Document the new DAMON sysfs file, refresh_ms, on the ABI document.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 Documentation/ABI/testing/sysfs-kernel-mm-damon | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-kernel-mm-damon b/Documentation/ABI/testing/sysfs-kernel-mm-damon
index e98974dfac7a..6791d879759e 100644
--- a/Documentation/ABI/testing/sysfs-kernel-mm-damon
+++ b/Documentation/ABI/testing/sysfs-kernel-mm-damon
@@ -44,6 +44,13 @@ Contact:	SeongJae Park <sj@kernel.org>
 Description:	Reading this file returns the pid of the kdamond if it is
 		running.
 
+What:		/sys/kernel/mm/damon/admin/kdamonds/<K>/refresh_ms
+Date:		Jul 2025
+Contact:	SeongJae Park <sj@kernel.org>
+Description:	Writing a value to this file sets the time interval for
+		automatic DAMON status file contents update.  Writing '0'
+		disables the update.  Reading this file returns the value.
+
 What:		/sys/kernel/mm/damon/admin/kdamonds/<K>/contexts/nr_contexts
 Date:		Mar 2022
 Contact:	SeongJae Park <sj@kernel.org>
-- 
2.39.5