[PATCH] pagemap: document KPF_KSM and show it in page-types

[Wu Fengguang <fengguang.wu@intel.com>]

It indicates to the system admin that processes mapping such pages may be
eating less physical memory than the reported numbers by legacy tools.

CC: Hugh Dickins <hugh.dickins@tiscali.co.uk>
CC: Chris Wright <chrisw@redhat.com>
CC: Izik Eidus <ieidus@redhat.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
---
 Documentation/vm/pagemap.txt |    4 ++++
 tools/vm/page-types.c        |    2 ++
 2 files changed, 6 insertions(+)

--- linux-mm.orig/Documentation/vm/pagemap.txt	2009-08-31 15:02:55.000000000 +0800
+++ linux-mm/Documentation/vm/pagemap.txt	2009-08-31 15:05:02.000000000 +0800
@@ -59,6 +59,7 @@ There are three components to pagemap:
     18. UNEVICTABLE
     19. HWPOISON
     20. NOPAGE
+    21. KSM
 
 Short descriptions to the page flags:
 
@@ -93,6 +94,9 @@ Short descriptions to the page flags:
 20. NOPAGE
     no page frame exists at the requested address
 
+21. KSM
+    identical memory pages dynamicly shared between one or more processes
+
     [IO related page flags]
  1. ERROR     IO error occurred
  3. UPTODATE  page has up-to-date data
--- linux-mm.orig/tools/vm/page-types.c	2009-08-31 15:00:24.000000000 +0800
+++ linux-mm/tools/vm/page-types.c	2009-08-31 15:02:10.000000000 +0800
@@ -49,6 +49,7 @@
 #define KPF_UNEVICTABLE		18
 #define KPF_HWPOISON		19
 #define KPF_NOPAGE		20
+#define KPF_KSM			21
 
 /* [32-] kernel hacking assistances */
 #define KPF_RESERVED		32
@@ -97,6 +98,7 @@ static char *page_flag_names[] = {
 	[KPF_UNEVICTABLE]	= "u:unevictable",
 	[KPF_HWPOISON]		= "X:hwpoison",
 	[KPF_NOPAGE]		= "n:nopage",
+	[KPF_KSM]		= "x:ksm",
 
 	[KPF_RESERVED]		= "r:reserved",
 	[KPF_MLOCKED]		= "m:mlocked",