Date: Mon, 28 Apr 2003 19:36:08 +0200 From: Carl-Daniel Hailfinger User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2) Gecko/20021126 X-Accept-Language: de, en MIME-Version: 1.0 To: Dave Hansen CC: Andi Kleen , Henti Smith , linux-kernel@vger.kernel.org, lse-tech@lists.sourceforge.net, Riley Williams Subject: Re: [Lse-tech] Re: maximum possible memory limit .. References: <20030424200524.5030a86b.bain@tcsn.co.za> <3EAD27B2.9010807@gmx.net> <20030428141023.GC4525@Wotan.suse.de> <3EAD5AC1.7090003@us.ibm.com> <3EAD5D90.7010101@gmx.net> <3EAD61FB.30907@us.ibm.com> In-Reply-To: <3EAD61FB.30907@us.ibm.com> X-Enigmail-Version: 0.71.0.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Dave Hansen wrote: > Carl-Daniel Hailfinger wrote: > >>Cool. Sorry to be pestering about the 64-bit limits, but can we really >>use 2^64 bytes of memory on ia64/ppc64/x86-64 etc.? (AFAIK, 64-bit >>arches don't suffer from a small ZONE_LOWMEM.) > > [...] > Don't forget that highmem starts to be needed before the 4G boundary. > The kernel has only 1GB of virtual space (look for PAGE_OFFSET, which > defines it), which means that you start needing to pull all of the > highmem trickery before you get to the actual limits. It seems I misunderstood the concept of highmem. I thought highmem was not needed on 64-bit arches. Thanks for pointing that out to me. > > Nobody knows how far it will go. It's fairly safe to say that, at this > rate, Linux will keep up with whatever hardware anyone produces. That is the answer the original poster was looking for. > Unless, of course, someone gets even more perverse than PAE. :) hehe ;-) Can you say PAE in userspace? Regards, Carl-Daniel -- http://www.hailfinger.org/