mm: update_lru_size do the __mod_zone_page_state

[karo-tx-linux.git] / mm / memcontrol.c

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index fe787f5c41bd1332eeca88e85a3f0bf483bb552b..1b40dcad2b90f9395a99dfe027cb0331b0565ec2 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1023,22 +1023,40 @@ out:
  * @lru: index of lru list the page is sitting on
  * @nr_pages: positive when adding or negative when removing
  *
- * This function must be called when a page is added to or removed from an
- * lru list.
+ * This function must be called under lru_lock, just before a page is added
+ * to or just after a page is removed from an lru list (that ordering being
+ * so as to allow it to check that lru_size 0 is consistent with list_empty).
  */
 void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
                                int nr_pages)
 {
        struct mem_cgroup_per_zone *mz;
        unsigned long *lru_size;
+       long size;
+       bool empty;
+
+       __update_lru_size(lruvec, lru, nr_pages);
 
        if (mem_cgroup_disabled())
                return;
 
        mz = container_of(lruvec, struct mem_cgroup_per_zone, lruvec);
        lru_size = mz->lru_size + lru;
-       *lru_size += nr_pages;
-       VM_BUG_ON((long)(*lru_size) < 0);
+       empty = list_empty(lruvec->lists + lru);
+
+       if (nr_pages < 0)
+               *lru_size += nr_pages;
+
+       size = *lru_size;
+       if (WARN_ONCE(size < 0 || empty != !size,
+               "%s(%p, %d, %d): lru_size %ld but %sempty\n",
+               __func__, lruvec, lru, nr_pages, size, empty ? "" : "not ")) {
+               VM_BUG_ON(1);
+               *lru_size = 0;
+       }
+
+       if (nr_pages > 0)
+               *lru_size += nr_pages;
 }
 
 bool task_in_mem_cgroup(struct task_struct *task, struct mem_cgroup *memcg)
@@ -1389,14 +1407,11 @@ int mem_cgroup_select_victim_node(struct mem_cgroup *memcg)
        mem_cgroup_may_update_nodemask(memcg);
        node = memcg->last_scanned_node;
 
-       node = next_node(node, memcg->scan_nodes);
-       if (node == MAX_NUMNODES)
-               node = first_node(memcg->scan_nodes);
+       node = next_node_in(node, memcg->scan_nodes);
        /*
-        * We call this when we hit limit, not when pages are added to LRU.
-        * No LRU may hold pages because all pages are UNEVICTABLE or
-        * memcg is too small and all pages are not on LRU. In that case,
-        * we use curret node.
+        * mem_cgroup_may_update_nodemask might have seen no reclaimmable pages
+        * last time it really checked all the LRUs due to rate limiting.
+        * Fallback to the current node in that case for simplicity.
         */
        if (unlikely(node == MAX_NUMNODES))
                node = numa_node_id();