From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 6668D7DE78 for ; Fri, 13 Apr 2018 15:54:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751024AbeDMPyG (ORCPT ); Fri, 13 Apr 2018 11:54:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:49602 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751011AbeDMPyG (ORCPT ); Fri, 13 Apr 2018 11:54:06 -0400 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4F3BF2177F; Fri, 13 Apr 2018 15:54:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4F3BF2177F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=rostedt@goodmis.org Date: Fri, 13 Apr 2018 11:54:03 -0400 From: Steven Rostedt To: Steffen Maier Cc: linux-doc@vger.kernel.org, Ingo Molnar , Jonathan Corbet Subject: Re: [PATCH v2] Documentation: ftrace: clarify filters with dynamic ftrace and graph Message-ID: <20180413115403.757b8c27@gandalf.local.home> In-Reply-To: <20180413153915.26931-1-maier@linux.ibm.com> References: <20180413095745.4662eb8f@gandalf.local.home> <20180413153915.26931-1-maier@linux.ibm.com> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Fri, 13 Apr 2018 17:39:15 +0200 Steffen Maier wrote: > I fell into the trap of having set up function tracer with a very > limited filter and then switched over to function_graph and was > erroneously wondering why the latter did not trace what I expected, > which was the full unabridged graph recursion. > > Signed-off-by: Steffen Maier > Cc: Steven Rostedt Looks good. Reviewed-by: Steven Rostedt (VMware) > Cc: Ingo Molnar > Cc: Jonathan Corbet Jon, you want to take it in your tree? -- Steve > Cc: linux-doc@vger.kernel.org > --- > > Changes since v1: > Integrated review comments by Steven Rostedt > * less emotional phrasing > * also mention function profiling with set_ftrace_filter > (hopefully I got that right as I don't have experience with it) > > Documentation/trace/ftrace.rst | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst > index e45f0786f3f9..9bbd3aefadb2 100644 > --- a/Documentation/trace/ftrace.rst > +++ b/Documentation/trace/ftrace.rst > @@ -224,6 +224,8 @@ of ftrace. Here is a list of some of the key files: > has a side effect of enabling or disabling specific functions > to be traced. Echoing names of functions into this file > will limit the trace to only those functions. > + This influences the tracers "function" and "function_graph" > + and thus also function profiling (see "function_profile_enabled"). > > The functions listed in "available_filter_functions" are what > can be written into this file. > @@ -265,6 +267,8 @@ of ftrace. Here is a list of some of the key files: > Functions listed in this file will cause the function graph > tracer to only trace these functions and the functions that > they call. (See the section "dynamic ftrace" for more details). > + Note, set_ftrace_filter and set_ftrace_notrace still affects > + what functions are being traced. > > set_graph_notrace: > > @@ -277,7 +281,8 @@ of ftrace. Here is a list of some of the key files: > > This lists the functions that ftrace has processed and can trace. > These are the function names that you can pass to > - "set_ftrace_filter" or "set_ftrace_notrace". > + "set_ftrace_filter", "set_ftrace_notrace", > + "set_graph_function", or "set_graph_notrace". > (See the section "dynamic ftrace" below for more details.) > > dyn_ftrace_total_info: -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html