From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261811AbVGOBxE (ORCPT ); Thu, 14 Jul 2005 21:53:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263125AbVGOBxD (ORCPT ); Thu, 14 Jul 2005 21:53:03 -0400 Received: from ozlabs.org ([203.10.76.45]:29661 "EHLO ozlabs.org") by vger.kernel.org with ESMTP id S261811AbVGOBxC (ORCPT ); Thu, 14 Jul 2005 21:53:02 -0400 Date: Fri, 15 Jul 2005 11:14:28 +1000 From: David Gibson To: Christoph Lameter Cc: linux-kernel@vger.kernel.org, linuxppc64-dev@ozlabs.org Subject: Re: RFC: Hugepage COW Message-ID: <20050715011428.GC7750@localhost.localdomain> Mail-Followup-To: Christoph Lameter , linux-kernel@vger.kernel.org, linuxppc64-dev@ozlabs.org References: <20050707055554.GC11246@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.6+20040907i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 14, 2005 at 10:24:33AM -0700, Christoph Lameter wrote: > On Thu, 7 Jul 2005, David Gibson wrote: > > > Now that the hugepage code has been consolidated across the > > architectures, it becomes much easier to implement copy-on-write. > > Hugepage COW is of limited utility of itself, however, it is > > essentially a prerequisite for any of a number of methods of allowing > > userland programs to automatically use hugepages without code changes > > e.g. hugepage malloc() libraries, implicit hugepage mmap(), hugepage > > ELF segments. For certain applications (particularly enormous HPC > > FORTRAN programs), these can result in a large performance > > improvement. > > > > Thoughts? Flames? > > Great stuff. I am glad that you are cleaning up the hugepages and are > making progress improving them. What are your thoughts on implementing > fault handling for huge pages? Well, the COW patch implements a fault handler, obviously. What specifically where you thinking about? -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/people/dgibson