--- a/contrib/perf.py	Thu Jan 08 00:01:03 2015 +0100
+++ b/contrib/perf.py	Sat Jan 10 21:13:10 2015 -0600
@@ -14,6 +14,10 @@
 
     This functions exist to gather the creation of formatter in a single
     place instead of duplicating it in all performance command."""
+
+    # enforce an idle period before execution to counteract power management
+    time.sleep(ui.configint("perf", "presleep", 1))
+
     if opts is None:
         opts = {}
     # redirect all to stderr