1 files changed, 38 insertions, 5 deletions

diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 247d1f175739..f2f5b4818e94 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -76,8 +76,13 @@ int set_migratetype_isolate(struct page *page)
 
 out:
         if (!ret) {
+                unsigned long nr_pages;
+                int migratetype = get_pageblock_migratetype(page);
+
                 set_pageblock_isolate(page);
-                move_freepages_block(zone, page, MIGRATE_ISOLATE);
+                nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE);
+
+                __mod_zone_freepage_state(zone, -nr_pages, migratetype);
         }
 
         spin_unlock_irqrestore(&zone->lock, flags);
@@ -89,12 +94,14 @@ out:
 void unset_migratetype_isolate(struct page *page, unsigned migratetype)
 {
         struct zone *zone;
-        unsigned long flags;
+        unsigned long flags, nr_pages;
+
         zone = page_zone(page);
         spin_lock_irqsave(&zone->lock, flags);
         if (get_pageblock_migratetype(page) != MIGRATE_ISOLATE)
                 goto out;
-        move_freepages_block(zone, page, migratetype);
+        nr_pages = move_freepages_block(zone, page, migratetype);
+        __mod_zone_freepage_state(zone, nr_pages, migratetype);
         restore_pageblock_isolate(page, migratetype);
 out:
         spin_unlock_irqrestore(&zone->lock, flags);
@@ -193,10 +200,25 @@ __test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn)
                         continue;
                 }
                 page = pfn_to_page(pfn);
-                if (PageBuddy(page))
+                if (PageBuddy(page)) {
+                        /*
+                         * If race between isolatation and allocation happens,
+                         * some free pages could be in MIGRATE_MOVABLE list
+                         * although pageblock's migratation type of the page
+                         * is MIGRATE_ISOLATE. Catch it and move the page into
+                         * MIGRATE_ISOLATE list.
+                         */
+                        if (get_freepage_migratetype(page) != MIGRATE_ISOLATE) {
+                                struct page *end_page;
+
+                                end_page = page + (1 << page_order(page)) - 1;
+                                move_freepages(page_zone(page), page, end_page,
+                                                MIGRATE_ISOLATE);
+                        }
                         pfn += 1 << page_order(page);
+                }
                 else if (page_count(page) == 0 &&
-                                page_private(page) == MIGRATE_ISOLATE)
+                        get_freepage_migratetype(page) == MIGRATE_ISOLATE)
                         pfn += 1;
                 else
                         break;
@@ -233,3 +255,14 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
         spin_unlock_irqrestore(&zone->lock, flags);
         return ret ? 0 : -EBUSY;
 }
+
+struct page *alloc_migrate_target(struct page *page, unsigned long private,
+                                  int **resultp)
+{
+        gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE;
+
+        if (PageHighMem(page))
+                gfp_mask |= __GFP_HIGHMEM;
+
+        return alloc_page(gfp_mask);
+}