--- a/contrib/perf.py	Wed Apr 26 21:56:47 2017 +0900
+++ b/contrib/perf.py	Wed Apr 26 22:03:37 2017 +0900
@@ -26,7 +26,6 @@
 import sys
 import time
 from mercurial import (
-    bdiff,
     changegroup,
     cmdutil,
     commands,
@@ -812,7 +811,7 @@
 
     def d():
         for pair in textpairs:
-            bdiff.bdiff(*pair)
+            mdiff.textdiff(*pair)
 
     timer, fm = gettimer(ui, opts)
     timer(d)