Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[platform/adaptation/renesas_rcar/renesas_kernel.git] / mm / memcontrol.c

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 5585dc3..58a08fc 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -230,10 +230,30 @@ struct mem_cgroup {
         * the counter to account for memory usage
         */
        struct res_counter res;
-       /*
-        * the counter to account for mem+swap usage.
-        */
-       struct res_counter memsw;
+
+       union {
+               /*
+                * the counter to account for mem+swap usage.
+                */
+               struct res_counter memsw;
+
+               /*
+                * rcu_freeing is used only when freeing struct mem_cgroup,
+                * so put it into a union to avoid wasting more memory.
+                * It must be disjoint from the css field.  It could be
+                * in a union with the res field, but res plays a much
+                * larger part in mem_cgroup life than memsw, and might
+                * be of interest, even at time of free, when debugging.
+                * So share rcu_head with the less interesting memsw.
+                */
+               struct rcu_head rcu_freeing;
+               /*
+                * But when using vfree(), that cannot be done at
+                * interrupt time, so we must then queue the work.
+                */
+               struct work_struct work_freeing;
+       };
+
        /*
         * Per cgroup active and inactive list, similar to the
         * per zone LRU lists.
@@ -4780,6 +4800,27 @@ out_free:
 }
 
 /*
+ * Helpers for freeing a vzalloc()ed mem_cgroup by RCU,
+ * but in process context.  The work_freeing structure is overlaid
+ * on the rcu_freeing structure, which itself is overlaid on memsw.
+ */
+static void vfree_work(struct work_struct *work)
+{
+       struct mem_cgroup *memcg;
+
+       memcg = container_of(work, struct mem_cgroup, work_freeing);
+       vfree(memcg);
+}
+static void vfree_rcu(struct rcu_head *rcu_head)
+{
+       struct mem_cgroup *memcg;
+
+       memcg = container_of(rcu_head, struct mem_cgroup, rcu_freeing);
+       INIT_WORK(&memcg->work_freeing, vfree_work);
+       schedule_work(&memcg->work_freeing);
+}
+
+/*
  * At destroying mem_cgroup, references from swap_cgroup can remain.
  * (scanning all at force_empty is too costly...)
  *
@@ -4802,9 +4843,9 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg)
 
        free_percpu(memcg->stat);
        if (sizeof(struct mem_cgroup) < PAGE_SIZE)
-               kfree(memcg);
+               kfree_rcu(memcg, rcu_freeing);
        else
-               vfree(memcg);
+               call_rcu(&memcg->rcu_freeing, vfree_rcu);
 }
 
 static void mem_cgroup_get(struct mem_cgroup *memcg)
@@ -5075,7 +5116,7 @@ static struct page *mc_handle_present_pte(struct vm_area_struct *vma,
                return NULL;
        if (PageAnon(page)) {
                /* we don't move shared anon */
-               if (!move_anon() || page_mapcount(page) > 1)
+               if (!move_anon() || page_mapcount(page) > 2)
                        return NULL;
        } else if (!move_file())
                /* we ignore mapcount for file pages */