memcg swap: mem_cgroup_move_swap_account never needs fixup

The need_fixup arg to mem_cgroup_move_swap_account() is always false,
so just remove it.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e7db70f3d2d6a90d047a635a33148f3528a16f37..d5ba631e0ec79a2a0f6cf9b9c5b3c57809c70a9d 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3165,7 +3165,6 @@ void mem_cgroup_uncharge_swap(swp_entry_t ent)
  * @entry: swap entry to be moved
  * @from:  mem_cgroup which the entry is moved from
  * @to:  mem_cgroup which the entry is moved to
- * @need_fixup: whether we should fixup res_counters and refcounts.
  *
  * It succeeds only when the swap_cgroup's record for this entry is the same
  * as the mem_cgroup's id of @from.
@@ -3176,7 +3175,7 @@ void mem_cgroup_uncharge_swap(swp_entry_t ent)
  * both res and memsw, and called css_get().
  */
 static int mem_cgroup_move_swap_account(swp_entry_t entry,
-               struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
+                               struct mem_cgroup *from, struct mem_cgroup *to)
 {
        unsigned short old_id, new_id;
 
@@ -3195,24 +3194,13 @@ static int mem_cgroup_move_swap_account(swp_entry_t entry,
                 * swap-in, the refcount of @to might be decreased to 0.
                 */
                mem_cgroup_get(to);
-               if (need_fixup) {
-                       if (!mem_cgroup_is_root(from))
-                               res_counter_uncharge(&from->memsw, PAGE_SIZE);
-                       mem_cgroup_put(from);
-                       /*
-                        * we charged both to->res and to->memsw, so we should
-                        * uncharge to->res.
-                        */
-                       if (!mem_cgroup_is_root(to))
-                               res_counter_uncharge(&to->res, PAGE_SIZE);
-               }
                return 0;
        }
        return -EINVAL;
 }
 #else
 static inline int mem_cgroup_move_swap_account(swp_entry_t entry,
-               struct mem_cgroup *from, struct mem_cgroup *to, bool need_fixup)
+                               struct mem_cgroup *from, struct mem_cgroup *to)
 {
        return -EINVAL;
 }
@@ -5546,8 +5534,7 @@ put:                      /* get_mctgt_type() gets the page */
                        break;
                case MC_TARGET_SWAP:
                        ent = target.ent;
-                       if (!mem_cgroup_move_swap_account(ent,
-                                               mc.from, mc.to, false)) {
+                       if (!mem_cgroup_move_swap_account(ent, mc.from, mc.to)) {
                                mc.precharge--;
                                /* we fixup refcnts and charges later. */
                                mc.moved_swap++;