code: public void advise(long position, long length) throws IOException {
          final long ap = address+position;
          final long a = (ap)/PAGE_SIZE*PAGE_SIZE;
          final long l = Math.min(length+(ap-a), address+memory.length()-ap);
          final int err = madvise(a, l);
          if (err != 0) {
              throw new IOException("madvise failed with error code: "+err);
          }
      }
docs: this is not particularly useful, the syscall takes forever