From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 26 Dec 2002 22:55:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 26 Dec 2002 22:55:40 -0500 Received: from almesberger.net ([63.105.73.239]:38411 "EHLO host.almesberger.net") by vger.kernel.org with ESMTP id ; Thu, 26 Dec 2002 22:55:40 -0500 Date: Fri, 27 Dec 2002 01:03:38 -0300 From: Werner Almesberger To: Anomalous Force Cc: ebiederm@xmission.com, linux-kernel@vger.kernel.org Subject: Re: holy grail Message-ID: <20021227010338.A1406@almesberger.net> References: <20021227005118.18686.qmail@web13202.mail.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20021227005118.18686.qmail@web13202.mail.yahoo.com>; from anomalous_force@yahoo.com on Thu, Dec 26, 2002 at 04:51:18PM -0800 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Anomalous Force wrote: > a hot swap kernel would be something like the holy grail of kernel > hacking. :-) This comes up every once in a while. The closest approximation you have for this is swsusp. But you'd of course want to start a non-identical kernel. And that's where the hard problems lie. An older or newer kernel would have different data structures, and possibly even data structures which are arranged in a different way (e.g. a hash becomes some kind of tree, etc.). So you'd need some translation mechanism that "upgrades" or "downgrades" all kernel data, including all pointers and offsets that may be sitting around somewhere. Good luck :-) Your best bet would be to use a system that already implements some form of checkpointing or process migration, and use this to preserve user space state across kexec reboots. openMosix may be relatively close to being able to do this for general user space. (I don't know what openMosix currently can do, but many of the problems they need to solve are similar in nature.) - Werner -- _________________________________________________________________________ / Werner Almesberger, Buenos Aires, Argentina wa@almesberger.net / /_http://www.almesberger.net/____________________________________________/