Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262254AbUCVTBQ (ORCPT ); Mon, 22 Mar 2004 14:01:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262257AbUCVTBL (ORCPT ); Mon, 22 Mar 2004 14:01:11 -0500 Received: from waste.org ([209.173.204.2]:33232 "EHLO waste.org") by vger.kernel.org with ESMTP id S262260AbUCVTA6 (ORCPT ); Mon, 22 Mar 2004 14:00:58 -0500 Date: Mon, 22 Mar 2004 13:00:50 -0600 From: Matt Mackall To: Matt Miller Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] 2.6: mmap complement, fdmap Message-ID: <20040322190047.GC8366@waste.org> References: <20040322053025.GR31500@parcelfarce.linux.theplanet.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1641 Lines: 40 On Mon, Mar 22, 2004 at 12:14:56AM -0600, Matt Miller wrote: > > On Sun, Mar 21, 2004 at 10:43:07PM -0600, Matt Miller wrote: > > > ``flags'' can be one of O_RDONLY, O_WRONLY, or O_RDWR. > > > > > > I have verified functionality on ia32 and sparc as these are the only > > > architectures I currently have some type of access to. To test, start the > > > kernel configuration process and go under File systems/Pseudo filesystems > > > and select this option: > > > > > > [*] Virtual memory file descriptor mapping support > > > > > > Please let me know about any and all suggestions/bugs/flames. I tried to > > > > *boggle* > > > > a) what the hell for? > > It's targetted mainly as a performance enhancer. Some of the specific > scenarios where it would be useful are: > > a) When one cannot afford to take the performance hit of synchronizing > a memory range to disk due to disk size limitations or speed > requirements. > b) Some things can benefit from the ability to interface with memory as a > file. > > The specific reason for implementing this was to allow for loading dynamic > libraries in the context of a process without having to write them to > disk. How about tmpfs/ramfs instead? Open a file on tmpfs and mmap it and you've got the same thing without any of the nasty corner cases. -- Matt Mackall : http://www.selenic.com : Linux development and consulting - 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/