From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754180AbZBQKmv (ORCPT ); Tue, 17 Feb 2009 05:42:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751376AbZBQKmm (ORCPT ); Tue, 17 Feb 2009 05:42:42 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:49998 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751378AbZBQKml (ORCPT ); Tue, 17 Feb 2009 05:42:41 -0500 Date: Tue, 17 Feb 2009 11:42:13 +0100 From: Ingo Molnar To: Steven Rostedt , Sam Ravnborg Cc: linux-kernel@vger.kernel.org, Andrew Morton , Peter Zijlstra , Frederic Weisbecker , Arnaldo Carvalho de Melo , Peter Zijlstra , Thomas Gleixner Subject: Re: [PATCH 00/15] [git pull] for tip/tracing/ftrace Message-ID: <20090217104213.GC6602@elte.hu> References: <20090217051227.957864159@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090217051227.957864159@goodmis.org> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Steven Rostedt wrote: > Ingo, > > This is a patch series that offers a variety of features. > > The first is to add: > > #### all functions enabled #### > > to set_ftrace_filter when all functions will be traced when function > tracing is on. > > The next is to add a :command: interface, and the module command: > > echo '*:mod:ext4' > set_ftrace_filter > > Will select all functions in the ext4 module. > > echo '!*write*:mod:ext4' > set_ftrace_filter > > will remove all functions with the characters 'write' and are > in ext4. Very nice feature! I'm wondering, would it be possible to somehow extend this to built-in drivers too, so that we get symmetry of usage independently of whether something is built in or a module? I suspect it needs some extensions to kbuild though ... > Next we extend the :command: interface as well as add a way to > hook tracers to specific functions. Instead of tracing all functions > the same, this patch series adds a hash to be able to trace different > functions differently. That's a nice extension too! Small naming detail: instead of calling it a 'hook' (which really has a bad sound to it for various reasons), how about calling it a 'trigger' and/or a 'callback'? > I implement a 'traceon' and 'traceoff' to have a function > start or stop tracing when it is hit. It also includes a > counter for the number of times to implement the trace on/off. > > echo '*_lock:traceon:4' > set_ftrace_filter > echo '*_unlock:traceoff:5' > set_ftrace_filter if there's no counter specified, does it default to 1 [single-shot trigger] or infinity? > This will have all functions that end with _lock turn on > tracing and all that end with _unlock disable it, 4 times > each. > > The following patches are in: > > git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git > > branch: tip/tracing/ftrace > > > Steven Rostedt (15): > ftrace: state that all functions are enabled in set_ftrace_filter > ftrace: add do_for_each_ftrace_rec and while_for_each_ftrace_rec > ftrace: rename ftrace_match to ftrace_match_records > ftrace: break up ftrace_match_records into smaller components > ftrace: add module command function filter selection > ftrace: enable filtering only when a function is filtered on > ftrace: add command interface for function selection > ftrace: convert ftrace_lock from a spinlock to mutex > ftrace: consolidate mutexes > ftrace: trace different functions with a different tracer > ring-buffer: add tracing_is_on to test if ring buffer is enabled > ftrace: add traceon traceoff commands to enable/disable the buffers > ftrace: show selected functions in set_ftrace_filter > ftrace: add pretty print to selected fuction traces > ftrace: add pretty print function for traceon and traceoff hooks > > ---- > include/linux/ftrace.h | 40 ++ > include/linux/ring_buffer.h | 2 + > kernel/trace/ftrace.c | 929 +++++++++++++++++++++++++++++++--------- > kernel/trace/ring_buffer.c | 9 + > kernel/trace/trace_functions.c | 163 +++++++ > 5 files changed, 946 insertions(+), 197 deletions(-) Pulled into tip:tracing/ftrace, thanks Steve! Ingo