From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266449AbUGBDyk (ORCPT ); Thu, 1 Jul 2004 23:54:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266442AbUGBDyh (ORCPT ); Thu, 1 Jul 2004 23:54:37 -0400 Received: from ozlabs.org ([203.10.76.45]:9908 "EHLO ozlabs.org") by vger.kernel.org with ESMTP id S266436AbUGBDx6 (ORCPT ); Thu, 1 Jul 2004 23:53:58 -0400 Date: Fri, 2 Jul 2004 13:49:37 +1000 From: David Gibson To: William Lee Irwin III , Oleg Nesterov , linux-kernel@vger.kernel.org, Andrew Morton , Linus Torvalds Subject: Re: [BUG] hugetlb MAP_PRIVATE mapping vs /dev/zero Message-ID: <20040702034937.GE5937@zax> Mail-Followup-To: David Gibson , William Lee Irwin III , Oleg Nesterov , linux-kernel@vger.kernel.org, Andrew Morton , Linus Torvalds References: <40E43BDE.85C5D670@tv-sign.ru> <20040702012012.GC5937@zax> <20040702024422.GG21066@holomorphy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040702024422.GG21066@holomorphy.com> User-Agent: Mutt/1.5.6+20040523i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 01, 2004 at 07:44:22PM -0700, William Lee Irwin wrote: > On Thu, Jul 01, 2004 at 08:29:18PM +0400, Oleg Nesterov wrote: > >> We can fix hugetlbfs_file_mmap() or read_zero_pagealigned() > >> or both. > > On Fri, Jul 02, 2004 at 11:20:12AM +1000, David Gibson wrote: > > Err... surely we need to fix both, yes? > > No. /dev/zero is innocent. hugetlb is demanding VM_SHARED semantics > without actually setting VM_SHARED. /dev/zero tripping over its > nonstandard pagetable structure is not something to be dealt with > in /dev/zero itself. Duh, sorry, misread the sense of the VM_SHARED test in the zeromap code. -- David Gibson | For every complex problem there is a david AT gibson.dropbear.id.au | solution which is simple, neat and | wrong. http://www.ozlabs.org/people/dgibson