From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758563Ab0DWSCs (ORCPT ); Fri, 23 Apr 2010 14:02:48 -0400 Received: from adelie.canonical.com ([91.189.90.139]:40731 "EHLO adelie.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758466Ab0DWSCp (ORCPT ); Fri, 23 Apr 2010 14:02:45 -0400 From: Chase Douglas To: linux-kernel@vger.kernel.org Cc: Steven Rostedt , Frederic Weisbecker , Ingo Molnar Subject: [PATCH] ftrace: add documentation for trace commands mod, traceon/traceoff Date: Fri, 23 Apr 2010 14:02:39 -0400 Message-Id: <1272045759-32018-1-git-send-email-chase.douglas@canonical.com> X-Mailer: git-send-email 1.7.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The mod command went in as commit 64e7c440618998fd69eee6ab490b042d12248021 The traceon/traceoff commands went in as commit 23b4ff3aa479c9e3bb23cb6b2d0a97878399784a Signed-off-by: Chase Douglas --- Documentation/trace/ftrace.txt | 44 ++++++++++++++++++++++++++++++++++++++++ 1 files changed, 44 insertions(+), 0 deletions(-) diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index 03485bf..8105e16 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -155,6 +155,9 @@ of ftrace. Here is a list of some of the key files: to be traced. Echoing names of functions into this file will limit the trace to only those functions. + This interface also allows for commands to be used. See the + "Filter commands" section for more details. + set_ftrace_notrace: This has an effect opposite to that of @@ -1822,6 +1825,47 @@ this special filter via: echo > set_graph_function +Filter commands +--------------- + +A few commands are supported by the set_ftrace_filter interface. +Trace commands have the following format: + +:: + +The following commands are supported: + +- mod + This command enables function filtering per module. The + parameter defines the module. For example, if only the write* + functions in the ext3 module are desired, run: + + echo 'write*:mod:ext3' > set_ftrace_filter + + This command interacts with the filter in the same way as + filtering based on function names. Thus, adding more functions + in a different module is accomplished by appending (>>) to the + filter file. Remove specific module functions by prepending + '!': + + echo '!writeback*:mod:ext3' >> set_ftrace_filter + +- traceon/traceoff + These commands turn tracing on and off when the specified + functions are hit. The parameter determines how many times the + tracing system is turned on and off. If unspecified, there is + no limit. For example, to disable tracing when a schedule bug + is hit the first 5 times, run: + + echo '__schedule_bug:traceoff:5' > set_ftrace_filter + + These commands are cumulative whether or not they are appended + to set_ftrace_filter. To remove a command, prepend it by '!' + and drop the parameter: + + echo '!__schedule_bug:traceoff' > set_ftrace_filter + + trace_pipe ---------- -- 1.7.0