From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261313AbVGGLvT (ORCPT ); Thu, 7 Jul 2005 07:51:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261295AbVGGLqp (ORCPT ); Thu, 7 Jul 2005 07:46:45 -0400 Received: from ozlabs.org ([203.10.76.45]:39362 "EHLO ozlabs.org") by vger.kernel.org with ESMTP id S261320AbVGGLpp (ORCPT ); Thu, 7 Jul 2005 07:45:45 -0400 Date: Thu, 7 Jul 2005 19:24:25 +1000 From: David Gibson To: Avi Kivity Cc: linux-kernel@vger.kernel.org, linuxppc64-dev@ozlabs.org Subject: Re: RFC: Hugepage COW Message-ID: <20050707092425.GA10044@localhost.localdomain> Mail-Followup-To: Avi Kivity , linux-kernel@vger.kernel.org, linuxppc64-dev@ozlabs.org References: <20050707055554.GC11246@localhost.localdomain> <1120718967.2989.7.camel@blast.q> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1120718967.2989.7.camel@blast.q> 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 07, 2005 at 09:49:27AM +0300, Avi Kivity wrote: > On Thu, 2005-07-07 at 15:55 +1000, David Gibson wrote: > > > MAP_PRIVATE|MAP_WRITE mappings of hugetlbfs. Because the pool of > > hugepages is limited, a write to a MAP_PRIVATE hugepage region may > > result in a SIGBUS, if a new hugepage cannot be allocated. This patch > > in that case you might allocate regular pages for the new copy. That's not necessarily possible. On some archs - ppc64 for one - the mmu has to be set up for hugepages on a granularity greater than the hugepage size. So you can just arbitrarily substitute normal pages for hugepages. -- 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