i40e sr-iov packets latency

Hi all,

Currently, I'm using XL710 SR-IOV in VM. We are using DPDK 1.8 PMD driver. The VM can communicate with other equipment, but the packets have long latency. you can refer below picture.

I don't know reason, it seemed rte_eth_rx_burst didn't return the packets it received in time.

Does anyone meet this problem before? or I just need to modify some macro in the code?

BTW: I have tried modify RTE_LIBRTE_I40E_ITR_INTERVAL and RTE_LIBRTE_I40E_QUEUE_NUM_PER_VF, and no effect.

Any answer will be appreciated!