1 files changed, 11 insertions, 11 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index a7165a60d0a7..b659260c56ad 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2476,10 +2476,10 @@ struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
 static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg,
                                        struct page *page,
                                        unsigned int nr_pages,
-                                       struct page_cgroup *pc,
                                        enum charge_type ctype,
                                        bool lrucare)
 {
+        struct page_cgroup *pc = lookup_page_cgroup(page);
         struct zone *uninitialized_var(zone);
         bool was_on_lru = false;
         bool anon;
@@ -2716,7 +2716,6 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
 {
         struct mem_cgroup *memcg = NULL;
         unsigned int nr_pages = 1;
-        struct page_cgroup *pc;
         bool oom = true;
         int ret;
 
@@ -2730,11 +2729,10 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm,
                 oom = false;
         }
 
-        pc = lookup_page_cgroup(page);
         ret = __mem_cgroup_try_charge(mm, gfp_mask, nr_pages, &memcg, oom);
         if (ret == -ENOMEM)
                 return ret;
-        __mem_cgroup_commit_charge(memcg, page, nr_pages, pc, ctype, false);
+        __mem_cgroup_commit_charge(memcg, page, nr_pages, ctype, false);
         return 0;
 }
 
@@ -2831,16 +2829,13 @@ static void
 __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *memcg,
                                         enum charge_type ctype)
 {
-        struct page_cgroup *pc;
-
         if (mem_cgroup_disabled())
                 return;
         if (!memcg)
                 return;
         cgroup_exclude_rmdir(&memcg->css);
 
-        pc = lookup_page_cgroup(page);
-        __mem_cgroup_commit_charge(memcg, page, 1, pc, ctype, true);
+        __mem_cgroup_commit_charge(memcg, page, 1, ctype, true);
         /*
          * Now swap is on-memory. This means this page may be
          * counted both as mem and swap....double count.
@@ -3298,14 +3293,13 @@ int mem_cgroup_prepare_migration(struct page *page,
          * page. In the case new page is migrated but not remapped, new page's
          * mapcount will be finally 0 and we call uncharge in end_migration().
          */
-        pc = lookup_page_cgroup(newpage);
         if (PageAnon(page))
                 ctype = MEM_CGROUP_CHARGE_TYPE_MAPPED;
         else if (page_is_file_cache(page))
                 ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
         else
                 ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
-        __mem_cgroup_commit_charge(memcg, newpage, 1, pc, ctype, false);
+        __mem_cgroup_commit_charge(memcg, newpage, 1, ctype, false);
         return ret;
 }
 
@@ -3392,7 +3386,7 @@ void mem_cgroup_replace_page_cache(struct page *oldpage,
          * the newpage may be on LRU(or pagevec for LRU) already. We lock
          * LRU while we overwrite pc->mem_cgroup.
          */
-        __mem_cgroup_commit_charge(memcg, newpage, 1, pc, type, true);
+        __mem_cgroup_commit_charge(memcg, newpage, 1, type, true);
 }
 
 #ifdef CONFIG_DEBUG_VM
@@ -4513,6 +4507,12 @@ static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp,
 swap_buffers:
         /* Swap primary and spare array */
         thresholds->spare = thresholds->primary;
+        /* If all events are unregistered, free the spare array */
+        if (!new) {
+                kfree(thresholds->spare);
+                thresholds->spare = NULL;
+        }
+
         rcu_assign_pointer(thresholds->primary, new);
 
         /* To be sure that nobody uses thresholds */