Re: [RFC PATCH v3] ethdev: support selective Rx data

Stephen Hemminger
2026-01-19T16:37:10Z

On Mon, 19 Jan 2026 13:23:02 +0200 (IST)
"Etelson, Gregory" <getelson@nvidia.com> wrote:

> Hello,
>
> >> In some cases application does not need to receive entire packet
> >> from port hardware.
> >
> > Which scenarios need to be used?
>
> A typical use case for the selective Rx data read can be the SAMPLE flow action.
> In that scenario, Rx queue that receives sampled packet copy can be configured
> to deliver to application partial packet data.
>
> > What is the behavior when
> > LRO(TCP packet aggregation is performed by hardware) is enabled?
> >
>
> The selective Rx data read is applied to MBUF layout that will be delivered to
> an application.
> That functionality comes after all HW Rx offloads.

What is the intended behavior in the selective case. Is there any mechanism for
application to see original length?