3 files changed, 10 insertions, 34 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 09b2c4f50e38..fef08c6cf75e 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -36,9 +36,8 @@
 #define MIGRATE_UNMOVABLE     0
 #define MIGRATE_RECLAIMABLE   1
 #define MIGRATE_MOVABLE       2
-#define MIGRATE_HIGHATOMIC    3
-#define MIGRATE_RESERVE       4
-#define MIGRATE_TYPES         5
+#define MIGRATE_RESERVE       3
+#define MIGRATE_TYPES         4
 
 #define for_each_migratetype_order(order, type) \
         for (order = 0; order < MAX_ORDER; order++) \
diff --git a/include/linux/pageblock-flags.h b/include/linux/pageblock-flags.h
index fa3b1001894b..5456da6b4ade 100644
--- a/include/linux/pageblock-flags.h
+++ b/include/linux/pageblock-flags.h
@@ -31,7 +31,7 @@
 
 /* Bit indices that affect a whole block of pages */
 enum pageblock_bits {
-        PB_range(PB_migrate, 3), /* 3 bits required for migrate types */
+        PB_range(PB_migrate, 2), /* 2 bits required for migrate types */
         NR_PAGEBLOCK_BITS
 };
 
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8aec4d4601e7..ac8fc51825bb 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -174,18 +174,13 @@ static void set_pageblock_migratetype(struct page *page, int migratetype)
                                         PB_migrate, PB_migrate_end);
 }
 
-static inline int allocflags_to_migratetype(gfp_t gfp_flags, int order)
+static inline int allocflags_to_migratetype(gfp_t gfp_flags)
 {
         WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK);
 
         if (unlikely(page_group_by_mobility_disabled))
                 return MIGRATE_UNMOVABLE;
 
-        /* Cluster high-order atomic allocations together */
-        if (unlikely(order > 0) &&
-                        (!(gfp_flags & __GFP_WAIT) || in_interrupt()))
-                return MIGRATE_HIGHATOMIC;
-
         /* Cluster based on mobility */
         return (((gfp_flags & __GFP_MOVABLE) != 0) << 1) |
                 ((gfp_flags & __GFP_RECLAIMABLE) != 0);
@@ -706,11 +701,10 @@ static struct page *__rmqueue_smallest(struct zone *zone, unsigned int order,
  * the free lists for the desirable migrate type are depleted
  */
 static int fallbacks[MIGRATE_TYPES][MIGRATE_TYPES-1] = {
-        [MIGRATE_UNMOVABLE]   = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE,   MIGRATE_HIGHATOMIC, MIGRATE_RESERVE },
-        [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE,   MIGRATE_MOVABLE,   MIGRATE_HIGHATOMIC, MIGRATE_RESERVE },
-        [MIGRATE_MOVABLE]     = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_HIGHATOMIC, MIGRATE_RESERVE },
-        [MIGRATE_HIGHATOMIC]  = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_MOVABLE,    MIGRATE_RESERVE },
-        [MIGRATE_RESERVE]     = { MIGRATE_RESERVE,     MIGRATE_RESERVE,   MIGRATE_RESERVE,    MIGRATE_RESERVE }, /* Never used */
+        [MIGRATE_UNMOVABLE]   = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE,   MIGRATE_RESERVE },
+        [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE,   MIGRATE_MOVABLE,   MIGRATE_RESERVE },
+        [MIGRATE_MOVABLE]     = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE },
+        [MIGRATE_RESERVE]     = { MIGRATE_RESERVE,     MIGRATE_RESERVE,   MIGRATE_RESERVE }, /* Never used */
 };
 
 /*
@@ -804,9 +798,7 @@ static struct page *__rmqueue_fallback(struct zone *zone, int order,
         int current_order;
         struct page *page;
         int migratetype, i;
-        int nonatomic_fallback_atomic = 0;
 
-retry:
         /* Find the largest possible block of pages in the other list */
         for (current_order = MAX_ORDER-1; current_order >= order;
                                                 --current_order) {
@@ -816,14 +808,6 @@ retry:
                         /* MIGRATE_RESERVE handled later if necessary */
                         if (migratetype == MIGRATE_RESERVE)
                                 continue;
-                        /*
-                         * Make it hard to fallback to blocks used for
-                         * high-order atomic allocations
-                         */
-                        if (migratetype == MIGRATE_HIGHATOMIC &&
-                                start_migratetype != MIGRATE_UNMOVABLE &&
-                                !nonatomic_fallback_atomic)
-                                continue;
 
                         area = &(zone->free_area[current_order]);
                         if (list_empty(&area->free_list[migratetype]))
@@ -849,8 +833,7 @@ retry:
                                                                 start_migratetype);
 
                                 /* Claim the whole block if over half of it is free */
-                                if ((pages << current_order) >= (1 << (MAX_ORDER-2)) &&
-                                                migratetype != MIGRATE_HIGHATOMIC)
+                                if ((pages << current_order) >= (1 << (MAX_ORDER-2)))
                                         set_pageblock_migratetype(page,
                                                                 start_migratetype);
 
@@ -872,12 +855,6 @@ retry:
                 }
         }
 
-        /* Allow fallback to high-order atomic blocks if memory is that low */
-        if (!nonatomic_fallback_atomic) {
-                nonatomic_fallback_atomic = 1;
-                goto retry;
-        }
-
         /* Use MIGRATE_RESERVE rather than fail an allocation */
         return __rmqueue_smallest(zone, order, MIGRATE_RESERVE);
 }
@@ -1112,7 +1089,7 @@ static struct page *buffered_rmqueue(struct zonelist *zonelist,
         struct page *page;
         int cold = !!(gfp_flags & __GFP_COLD);
         int cpu;
-        int migratetype = allocflags_to_migratetype(gfp_flags, order);
+        int migratetype = allocflags_to_migratetype(gfp_flags);
 
 again:
         cpu  = get_cpu();