1 files changed, 35 insertions, 10 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index d9a0e0d3aac7..79c809895fba 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -561,18 +561,18 @@ redo:
 enum page_references {
         PAGEREF_RECLAIM,
         PAGEREF_RECLAIM_CLEAN,
+        PAGEREF_KEEP,
         PAGEREF_ACTIVATE,
 };
 
 static enum page_references page_check_references(struct page *page,
                                                   struct scan_control *sc)
 {
+        int referenced_ptes, referenced_page;
         unsigned long vm_flags;
-        int referenced;
 
-        referenced = page_referenced(page, 1, sc->mem_cgroup, &vm_flags);
-        if (!referenced)
-                return PAGEREF_RECLAIM;
+        referenced_ptes = page_referenced(page, 1, sc->mem_cgroup, &vm_flags);
+        referenced_page = TestClearPageReferenced(page);
 
         /* Lumpy reclaim - ignore references */
         if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
@@ -585,11 +585,36 @@ static enum page_references page_check_references(struct page *page,
         if (vm_flags & VM_LOCKED)
                 return PAGEREF_RECLAIM;
 
-        if (page_mapped(page))
-                return PAGEREF_ACTIVATE;
+        if (referenced_ptes) {
+                if (PageAnon(page))
+                        return PAGEREF_ACTIVATE;
+                /*
+                 * All mapped pages start out with page table
+                 * references from the instantiating fault, so we need
+                 * to look twice if a mapped file page is used more
+                 * than once.
+                 *
+                 * Mark it and spare it for another trip around the
+                 * inactive list.  Another page table reference will
+                 * lead to its activation.
+                 *
+                 * Note: the mark is set for activated pages as well
+                 * so that recently deactivated but used pages are
+                 * quickly recovered.
+                 */
+                SetPageReferenced(page);
+
+                if (referenced_page)
+                        return PAGEREF_ACTIVATE;
+
+                return PAGEREF_KEEP;
+        }
 
         /* Reclaim if clean, defer dirty pages to writeback */
-        return PAGEREF_RECLAIM_CLEAN;
+        if (referenced_page)
+                return PAGEREF_RECLAIM_CLEAN;
+
+        return PAGEREF_RECLAIM;
 }
 
 /*
@@ -657,6 +682,8 @@ static unsigned long shrink_page_list(struct list_head *page_list,
                 switch (references) {
                 case PAGEREF_ACTIVATE:
                         goto activate_locked;
+                case PAGEREF_KEEP:
+                        goto keep_locked;
                 case PAGEREF_RECLAIM:
                 case PAGEREF_RECLAIM_CLEAN:
                         ; /* try to reclaim the page below */
@@ -1359,9 +1386,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
                         continue;
                 }
 
-                /* page_referenced clears PageReferenced */
-                if (page_mapped(page) &&
-                    page_referenced(page, 0, sc->mem_cgroup, &vm_flags)) {
+                if (page_referenced(page, 0, sc->mem_cgroup, &vm_flags)) {
                         nr_rotated++;
                         /*
                          * Identify referenced, file-backed active pages and