Re: AF_XDP (i40e) behavior change in 5.11?

On Wed, Mar 24, 2021 at 10:22 AM Dan Siemon <[email protected]> wrote:
>
> ./xsk_fwd -i ens1f0 -q 2 -i ens1f1 -q 2 -c 5 -i ens1f0 -q 3 -i ens1f1 -
> q 3 -c 6
>
> On 5.10, the cores (2,3) assigned interrupts for the queues (2,3) are
> idle when there is no traffic.
>
> On 5.11, the cores immediately go to 100% system time when the program
> starts (as viewed in htop). There is no network traffic.
>
> Intel 710/i40e.
>
> I tried this with xsk_fwd built from 5.10 and 5.11 trees with the same
> result.
>
> Is this behavior change expected?

Thanks for reporting this. No, this is not intentional. I did send up
a fix for a bug in the i40e driver that was introduced in 5.11. It
might be the culprit. Could you please try the patch below and see if
it works? It is not yet in net.

https://www.spinics.net/lists/netdev/msg729128.html

/Magnus