In CompactibleFreeListSpace::refillLinearAllocBlockIfNeeded() we have this code:

  if (PrintMiscellaneous && Verbose) {
    if (blk->_word_size == 0) {
      warning("CompactibleFreeListSpace(prologue):: Linear allocation failure");
    }

It is a bit strange to guard a warning() this way. Verbose is a develop flag so the warning is never printed in product builds. This is also the only use of PrintMiscellaneous in the GC code.

Another strange thing about this logging is that is says "(prologue)" but refillLinearAllocBlockIfNeeded() is called from three places:

CompactibleFreeListSpace::gc_prologue()
CompactibleFreeListSpace::reset_after_compaction()
CompactibleFreeListSpace::sweep_completed()