--- old/src/share/vm/runtime/jniHandles.cpp	2017-07-18 19:33:56.361437107 -0400
+++ new/src/share/vm/runtime/jniHandles.cpp	2017-07-18 19:33:56.233430452 -0400
@@ -444,6 +444,15 @@
       assert(current->_last == NULL, "only first block should have _last set");
       assert(current->_free_list == NULL,
              "only first block should have _free_list set");
+      if (current->_top == 0) {
+        // All blocks after the first clear trailing block are already cleared.
+#ifdef ASSERT
+        for ( ; current != NULL; current = current->_next) {
+          assert(current->_top == 0, "trailing blocks must already be cleared");
+        }
+#endif
+        break;
+      }
       current->_top = 0;
       if (ZapJNIHandleArea) current->zap();
     }