2 files changed, 17 insertions, 0 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 48bf12ef6620..ffe66e381c04 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -431,6 +431,15 @@ struct zone {
          */
         int                     nr_migrate_reserve_block;
 
+#ifdef CONFIG_MEMORY_ISOLATION
+        /*
+         * Number of isolated pageblock. It is used to solve incorrect
+         * freepage counting problem due to racy retrieving migratetype
+         * of pageblock. Protected by zone->lock.
+         */
+        unsigned long           nr_isolate_pageblock;
+#endif
+
 #ifdef CONFIG_MEMORY_HOTPLUG
         /* see spanned/present_pages for more description */
         seqlock_t               span_seqlock;
diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h
index 3fff8e774067..2dc1e1697b45 100644
--- a/include/linux/page-isolation.h
+++ b/include/linux/page-isolation.h
@@ -2,6 +2,10 @@
 #define __LINUX_PAGEISOLATION_H
 
 #ifdef CONFIG_MEMORY_ISOLATION
+static inline bool has_isolate_pageblock(struct zone *zone)
+{
+        return zone->nr_isolate_pageblock;
+}
 static inline bool is_migrate_isolate_page(struct page *page)
 {
         return get_pageblock_migratetype(page) == MIGRATE_ISOLATE;
@@ -11,6 +15,10 @@ static inline bool is_migrate_isolate(int migratetype)
         return migratetype == MIGRATE_ISOLATE;
 }
 #else
+static inline bool has_isolate_pageblock(struct zone *zone)
+{
+        return false;
+}
 static inline bool is_migrate_isolate_page(struct page *page)
 {
         return false;