code: public static void mlock(Pointer addr, long len) {
  
          int res = Delegate.mlock(addr, new NativeLong(len));
          if(res != 0) {
              if(logger.isDebugEnabled()) {
                  logger.debug("Mlock failed probably because of insufficient privileges, errno:"
                               + errno.strerror() + ", return value:" + res);
              }
          } else {
              if(logger.isDebugEnabled())
                  logger.debug("Mlock successfull");
  
          }
  
      }
docs: Lock the given region.  Does not report failures.