3 files changed, 29 insertions, 7 deletions

diff --git a/mm/compaction.c b/mm/compaction.c
index 8c0d9459b54a..a18201a8124e 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1174,13 +1174,24 @@ static int __compact_finished(struct zone *zone, struct compact_control *cc,
         /* Direct compactor: Is a suitable page free? */
         for (order = cc->order; order < MAX_ORDER; order++) {
                 struct free_area *area = &zone->free_area[order];
+                bool can_steal;
 
                 /* Job done if page is free of the right migratetype */
                 if (!list_empty(&area->free_list[migratetype]))
                         return COMPACT_PARTIAL;
 
-                /* Job done if allocation would set block type */
-                if (order >= pageblock_order && area->nr_free)
+#ifdef CONFIG_CMA
+                /* MIGRATE_MOVABLE can fallback on MIGRATE_CMA */
+                if (migratetype == MIGRATE_MOVABLE &&
+                        !list_empty(&area->free_list[MIGRATE_CMA]))
+                        return COMPACT_PARTIAL;
+#endif
+                /*
+                 * Job done if allocation would steal freepages from
+                 * other migratetype buddy lists.
+                 */
+                if (find_suitable_fallback(area, order, migratetype,
+                                                true, &can_steal) != -1)
                         return COMPACT_PARTIAL;
         }
 
diff --git a/mm/internal.h b/mm/internal.h
index 7df78a5269f3..edaab69a9c35 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -200,6 +200,8 @@ isolate_freepages_range(struct compact_control *cc,
 unsigned long
 isolate_migratepages_range(struct compact_control *cc,
                            unsigned long low_pfn, unsigned long end_pfn);
+int find_suitable_fallback(struct free_area *area, unsigned int order,
+                        int migratetype, bool only_stealable, bool *can_steal);
 
 #endif
 
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 31aa943365d8..6dfa5b24cc79 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1194,9 +1194,14 @@ static void steal_suitable_fallback(struct zone *zone, struct page *page,
                 set_pageblock_migratetype(page, start_type);
 }
 
-/* Check whether there is a suitable fallback freepage with requested order. */
-static int find_suitable_fallback(struct free_area *area, unsigned int order,
-                                        int migratetype, bool *can_steal)
+/*
+ * Check whether there is a suitable fallback freepage with requested order.
+ * If only_stealable is true, this function returns fallback_mt only if
+ * we can steal other freepages all together. This would help to reduce
+ * fragmentation due to mixed migratetype pages in one pageblock.
+ */
+int find_suitable_fallback(struct free_area *area, unsigned int order,
+                        int migratetype, bool only_stealable, bool *can_steal)
 {
         int i;
         int fallback_mt;
@@ -1216,7 +1221,11 @@ static int find_suitable_fallback(struct free_area *area, unsigned int order,
                 if (can_steal_fallback(order, migratetype))
                         *can_steal = true;
 
-                return fallback_mt;
+                if (!only_stealable)
+                        return fallback_mt;
+
+                if (*can_steal)
+                        return fallback_mt;
         }
 
         return -1;
@@ -1238,7 +1247,7 @@ __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype)
                                 --current_order) {
                 area = &(zone->free_area[current_order]);
                 fallback_mt = find_suitable_fallback(area, current_order,
-                                start_migratetype, &can_steal);
+                                start_migratetype, false, &can_steal);
                 if (fallback_mt == -1)
                         continue;