Fast open pickle in Python3

Question

I notice a fast unpickle method in gork. Here is the code:

@contextlib.contextmanager
def copy_to_shm(file: str):
    if file.startswith("/dev/shm/"):
        # Nothing to do, the file is already in shared memory.
        yield file
        return

    tmp_dir = "/dev/shm/"
    fd, tmp_path = tempfile.mkstemp(dir=tmp_dir)
    try:
        shutil.copyfile(file, tmp_path)
        yield tmp_path
    finally:
        os.remove(tmp_path)
        os.close(fd)

def fast_unpickle(path: str) -> Any:
    with copy_to_shm(path) as tmp_path:
        with open(tmp_path, "rb") as f:
            return pickle.load(f)

Is it helpful to copy the file into /dev/shm/ before opening the file? What size of files will benefit from it?