--- a/mercurial/debugcommands.py	Tue May 02 19:05:58 2017 +0200
+++ b/mercurial/debugcommands.py	Tue May 02 21:35:06 2017 +0200
@@ -2130,6 +2130,13 @@
             displayer.show(repo[r], **props)
         displayer.close()
 
+@command('debugupdatecaches', [])
+def debugupdatecaches(ui, repo, *pats, **opts):
+    """warm all known caches in the repository"""
+    with repo.wlock():
+        with repo.lock():
+            repo.updatecaches()
+
 @command('debugupgraderepo', [
     ('o', 'optimize', [], _('extra optimization to perform'), _('NAME')),
     ('', 'run', False, _('performs an upgrade')),

--- a/tests/test-completion.t	Tue May 02 19:05:58 2017 +0200
+++ b/tests/test-completion.t	Tue May 02 21:35:06 2017 +0200
@@ -111,6 +111,7 @@
   debugsub
   debugsuccessorssets
   debugtemplate
+  debugupdatecaches
   debugupgraderepo
   debugwalk
   debugwireargs
@@ -285,6 +286,7 @@
   debugsub: rev
   debugsuccessorssets: 
   debugtemplate: rev, define
+  debugupdatecaches: 
   debugupgraderepo: optimize, run
   debugwalk: include, exclude
   debugwireargs: three, four, five, ssh, remotecmd, insecure

--- a/tests/test-debugcommands.t	Tue May 02 19:05:58 2017 +0200
+++ b/tests/test-debugcommands.t	Tue May 02 21:35:06 2017 +0200
@@ -109,6 +109,16 @@
       6     5    -1   ???   ???        ???  ???  ???    0     ???      ????           ?     1        1 (glob)
       7     6    -1   ???   ???        ???  ???  ???    0     ???      ????           ?     1        2 (glob)
       8     7    -1   ???   ???        ???  ???  ???    0     ???      ????           ?     1        3 (glob)
+
+Test cache warming command
+
+  $ rm -rf .hg/cache/
+  $ hg debugupdatecaches --debug
+  $ ls -r .hg/cache/*
+  .hg/cache/rbc-revs-v1
+  .hg/cache/rbc-names-v1
+  .hg/cache/branch2-served
+
   $ cd ..
 
 Test internal debugstacktrace command

--- a/tests/test-help.t	Tue May 02 19:05:58 2017 +0200
+++ b/tests/test-help.t	Tue May 02 21:35:06 2017 +0200
@@ -931,6 +931,8 @@
                  show set of successors for revision
    debugtemplate
                  parse and apply a template
+   debugupdatecaches
+                 warm all known caches in the repository
    debugupgraderepo
                  upgrade a repository to use different features
    debugwalk     show how files match on given patterns