From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 3 May 2002 12:05:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 3 May 2002 12:05:48 -0400 Received: from mail3.aracnet.com ([216.99.193.38]:38372 "EHLO mail3.aracnet.com") by vger.kernel.org with ESMTP id ; Fri, 3 May 2002 12:05:46 -0400 Date: Fri, 03 May 2002 09:05:05 -0700 From: "Martin J. Bligh" Reply-To: "Martin J. Bligh" To: Leandro Tavares Carneiro , Kernel Mailing List Subject: Re: High Memory Address Space Message-ID: <4058141609.1020416704@[10.10.2.3]> In-Reply-To: <1020437001.2951.45.camel@linux60> X-Mailer: Mulberry/2.1.2 (Win32) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > How is the maximum memory address space, per process or for all process, > using High Memory Suport to 64Gb? Roughly speaking, the high memory (above 896MB phys) is mapped directly into user address spaces, mapped a page at a time into the kernel virtual address space via kmap and friends into a small window. > Is possible to alocate more than 3GB for one process? Not really, you could shift the boundary to 3.5Gb or so in theory, and eek out a little more, but in practice that just makes you run out of kernel address space instead if you have enough memory to make it worthwhile (unless you wanted the users pages swapped out). M.