--- a/bench.py	Thu May 26 00:09:38 2016 +0800
+++ b/bench.py	Mon Jul 04 17:52:42 2016 +0800
@@ -4,10 +4,10 @@
 import os
 import shutil
 import sqlite3
-import subprocess
 import time
 from argparse import ArgumentParser
 from collections import OrderedDict
+from subprocess import check_output, CalledProcessError, STDOUT
 
 from settings import DBPATH, HG, LOCKFILE, TESTHGREPO, TESTREPO, rel
 
@@ -71,8 +71,8 @@
             shutil.rmtree(rel(TESTREPO, '.hg', 'cache'), ignore_errors=True)
         start = time.time()
         try:
-            subprocess.check_output(cmd)
-        except subprocess.CalledProcessError:
+            check_output(cmd)
+        except CalledProcessError:
             return None
         results.append(time.time() - start)
 
@@ -83,14 +83,14 @@
     cmd = [HG, 'log', '-R', TESTHGREPO, '-T', '{node}\n']
     for revset in revsets:
         cmd += ['-r', revset]
-    output = subprocess.check_output(cmd)
+    output = check_output(cmd)
     return output.split()
 
 
 def guessnew(maxrevs):
     """ Pick one continuous span of nodes that still need testing. """
     cmd = [HG, 'log', '-R', TESTHGREPO, '-T', '{node}\n', '-r', 'sort(all(), rev)']
-    output = subprocess.check_output(cmd)
+    output = check_output(cmd)
     nodes = output.split()
     picking = False
     todo = []
@@ -109,7 +109,7 @@
 
 def guessspikes(maxrevs):
     cmd = [HG, 'log', '-R', TESTHGREPO, '-T', '{node}\n', '-r', 'sort(all(), -rev)']
-    output = subprocess.check_output(cmd)
+    output = check_output(cmd)
     nodes = output.split()
     todo = []
     conn = sqlite3.connect(DBPATH)
@@ -157,12 +157,12 @@
 
 
 def makeclean():
-    subprocess.check_output(['make', '--directory', TESTHGREPO, 'clean'], stderr=subprocess.STDOUT)
+    check_output(['make', '--directory', TESTHGREPO, 'clean'], stderr=STDOUT)
 
 
 def makelocal(node):
-    subprocess.check_output([HG, 'update', '-R', TESTHGREPO, '--clean', node], stderr=subprocess.STDOUT)
-    subprocess.check_output(['make', '--directory', TESTHGREPO, 'local'], stderr=subprocess.STDOUT)
+    check_output([HG, 'update', '-R', TESTHGREPO, '--clean', node], stderr=STDOUT)
+    check_output(['make', '--directory', TESTHGREPO, 'local'], stderr=STDOUT)
 
 
 def dbinit():