4 files changed, 77 insertions, 3 deletions

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 45add35dda1b..e46a0734ab6e 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -117,7 +117,7 @@ static inline bool mem_cgroup_disabled(void)
 }
 
 extern bool mem_cgroup_oom_called(struct task_struct *task);
-
+void mem_cgroup_update_mapped_file_stat(struct page *page, int val);
 #else /* CONFIG_CGROUP_MEM_RES_CTLR */
 struct mem_cgroup;
 
@@ -271,6 +271,11 @@ mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
 {
 }
 
+static inline void mem_cgroup_update_mapped_file_stat(struct page *page,
+                                                        int val)
+{
+}
+
 #endif /* CONFIG_CGROUP_MEM_CONT */
 
 #endif /* _LINUX_MEMCONTROL_H */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 70db6e0a5eec..6f682901deb5 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -62,7 +62,8 @@ enum mem_cgroup_stat_index {
          * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
          */
         MEM_CGROUP_STAT_CACHE,     /* # of pages charged as cache */
-        MEM_CGROUP_STAT_RSS,       /* # of pages charged as rss */
+        MEM_CGROUP_STAT_RSS,       /* # of pages charged as anon rss */
+        MEM_CGROUP_STAT_MAPPED_FILE,  /* # of pages charged as file rss */
         MEM_CGROUP_STAT_PGPGIN_COUNT,   /* # of pages paged in */
         MEM_CGROUP_STAT_PGPGOUT_COUNT,  /* # of pages paged out */
 
@@ -900,6 +901,44 @@ static void record_last_oom(struct mem_cgroup *mem)
         mem_cgroup_walk_tree(mem, NULL, record_last_oom_cb);
 }
 
+/*
+ * Currently used to update mapped file statistics, but the routine can be
+ * generalized to update other statistics as well.
+ */
+void mem_cgroup_update_mapped_file_stat(struct page *page, int val)
+{
+        struct mem_cgroup *mem;
+        struct mem_cgroup_stat *stat;
+        struct mem_cgroup_stat_cpu *cpustat;
+        int cpu;
+        struct page_cgroup *pc;
+
+        if (!page_is_file_cache(page))
+                return;
+
+        pc = lookup_page_cgroup(page);
+        if (unlikely(!pc))
+                return;
+
+        lock_page_cgroup(pc);
+        mem = pc->mem_cgroup;
+        if (!mem)
+                goto done;
+
+        if (!PageCgroupUsed(pc))
+                goto done;
+
+        /*
+         * Preemption is already disabled, we don't need get_cpu()
+         */
+        cpu = smp_processor_id();
+        stat = &mem->stat;
+        cpustat = &stat->cpustat[cpu];
+
+        __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE, val);
+done:
+        unlock_page_cgroup(pc);
+}
 
 /*
  * Unlike exported interface, "oom" parameter is added. if oom==true,
@@ -1098,6 +1137,10 @@ static int mem_cgroup_move_account(struct page_cgroup *pc,
         struct mem_cgroup_per_zone *from_mz, *to_mz;
         int nid, zid;
         int ret = -EBUSY;
+        struct page *page;
+        int cpu;
+        struct mem_cgroup_stat *stat;
+        struct mem_cgroup_stat_cpu *cpustat;
 
         VM_BUG_ON(from == to);
         VM_BUG_ON(PageLRU(pc->page));
@@ -1118,6 +1161,23 @@ static int mem_cgroup_move_account(struct page_cgroup *pc,
 
         res_counter_uncharge(&from->res, PAGE_SIZE);
         mem_cgroup_charge_statistics(from, pc, false);
+
+        page = pc->page;
+        if (page_is_file_cache(page) && page_mapped(page)) {
+                cpu = smp_processor_id();
+                /* Update mapped_file data for mem_cgroup "from" */
+                stat = &from->stat;
+                cpustat = &stat->cpustat[cpu];
+                __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE,
+                                                -1);
+
+                /* Update mapped_file data for mem_cgroup "to" */
+                stat = &to->stat;
+                cpustat = &stat->cpustat[cpu];
+                __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE,
+                                                1);
+        }
+
         if (do_swap_account)
                 res_counter_uncharge(&from->memsw, PAGE_SIZE);
         css_put(&from->css);
@@ -2046,6 +2106,7 @@ static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
 enum {
         MCS_CACHE,
         MCS_RSS,
+        MCS_MAPPED_FILE,
         MCS_PGPGIN,
         MCS_PGPGOUT,
         MCS_INACTIVE_ANON,
@@ -2066,6 +2127,7 @@ struct {
 } memcg_stat_strings[NR_MCS_STAT] = {
         {"cache", "total_cache"},
         {"rss", "total_rss"},
+        {"mapped_file", "total_mapped_file"},
         {"pgpgin", "total_pgpgin"},
         {"pgpgout", "total_pgpgout"},
         {"inactive_anon", "total_inactive_anon"},
@@ -2086,6 +2148,8 @@ static int mem_cgroup_get_local_stat(struct mem_cgroup *mem, void *data)
         s->stat[MCS_CACHE] += val * PAGE_SIZE;
         val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
         s->stat[MCS_RSS] += val * PAGE_SIZE;
+        val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_MAPPED_FILE);
+        s->stat[MCS_MAPPED_FILE] += val * PAGE_SIZE;
         val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGIN_COUNT);
         s->stat[MCS_PGPGIN] += val;
         val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGOUT_COUNT);
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 4f31c9b3e940..672089d5819f 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -99,6 +99,8 @@ struct page_cgroup *lookup_page_cgroup(struct page *page)
         unsigned long pfn = page_to_pfn(page);
         struct mem_section *section = __pfn_to_section(pfn);
 
+        if (!section->page_cgroup)
+                return NULL;
         return section->page_cgroup + pfn;
 }
 
diff --git a/mm/rmap.c b/mm/rmap.c
index c9ccc1a72dc3..836c6c63e1f2 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -703,8 +703,10 @@ void page_add_new_anon_rmap(struct page *page,
  */
 void page_add_file_rmap(struct page *page)
 {
-        if (atomic_inc_and_test(&page->_mapcount))
+        if (atomic_inc_and_test(&page->_mapcount)) {
                 __inc_zone_page_state(page, NR_FILE_MAPPED);
+                mem_cgroup_update_mapped_file_stat(page, 1);
+        }
 }
 
 #ifdef CONFIG_DEBUG_VM
@@ -753,6 +755,7 @@ void page_remove_rmap(struct page *page)
                         mem_cgroup_uncharge_page(page);
                 __dec_zone_page_state(page,
                         PageAnon(page) ? NR_ANON_PAGES : NR_FILE_MAPPED);
+                mem_cgroup_update_mapped_file_stat(page, -1);
                 /*
                  * It would be tidy to reset the PageAnon mapping here,
                  * but that might overwrite a racing page_add_anon_rmap