diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index 3d385c8..2696c1f 100644
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -122,7 +122,7 @@
 
 struct shared_policy {
 	struct rb_root root;
-	spinlock_t lock;
+	rwlock_t lock;
 };
 
 int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst);