3 files changed, 92 insertions, 13 deletions

diff --git a/mm/internal.h b/mm/internal.h
index 69488205723d..4c98630f0f77 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -39,6 +39,15 @@ static inline void __put_page(struct page *page)
 
 extern unsigned long highest_memmap_pfn;
 
+#ifdef CONFIG_SMP
+extern int putback_active_lru_page(struct zone *zone, struct page *page);
+#else
+static inline int putback_active_lru_page(struct zone *zone, struct page *page)
+{
+        return 0;
+}
+#endif
+
 /*
  * in mm/vmscan.c:
  */
diff --git a/mm/swap.c b/mm/swap.c
index ab498ea04ae3..bbc1ce9f9460 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -271,27 +271,94 @@ static void update_page_reclaim_stat(struct zone *zone, struct page *page,
 }
 
 /*
- * FIXME: speed this up?
+ * A page will go to active list either by activate_page or putback_lru_page.
+ * In the activate_page case, the page hasn't active bit set. The page might
+ * not in LRU list because it's isolated before it gets a chance to be moved to
+ * active list. The window is small because pagevec just stores several pages.
+ * For such case, we do nothing for such page.
+ * In the putback_lru_page case, the page isn't in lru list but has active
+ * bit set
  */
-void activate_page(struct page *page)
+static void __activate_page(struct page *page, void *arg)
 {
         struct zone *zone = page_zone(page);
+        int file = page_is_file_cache(page);
+        int lru = page_lru_base_type(page);
+        bool putback = !PageLRU(page);
 
-        spin_lock_irq(&zone->lru_lock);
-        if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
-                int file = page_is_file_cache(page);
-                int lru = page_lru_base_type(page);
+        /* The page is isolated before it's moved to active list */
+        if (!PageLRU(page) && !PageActive(page))
+                return;
+        if ((PageLRU(page) && PageActive(page)) || PageUnevictable(page))
+                return;
+
+        if (!putback)
                 del_page_from_lru_list(zone, page, lru);
+        else
+                SetPageLRU(page);
 
-                SetPageActive(page);
-                lru += LRU_ACTIVE;
-                add_page_to_lru_list(zone, page, lru);
-                __count_vm_event(PGACTIVATE);
+        SetPageActive(page);
+        lru += LRU_ACTIVE;
+        add_page_to_lru_list(zone, page, lru);
+
+        if (putback)
+                return;
+        __count_vm_event(PGACTIVATE);
+        update_page_reclaim_stat(zone, page, file, 1);
+}
+
+#ifdef CONFIG_SMP
+static DEFINE_PER_CPU(struct pagevec, activate_page_pvecs);
+
+static void activate_page_drain(int cpu)
+{
+        struct pagevec *pvec = &per_cpu(activate_page_pvecs, cpu);
+
+        if (pagevec_count(pvec))
+                pagevec_lru_move_fn(pvec, __activate_page, NULL);
+}
+
+void activate_page(struct page *page)
+{
+        if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
+                struct pagevec *pvec = &get_cpu_var(activate_page_pvecs);
+
+                page_cache_get(page);
+                if (!pagevec_add(pvec, page))
+                        pagevec_lru_move_fn(pvec, __activate_page, NULL);
+                put_cpu_var(activate_page_pvecs);
+        }
+}
 
-                update_page_reclaim_stat(zone, page, file, 1);
+/* Caller should hold zone->lru_lock */
+int putback_active_lru_page(struct zone *zone, struct page *page)
+{
+        struct pagevec *pvec = &get_cpu_var(activate_page_pvecs);
+
+        if (!pagevec_add(pvec, page)) {
+                spin_unlock_irq(&zone->lru_lock);
+                pagevec_lru_move_fn(pvec, __activate_page, NULL);
+                spin_lock_irq(&zone->lru_lock);
         }
+        put_cpu_var(activate_page_pvecs);
+        return 1;
+}
+
+#else
+static inline void activate_page_drain(int cpu)
+{
+}
+
+void activate_page(struct page *page)
+{
+        struct zone *zone = page_zone(page);
+
+        spin_lock_irq(&zone->lru_lock);
+        if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page))
+                __activate_page(page, NULL);
         spin_unlock_irq(&zone->lru_lock);
 }
+#endif
 
 /*
  * Mark a page as having seen activity.
@@ -390,6 +457,7 @@ static void drain_cpu_pagevecs(int cpu)
                 pagevec_move_tail(pvec);
                 local_irq_restore(flags);
         }
+        activate_page_drain(cpu);
 }
 
 void lru_add_drain(void)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 47a50962ce81..99999a9b2b0b 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1271,14 +1271,16 @@ putback_lru_pages(struct zone *zone, struct scan_control *sc,
                         spin_lock_irq(&zone->lru_lock);
                         continue;
                 }
-                SetPageLRU(page);
                 lru = page_lru(page);
-                add_page_to_lru_list(zone, page, lru);
                 if (is_active_lru(lru)) {
                         int file = is_file_lru(lru);
                         int numpages = hpage_nr_pages(page);
                         reclaim_stat->recent_rotated[file] += numpages;
+                        if (putback_active_lru_page(zone, page))
+                                continue;
                 }
+                SetPageLRU(page);
+                add_page_to_lru_list(zone, page, lru);
                 if (!pagevec_add(&pvec, page)) {
                         spin_unlock_irq(&zone->lru_lock);
                         __pagevec_release(&pvec);