From: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Date: Wed, 21 Mar 2012 23:33:58 +0000 (-0700)
Subject: pagemap: document KPF_THP and make page-types aware of it
X-Git-Tag: upstream/snapshot3+hdmi~7935^2~61
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=807f0ccfe15551afd514c062585045c88ca62037;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git

pagemap: document KPF_THP and make page-types aware of it

page-types, which is a common user of pagemap, gets aware of thp with this
patch.  This helps system admins and kernel hackers know about how thp
works.  Here is a sample output of page-types over a thp:

  $ page-types -p <pid> --raw --list

  voffset offset  len     flags
  ...
  7f9d40200       3f8400  1       ___U_lA____Ma_bH______t____________
  7f9d40201       3f8401  1ff     ________________T_____t____________

               flags      page-count       MB  symbolic-flags                     long-symbolic-flags
  0x0000000000410000             511        1  ________________T_____t____________        compound_tail,thp
  0x000000000040d868               1        0  ___U_lA____Ma_bH______t____________        uptodate,lru,active,mmap,anonymous,swapbacked,compound_head,thp

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/Documentation/vm/page-types.c b/Documentation/vm/page-types.c
index 7445caa..0b13f02 100644
--- a/Documentation/vm/page-types.c
+++ b/Documentation/vm/page-types.c
@@ -98,6 +98,7 @@
 #define KPF_HWPOISON		19
 #define KPF_NOPAGE		20
 #define KPF_KSM			21
+#define KPF_THP			22
 
 /* [32-] kernel hacking assistances */
 #define KPF_RESERVED		32
@@ -147,6 +148,7 @@ static const char *page_flag_names[] = {
 	[KPF_HWPOISON]		= "X:hwpoison",
 	[KPF_NOPAGE]		= "n:nopage",
 	[KPF_KSM]		= "x:ksm",
+	[KPF_THP]		= "t:thp",
 
 	[KPF_RESERVED]		= "r:reserved",
 	[KPF_MLOCKED]		= "m:mlocked",
diff --git a/Documentation/vm/pagemap.txt b/Documentation/vm/pagemap.txt
index df09b96..4600cbe 100644
--- a/Documentation/vm/pagemap.txt
+++ b/Documentation/vm/pagemap.txt
@@ -60,6 +60,7 @@ There are three components to pagemap:
     19. HWPOISON
     20. NOPAGE
     21. KSM
+    22. THP
 
 Short descriptions to the page flags:
 
@@ -97,6 +98,9 @@ Short descriptions to the page flags:
 21. KSM
     identical memory pages dynamically shared between one or more processes
 
+22. THP
+    contiguous pages which construct transparent hugepages
+
     [IO related page flags]
  1. ERROR     IO error occurred
  3. UPTODATE  page has up-to-date data