def METHOD_NAME(mount_process, mnt_dir):
    # Don't bother trying Valgrind if things already went wrong
    if 'bsd' in sys.platform or 'dragonfly' in sys.platform:
        cmd = [ 'umount', '-f', mnt_dir ]
    else:
        cmd = [pjoin(basename, 'util', 'fusermount3'),
                         '-z', '-u', mnt_dir]
    subprocess.call(cmd, stdout=subprocess.DEVNULL,
                    stderr=subprocess.STDOUT)
    mount_process.terminate()
    try:
        mount_process.wait(1)
    except subprocess.TimeoutExpired:
        mount_process.kill()