From fc84d73509f14f5f3dc9ddb61f7d669efd979330 Mon Sep 17 00:00:00 2001
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Date: Wed, 21 Mar 2012 16:34:25 -0700
Subject: [PATCH] --- yaml --- r: 292689 b: refs/heads/master c:
 2ff76f1193f8481f7e6c29304eea4006e8e51569 h: refs/heads/master i:   292687:
 d51b3015491e748b5eaae89ebbd3e4b458f06d68 v: v3

---
 [refs]                            |  2 +-
 trunk/include/linux/page_cgroup.h |  6 ------
 trunk/mm/memcontrol.c             | 11 ++++++-----
 3 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/[refs] b/[refs]
index 9576d742dfc0..ffd5d8f22f28 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 89c06bd52fb9ffceddf84f7309d2e8c9f1666216
+refs/heads/master: 2ff76f1193f8481f7e6c29304eea4006e8e51569
diff --git a/trunk/include/linux/page_cgroup.h b/trunk/include/linux/page_cgroup.h
index 7a3af748f32b..a88cdba27809 100644
--- a/trunk/include/linux/page_cgroup.h
+++ b/trunk/include/linux/page_cgroup.h
@@ -6,8 +6,6 @@ enum {
 	PCG_LOCK,  /* Lock for pc->mem_cgroup and following bits. */
 	PCG_USED, /* this object is in use. */
 	PCG_MIGRATION, /* under page migration */
-	/* flags for mem_cgroup and file and I/O status */
-	PCG_FILE_MAPPED, /* page is accounted as "mapped" */
 	__NR_PCG_FLAGS,
 };
 
@@ -66,10 +64,6 @@ TESTPCGFLAG(Used, USED)
 CLEARPCGFLAG(Used, USED)
 SETPCGFLAG(Used, USED)
 
-SETPCGFLAG(FileMapped, FILE_MAPPED)
-CLEARPCGFLAG(FileMapped, FILE_MAPPED)
-TESTPCGFLAG(FileMapped, FILE_MAPPED)
-
 SETPCGFLAG(Migration, MIGRATION)
 CLEARPCGFLAG(Migration, MIGRATION)
 TESTPCGFLAG(Migration, MIGRATION)
diff --git a/trunk/mm/memcontrol.c b/trunk/mm/memcontrol.c
index df1e180f6c30..0e13b2aeea61 100644
--- a/trunk/mm/memcontrol.c
+++ b/trunk/mm/memcontrol.c
@@ -1966,10 +1966,6 @@ void mem_cgroup_update_page_stat(struct page *page,
 
 	switch (idx) {
 	case MEMCG_NR_FILE_MAPPED:
-		if (val > 0)
-			SetPageCgroupFileMapped(pc);
-		else if (!page_mapped(page))
-			ClearPageCgroupFileMapped(pc);
 		idx = MEM_CGROUP_STAT_FILE_MAPPED;
 		break;
 	default:
@@ -2617,7 +2613,7 @@ static int mem_cgroup_move_account(struct page *page,
 
 	move_lock_mem_cgroup(from, &flags);
 
-	if (PageCgroupFileMapped(pc)) {
+	if (!anon && page_mapped(page)) {
 		/* Update mapped_file data for mem_cgroup */
 		preempt_disable();
 		__this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
@@ -2982,6 +2978,11 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
 
 	switch (ctype) {
 	case MEM_CGROUP_CHARGE_TYPE_MAPPED:
+		/*
+		 * Generally PageAnon tells if it's the anon statistics to be
+		 * updated; but sometimes e.g. mem_cgroup_uncharge_page() is
+		 * used before page reached the stage of being marked PageAnon.
+		 */
 		anon = true;
 		/* fallthrough */
 	case MEM_CGROUP_CHARGE_TYPE_DROP: