diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
index 89dd977..a920935 100644
--- a/Documentation/filesystems/f2fs.txt
+++ b/Documentation/filesystems/f2fs.txt
@@ -194,6 +194,10 @@
 			      Otherwise, it needs to decrease this value to
 			      reduce the space overhead. The default value is 0.
 
+ ram_thresh                   This parameter controls the memory footprint used
+			      by free nids and cached nat entries. By default,
+			      10 is set, which indicates 10 MB / 1 GB RAM.
+
 ================================================================================
 USAGE
 ================================================================================