1 files changed, 23 insertions, 7 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 0093bc36c5fc..d5ff3ce13029 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -89,6 +89,7 @@ static const char * const mem_cgroup_stat_names[] = {
         "rss",
         "rss_huge",
         "mapped_file",
+        "writeback",
         "swap",
 };
 
@@ -3654,6 +3655,20 @@ void mem_cgroup_split_huge_fixup(struct page *head)
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
+static inline
+void mem_cgroup_move_account_page_stat(struct mem_cgroup *from,
+                                        struct mem_cgroup *to,
+                                        unsigned int nr_pages,
+                                        enum mem_cgroup_stat_index idx)
+{
+        /* Update stat data for mem_cgroup */
+        preempt_disable();
+        WARN_ON_ONCE(from->stat->count[idx] < nr_pages);
+        __this_cpu_add(from->stat->count[idx], -nr_pages);
+        __this_cpu_add(to->stat->count[idx], nr_pages);
+        preempt_enable();
+}
+
 /**
  * mem_cgroup_move_account - move account of the page
  * @page: the page
@@ -3699,13 +3714,14 @@ static int mem_cgroup_move_account(struct page *page,
 
         move_lock_mem_cgroup(from, &flags);
 
-        if (!anon && page_mapped(page)) {
-                /* Update mapped_file data for mem_cgroup */
-                preempt_disable();
-                __this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
-                __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
-                preempt_enable();
-        }
+        if (!anon && page_mapped(page))
+                mem_cgroup_move_account_page_stat(from, to, nr_pages,
+                        MEM_CGROUP_STAT_FILE_MAPPED);
+
+        if (PageWriteback(page))
+                mem_cgroup_move_account_page_stat(from, to, nr_pages,
+                        MEM_CGROUP_STAT_WRITEBACK);
+
         mem_cgroup_charge_statistics(from, page, anon, -nr_pages);
 
         /* caller should have done css_get */