At dpdk19.08, I executed twice for the same mbuf by rte_pktmbuf_free_seg(), which stores two identical pointers in the cache, causes the device to be overwritten when I apply for mbuf consecutively, because rte_pktbuf_free_seg guarantees refcnt==1 after the mbuf is released. Why do you want to do this? This is not the problem at 17.02,when the refcnt is 0 after mbuf released