From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 8 May 2002 04:29:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 8 May 2002 04:29:02 -0400 Received: from penguin.e-mind.com ([195.223.140.120]:27664 "EHLO penguin.e-mind.com") by vger.kernel.org with ESMTP id ; Wed, 8 May 2002 04:29:01 -0400 Date: Wed, 8 May 2002 10:29:34 +0200 From: Andrea Arcangeli To: Robert Love Cc: Clifford White , linux-kernel@vger.kernel.org Subject: Re: x86 question: Can a process have > 3GB memory? Message-ID: <20020508102934.Z31998@dualathlon.random> In-Reply-To: <1020812936.2079.31.camel@bigsur> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.22.1i X-GnuPG-Key-URL: http://e-mind.com/~andrea/aa.gnupg.asc X-PGP-Key-URL: http://e-mind.com/~andrea/aa.asc Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 07, 2002 at 04:08:55PM -0700, Robert Love wrote: > On Tue, 2002-05-07 at 16:03, Clifford White wrote: > > > We are working with a database that requires a large amount of memory > > allocated by a single process. > > This is on an Intel 32-bit platform. > > We'd like to go > 3GB of memory per process. > > Is this possible on a 32-bit machine? I have been reading the various > > 'highmem' discussions, but that's kernel page tables... > > Or is this a glibc issue, and not proper for a kernel-list question? > > Any pointers would be appreciated. The Intel ESMA (Extended Server Memory > > Arch) page states that it's possible, but.....how? > > You can go to 3.5GB, anything more and stuff starts getting real tight > and not very nice. You can only do 3.5/0.5 on non-PAE, though - PAE > requires segments to be aligned on 1GB-boundaries. > > The attached patch (for which credit goes elsewhere - Ingo or Randy, I > think?) implements the full range of 1 to 3.5GB user space partitioning, actually I'm the one who wrote the 3.5G config option both in 2.2 and recently I forward ported it to 2.4 due the number of requests I was getting. > selectable at compile-time. > > Robert Love > Andrea