uint16_t elts_free; /* available elts remain. */
uint16_t wqe_free; /* available wqe remain. */
uint16_t mbuf_off; /* data offset in current mbuf. */
uint16_t elts_free; /* available elts remain. */
uint16_t wqe_free; /* available wqe remain. */
uint16_t mbuf_off; /* data offset in current mbuf. */