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 @@
[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 @@
19. HWPOISON
20. NOPAGE
21. KSM
+ 22. THP
Short descriptions to the page flags:
@@ -97,6 +98,9 @@
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