---

yaml
---
r: 191446
b: refs/heads/master
c: 07271aa
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a838b2e634405fb89ddbf4fa9412acb33911911f
+refs/heads/master: 07271aa42d13378e67ebd79ea9ca1c4a5e2ad46f

trunk/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
@@ -1824,6 +1827,47 @@ 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:
+
+<function>:<command>:<parameter>
+
+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
 ----------