--- old/src/share/vm/gc/parallel/vmStructs_parallelgc.hpp	2016-04-06 17:17:31.474383751 +0200
+++ new/src/share/vm/gc/parallel/vmStructs_parallelgc.hpp	2016-04-06 17:17:31.370383749 +0200
@@ -26,7 +26,8 @@
 #define SHARE_VM_GC_PARALLEL_VMSTRUCTS_PARALLELGC_HPP
 
 #define VM_STRUCTS_PARALLELGC(nonstatic_field, \
-                   static_field) \
+                              volatile_nonstatic_field, \
+                              static_field) \
                                                                                                                                      \
   /**********************/                                                                                                           \
   /* Parallel GC fields */                                                                                                           \
@@ -40,7 +41,7 @@
   nonstatic_field(ImmutableSpace,              _bottom,                                       HeapWord*)                             \
   nonstatic_field(ImmutableSpace,              _end,                                          HeapWord*)                             \
                                                                                                                                      \
-  nonstatic_field(MutableSpace,                _top,                                          HeapWord*)                             \
+  volatile_nonstatic_field(MutableSpace,       _top,                                          HeapWord*)                             \
                                                                                                                                      \
   nonstatic_field(PSYoungGen,                  _reserved,                                     MemRegion)                             \
   nonstatic_field(PSYoungGen,                  _virtual_space,                                PSVirtualSpace*)                       \