--- a/bench.py	Thu Aug 04 14:16:22 2016 +0800
+++ b/bench.py	Thu Aug 04 14:34:15 2016 +0800
@@ -33,6 +33,7 @@
 group = parser.add_mutually_exclusive_group()
 group.add_argument('revsets', metavar='REVSET', default=('last(all(), 120)',), nargs='*', help='update these revisions')
 group.add_argument('--auto', metavar='MAXREVS', type=int, help='guess revisions, up to MAXREVS')
+parser.add_argument('--marks', metavar='MARKS', default='all', help='test only these commands (comma-separated, default: all)')
 parser.add_argument('--retry', action='store_true', help='try and reduce existing timings')
 
 
@@ -190,17 +191,17 @@
     conn.close()
 
 
-def dbupdate(revsets, retry=False):
+def dbupdate(revsets, marks, retry=False):
     conn = sqlite3.connect(DBPATH)
     makeclean()
     nodes = getnodes(revsets)
     numwidth = len(str(len(nodes)))
-    markwidth = max(len(mark) for mark in MARKS)
+    markwidth = max(len(mark) for mark in marks)
 
     for i, node in enumerate(nodes, 1):
         madelocal = False
 
-        for mark in MARKS:
+        for mark in marks:
             for cache in (False, True):
                 old = conn.execute(
                     'SELECT time FROM results'
@@ -274,7 +275,11 @@
                 args.revsets = guessspikes(args.auto)
             else:
                 args.revsets = guessnew(args.auto)
-        dbupdate(args.revsets, args.retry)
+        if args.marks == 'all':
+            marks = MARKS
+        else:
+            marks = OrderedDict((k, v) for k, v in MARKS.items() if k in args.marks.split(','))
+        dbupdate(args.revsets, marks, args.retry)
     finally:
         unlock()