1 files changed, 13 insertions, 7 deletions

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index dfa718ffdd4f..4e7809408073 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -53,15 +53,21 @@ struct vmap_area {
         unsigned long va_start;
         unsigned long va_end;
 
-        /*
-         * Largest available free size in subtree.
-         */
-        unsigned long subtree_max_size;
-        unsigned long flags;
         struct rb_node rb_node;         /* address sorted rbtree */
         struct list_head list;          /* address sorted list */
-        struct llist_node purge_list;    /* "lazy purge" list */
-        struct vm_struct *vm;
+
+        /*
+         * The following three variables can be packed, because
+         * a vmap_area object is always one of the three states:
+         *    1) in "free" tree (root is vmap_area_root)
+         *    2) in "busy" tree (root is free_vmap_area_root)
+         *    3) in purge list  (head is vmap_purge_list)
+         */
+        union {
+                unsigned long subtree_max_size; /* in "free" tree */
+                struct vm_struct *vm;           /* in "busy" tree */
+                struct llist_node purge_list;   /* in purge list */
+        };
 };
 
 /*