Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757667Ab0BLA1B (ORCPT ); Thu, 11 Feb 2010 19:27:01 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51672 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757523Ab0BLA1A (ORCPT ); Thu, 11 Feb 2010 19:27:00 -0500 Subject: Re: [PATCH 1/1] ftrace - add support for tracing_thresh to function_graph tracer From: Steven Rostedt To: Tim Bird Cc: linux kernel , Frederic Weisbecker In-Reply-To: <4B749A42.2080703@am.sony.com> References: <4B733721.3030503@am.sony.com> <4B7338BF.1070505@am.sony.com> <1265929831.2737.340.camel@localhost.localdomain> <4B749A42.2080703@am.sony.com> Content-Type: text/plain Organization: Red Hat Date: Thu, 11 Feb 2010 19:26:55 -0500 Message-Id: <1265934415.2737.344.camel@localhost.localdomain> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1730 Lines: 41 On Thu, 2010-02-11 at 16:01 -0800, Tim Bird wrote: > On 02/11/2010 03:10 PM, Steven Rostedt wrote: > > On Wed, 2010-02-10 at 14:52 -0800, Tim Bird wrote: > >> static struct tracer_opt trace_opts[] = { > >> /* Display overruns? (for self-debug purpose) */ > >> @@ -53,6 +54,8 @@ static struct tracer_opt trace_opts[] = { > >> { TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) }, > >> /* Display absolute time of an entry */ > >> { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) }, > >> + /* Display function name on exit, instead of just closing brace */ > >> + { TRACER_OPT(funcgraph-exit, TRACE_GRAPH_PRINT_FUNC_EXIT) }, > >> { } /* Empty entry */ > > > > I wonder if this should be enabled on start up of the function graph > > tracer if the threshold is set? > > > > Otherwise people will wonder WTF? > > Indeed. I'm not sure exactly how to do this. > > Would it be better to set the option when current_tracer > is set with 'function_graph', and tracing_thresh is non-zero? The above is the only one I would do. If tracing_thresh is non-zero when the function_graph tracer is set, on the start up code in the function tracer (graph_trace_init). Just enable the option if trace_thresh is set. If you enable function graph tracer and have the trace_thresh set, then this type of tracing starts immediately. It also keeps the code nicely in the trace_function_graph.c file, and does not need to touch the setting of tracing_thresh. -- Steve -- 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/