Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265626AbTGDBWD (ORCPT ); Thu, 3 Jul 2003 21:22:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265629AbTGDBWD (ORCPT ); Thu, 3 Jul 2003 21:22:03 -0400 Received: from holomorphy.com ([66.224.33.161]:35269 "EHLO holomorphy") by vger.kernel.org with ESMTP id S265626AbTGDBWA (ORCPT ); Thu, 3 Jul 2003 21:22:00 -0400 Date: Thu, 3 Jul 2003 18:36:12 -0700 From: William Lee Irwin III To: Andrea Arcangeli Cc: Jamie Lokier , "Martin J. Bligh" , Mel Gorman , Linux Memory Management List , Linux Kernel Mailing List Subject: Re: What to expect with the 2.6 VM Message-ID: <20030704013612.GV26348@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Andrea Arcangeli , Jamie Lokier , "Martin J. Bligh" , Mel Gorman , Linux Memory Management List , Linux Kernel Mailing List References: <20030702233014.GW23578@dualathlon.random> <20030702235540.GK26348@holomorphy.com> <20030703113144.GY23578@dualathlon.random> <20030703114626.GP26348@holomorphy.com> <20030703125839.GZ23578@dualathlon.random> <20030703184825.GA17090@mail.jlokier.co.uk> <20030703185431.GQ26348@holomorphy.com> <20030703193328.GN23578@dualathlon.random> <20030703222113.GS26348@holomorphy.com> <20030704004641.GR23578@dualathlon.random> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030704004641.GR23578@dualathlon.random> Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1497 Lines: 28 On Thu, Jul 03, 2003 at 03:21:13PM -0700, William Lee Irwin III wrote: >> It's obvious what to do about protections. On Fri, Jul 04, 2003 at 02:46:41AM +0200, Andrea Arcangeli wrote: > so you agree it'd better be a separate syscall, also given it seems > the current remap_file_pages api in 2.5 seems unfortunately already > frozen since I think it's wrong as it should only work on VM_NONLINEAR > vmas, it's very unclean to allow remap_file_pages to mangle whatever vma > out there despite it has to deal with truncate etc.. I think the minium > required change to the API is to add a MAP_NONLINEAR that converts in > kernel space to a VM_NONLINEAR. You allocate the mapping with > mmap(MAP_NONLINAER) and only then remap_file_pages will work. This > solves all the current brekages (and it'll be trivial to skip over > VM_NONLINEAR in the 2.4 vm too). (then there's the rmap/mlock/munlock > issue but that's an implementation issue non visible from userspace > [modulo security with the sysctl], this one instead is a API bug IMHO > and it'd better be fixed before people puts the backport in production) sys_chattr_file_pages() etc. sounds fine to me; GC's would love it. I'll tackle the rest in another (somewhat more inflammatory) post. -- wli - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/