From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754666AbYITOMr (ORCPT ); Sat, 20 Sep 2008 10:12:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754565AbYITOMd (ORCPT ); Sat, 20 Sep 2008 10:12:33 -0400 Received: from casper.infradead.org ([85.118.1.10]:60061 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754866AbYITOMc (ORCPT ); Sat, 20 Sep 2008 10:12:32 -0400 Date: Sat, 20 Sep 2008 07:12:32 -0700 From: Arjan van de Ven To: Mathieu Desnoyers Cc: Steven Rostedt , Martin Bligh , Linux Kernel Mailing List , Linus Torvalds , Thomas Gleixner , od@novell.com, "Frank Ch. Eigler" Subject: Re: Unified tracing buffer Message-ID: <20080920071232.46908040@infradead.org> In-Reply-To: <20080920135548.GB23215@Krystal> References: <33307c790809191433w246c0283l55a57c196664ce77@mail.gmail.com> <20080920135548.GB23215@Krystal> Organization: Intel X-Mailer: Claws Mail 3.5.0 (GTK+ 2.12.11; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 20 Sep 2008 09:55:48 -0400 Mathieu Desnoyers wrote: > How about : > > trace_mark(ftrace_evname, "size %lu binary %pW", > sizeof(mystruct), mystruct); > or > trace_mark(sched_wakeup, "target_pid %ld", task->pid); > > Note the namespacing with buffers being "ftrace" and "sched" here. > > That would encapsulate the whole > - Event ID registration > - Event type registration > - Sending data out > - Enabling the event source directly at the source > > We can then export the markers through a debugfs file and let userland > enable them one by one and possibly connect systemtap filters on them > (one table of registered filters, one table for the markers, a command > file to connect/disconnect filters to/from markers). I would like to ask for the following from the start: have a field for a longer description of the marker that describes it's usage and context. Getting this there from the start is critical, because only when adding the marker point do people still really remember why/what (and having to type a good description also helps them to realize if this is the right point or not). This can then be exposed to the user so he has a standing chance of knowing what the marker is about. It also has a standing chance of being updated when the code changes this way -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org