From b3fdd1f92c1a12b2feda08fcad8ef29a40759bd2 Mon Sep 17 00:00:00 2001
From: Changbin Du <changbin.du@intel.com>
Date: Sat, 17 Feb 2018 13:39:36 +0800
Subject: [PATCH] trace doc: add ftrace-uses.rst to doc tree
Add ftrace-uses.rst into Sphinx TOC tree. Few format issues are fixed.
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
---
Documentation/trace/ftrace-uses.rst | 23 ++++++++++++-----------
Documentation/trace/index.rst | 1 +
2 files changed, 13 insertions(+), 11 deletions(-)
diff --git a/Documentation/trace/ftrace-uses.rst b/Documentation/trace/ftrace-uses.rst
index 3aed560a12ee9..998a60a930159 100644
--- a/Documentation/trace/ftrace-uses.rst
+++ b/Documentation/trace/ftrace-uses.rst
@@ -21,13 +21,14 @@ how to use ftrace to implement your own function callbacks.
The ftrace context
==================
+.. warning::
-WARNING: The ability to add a callback to almost any function within the
-kernel comes with risks. A callback can be called from any context
-(normal, softirq, irq, and NMI). Callbacks can also be called just before
-going to idle, during CPU bring up and takedown, or going to user space.
-This requires extra care to what can be done inside a callback. A callback
-can be called outside the protective scope of RCU.
+ The ability to add a callback to almost any function within the
+ kernel comes with risks. A callback can be called from any context
+ (normal, softirq, irq, and NMI). Callbacks can also be called just before
+ going to idle, during CPU bring up and takedown, or going to user space.
+ This requires extra care to what can be done inside a callback. A callback
+ can be called outside the protective scope of RCU.
The ftrace infrastructure has some protections agains recursions and RCU
but one must still be very careful how they use the callbacks.
@@ -54,15 +55,15 @@ an ftrace_ops with ftrace:
Both .flags and .private are optional. Only .func is required.
-To enable tracing call::
+To enable tracing call:
.. c:function:: register_ftrace_function(&ops);
-To disable tracing call::
+To disable tracing call:
.. c:function:: unregister_ftrace_function(&ops);
-The above is defined by including the header::
+The above is defined by including the header:
.. c:function:: #include <linux/ftrace.h>
@@ -200,7 +201,7 @@ match a specific pattern.
See Filter Commands in :file:`Documentation/trace/ftrace.txt`.
-To just trace the schedule function::
+To just trace the schedule function:
.. code-block:: c
@@ -210,7 +211,7 @@ To add more functions, call the ftrace_set_filter() more than once with the
@reset parameter set to zero. To remove the current filter set and replace it
with new functions defined by @buf, have @reset be non-zero.
-To remove all the filtered functions and trace all functions::
+To remove all the filtered functions and trace all functions:
.. code-block:: c
diff --git a/Documentation/trace/index.rst b/Documentation/trace/index.rst
index c8000babe5087..aa2baad9edf3b 100644
--- a/Documentation/trace/index.rst
+++ b/Documentation/trace/index.rst
@@ -6,3 +6,4 @@ Linux Tracing Technologies
:maxdepth: 2
ftrace-design
+ ftrace-uses
--
GitLab