Added man pages describing these functions:
tracefs_marker_init()
tracefs_marker_print()
tracefs_marker_vprint()
tracefs_marker_write()
tracefs_marker_close()
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
---
Documentation/libtracefs-marker.txt | 127 ++++++++++++++++++++++++++++
1 file changed, 127 insertions(+)
create mode 100644 Documentation/libtracefs-marker.txt
diff --git a/Documentation/libtracefs-marker.txt b/Documentation/libtracefs-marker.txt
new file mode 100644
index 0000000..e2673d9
--- /dev/null
+++ b/Documentation/libtracefs-marker.txt
@@ -0,0 +1,127 @@
+libtracefs(3)
+=============
+
+NAME
+----
+tracefs_marker_init, tracefs_marker_close, tracefs_marker_print, tracefs_marker_vprint, tracefs_marker_write -
+Open, close and write data in the frace marker file.
+
+SYNOPSIS
+--------
+[verse]
+--
+*#include <tracefs.h>*
+
+int *tracefs_marker_init*(struct tracefs_instance pass:[*]_instance_);
+int *tracefs_marker_print*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_fmt_, _..._);
+int *tracefs_marker_vprint*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_fmt_, va_list _ap_);
+int *tracefs_marker_write*(struct tracefs_instance pass:[*]_instance_, void pass:[*]_data_, int _len_);
+void *tracefs_marker_close*(struct tracefs_instance pass:[*]_instance_);
+
+--
+
+DESCRIPTION
+-----------
+Set of functions to work with ftrace maker. See Documentation/trace/ftrace.rst from the Linux
+kernel tree for more information about ftrace marker functionality. All these APIs have _instance_
+as a first argument. If NULL is passed as _instance_, the top trace instance is used.
+
+The _tracefs_marker_init()_ function initializes the library for working with ftrace marker of
+the selected _instance_. It is not mandatory to call this API before working with the marker, any
+of the marker APIs will call it automatically, if the library is not yet initialized to work with
+the marker form given instance. But calling _tracefs_marker_init()_ in advance will speed up
+the other marker APIs.
+
+The _tracefs_marker_print()_ function writes a formatted string in the trace marker of the selected
+_instance_. The _fmt_ argument is a string in printf format, followed by variable arguments _..._.
+
+The _tracefs_marker_vprint()_ function writes a formatted string in the trace marker of the selected
+_instance_. The _fmt_ argument is a string in printf format, followed by list _ap_ of arguments.
+
+The _tracefs_marker_write()_ function writes a binary data in the trace marker of the selected
+_instance_. The _data_ points to the data with length _len_, that is going to be written in
+the trace marker.
+
+The _tracefs_marker_close()_ function closes the ftrace marker of the selected instance.
+
+RETURN VALUE
+------------
+The _tracefs_marker_init()_, _tracefs_marker_print()_, _tracefs_marker_vprint()_ and
+_tracefs_marker_write()_ functions return 0 if the operation is successful, or -1 in case of an error.
+
+EXAMPLE
+-------
+[source,c]
+--
+#include <tracefs.h>
+
+if (tracefs_marker_init(NULL) < 0) {
+ /* Failed to initialize the library with the ftrace marker of the top trace instance */
+}
+
+void foo_print(char *format, ...)
+{
+ va_list ap;
+ va_start(ap, format);
+ if (tracefs_marker_vprint(NULL, format, ap) < 0) {
+ /* Failed to print in the trace marker */
+ }
+ va_end(ap);
+}
+
+void foo_print_string(char *message)
+{
+ if (tracefs_marker_print(NULL, "Message from user space: %s", message) < 0) {
+ /* Failed to print in the trace marker */
+ }
+}
+
+unsigned int data = 0xdeadbeef;
+
+ if (tracefs_marker_write(NULL, &data, sizeof(data)) < 0) {
+ /* Failed to write in the trace marker */
+ }
+
+
+tracefs_marker_close();
+--
+FILES
+-----
+[verse]
+--
+*tracefs.h*
+ Header file to include in order to have access to the library APIs.
+*-ltracefs*
+ Linker switch to add when building a program that uses the library.
+--
+
+SEE ALSO
+--------
+_libtracefs(3)_,
+_libtraceevent(3)_,
+_trace-cmd(1)_,
+Documentation/trace/ftrace.rst from the Linux kernel tree
+
+AUTHOR
+------
+[verse]
+--
+*Steven Rostedt* <rostedt@xxxxxxxxxxx>
+*Tzvetomir Stoyanov* <tz.stoyanov@xxxxxxxxx>
+--
+REPORTING BUGS
+--------------
+Report bugs to <linux-trace-devel@xxxxxxxxxxxxxxx>
+
+LICENSE
+-------
+libtracefs is Free Software licensed under the GNU LGPL 2.1
+
+RESOURCES
+---------
+https://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git/
+
+COPYING
+-------
+Copyright \(C) 2021 VMware, Inc. Free use of this software is granted under
+the terms of the GNU Public License (GPL).
--
2.30.2
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