@@ -38,9 +38,9 @@ DAMON provides below three interfaces fo
debugfs Interface
=================
-DAMON exports five files, ``attrs``, ``target_ids``, ``init_regions``,
-``schemes`` and ``monitor_on`` under its debugfs directory,
-``<debugfs>/damon/``.
+DAMON exports eight files, ``attrs``, ``target_ids``, ``init_regions``,
+``schemes``, ``monitor_on``, ``kdamond_pid``, ``mk_contexts`` and
+``rm_contexts`` under its debugfs directory, ``<debugfs>/damon/``.
Attributes
@@ -273,6 +273,52 @@ the monitoring is turned on. If you wri
an error code such as ``-EBUSY`` will be returned.
+Monitoring Thread PID
+---------------------
+
+DAMON does requested monitoring with a kernel thread called ``kdamond``. You
+can get the pid of the thread by reading the ``kdamond_pid`` file. When the
+monitoring is turned off, reading the file returns ``none``. ::
+
+ # cd <debugfs>/damon
+ # cat monitor_on
+ off
+ # cat kdamond_pid
+ none
+ # echo on > monitor_on
+ # cat kdamond_pid
+ 18594
+
+
+Using Multiple Monitoring Threads
+---------------------------------
+
+One ``kdamond`` thread is created for each monitoring context. You can create
+and remove monitoring contexts for multiple ``kdamond`` required use case using
+the ``mk_contexts`` and ``rm_contexts`` files.
+
+Writing the name of the new context to the ``mk_contexts`` file creates a
+directory of the name on the DAMON debugfs directory. The directory will have
+DAMON debugfs files for the context. ::
+
+ # cd <debugfs>/damon
+ # ls foo
+ # ls: cannot access 'foo': No such file or directory
+ # echo foo > mk_contexts
+ # ls foo
+ # attrs init_regions kdamond_pid schemes target_ids
+
+If the context is not needed anymore, you can remove it and the corresponding
+directory by putting the name of the context to the ``rm_contexts`` file. ::
+
+ # echo foo > rm_contexts
+ # ls foo
+ # ls: cannot access 'foo': No such file or directory
+
+Note that ``mk_contexts``, ``rm_contexts``, and ``monitor_on`` files are in the
+root directory only.
+
+
.. _tracepoint:
Tracepoint for Monitoring Results