diff --git a/contrib/perf.py b/contrib/perf.py
--- a/contrib/perf.py
+++ b/contrib/perf.py
@@ -1124,6 +1124,8 @@ def perfdirstate(ui, repo, **opts):
 
 @command(b'perfdirstatedirs', formatteropts)
 def perfdirstatedirs(ui, repo, **opts):
+    """benchmap a 'dirstate.hasdir' call from an empty `dirs` cache
+    """
     opts = _byteskwargs(opts)
     timer, fm = gettimer(ui, opts)
     b"a" in repo.dirstate
diff --git a/tests/test-contrib-perf.t b/tests/test-contrib-perf.t
--- a/tests/test-contrib-perf.t
+++ b/tests/test-contrib-perf.t
@@ -109,7 +109,7 @@ perfstatus
    perfdirs      (no help text available)
    perfdirstate  benchmap the time necessary to load a dirstate from scratch
    perfdirstatedirs
-                 (no help text available)
+                 benchmap a 'dirstate.hasdir' call from an empty 'dirs' cache
    perfdirstatefoldmap
                  (no help text available)
    perfdirstatewrite