Somehow during the backport of 6631166 from hs17 to hs16 the following code was removed:

------- compactibleFreeListSpace.cpp -------
*** /tmp/sccs.j6a4JL Fri Jun 18 20:18:21 2010
--- compactibleFreeListSpace.cpp Fri Jun 18 20:06:07 2010
***************
*** 556,562 ****
            _smallLinearAllocBlock._ptr = prevEnd;
            _smallLinearAllocBlock._word_size = newFcSize;
            repairLinearAllocBlock(&_smallLinearAllocBlock);
! }
          // Births of chunks put into a LinAB are not recorded. Births
          // of chunks as they are allocated out of a LinAB are.
        } else {
--- 579,591 ----
            _smallLinearAllocBlock._ptr = prevEnd;
            _smallLinearAllocBlock._word_size = newFcSize;
            repairLinearAllocBlock(&_smallLinearAllocBlock);
! } else { // ParallelGCThreads > 0
! MutexLockerEx x(parDictionaryAllocLock(),
! Mutex::_no_safepoint_check_flag);
! _smallLinearAllocBlock._ptr = prevEnd;
! _smallLinearAllocBlock._word_size = newFcSize;
! repairLinearAllocBlock(&_smallLinearAllocBlock);
! }
          // Births of chunks put into a LinAB are not recorded. Births
          // of chunks as they are allocated out of a LinAB are.
        } else {