new file mode 100644
--- /dev/null
+++ b/contrib/hggitperf.py
@@ -0,0 +1,71 @@
+# hggitperf.py - performance test routines
+'''helper extension to measure performance of hg-git operations
+
+This requires both the hggit and hggitperf extensions to be enabled and
+available.
+'''
+
+from mercurial import cmdutil
+import time, os
+import functools
+
+cmdtable = {}
+command = cmdutil.command(cmdtable)
+
+# the timer functions are copied from mercurial/contrib/perf.py
+def gettimer(ui, opts=None):
+    """return a timer function and formatter: (timer, formatter)
+
+    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
+    ui = ui.copy()
+    ui.fout = ui.ferr
+    # get a formatter
+    fm = ui.formatter('perf', opts)
+    return functools.partial(_timer, fm), fm
+
+def _timer(fm, func, title=None):
+    results = []
+    begin = time.time()
+    count = 0
+    while True:
+        ostart = os.times()
+        cstart = time.time()
+        r = func()
+        cstop = time.time()
+        ostop = os.times()
+        count += 1
+        a, b = ostart, ostop
+        results.append((cstop - cstart, b[0] - a[0], b[1]-a[1]))
+        if cstop - begin > 3 and count >= 100:
+            break
+        if cstop - begin > 10 and count >= 3:
+            break
+
+    fm.startitem()
+
+    if title:
+        fm.write('title', '! %s\n', title)
+    if r:
+        fm.write('result', '! result: %s\n', r)
+    m = min(results)
+    fm.plain('!')
+    fm.write('wall', ' wall %f', m[0])
+    fm.write('comb', ' comb %f', m[1] + m[2])
+    fm.write('user', ' user %f', m[1])
+    fm.write('sys',  ' sys %f', m[2])
+    fm.write('count',  ' (best of %d)', count)
+    fm.plain('\n')
+
+@command('perfgitloadmap')
+def perfgitloadmap(ui, repo):
+    timer, fm = gettimer(ui)
+    timer(repo.githandler.load_map)
+    fm.end()