[Intel-wired-lan] using XPS on Intel i40e

[Alexander Duyck]

On Sun, Sep 16, 2018 at 12:55 AM Kushal Gautam <kushal.gautam at gmail.com> wrote:
>
> Hi:
>
> I am using the Intel i40e driver from kernel source tree of Kernel 4.15.12
> My NIC is Intel X710.
>
> I am composing and sending a packet from my custom kernel module as:
>
> ...
> skb->dev->netdev_ops->ndo_start_xmit(skb, skb->dev);
> ...
>
> Just like FDIR on the receiving side, is it possible to have a similar configuration on the sending side?
>
> For instance, I want my packets sent via kernel module to pass through TX-Queue 5. Right now all my packets are being sent through just Tx-Queue 0. And maybe after that, it would make sense to use XPS(https://github.com/torvalds/linux/blob/v3.13/Documentation/networking/scaling.txt#L364)
>
> Regards,
> Kushal.

Right now you are bypassing XPS entirely if you are using
ndo_start_xmit to send you frames.

You might take a look at the pktgen code in the kernel as I believe
that has examples where they use specific queues to send packets. All
that is really involved is updating a field in the sk_buff data
structure before you call ndo_start_xmit.

Hope that helps.

- Alex