sq_to_tg
struct throtl_grp *parent_tg = sq_to_tg(parent_sq);
struct throtl_grp *tg = sq_to_tg(sq);
struct throtl_grp *__tg = sq_to_tg((sq)); \
tg = sq_to_tg(sq);
tg = sq_to_tg(sq);
struct throtl_grp *parent_tg = sq_to_tg(tg->service_queue.parent_sq);
struct throtl_grp *tg = sq_to_tg(sq);