Hi, My user-space TCP/IP stack works fine on DPDK 17.02, now I upgrade it to 18.02. And then I use wrk http benchmark to test my stack, it work well fine, but after a while, it couldn't send packet. I debug with gdb and find the rte_eth_tx_burst always return 0, which means there is no available transmit descriptor. And then I enable DPDK debug mode, the ixgbe_xmit_pkts has been called to send packets (My NIC is Intel 82599ES 10G) and it called ixgbe_xmit_cleanup to recycle used transmit descriptor, but ixgbe_xmit_cleanup always return -1. The relevant code is blew.
/* Check to make sure the last descriptor to clean is done */ desc_to_clean_to = sw_ring[desc_to_clean_to].last_id; status = txr[desc_to_clean_to].wb.status; if (!(status & rte_cpu_to_le_32(IXGBE_TXD_STAT_DD))) { PMD_TX_FREE_LOG(DEBUG, "TX descriptor %4u is not done" "(port=%d queue=%d)", desc_to_clean_to, txq->port_id, txq->queue_id); /* Failed to clean any descriptors, better luck next time */ return -(1); } I'm stuck here, and wonder how DPDK upgrade brings up this issue. Btw, there was a similar mail which encountered the same issue, http://mails.dpdk.org/archives/dev/2017-August/073240.html, but I find no final solution for it. Thanks a lot for your time, and dying for your reply! Huiyou