From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264315AbUAGXn6 (ORCPT ); Wed, 7 Jan 2004 18:43:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264340AbUAGXn6 (ORCPT ); Wed, 7 Jan 2004 18:43:58 -0500 Received: from [193.138.115.2] ([193.138.115.2]:24071 "HELO diftmgw.backbone.dif.dk") by vger.kernel.org with SMTP id S264315AbUAGXnv (ORCPT ); Wed, 7 Jan 2004 18:43:51 -0500 Date: Thu, 8 Jan 2004 00:40:34 +0100 (CET) From: Jesper Juhl To: Mike Fedyk cc: Mike Waychison , "H. Peter Anvin" , linux-kernel@vger.kernel.org Subject: Re: [autofs] [RFC] Towards a Modern Autofs In-Reply-To: <20040107211134.GR1882@matchmail.com> Message-ID: References: <1b5GC-29h-1@gated-at.bofh.it> <1b6CO-3v0-15@gated-at.bofh.it> <3FFC46EB.9050201@zytor.com> <3FFC7469.3050700@sun.com> <20040107211134.GR1882@matchmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 7 Jan 2004, Mike Fedyk wrote: > On Wed, Jan 07, 2004 at 04:04:41PM -0500, Mike Waychison wrote: > > H. Peter Anvin wrote: > > > > >>Also when /home or other important fs are mounted via autofs there is > > >>not much practical difference between a hung kernel and a hung > > >>daemon. You have to reboot the system anyways. > > > > > > > > >a) Guess which one is easier to debug? > > > > When they may both equally hang your machine, neither. > > Let's see. > > If it's in userspace, then setup your debug area in an area your system > doesn't depend on, and wham, the hang won't affect the entire system anymore. > > Also, if you have /home automounted then it only affects the users on /home, > and root's $home should be /home... > >>From a user point of view I have to agree with you. Keeping it out of the kernel makes perfect sense to me. Easier to test your setup - errors will not hang the box. In the case the implementation is buggy a daemon can easily be restarted nightly without disrupting other things running on the box (a nightly reboot is not as friendly). >>From a developer point of view, I also agree. Debugging kernel code is in general a much harder thing to do than debugging a userspace daemon. I'd also guess that more people will be inclined to contribute development time to a userspace program than a kernel based implementation - just the fact that it's in-kernel will be percieved as having a much higher barrier-to-entry and I suspect that fact alone might discourage potential contributers. - Jesper Juhl