memcg: remove MEMCG_NR_FILE_MAPPED

While accounting memcg page stat, it's not worth to use
MEMCG_NR_FILE_MAPPED as an extra layer of indirection because of the
complexity and presumed performance overhead.  We can use
MEM_CGROUP_STAT_FILE_MAPPED directly.

Signed-off-by: Sha Zhengju <handai.szj@taobao.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Fengguang Wu <fengguang.wu@intel.com>
Reviewed-by: Greg Thelen <gthelen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 19 insertions, 8 deletions

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 89d576cfcc4c..f952a07ce7a9 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -30,9 +30,20 @@ struct page;
 struct mm_struct;
 struct kmem_cache;
 
-/* Stats that can be updated by kernel. */
-enum mem_cgroup_page_stat_item {
-        MEMCG_NR_FILE_MAPPED, /* # of pages charged as file rss */
+/*
+ * The corresponding mem_cgroup_stat_names is defined in mm/memcontrol.c,
+ * These two lists should keep in accord with each other.
+ */
+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 anon rss */
+        MEM_CGROUP_STAT_RSS_HUGE,       /* # of pages charged as anon huge */
+        MEM_CGROUP_STAT_FILE_MAPPED,    /* # of pages charged as file rss */
+        MEM_CGROUP_STAT_SWAP,           /* # of pages, swapped out */
+        MEM_CGROUP_STAT_NSTATS,
 };
 
 struct mem_cgroup_reclaim_cookie {
@@ -233,17 +244,17 @@ static inline void mem_cgroup_end_update_page_stat(struct page *page,
 }
 
 void mem_cgroup_update_page_stat(struct page *page,
-                                 enum mem_cgroup_page_stat_item idx,
+                                 enum mem_cgroup_stat_index idx,
                                  int val);
 
 static inline void mem_cgroup_inc_page_stat(struct page *page,
-                                            enum mem_cgroup_page_stat_item idx)
+                                            enum mem_cgroup_stat_index idx)
 {
         mem_cgroup_update_page_stat(page, idx, 1);
 }
 
 static inline void mem_cgroup_dec_page_stat(struct page *page,
-                                            enum mem_cgroup_page_stat_item idx)
+                                            enum mem_cgroup_stat_index idx)
 {
         mem_cgroup_update_page_stat(page, idx, -1);
 }
@@ -449,12 +460,12 @@ static inline bool mem_cgroup_oom_synchronize(void)
 }
 
 static inline void mem_cgroup_inc_page_stat(struct page *page,
-                                            enum mem_cgroup_page_stat_item idx)
+                                            enum mem_cgroup_stat_index idx)
 {
 }
 
 static inline void mem_cgroup_dec_page_stat(struct page *page,
-                                            enum mem_cgroup_page_stat_item idx)
+                                            enum mem_cgroup_stat_index idx)
 {
 }