rbtree_test: add extra rbtree integrity check

Account for the rbtree having  2**bh(v)-1 internal nodes.

While this can be seen as a consequence of other checks, Michel states
that it nicely sums up what the other properties are for.

Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Reviewed-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/lib/rbtree_test.c b/lib/rbtree_test.c
index af38aedbd874..99515038ff6d 100644
--- a/lib/rbtree_test.c
+++ b/lib/rbtree_test.c
@@ -117,8 +117,7 @@ static int black_path_count(struct rb_node *rb)
 static void check(int nr_nodes)
 {
         struct rb_node *rb;
-        int count = 0;
-        int blacks = 0;
+        int count = 0, blacks = 0;
         u32 prev_key = 0;
 
         for (rb = rb_first(&root); rb; rb = rb_next(rb)) {
@@ -134,7 +133,9 @@ static void check(int nr_nodes)
                 prev_key = node->key;
                 count++;
         }
+
         WARN_ON_ONCE(count != nr_nodes);
+        WARN_ON_ONCE(count < (1 << black_path_count(rb_last(&root))) - 1);
 }
 
 static void check_augmented(int nr_nodes)