public static int bytesToMmapChunksUp(int bytes) { return (bytes + (LazyMmapper.MMAP_CHUNK_SIZE - 1)) >>> LazyMmapper.LOG_MMAP_CHUNK_SIZE;
public static int bytesToMmapChunksUp(VM_Extent bytes) { return bytes.add(LazyMmapper.MMAP_CHUNK_SIZE - 1).toWord().rshl(LazyMmapper.LOG_MMAP_CHUNK_SIZE).toInt();
  public static int bytesToMmapChunksUp(int bytes) {    return (bytes + (LazyMmapper.MMAP_CHUNK_SIZE - 1)) >>> LazyMmapper.LOG_MMAP_CHUNK_SIZE;  }