mercurial/configitems.py

--- a/mercurial/configitems.py	Wed Oct 03 13:07:28 2018 -0700
+++ b/mercurial/configitems.py	Mon Oct 08 17:45:51 2018 -0700
@@ -604,6 +604,9 @@
 coreconfigitem('experimental', 'revisions.disambiguatewithin',
     default=None,
 )
+coreconfigitem('experimental', 'server.manifestdata.recommended-batch-size',
+    default=100000,
+)
 coreconfigitem('experimental', 'single-head-per-branch',
     default=False,
 )