1 files changed, 51 insertions, 40 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6d59a2bd520..848b42195e5 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1614,7 +1614,7 @@ void mem_cgroup_update_page_stat(struct page *page,
 	if (unlikely(!mem || !PageCgroupUsed(pc)))
 		goto out;
 	/* pc->mem_cgroup is unstable ? */
-	if (unlikely(mem_cgroup_stealed(mem))) {
+	if (unlikely(mem_cgroup_stealed(mem)) || PageTransHuge(page)) {
 		/* take a lock against to access pc->mem_cgroup */
 		move_lock_page_cgroup(pc, &flags);
 		need_unlock = true;
@@ -2083,14 +2083,27 @@ struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
 	return mem;
 }
 
-/*
- * commit a charge got by __mem_cgroup_try_charge() and makes page_cgroup to be
- * USED state. If already USED, uncharge and return.
- */
-static void ____mem_cgroup_commit_charge(struct mem_cgroup *mem,
-					 struct page_cgroup *pc,
-					 enum charge_type ctype)
+static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
+				       struct page_cgroup *pc,
+				       enum charge_type ctype,
+				       int page_size)
 {
+	int nr_pages = page_size >> PAGE_SHIFT;
+
+	/* try_charge() can return NULL to *memcg, taking care of it. */
+	if (!mem)
+		return;
+
+	lock_page_cgroup(pc);
+	if (unlikely(PageCgroupUsed(pc))) {
+		unlock_page_cgroup(pc);
+		mem_cgroup_cancel_charge(mem, page_size);
+		return;
+	}
+	/*
+	 * we don't need page_cgroup_lock about tail pages, becase they are not
+	 * accessed by any other context at this point.
+	 */
 	pc->mem_cgroup = mem;
 	/*
 	 * We access a page_cgroup asynchronously without lock_page_cgroup().
@@ -2114,35 +2127,7 @@ static void ____mem_cgroup_commit_charge(struct mem_cgroup *mem,
 		break;
 	}
 
-	mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), 1);
-}
-
-static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
-				       struct page_cgroup *pc,
-				       enum charge_type ctype,
-				       int page_size)
-{
-	int i;
-	int count = page_size >> PAGE_SHIFT;
-
-	/* try_charge() can return NULL to *memcg, taking care of it. */
-	if (!mem)
-		return;
-
-	lock_page_cgroup(pc);
-	if (unlikely(PageCgroupUsed(pc))) {
-		unlock_page_cgroup(pc);
-		mem_cgroup_cancel_charge(mem, page_size);
-		return;
-	}
-
-	/*
-	 * we don't need page_cgroup_lock about tail pages, becase they are not
-	 * accessed by any other context at this point.
-	 */
-	for (i = 0; i < count; i++)
-		____mem_cgroup_commit_charge(mem, pc + i, ctype);
-
+	mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), nr_pages);
 	unlock_page_cgroup(pc);
 	/*
 	 * "charge_statistics" updated event counter. Then, check it.
@@ -2152,6 +2137,34 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
 	memcg_check_events(mem, pc->page);
 }
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+
+#define PCGF_NOCOPY_AT_SPLIT ((1 << PCG_LOCK) | (1 << PCG_MOVE_LOCK) |\
+			(1 << PCG_ACCT_LRU) | (1 << PCG_MIGRATION))
+/*
+ * Because tail pages are not marked as "used", set it. We're under
+ * zone->lru_lock, 'splitting on pmd' and compund_lock.
+ */
+void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail)
+{
+	struct page_cgroup *head_pc = lookup_page_cgroup(head);
+	struct page_cgroup *tail_pc = lookup_page_cgroup(tail);
+	unsigned long flags;
+
+	/*
+	 * We have no races witch charge/uncharge but will have races with
+	 * page state accounting.
+	 */
+	move_lock_page_cgroup(head_pc, &flags);
+
+	tail_pc->mem_cgroup = head_pc->mem_cgroup;
+	smp_wmb(); /* see __commit_charge() */
+	/* we don't need to copy all flags...*/
+	tail_pc->flags = head_pc->flags & ~PCGF_NOCOPY_AT_SPLIT;
+	move_unlock_page_cgroup(head_pc, &flags);
+}
+#endif
+
 /**
  * __mem_cgroup_move_account - move account of the page
  * @pc:	page_cgroup of the page.
@@ -2545,7 +2558,6 @@ direct_uncharge:
 static struct mem_cgroup *
 __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
 {
-	int i;
 	int count;
 	struct page_cgroup *pc;
 	struct mem_cgroup *mem = NULL;
@@ -2595,8 +2607,7 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
 		break;
 	}
 
-	for (i = 0; i < count; i++)
-		mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), -1);
+	mem_cgroup_charge_statistics(mem, PageCgroupCache(pc), -count);
 
 	ClearPageCgroupUsed(pc);
 	/*