[dpdk-users] high jitter in dpdk kni

[Jay Rolette]

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
>