diff -r 1174c8abbdb6 -r 3205e78d8193 src/share/vm/oops/instanceKlass.cpp --- a/src/share/vm/oops/instanceKlass.cpp Thu Dec 05 15:13:12 2013 -0800 +++ b/src/share/vm/oops/instanceKlass.cpp Mon Dec 02 10:26:14 2013 +0100 @@ -1203,7 +1203,11 @@ MutexLocker x(OopMapCacheAlloc_lock); // First time use. Allocate a cache in C heap if (_oop_map_cache == NULL) { - _oop_map_cache = new OopMapCache(); + // Release stores from OopMapCache constructor before assignment + // to _oop_map_cache. C++ compilers on ppc do not emit the + // required memory barrier only because of the volatile + // qualifier of _oop_map_cache. + OrderAccess::release_store_ptr(&_oop_map_cache, new OopMapCache()); } } // _oop_map_cache is constant after init; lookup below does is own locking.