memcg: fix swap accounting

[safe/jmp/linux-2.6] / mm / swapfile.c

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 28faa01..d1ade1a 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -583,8 +583,9 @@ static int swap_entry_free(struct swap_info_struct *p,
                        swap_list.next = p - swap_info;
                nr_swap_pages++;
                p->inuse_pages--;
-               mem_cgroup_uncharge_swap(ent);
        }
+       if (!swap_count(count))
+               mem_cgroup_uncharge_swap(ent);
        return count;
 }
 
@@ -609,12 +610,19 @@ void swap_free(swp_entry_t entry)
 void swapcache_free(swp_entry_t entry, struct page *page)
 {
        struct swap_info_struct *p;
+       int ret;
 
-       if (page)
-               mem_cgroup_uncharge_swapcache(page, entry);
        p = swap_info_get(entry);
        if (p) {
-               swap_entry_free(p, entry, SWAP_CACHE);
+               ret = swap_entry_free(p, entry, SWAP_CACHE);
+               if (page) {
+                       bool swapout;
+                       if (ret)
+                               swapout = true; /* the end of swap out */
+                       else
+                               swapout = false; /* no more swap users! */
+                       mem_cgroup_uncharge_swapcache(page, entry, swapout);
+               }
                spin_unlock(&swap_lock);
        }
        return;