From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266308AbUGBGUy (ORCPT ); Fri, 2 Jul 2004 02:20:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266459AbUGBGUx (ORCPT ); Fri, 2 Jul 2004 02:20:53 -0400 Received: from fw.osdl.org ([65.172.181.6]:51687 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S266308AbUGBGUt (ORCPT ); Fri, 2 Jul 2004 02:20:49 -0400 Date: Thu, 1 Jul 2004 23:18:44 -0700 From: Andrew Morton To: karim@opersys.com Cc: peterm@redhat.com, faith@redhat.com, davidm@hpl.hp.com, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, ray.lanza@hp.com, trz@us.ibm.com, richardj_moore@uk.ibm.com, bob@watson.ibm.com, michel.dagenais@polymtl.ca Subject: Re: [PATCH] IA64 audit support Message-Id: <20040701231844.0aed5201.akpm@osdl.org> In-Reply-To: <40E4D4AD.2020302@opersys.com> References: <200406301556.i5UFuGg8009251@redrum.boston.redhat.com> <20040701124644.5e301ca0.akpm@osdl.org> <40E4B20F.8010503@opersys.com> <20040701182954.43351d36.akpm@osdl.org> <40E4D4AD.2020302@opersys.com> X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Karim Yaghmour wrote: > > > Developer support tools are good, but are not as persuasive as end-user > > features. Because the audience is smaller, and developers know how to > > apply patches and rebuild stuff. > > This is probably one of the biggest misconception about LTT amongst kernel > developers. So let me present this once more: LTT is _NOT_ for kernel > developers, it has never been developed with this crowd in mind. LTT is and > has _ALWAYS_ been intended for the end user. Note I said "developer", not "kernel developer". If the audience for a feature is kernel developers, userspace developers and perhaps the most sophisticated sysadmins then that's a small audience. It's certainly an _important_ audience, but the feature is not as important as those codepaths which Uncle Tillie needs to run his applications. > Again, LTT is of marginal use to kernel developers, the benefits all go > to the end users' ability to understand what's going on in their system (see > above for examples.) To me, an "end user" is one who is capable of identifying the power switch and the ANY key, not an application programmer! > On the topic of maintenance cost, I fail to see how one-liners such as the > above can be of any burden to any kernel developer, they have remained > virtually unchanged for the past 5 years and any look throughout the LTT > archives or the kernel mailing list archive for LTT patches will readily > show this. Fair enough. > > If it could use kprobes hooks that'd be neat. kprobes is low-impact. > > The issues about the spread of trace points across the source code are > exactly the same, you still need to mark the code-paths (and maintain > these markings for each version) regardless of the mechanism being used. Nope, kprobes allows a kernel module to patch hooks into the running binary. That's all it does, really. See http://www-124.ibm.com/linux/projects/kprobes/