diff -r dd50a370c8cb -r 5dcbd2045dcb mercurial/configitems.py
--- a/mercurial/configitems.py	Fri Jun 30 03:43:35 2017 +0200
+++ b/mercurial/configitems.py	Fri Jun 30 03:45:58 2017 +0200
@@ -155,3 +155,6 @@
 coreconfigitem('ui', 'quiet',
     default=False,
 )
+coreconfigitem('worker', 'backgroundclosemaxqueue',
+    default=384,
+)