2 files changed, 15 insertions, 28 deletions

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 70789df7dab4..8b1c4295848b 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -35,7 +35,8 @@ extern void mm_free_cgroup(struct mm_struct *mm);
 extern struct page_cgroup *page_get_page_cgroup(struct page *page);
 extern int mem_cgroup_charge(struct page *page, struct mm_struct *mm,
                                 gfp_t gfp_mask);
-extern void mem_cgroup_uncharge(struct page_cgroup *pc);
+extern int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
+                                        gfp_t gfp_mask);
 extern void mem_cgroup_uncharge_page(struct page *page);
 extern void mem_cgroup_move_lists(struct page *page, bool active);
 extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
@@ -45,8 +46,6 @@ extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
                                         struct mem_cgroup *mem_cont,
                                         int active);
 extern void mem_cgroup_out_of_memory(struct mem_cgroup *mem, gfp_t gfp_mask);
-extern int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
-                                        gfp_t gfp_mask);
 int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem);
 
 #define mm_match_cgroup(mm, cgroup)     \
@@ -92,14 +91,16 @@ static inline struct page_cgroup *page_get_page_cgroup(struct page *page)
         return NULL;
 }
 
-static inline int mem_cgroup_charge(struct page *page, struct mm_struct *mm,
-                                        gfp_t gfp_mask)
+static inline int mem_cgroup_charge(struct page *page,
+                                        struct mm_struct *mm, gfp_t gfp_mask)
 {
         return 0;
 }
 
-static inline void mem_cgroup_uncharge(struct page_cgroup *pc)
+static inline int mem_cgroup_cache_charge(struct page *page,
+                                        struct mm_struct *mm, gfp_t gfp_mask)
 {
+        return 0;
 }
 
 static inline void mem_cgroup_uncharge_page(struct page *page)
@@ -110,13 +111,6 @@ static inline void mem_cgroup_move_lists(struct page *page, bool active)
 {
 }
 
-static inline int mem_cgroup_cache_charge(struct page *page,
-                                                struct mm_struct *mm,
-                                                gfp_t gfp_mask)
-{
-        return 0;
-}
-
 static inline int mm_match_cgroup(struct mm_struct *mm, struct mem_cgroup *mem)
 {
         return 1;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 83ba13ad31e1..1333d25163bb 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -697,20 +697,22 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
 
 /*
  * Uncharging is always a welcome operation, we never complain, simply
- * uncharge. This routine should be called with lock_page_cgroup held
+ * uncharge.
  */
-void mem_cgroup_uncharge(struct page_cgroup *pc)
+void mem_cgroup_uncharge_page(struct page *page)
 {
+        struct page_cgroup *pc;
         struct mem_cgroup *mem;
         struct mem_cgroup_per_zone *mz;
-        struct page *page;
         unsigned long flags;
 
         /*
          * Check if our page_cgroup is valid
          */
+        lock_page_cgroup(page);
+        pc = page_get_page_cgroup(page);
         if (!pc)
-                return;
+                goto unlock;
 
         if (atomic_dec_and_test(&pc->ref_cnt)) {
                 page = pc->page;
@@ -731,12 +733,8 @@ void mem_cgroup_uncharge(struct page_cgroup *pc)
                 }
                 lock_page_cgroup(page);
         }
-}
 
-void mem_cgroup_uncharge_page(struct page *page)
-{
-        lock_page_cgroup(page);
-        mem_cgroup_uncharge(page_get_page_cgroup(page));
+unlock:
         unlock_page_cgroup(page);
 }
 
@@ -759,12 +757,7 @@ int mem_cgroup_prepare_migration(struct page *page)
 
 void mem_cgroup_end_migration(struct page *page)
 {
-        struct page_cgroup *pc;
-
-        lock_page_cgroup(page);
-        pc = page_get_page_cgroup(page);
-        mem_cgroup_uncharge(pc);
-        unlock_page_cgroup(page);
+        mem_cgroup_uncharge_page(page);
 }
 /*
  * We know both *page* and *newpage* are now not-on-LRU and Pg_locked.