Re: [PATCH 1/2] memcg: remove MEMCG_NR_FILE_MAPPED

---
  include/linux/memcontrol.h |   22 ++++++++++++++++------
  mm/memcontrol.c            |   25 +------------------------
  mm/rmap.c                  |    4 ++--
  3 files changed, 19 insertions(+), 32 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index f94efd2..a337c2e 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h

@@ -27,9 +27,19 @@ struct page_cgroup;
  struct page;
  struct mm_struct;

-/* Stats that can be updated by kernel. */
-enum mem_cgroup_page_stat_item {
-	MEMCG_NR_FILE_MAPPED, /* # of pages charged as file rss */
+/*
+ * Statistics for memory cgroup.
+ */
+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_FILE_MAPPED,  /* # of pages charged as file rss */
+	MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */
+	MEM_CGROUP_STAT_DATA, /* end of data requires synchronization */
+	MEM_CGROUP_STAT_NSTATS,
  };

  struct mem_cgroup_reclaim_cookie {

@@ -170,17 +180,17 @@ 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);
  }

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 7685d4a..9102b8c 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c

@@ -77,21 +77,6 @@ static int really_do_swap_account __initdata = 0;
  #endif


-/*
- * Statistics for memory cgroup.
- */
-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_FILE_MAPPED,  /* # of pages charged as file rss */
-	MEM_CGROUP_STAT_SWAPOUT, /* # of pages, swapped out */
-	MEM_CGROUP_STAT_DATA, /* end of data requires synchronization */
-	MEM_CGROUP_STAT_NSTATS,
-};
-
  enum mem_cgroup_events_index {
  	MEM_CGROUP_EVENTS_PGPGIN,	/* # of pages paged in */
  	MEM_CGROUP_EVENTS_PGPGOUT,	/* # of pages paged out */

@@ -1958,7 +1943,7 @@ void __mem_cgroup_end_update_page_stat(struct page *page, unsigned long *flags)
  }

  void mem_cgroup_update_page_stat(struct page *page,
-				 enum mem_cgroup_page_stat_item idx, int val)
+				 enum mem_cgroup_stat_index idx, int val)
  {
  	struct mem_cgroup *memcg;
  	struct page_cgroup *pc = lookup_page_cgroup(page);

@@ -1971,14 +1956,6 @@ void mem_cgroup_update_page_stat(struct page *page,
  	if (unlikely(!memcg || !PageCgroupUsed(pc)))
  		return;

-	switch (idx) {
-	case MEMCG_NR_FILE_MAPPED:
-		idx = MEM_CGROUP_STAT_FILE_MAPPED;
-		break;
-	default:
-		BUG();
-	}
-
  	this_cpu_add(memcg->stat->count[idx], val);
  }

diff --git a/mm/rmap.c b/mm/rmap.c
index 5b5ad58..7e4e481 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c

@@ -1154,7 +1154,7 @@ void page_add_file_rmap(struct page *page)
  	mem_cgroup_begin_update_page_stat(page,&locked,&flags);
  	if (atomic_inc_and_test(&page->_mapcount)) {
  		__inc_zone_page_state(page, NR_FILE_MAPPED);
-		mem_cgroup_inc_page_stat(page, MEMCG_NR_FILE_MAPPED);
+		mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED);
  	}
  	mem_cgroup_end_update_page_stat(page,&locked,&flags);
  }

@@ -1208,7 +1208,7 @@ void page_remove_rmap(struct page *page)
  					      NR_ANON_TRANSPARENT_HUGEPAGES);
  	} else {
  		__dec_zone_page_state(page, NR_FILE_MAPPED);
-		mem_cgroup_dec_page_stat(page, MEMCG_NR_FILE_MAPPED);
+		mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED);
  	}
  	/*
  	 * It would be tidy to reset the PageAnon mapping here,