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>

1 files changed, 3 insertions, 16 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e7db70f3d2d6..d5ba631e0ec7 100644
--- 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++;