[PATCH] perf: document the perfmanifest command

[Boris Feld]

# HG changeset patch
# User Boris Feld <boris.feld at octobus.net>
# Date 1531298775 -7200
#      Wed Jul 11 10:46:15 2018 +0200
# Node ID 24d42facbae0722990b7088d25e21dbe4cba4b92
# Parent  3700564c63fee7b26ca948e75dee2ea631b1dd4e
# EXP-Topic doc-perf
# Available At https://bitbucket.org/octobus/mercurial-devel/
#              hg pull https://bitbucket.org/octobus/mercurial-devel/ -r 24d42facbae0
perf: document the perfmanifest command

diff --git a/contrib/perf.py b/contrib/perf.py
--- a/contrib/perf.py
+++ b/contrib/perf.py
@@ -774,6 +774,10 @@ def perfphases(ui, repo, **opts):
 
 @command('perfmanifest', [], 'REV')
 def perfmanifest(ui, repo, rev, **opts):
+    """benchmark the time to read a manifest from disk and return a usable
+    dict-like object
+
+    Manifest caches are cleared before retrieval."""
     timer, fm = gettimer(ui, opts)
     ctx = scmutil.revsingle(repo, rev, rev)
     t = ctx.manifestnode()
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
@@ -88,7 +88,8 @@ perfstatus
    perflookup    (no help text available)
    perflrucachedict
                  (no help text available)
-   perfmanifest  (no help text available)
+   perfmanifest  benchmark the time to read a manifest from disk and return a
+                 usable
    perfmergecalculate
                  (no help text available)
    perfmoonwalk  benchmark walking the changelog backwards