I dug into essentially the same issue last year. This post explains what I found and what I did to improve the situation:
http://dpdk.org/ml/archives/dev/2015-June/018850.html Jay On Sat, Jan 23, 2016 at 8:17 AM, Masoud Moshref Javadi < masood.moshref.j at gmail.com> wrote: > I see jitter in KNI RTT. I have two servers. I run kni sample application > on one, configure its IP and ping an external interface. > > sudo -E build/kni -c 0xaaaa -n 4 -- -p 0x1 -P --config="(0,3,5)" > sudo ifconfig vEth0 192.168.1.2/24 > ping 192.168.1.3 > > This is the ping result: > 64 bytes from 192.168.1.2: icmp_seq=5 ttl=64 time=1.93 ms > 64 bytes from 192.168.1.2: icmp_seq=6 ttl=64 time=0.907 ms > 64 bytes from 192.168.1.2: icmp_seq=7 ttl=64 time=3.15 ms > 64 bytes from 192.168.1.2: icmp_seq=8 ttl=64 time=1.96 ms > 64 bytes from 192.168.1.2: icmp_seq=9 ttl=64 time=3.95 ms > 64 bytes from 192.168.1.2: icmp_seq=10 ttl=64 time=2.90 ms > 64 bytes from 192.168.1.2: icmp_seq=11 ttl=64 time=0.933 ms > > The ping delay between two servers without kni is 0.170ms. > I'm using dpdk 2.2. > > Any thought on how to keep KNI delay predictable? > > Thanks >
