vmscan: fix pagecache reclaim referenced bit check
[linux-2.6.git] / mm / vmscan.c
index c82ee9a..9588973 100644 (file)
@@ -1064,7 +1064,6 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
        int pgdeactivate = 0;
        unsigned long pgscanned;
        LIST_HEAD(l_hold);      /* The pages which were snipped off */
-       LIST_HEAD(l_active);
        LIST_HEAD(l_inactive);
        struct page *page;
        struct pagevec pvec;
@@ -1095,21 +1094,28 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
                cond_resched();
                page = lru_to_page(&l_hold);
                list_del(&page->lru);
+
+               /* page_referenced clears PageReferenced */
+               if (page_mapping_inuse(page) &&
+                   page_referenced(page, 0, sc->mem_cgroup))
+                       pgmoved++;
+
                list_add(&page->lru, &l_inactive);
        }
 
        /*
-        * Count the referenced pages as rotated, even when they are moved
-        * to the inactive list.  This helps balance scan pressure between
-        * file and anonymous pages in get_scan_ratio.
-        */
+        * Count referenced pages from currently used mappings as
+        * rotated, even though they are moved to the inactive list.
+        * This helps balance scan pressure between file and anonymous
+        * pages in get_scan_ratio.
+        */
        zone->recent_rotated[!!file] += pgmoved;
 
        /*
-        * Now put the pages back on the appropriate [file or anon] inactive
-        * and active lists.
+        * Move the pages to the [file or anon] inactive list.
         */
        pagevec_init(&pvec, 1);
+
        pgmoved = 0;
        lru = LRU_BASE + file * LRU_FILE;
        spin_lock_irq(&zone->lru_lock);
@@ -1142,31 +1148,6 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
                pagevec_strip(&pvec);
                spin_lock_irq(&zone->lru_lock);
        }
-
-       pgmoved = 0;
-       lru = LRU_ACTIVE + file * LRU_FILE;
-       while (!list_empty(&l_active)) {
-               page = lru_to_page(&l_active);
-               prefetchw_prev_lru_page(page, &l_active, flags);
-               VM_BUG_ON(PageLRU(page));
-               SetPageLRU(page);
-               VM_BUG_ON(!PageActive(page));
-
-               list_move(&page->lru, &zone->lru[lru].list);
-               mem_cgroup_move_lists(page, true);
-               pgmoved++;
-               if (!pagevec_add(&pvec, page)) {
-                       __mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
-                       pgmoved = 0;
-                       spin_unlock_irq(&zone->lru_lock);
-                       if (vm_swap_full())
-                               pagevec_swap_free(&pvec);
-                       __pagevec_release(&pvec);
-                       spin_lock_irq(&zone->lru_lock);
-               }
-       }
-       __mod_zone_page_state(zone, NR_LRU_BASE + lru, pgmoved);
-
        __count_zone_vm_events(PGREFILL, zone, pgscanned);
        __count_vm_events(PGDEACTIVATE, pgdeactivate);
        spin_unlock_irq(&zone->lru_lock);