memcg: remove mem_cgroup_uncharge

Nothing uses mem_cgroup_uncharge apart from mem_cgroup_uncharge_page, (a
trivial wrapper around it) and mem_cgroup_end_migration (which does the same
as mem_cgroup_uncharge_page).  And it often ends up having to lock just to let
its caller unlock.  Remove it (but leave the silly locking until a later
patch).

Moved mem_cgroup_cache_charge next to mem_cgroup_charge in memcontrol.h.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 13 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;