memcg: add zone_reclaim_stat

Introduce mem_cgroup_per_zone::reclaim_stat member and its statics
collecting function.

Now, get_scan_ratio() can calculate correct value on memcg reclaim.

[hugh@veritas.com: avoid reclaim_stat oops when disabled]
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 67 insertions, 23 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 313247e6c503..7b7f4dc05035 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -103,6 +103,8 @@ struct mem_cgroup_per_zone {
          */
         struct list_head        lists[NR_LRU_LISTS];
         unsigned long           count[NR_LRU_LISTS];
+
+        struct zone_reclaim_stat reclaim_stat;
 };
 /* Macro for accessing counter */
 #define MEM_CGROUP_ZSTAT(mz, idx)       ((mz)->count[(idx)])
@@ -458,6 +460,33 @@ unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
         return MEM_CGROUP_ZSTAT(mz, lru);
 }
 
+struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
+                                                      struct zone *zone)
+{
+        int nid = zone->zone_pgdat->node_id;
+        int zid = zone_idx(zone);
+        struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
+
+        return &mz->reclaim_stat;
+}
+
+struct zone_reclaim_stat *
+mem_cgroup_get_reclaim_stat_from_page(struct page *page)
+{
+        struct page_cgroup *pc;
+        struct mem_cgroup_per_zone *mz;
+
+        if (mem_cgroup_disabled())
+                return NULL;
+
+        pc = lookup_page_cgroup(page);
+        mz = page_cgroup_zoneinfo(pc);
+        if (!mz)
+                return NULL;
+
+        return &mz->reclaim_stat;
+}
+
 unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
                                         struct list_head *dst,
                                         unsigned long *scanned, int order,
diff --git a/mm/swap.c b/mm/swap.c
index 26b07e7bc3d3..8adb9feb61e1 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -151,13 +151,32 @@ void  rotate_reclaimable_page(struct page *page)
         }
 }
 
+static void update_page_reclaim_stat(struct zone *zone, struct page *page,
+                                     int file, int rotated)
+{
+        struct zone_reclaim_stat *reclaim_stat = &zone->reclaim_stat;
+        struct zone_reclaim_stat *memcg_reclaim_stat;
+
+        memcg_reclaim_stat = mem_cgroup_get_reclaim_stat_from_page(page);
+
+        reclaim_stat->recent_scanned[file]++;
+        if (rotated)
+                reclaim_stat->recent_rotated[file]++;
+
+        if (!memcg_reclaim_stat)
+                return;
+
+        memcg_reclaim_stat->recent_scanned[file]++;
+        if (rotated)
+                memcg_reclaim_stat->recent_rotated[file]++;
+}
+
 /*
  * FIXME: speed this up?
  */
 void activate_page(struct page *page)
 {
         struct zone *zone = page_zone(page);
-        struct zone_reclaim_stat *reclaim_stat = &zone->reclaim_stat;
 
         spin_lock_irq(&zone->lru_lock);
         if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
@@ -170,8 +189,7 @@ void activate_page(struct page *page)
                 add_page_to_lru_list(zone, page, lru);
                 __count_vm_event(PGACTIVATE);
 
-                reclaim_stat->recent_rotated[!!file]++;
-                reclaim_stat->recent_scanned[!!file]++;
+                update_page_reclaim_stat(zone, page, !!file, 1);
         }
         spin_unlock_irq(&zone->lru_lock);
 }
@@ -386,7 +404,6 @@ void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru)
 {
         int i;
         struct zone *zone = NULL;
-        struct zone_reclaim_stat *reclaim_stat = NULL;
 
         VM_BUG_ON(is_unevictable_lru(lru));
 
@@ -394,24 +411,23 @@ void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru)
                 struct page *page = pvec->pages[i];
                 struct zone *pagezone = page_zone(page);
                 int file;
+                int active;
 
                 if (pagezone != zone) {
                         if (zone)
                                 spin_unlock_irq(&zone->lru_lock);
                         zone = pagezone;
-                        reclaim_stat = &zone->reclaim_stat;
                         spin_lock_irq(&zone->lru_lock);
                 }
                 VM_BUG_ON(PageActive(page));
                 VM_BUG_ON(PageUnevictable(page));
                 VM_BUG_ON(PageLRU(page));
                 SetPageLRU(page);
+                active = is_active_lru(lru);
                 file = is_file_lru(lru);
-                reclaim_stat->recent_scanned[file]++;
-                if (is_active_lru(lru)) {
+                if (active)
                         SetPageActive(page);
-                        reclaim_stat->recent_rotated[file]++;
-                }
+                update_page_reclaim_stat(zone, page, file, active);
                 add_page_to_lru_list(zone, page, lru);
         }
         if (zone)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index d958d624d3ae..56fc7abe4d23 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -133,6 +133,9 @@ static DECLARE_RWSEM(shrinker_rwsem);
 static struct zone_reclaim_stat *get_reclaim_stat(struct zone *zone,
                                                   struct scan_control *sc)
 {
+        if (!scan_global_lru(sc))
+                return mem_cgroup_get_reclaim_stat(sc->mem_cgroup, zone);
+
         return &zone->reclaim_stat;
 }
 
@@ -1087,17 +1090,14 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
                 __mod_zone_page_state(zone, NR_INACTIVE_ANON,
                                                 -count[LRU_INACTIVE_ANON]);
 
-                if (scan_global_lru(sc)) {
+                if (scan_global_lru(sc))
                         zone->pages_scanned += nr_scan;
-                        reclaim_stat->recent_scanned[0] +=
-                                                      count[LRU_INACTIVE_ANON];
-                        reclaim_stat->recent_scanned[0] +=
-                                                      count[LRU_ACTIVE_ANON];
-                        reclaim_stat->recent_scanned[1] +=
-                                                      count[LRU_INACTIVE_FILE];
-                        reclaim_stat->recent_scanned[1] +=
-                                                      count[LRU_ACTIVE_FILE];
-                }
+
+                reclaim_stat->recent_scanned[0] += count[LRU_INACTIVE_ANON];
+                reclaim_stat->recent_scanned[0] += count[LRU_ACTIVE_ANON];
+                reclaim_stat->recent_scanned[1] += count[LRU_INACTIVE_FILE];
+                reclaim_stat->recent_scanned[1] += count[LRU_ACTIVE_FILE];
+
                 spin_unlock_irq(&zone->lru_lock);
 
                 nr_scanned += nr_scan;
@@ -1155,7 +1155,7 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
                         SetPageLRU(page);
                         lru = page_lru(page);
                         add_page_to_lru_list(zone, page, lru);
-                        if (PageActive(page) && scan_global_lru(sc)) {
+                        if (PageActive(page)) {
                                 int file = !!page_is_file_cache(page);
                                 reclaim_stat->recent_rotated[file]++;
                         }
@@ -1230,8 +1230,8 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
          */
         if (scan_global_lru(sc)) {
                 zone->pages_scanned += pgscanned;
-                reclaim_stat->recent_scanned[!!file] += pgmoved;
         }
+        reclaim_stat->recent_scanned[!!file] += pgmoved;
 
         if (file)
                 __mod_zone_page_state(zone, NR_ACTIVE_FILE, -pgmoved);
@@ -1272,8 +1272,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
          * This helps balance scan pressure between file and anonymous
          * pages in get_scan_ratio.
          */
-        if (scan_global_lru(sc))
-                reclaim_stat->recent_rotated[!!file] += pgmoved;
+        reclaim_stat->recent_rotated[!!file] += pgmoved;
 
         while (!list_empty(&l_inactive)) {
                 page = lru_to_page(&l_inactive);