Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752128Ab0DSVJc (ORCPT ); Mon, 19 Apr 2010 17:09:32 -0400 Received: from mail-va3.bigfish.com ([216.32.180.114]:60904 "EHLO mail184-va3-R.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752018Ab0DSVJU (ORCPT ); Mon, 19 Apr 2010 17:09:20 -0400 X-Greylist: delayed 1803 seconds by postgrey-1.27 at vger.kernel.org; Mon, 19 Apr 2010 17:09:19 EDT X-SpamScore: -27 X-BigFish: VPS-27(zz1432P98dN936eM9371Pzz1202hz4fhzz2fh2a8h61h) X-Spam-TCS-SCL: 0:0 X-FB-SS: 5, X-MS-Exchange-Organization-Antispam-Report: OrigIP: 160.33.98.74;Service: EHS Message-ID: <4BCCBF6D.3030105@am.sony.com> Date: Mon, 19 Apr 2010 13:39:09 -0700 From: Tim Bird User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.8) Gecko/20100301 Fedora/3.0.3-1.fc12 Thunderbird/3.0.3 MIME-Version: 1.0 To: "rostedt@goodmis.org" CC: Tom Zanussi , Ingo Molnar , Frederic Weisbecker , Thomas Gleixner , Chase Douglas , LKML Subject: Re: request to add trace off and trace on with events References: <1271707444.10448.12.camel@gandalf.stny.rr.com> In-Reply-To: <1271707444.10448.12.camel@gandalf.stny.rr.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Reverse-DNS: mail7.fw-bc.sony.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1453 Lines: 42 On 04/19/2010 01:04 PM, Steven Rostedt wrote: > Hi Tom, > > Could you add a way to do a call to tracing_on() or tracing_off() via > the filters. I would like to do something like: > > > echo 'if (pid == 1234) traceoff' > events/sched/sched_wakeup/filter > > Where, if the sched_wakeup event is hit with pid == 1234 it will turn > tracing off. Just a comment on the nomenclature. In KFT I called things like this "triggers". I'm not sure what other tracing systems call them. I'm a little worried about overloading the filtering abstraction with trigger semantics. (I like the idea of triggers, but it might be better to control them with another pseudo-file for clarity.) I suppose both are a form of conditional execution. Filtering has an implicit action of either 'trace this' or 'don't trace this', while triggering usually has an action, often explicit, to start or stop tracing. However, since they both use the conditional testing, it might be a pain to reproduce this code for a different pseudo-file. Just my 2 cents. -- Tim ============================= Tim Bird Architecture Group Chair, CE Linux Forum Senior Staff Engineer, Sony Network Entertainment ============================= -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/