static int __get_index(struct qtree_mem_dqinfo *info, qid_t id, int depth)
{
	unsigned int epb = info->dqi_usable_bs >> 2;

	depth = info->dqi_qtree_depth - depth - 1;
	while (depth--)
		id /= epb;
	return id % epb;
}
static int __get_index(struct qtree_mem_dqinfo *info, qid_t id, int depth)
{
	unsigned int epb = info->dqi_usable_bs >> 2;

	depth = info->dqi_qtree_depth - depth - 1;
	while (depth--)
		id /= epb;
	return id % epb;
}