diff --git a/mm/internal.h b/mm/internal.h
index 45f7c449ef7d..acf0161ca6a0 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -101,6 +101,31 @@ extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
 /*
  * in mm/page_alloc.c
  */
+
+/*
+ * Locate the struct page for both the matching buddy in our
+ * pair (buddy1) and the combined O(n+1) page they form (page).
+ *
+ * 1) Any buddy B1 will have an order O twin B2 which satisfies
+ * the following equation:
+ *     B2 = B1 ^ (1 << O)
+ * For example, if the starting buddy (buddy2) is #8 its order
+ * 1 buddy is #10:
+ *     B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
+ *
+ * 2) Any buddy B will have an order O+1 parent P which
+ * satisfies the following equation:
+ *     P = B & ~(1 << O)
+ *
+ * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
+ */
+static inline unsigned long
+__find_buddy_index(unsigned long page_idx, unsigned int order)
+{
+	return page_idx ^ (1 << order);
+}
+
+extern int __isolate_free_page(struct page *page, unsigned int order);
 extern void __free_pages_bootmem(struct page *page, unsigned int order);
 extern void prep_compound_page(struct page *page, unsigned long order);
 #ifdef CONFIG_MEMORY_FAILURE
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3ce422cfc015..348b3dc8f5db 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -478,29 +478,6 @@ static inline void rmv_page_order(struct page *page)
 	set_page_private(page, 0);
 }
 
-/*
- * Locate the struct page for both the matching buddy in our
- * pair (buddy1) and the combined O(n+1) page they form (page).
- *
- * 1) Any buddy B1 will have an order O twin B2 which satisfies
- * the following equation:
- *     B2 = B1 ^ (1 << O)
- * For example, if the starting buddy (buddy2) is #8 its order
- * 1 buddy is #10:
- *     B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
- *
- * 2) Any buddy B will have an order O+1 parent P which
- * satisfies the following equation:
- *     P = B & ~(1 << O)
- *
- * Assumption: *_mem_map is contiguous at least up to MAX_ORDER
- */
-static inline unsigned long
-__find_buddy_index(unsigned long page_idx, unsigned int order)
-{
-	return page_idx ^ (1 << order);
-}
-
 /*
  * This function checks whether a page is free && is the buddy
  * we can do coalesce a page and its buddy if
@@ -567,6 +544,7 @@ static inline void __free_one_page(struct page *page,
 	unsigned long combined_idx;
 	unsigned long uninitialized_var(buddy_idx);
 	struct page *buddy = NULL;
+	int max_order = MAX_ORDER;
 
 	VM_BUG_ON(!zone_is_initialized(zone));
 
@@ -575,15 +553,24 @@ static inline void __free_one_page(struct page *page,
 			return;
 
 	VM_BUG_ON(migratetype == -1);
-	if (!is_migrate_isolate(migratetype))
+	if (is_migrate_isolate(migratetype)) {
+		/*
+		 * We restrict max order of merging to prevent merge
+		 * between freepages on isolate pageblock and normal
+		 * pageblock. Without this, pageblock isolation
+		 * could cause incorrect freepage accounting.
+		 */
+		max_order = min(MAX_ORDER, pageblock_order + 1);
+	} else {
 		__mod_zone_freepage_state(zone, 1 << order, migratetype);
+	}
 
-	page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
+	page_idx = page_to_pfn(page) & ((1 << max_order) - 1);
 
 	VM_BUG_ON(page_idx & ((1 << order) - 1));
 	VM_BUG_ON(bad_range(zone, page));
 
-	while (order < MAX_ORDER-1) {
+	while (order < max_order - 1) {
 		buddy_idx = __find_buddy_index(page_idx, order);
 		buddy = page + (buddy_idx - page_idx);
 		if (!page_is_buddy(page, buddy, order))
@@ -1481,7 +1468,7 @@ void split_page(struct page *page, unsigned int order)
 }
 EXPORT_SYMBOL_GPL(split_page);
 
-static int __isolate_free_page(struct page *page, unsigned int order)
+int __isolate_free_page(struct page *page, unsigned int order)
 {
 	unsigned long watermark;
 	struct zone *zone;
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index b24a95dd77c9..f49a7a7433d4 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -75,17 +75,54 @@ void unset_migratetype_isolate(struct page *page, unsigned migratetype)
 {
 	struct zone *zone;
 	unsigned long flags, nr_pages;
+	struct page *isolated_page = NULL;
+	unsigned int order;
+	unsigned long page_idx, buddy_idx;
+	struct page *buddy;
 
 	zone = page_zone(page);
 	spin_lock_irqsave(&zone->lock, flags);
 	if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
 		goto out;
-	nr_pages = move_freepages_block(zone, page, migratetype);
-	__mod_zone_freepage_state(zone, nr_pages, migratetype);
+
+	/*
+	 * Because freepage with more than pageblock_order on isolated
+	 * pageblock is restricted to merge due to freepage counting problem,
+	 * it is possible that there is free buddy page.
+	 * move_freepages_block() doesn't care of merge so we need other
+	 * approach in order to merge them. Isolation and free will make
+	 * these pages to be merged.
+	 */
+	if (PageBuddy(page)) {
+		order = page_order(page);
+		if (order >= pageblock_order) {
+			page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1);
+			buddy_idx = __find_buddy_index(page_idx, order);
+			buddy = page + (buddy_idx - page_idx);
+
+			if (!is_migrate_isolate_page(buddy)) {
+				__isolate_free_page(page, order);
+				set_page_refcounted(page);
+				isolated_page = page;
+			}
+		}
+	}
+
+	/*
+	 * If we isolate freepage with more than pageblock_order, there
+	 * should be no freepage in the range, so we could avoid costly
+	 * pageblock scanning for freepage moving.
+	 */
+	if (!isolated_page) {
+		nr_pages = move_freepages_block(zone, page, migratetype);
+		__mod_zone_freepage_state(zone, nr_pages, migratetype);
+	}
 	set_pageblock_migratetype(page, migratetype);
 	zone->nr_isolate_pageblock--;
 out:
 	spin_unlock_irqrestore(&zone->lock, flags);
+	if (isolated_page)
+		__free_pages(isolated_page, order);
 }
 
 static inline struct page *