def pad_to_sequence_parallel(unpad_tokens: torch.Tensor):
    """pad the tokens such that the total length is a multiple of sp world size

    Args:
        unpad_tokens: (total_nnz, ...). Tokens after removing padding

    Returns:

    """
    total_nnz = unpad_tokens.shape[0]
    sp_world_size = mpu.get_tensor_model_parallel_world_size()

    if total_nnz % sp_world_size == 0:
        pad_size = 0
    else:
        pad_size = sp_world_size - total_nnz % sp_world_size

    if pad_size > 0:
        if unpad_tokens.ndim == 1:
            unpad_tokens = F.pad(unpad_tokens, (0, pad_size))
        elif unpad_tokens.ndim == 2:
            unpad_tokens = F.pad(unpad_tokens, (0, 0, 0, pad_size))
        else:
            raise NotImplementedError(f'Padding dim {unpad_tokens.ndim()} is not supported')

    return unpad_tokens
pad the tokens such that the total length is a multiple of sp world size

    Args:
        unpad_tokens: (total_nnz, ...). Tokens after removing padding

    Returns:

    
verl/utils/megatron/sequence_parallel.py