Hi DPDK users,

I met a dpdk tx issue with dpdk v19.11.10.

I use INTEL XXV710 25G NIC, two ports.

My app use pipeline mode, setup 1 rx and 6 tx queue for each ports, rx/tx desc 4096, share one pkt pool. Traffic is 18Gbps/300Wpps, so each port will have 9G rx and 9G tx.

Everything works fine at the beginning 1~2 hours. Then rte_eth_tx_burst starts to return 0 in a while. I add prints, and it shows the tx desc is not freed in that time:

"i40e_xmit_fixed_burst_vec_avx2(): avx:tx_free_thresh 512 tx_rs_thresh 32, nb_tx_free 0"

Since I do not have re-send action, once the issue occurs, thousands of pkts dropped due to tx failed. And then it will go back to normal since desc is released.

Does any one met the same issue before ? could you please give any suggestions ? Thank you so much!

Br,

Christian