X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=mm%2Fpage_alloc.c;h=cefe6fe8d991b32b1b0e66c86953d92e00c39aea;hb=c175a0ce7584e5b498fff8cbdb9aa7912aa9fbba;hp=a6326c71b663802fab4972b566a3e510e91bff78;hpb=19fdb9eefb21b72edbc365b838502780c392bad6;p=~andy%2Flinux

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a6326c71b66..cefe6fe8d99 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -475,6 +475,8 @@ static inline void __free_one_page(struct page *page,
 		int migratetype)
 {
 	unsigned long page_idx;
+	unsigned long combined_idx;
+	struct page *buddy;
 
 	if (unlikely(PageCompound(page)))
 		if (unlikely(destroy_compound_page(page, order)))
@@ -488,9 +490,6 @@ static inline void __free_one_page(struct page *page,
 	VM_BUG_ON(bad_range(zone, page));
 
 	while (order < MAX_ORDER-1) {
-		unsigned long combined_idx;
-		struct page *buddy;
-
 		buddy = __page_find_buddy(page, page_idx, order);
 		if (!page_is_buddy(page, buddy, order))
 			break;
@@ -505,8 +504,29 @@ static inline void __free_one_page(struct page *page,
 		order++;
 	}
 	set_page_order(page, order);
-	list_add(&page->lru,
-		&zone->free_area[order].free_list[migratetype]);
+
+	/*
+	 * If this is not the largest possible page, check if the buddy
+	 * of the next-highest order is free. If it is, it's possible
+	 * that pages are being freed that will coalesce soon. In case,
+	 * that is happening, add the free page to the tail of the list
+	 * so it's less likely to be used soon and more likely to be merged
+	 * as a higher order page
+	 */
+	if ((order < MAX_ORDER-1) && pfn_valid_within(page_to_pfn(buddy))) {
+		struct page *higher_page, *higher_buddy;
+		combined_idx = __find_combined_index(page_idx, order);
+		higher_page = page + combined_idx - page_idx;
+		higher_buddy = __page_find_buddy(higher_page, combined_idx, order + 1);
+		if (page_is_buddy(higher_page, higher_buddy, order + 1)) {
+			list_add_tail(&page->lru,
+				&zone->free_area[order].free_list[migratetype]);
+			goto out;
+		}
+	}
+
+	list_add(&page->lru, &zone->free_area[order].free_list[migratetype]);
+out:
 	zone->free_area[order].nr_free++;
 }
 
@@ -1970,10 +1990,13 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 	if (unlikely(!zonelist->_zonerefs->zone))
 		return NULL;
 
+	get_mems_allowed();
 	/* The preferred zone is used for statistics later */
 	first_zones_zonelist(zonelist, high_zoneidx, nodemask, &preferred_zone);
-	if (!preferred_zone)
+	if (!preferred_zone) {
+		put_mems_allowed();
 		return NULL;
+	}
 
 	/* First allocation attempt */
 	page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, nodemask, order,
@@ -1983,6 +2006,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 		page = __alloc_pages_slowpath(gfp_mask, order,
 				zonelist, high_zoneidx, nodemask,
 				preferred_zone, migratetype);
+	put_mems_allowed();
 
 	trace_mm_page_alloc(page, order, gfp_mask, migratetype);
 	return page;
@@ -2582,7 +2606,7 @@ static int default_zonelist_order(void)
          * ZONE_DMA and ZONE_DMA32 can be very small area in the system.
 	 * If they are really small and used heavily, the system can fall
 	 * into OOM very easily.
-	 * This function detect ZONE_DMA/DMA32 size and confgigures zone order.
+	 * This function detect ZONE_DMA/DMA32 size and configures zone order.
 	 */
 	/* Is there ZONE_NORMAL ? (ex. ppc has only DMA zone..) */
 	low_kmem_size = 0;
@@ -2594,6 +2618,15 @@ static int default_zonelist_order(void)
 				if (zone_type < ZONE_NORMAL)
 					low_kmem_size += z->present_pages;
 				total_size += z->present_pages;
+			} else if (zone_type == ZONE_NORMAL) {
+				/*
+				 * If any node has only lowmem, then node order
+				 * is preferred to allow kernel allocations
+				 * locally; otherwise, they can easily infringe
+				 * on other nodes when there is an abundance of
+				 * lowmem available to allocate from.
+				 */
+				return ZONELIST_ORDER_NODE;
 			}
 		}
 	}