Docs/ABI/damon: document scheme filters files

Document newly added DAMON sysfs interface files for DAMOS filtering on
the DAMON ABI document.

Link: https://lkml.kernel.org/r/20221205230830.144349-12-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Documentation/ABI/testing/sysfs-kernel-mm-damon

@@ -258,6 +258,35 @@ Contact:	SeongJae Park <sj@kernel.org>
 Description:	Writing to and reading from this file sets and gets the low
 		watermark of the scheme in permil.
 
+What:		/sys/kernel/mm/damon/admin/kdamonds/<K>/contexts/<C>/schemes/<S>/filters/nr_filters
+Date:		Dec 2022
+Contact:	SeongJae Park <sj@kernel.org>
+Description:	Writing a number 'N' to this file creates the number of
+		directories for setting filters of the scheme named '0' to
+		'N-1' under the filters/ directory.
+
+What:		/sys/kernel/mm/damon/admin/kdamonds/<K>/contexts/<C>/schemes/<S>/filters/<F>/type
+Date:		Dec 2022
+Contact:	SeongJae Park <sj@kernel.org>
+Description:	Writing to and reading from this file sets and gets the type of
+		the memory of the interest.  'anon' for anonymous pages, or
+		'memcg' for specific memory cgroup can be written and read.
+
+What:		/sys/kernel/mm/damon/admin/kdamonds/<K>/contexts/<C>/schemes/<S>/filters/<F>/memcg_path
+Date:		Dec 2022
+Contact:	SeongJae Park <sj@kernel.org>
+Description:	If 'memcg' is written to the 'type' file, writing to and
+		reading from this file sets and gets the path to the memory
+		cgroup of the interest.
+
+What:		/sys/kernel/mm/damon/admin/kdamonds/<K>/contexts/<C>/schemes/<S>/filters/<F>/matching
+Date:		Dec 2022
+Contact:	SeongJae Park <sj@kernel.org>
+Description:	Writing 'Y' or 'N' to this file sets whether to filter out
+		pages that do or do not match to the 'type' and 'memcg_path',
+		respectively.  Filter out means the action of the scheme will
+		not be applied to.
+
 What:		/sys/kernel/mm/damon/admin/kdamonds/<K>/contexts/<C>/schemes/<S>/stats/nr_tried
 Date:		Mar 2022
 Contact:	SeongJae Park <sj@kernel.org>