1 files changed, 6 insertions, 1 deletions

diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index fd8d0d594fc7..fcc22c982a25 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -473,7 +473,8 @@ This file is only present if the CONFIG_MMU kernel configuration option is
 enabled.
 
 The /proc/PID/clear_refs is used to reset the PG_Referenced and ACCESSED/YOUNG
-bits on both physical and virtual pages associated with a process.
+bits on both physical and virtual pages associated with a process, and the
+soft-dirty bit on pte (see Documentation/vm/soft-dirty.txt for details).
 To clear the bits for all the pages associated with the process
     > echo 1 > /proc/PID/clear_refs
 
@@ -482,6 +483,10 @@ To clear the bits for the anonymous pages associated with the process
 
 To clear the bits for the file mapped pages associated with the process
     > echo 3 > /proc/PID/clear_refs
+
+To clear the soft-dirty bit
+    > echo 4 > /proc/PID/clear_refs
+
 Any other value written to /proc/PID/clear_refs will have no effect.
 
 The /proc/pid/pagemap gives the PFN, which can be used to find the pageflags