--- a/mercurial/configitems.py	Tue Oct 02 10:31:36 2018 -0700
+++ b/mercurial/configitems.py	Wed Oct 03 12:54:39 2018 -0700
@@ -604,6 +604,9 @@
 coreconfigitem('experimental', 'revisions.disambiguatewithin',
     default=None,
 )
+coreconfigitem('experimental', 'server.filesdata.recommended-batch-size',
+    default=50000,
+)
 coreconfigitem('experimental', 'server.manifestdata.recommended-batch-size',
     default=100000,
 )