Re: [PATCH net-next v2 12/33] hv_netvsc: add XDP frame size to driver

Jesper Dangaard Brouer
2020-05-01T14:47:32Z

On Thu, 30 Apr 2020 14:20:20 +0000
Haiyang Zhang <haiyangz@microsoft.com> wrote:
> > -----Original Message-----
> > From: Jesper Dangaard Brouer <brouer@redhat.com>
> >
> > The hyperv NIC drivers XDP implementation is rather disappointing as it will
> > be a slowdown to enable XDP on this driver, given it will allocate a new page
> > for each packet and copy over the payload, before invoking the XDP BPF-
> > prog.
>
> This needs correction. As I said previously --
> This statement is not accurate -- The data path of netvsc driver does memory
> allocation and copy even without XDP, so it's not "a slowdown to enable XDP".

Okay, I have changed the paragraph text to:

The hyperv NIC driver does memory allocation and copy even without XDP.
In XDP mode it will allocate a new page for each packet and copy over
the payload, before invoking the XDP BPF-prog.

--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer