Question about kni performance

[Stephen Hemminger]

On Sat, 20 Dec 2025 01:10:51 +0800
"455434913" <455434913 at qq.com> wrote:

> Hello, I ran the KNI example from DPDK version 19.11 and performed a ping latency test from another machine. I found that after running KNI, the latency increased by over 100 times—from the original 0.05 ms to 7 ms, which is unacceptable for my use case. My network card is an mlx5 with a specification of 1000 Gbps. Is this performance degradation within normal parameters? What methods can be used to optimize it?

KNI is deprecated and removed do not use it.
All the wrappers around kernel networking (tap, virtio, pcap, ...) require a context switch
and sometimes a system call. You are seeing that overhead.