# HG changeset patch
# User Pierre-Yves David <pierre-yves.david@octobus.net>
# Date 1553528462 25200
# Node ID b900b392c1cc05bacbb41d0047b20abb8544c6e7
# Parent  dbca2e5563c39acd130afd64ac47ddb8e77c38aa
perf: document perfparents

diff -r dbca2e5563c3 -r b900b392c1cc contrib/perf.py
--- a/contrib/perf.py	Mon Mar 25 13:43:40 2019 +0100
+++ b/contrib/perf.py	Mon Mar 25 08:41:02 2019 -0700
@@ -1164,6 +1164,13 @@
 
 @command(b'perfparents', formatteropts)
 def perfparents(ui, repo, **opts):
+    """benchmark the time necessary to fetch one changeset's parents.
+
+    The fetch is done using the `node identifier`, traversing all object layer
+    from the repository object. The N first revision will be used for this
+    benchmark. N is controlled by the ``perf.parentscount`` config option
+    (default: 1000).
+    """
     opts = _byteskwargs(opts)
     timer, fm = gettimer(ui, opts)
     # control the number of commits perfparents iterates over
diff -r dbca2e5563c3 -r b900b392c1cc tests/test-contrib-perf.t
--- a/tests/test-contrib-perf.t	Mon Mar 25 13:43:40 2019 +0100
+++ b/tests/test-contrib-perf.t	Mon Mar 25 08:41:02 2019 -0700
@@ -129,7 +129,7 @@
                  (no help text available)
    perfnodemap   benchmark the time necessary to look up revision from a cold
                  nodemap
-   perfparents   (no help text available)
+   perfparents   benchmark the time necessary to fetch one changeset's parents.
    perfpathcopies
                  benchmark the copy tracing logic
    perfphases    benchmark phasesets computation