def set_bdev_options(client, bdev_io_pool_size=None, bdev_io_cache_size=None):
    """Set parameters for the bdev subsystem.

    Args:
        bdev_io_pool_size: number of bdev_io structures in shared buffer pool (optional)
        bdev_io_cache_size: maximum number of bdev_io structures cached per thread (optional)
    """
    params = {}

    if bdev_io_pool_size:
        params['bdev_io_pool_size'] = bdev_io_pool_size
    if bdev_io_cache_size:
        params['bdev_io_cache_size'] = bdev_io_cache_size

    return client.call('set_bdev_options', params)