Add a configure option to group pages by mobility

[sfrench/cifs-2.6.git] / mm / page_alloc.c

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e3e726bd2858f6b97df2e92e4cf7f3ea9073fbd2..fea1e3b56c3d6626c5cf59bccd14f84ea37fbaf4 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -158,6 +158,7 @@ int nr_node_ids __read_mostly = MAX_NUMNODES;
 EXPORT_SYMBOL(nr_node_ids);
 #endif
 
+#ifdef CONFIG_PAGE_GROUP_BY_MOBILITY
 static inline int get_pageblock_migratetype(struct page *page)
 {
        return get_pageblock_flags_group(page, PB_migrate, PB_migrate_end);
@@ -174,6 +175,22 @@ static inline int gfpflags_to_migratetype(gfp_t gfp_flags)
        return ((gfp_flags & __GFP_MOVABLE) != 0);
 }
 
+#else
+static inline int get_pageblock_migratetype(struct page *page)
+{
+       return MIGRATE_UNMOVABLE;
+}
+
+static void set_pageblock_migratetype(struct page *page, int migratetype)
+{
+}
+
+static inline int gfpflags_to_migratetype(gfp_t gfp_flags)
+{
+       return MIGRATE_UNMOVABLE;
+}
+#endif /* CONFIG_PAGE_GROUP_BY_MOBILITY */
+
 #ifdef CONFIG_DEBUG_VM
 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
 {
@@ -653,6 +670,7 @@ static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
        return 0;
 }
 
+#ifdef CONFIG_PAGE_GROUP_BY_MOBILITY
 /*
  * This array describes the order lists are fallen back to when
  * the free lists for the desirable migrate type are depleted
@@ -709,6 +727,13 @@ static struct page *__rmqueue_fallback(struct zone *zone, int order,
 
        return NULL;
 }
+#else
+static struct page *__rmqueue_fallback(struct zone *zone, int order,
+                                               int start_migratetype)
+{
+       return NULL;
+}
+#endif /* CONFIG_PAGE_GROUP_BY_MOBILITY */
 
 /* 
  * Do the hard work of removing an element from the buddy allocator.
@@ -953,27 +978,25 @@ again:
                        if (unlikely(!pcp->count))
                                goto failed;
                }
+
+#ifdef CONFIG_PAGE_GROUP_BY_MOBILITY
                /* Find a page of the appropriate migrate type */
-               list_for_each_entry(page, &pcp->list, lru) {
-                       if (page_private(page) == migratetype) {
-                               list_del(&page->lru);
-                               pcp->count--;
+               list_for_each_entry(page, &pcp->list, lru)
+                       if (page_private(page) == migratetype)
                                break;
-                       }
-               }
 
-               /*
-                * Check if a page of the appropriate migrate type
-                * was found. If not, allocate more to the pcp list
-                */
-               if (&page->lru == &pcp->list) {
+               /* Allocate more to the pcp list if necessary */
+               if (unlikely(&page->lru == &pcp->list)) {
                        pcp->count += rmqueue_bulk(zone, 0,
                                        pcp->batch, &pcp->list, migratetype);
                        page = list_entry(pcp->list.next, struct page, lru);
-                       VM_BUG_ON(page_private(page) != migratetype);
-                       list_del(&page->lru);
-                       pcp->count--;
                }
+#else
+               page = list_entry(pcp->list.next, struct page, lru);
+#endif /* CONFIG_PAGE_GROUP_BY_MOBILITY */
+
+               list_del(&page->lru);
+               pcp->count--;
        } else {
                spin_lock_irqsave(&zone->lock, flags);
                page = __rmqueue(zone, order, migratetype);