mm/memcg: move reclaim_stat into lruvec

With mem_cgroup_disabled() now explicit, it becomes clear that the
zone_reclaim_stat structure actually belongs in lruvec, per-zone when
memcg is disabled but per-memcg per-zone when it's enabled.

We can delete mem_cgroup_get_reclaim_stat(), and change
update_page_reclaim_stat() to update just the one set of stats, the one
which get_scan_count() will actually use.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@parallels.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>

2 files changed, 14 insertions, 24 deletions

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 18ea0b7baf32..cfe9050ad8da 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -126,8 +126,6 @@ int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg,
 int mem_cgroup_select_victim_node(struct mem_cgroup *memcg);
 unsigned long mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg,
                                         int nid, int zid, unsigned int lrumask);
-struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
-                                                      struct zone *zone);
 struct zone_reclaim_stat*
 mem_cgroup_get_reclaim_stat_from_page(struct page *page);
 extern void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
@@ -356,13 +354,6 @@ mem_cgroup_zone_nr_lru_pages(struct mem_cgroup *memcg, int nid, int zid,
         return 0;
 }
 
-
-static inline struct zone_reclaim_stat*
-mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg, struct zone *zone)
-{
-        return NULL;
-}
-
 static inline struct zone_reclaim_stat*
 mem_cgroup_get_reclaim_stat_from_page(struct page *page)
 {
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 4871e31ae277..1b89861eedc0 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -185,8 +185,22 @@ static inline int is_unevictable_lru(enum lru_list lru)
         return (lru == LRU_UNEVICTABLE);
 }
 
+struct zone_reclaim_stat {
+        /*
+         * The pageout code in vmscan.c keeps track of how many of the
+         * mem/swap backed and file backed pages are refeferenced.
+         * The higher the rotated/scanned ratio, the more valuable
+         * that cache is.
+         *
+         * The anon LRU stats live in [0], file LRU stats in [1]
+         */
+        unsigned long           recent_rotated[2];
+        unsigned long           recent_scanned[2];
+};
+
 struct lruvec {
         struct list_head lists[NR_LRU_LISTS];
+        struct zone_reclaim_stat reclaim_stat;
 };
 
 /* Mask used at gathering information at once (see memcontrol.c) */
@@ -313,19 +327,6 @@ enum zone_type {
 #error ZONES_SHIFT -- too many zones configured adjust calculation
 #endif
 
-struct zone_reclaim_stat {
-        /*
-         * The pageout code in vmscan.c keeps track of how many of the
-         * mem/swap backed and file backed pages are refeferenced.
-         * The higher the rotated/scanned ratio, the more valuable
-         * that cache is.
-         *
-         * The anon LRU stats live in [0], file LRU stats in [1]
-         */
-        unsigned long           recent_rotated[2];
-        unsigned long           recent_scanned[2];
-};
-
 struct zone {
         /* Fields commonly accessed by the page allocator */
 
@@ -407,8 +408,6 @@ struct zone {
         spinlock_t              lru_lock;
         struct lruvec           lruvec;
 
-        struct zone_reclaim_stat reclaim_stat;
-
         unsigned long           pages_scanned;     /* since last reclaim */
         unsigned long           flags;             /* zone flags, see below */