diff -r 5eb48e9d607a -r 625a5bdde0c5 src/hotspot/share/memory/metaspaceShared.cpp
--- a/src/hotspot/share/memory/metaspaceShared.cpp	Fri Aug 31 12:41:00 2018 +0200
+++ b/src/hotspot/share/memory/metaspaceShared.cpp	Fri Aug 31 07:03:46 2018 -0400
@@ -1619,7 +1619,7 @@
   LinkSharedClassesClosure link_closure(THREAD);
   do {
     link_closure.reset();
-    ClassLoaderDataGraph::loaded_classes_do(&link_closure);
+    ClassLoaderDataGraph::unlocked_loaded_classes_do(&link_closure);
     guarantee(!HAS_PENDING_EXCEPTION, "exception in link_class");
   } while (link_closure.made_progress());
 
@@ -1631,7 +1631,7 @@
       // we should come here only if there are unverifiable classes, which
       // shouldn't happen in normal cases. So better safe than sorry.
       check_closure.reset();
-      ClassLoaderDataGraph::loaded_classes_do(&check_closure);
+      ClassLoaderDataGraph::unlocked_loaded_classes_do(&check_closure);
     } while (check_closure.made_progress());
 
     if (IgnoreUnverifiableClassesDuringDump) {