1 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index d71ff763c9df..da8eb8ad9e9b 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -24,6 +24,14 @@
 #endif
 #define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1))
 
+/*
+ * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed
+ * costly to service.  That is between allocation orders which should
+ * coelesce naturally under reasonable reclaim pressure and those which
+ * will not.
+ */
+#define PAGE_ALLOC_COSTLY_ORDER 3
+
 struct free_area {
         struct list_head        free_list;
         unsigned long           nr_free;