diff --git a/contrib/perf.py b/contrib/perf.py
--- a/contrib/perf.py
+++ b/contrib/perf.py
@@ -1185,6 +1185,8 @@ def perfdirfoldmap(ui, repo, **opts):
 
 @command(b'perfdirstatewrite', formatteropts)
 def perfdirstatewrite(ui, repo, **opts):
+    """benchmap the time it take to write a dirstate on disk
+    """
     opts = _byteskwargs(opts)
     timer, fm = gettimer(ui, opts)
     ds = 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
@@ -113,7 +113,7 @@ perfstatus
    perfdirstatefoldmap
                  benchmap a 'dirstate._map.filefoldmap.get()' request
    perfdirstatewrite
-                 (no help text available)
+                 benchmap the time it take to write a dirstate on disk
    perfdiscovery
                  benchmark discovery between local repo and the peer at given
                  path