drivers/gpu/drm/i915/intel_bios.c: fix continuation line formats

[safe/jmp/linux-2.6] / mm / vmscan.c

diff --git a/mm/vmscan.c b/mm/vmscan.c
index ba4e87d..79c8098 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -262,27 +262,6 @@ unsigned long shrink_slab(unsigned long scanned, gfp_t gfp_mask,
        return ret;
 }
 
-/* Called without lock on whether page is mapped, so answer is unstable */
-static inline int page_mapping_inuse(struct page *page)
-{
-       struct address_space *mapping;
-
-       /* Page is in somebody's page tables. */
-       if (page_mapped(page))
-               return 1;
-
-       /* Be more reluctant to reclaim swapcache than pagecache */
-       if (PageSwapCache(page))
-               return 1;
-
-       mapping = page_mapping(page);
-       if (!mapping)
-               return 0;
-
-       /* File is mmap'd by somebody? */
-       return mapping_mapped(mapping);
-}
-
 static inline int is_page_cache_freeable(struct page *page)
 {
        /*
@@ -582,18 +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)
@@ -606,11 +585,36 @@ static enum page_references page_check_references(struct page *page,
        if (vm_flags & VM_LOCKED)
                return PAGEREF_RECLAIM;
 
-       if (page_mapping_inuse(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;
 }
 
 /*
@@ -678,6 +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 */
@@ -1380,9 +1386,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
                        continue;
                }
 
-               /* page_referenced clears PageReferenced */
-               if (page_mapping_inuse(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