--- old/src/share/vm/gc/g1/g1MarkSweep.cpp	2015-06-06 02:21:44.000000000 +0200
+++ new/src/share/vm/gc/g1/g1MarkSweep.cpp	2015-06-06 02:21:44.000000000 +0200
@@ -151,14 +151,16 @@
   // This is the point where the entire marking should have completed.
   assert(GenMarkSweep::_marking_stack.is_empty(), "Marking should have completed");
 
-  // Unload classes and purge the SystemDictionary.
-  bool purged_class = SystemDictionary::do_unloading(&GenMarkSweep::is_alive);
+  if (ClassUnloading) {
+    // Unload classes and purge the SystemDictionary.
+    bool purged_class = SystemDictionary::do_unloading(&GenMarkSweep::is_alive);
 
-  // Unload nmethods.
-  CodeCache::do_unloading(&GenMarkSweep::is_alive, purged_class);
+    // Unload nmethods.
+    CodeCache::do_unloading(&GenMarkSweep::is_alive, purged_class);
 
-  // Prune dead klasses from subklass/sibling/implementor lists.
-  Klass::clean_weak_klass_links(&GenMarkSweep::is_alive);
+    // Prune dead klasses from subklass/sibling/implementor lists.
+    Klass::clean_weak_klass_links(&GenMarkSweep::is_alive);
+  }
 
   // Delete entries for dead interned string and clean up unreferenced symbols in symbol table.
   g1h->unlink_string_and_symbol_table(&GenMarkSweep::is_alive);