RE: [PATCH] net/ring: Set mbuf->port for received packets

["Morten Brørup" <mb@smartsharesystems.com>]

> From: Sriram Yagnaraman [mailto:sriram.yagnaraman@ericsson.com]
> 
> Hi Morten,
> 
> > From: Morten Brørup <mb@smartsharesystems.com>
> >
> > > From: Sriram Yagnaraman [mailto:sriram.yagnaraman@ericsson.com]
> > >
> > > When using ring based ethdev, mbuf->port is not set on received packets.
> > >
> > > For applications that use the mbuf->port to identify the incoming
> > > port, especially when eventdev RX adapter pulls the packet on a
> > > different core and the application running on a worker core has no
> > > clue on the incoming port. This change adds some cycles at receive, to
> > > set the port of course.
> >
> > I agree that the mbuf->port field must be set before returning from
> > rte_eth_rx_burst().
> >
> > I'm not aware how applications use the ring based ethdev, so I might be
> > asking silly questions...
> >
> > How about all the other mbuf fields normally set by the PMD before
> > returning from rte_eth_rx_burst()?
> >
> > Is the enqueueing core supposed to set them?
> 
> I am integrating a couple of existing DPDK applications, and they use
> rte_eth_* API between them today. To keep the API consistent, and not make too
> many changes in the applications themselves, net_ring seems to be the best
> option. If someone has a better idea, I would love to hear.
> 
> There are no "HW" offloads when using net_ring, and IIUC there are no HW
> related fields that can be set at rx_burst.
> So, apart from port field, I didn't see much else that needed to be set.
> 
> >
> > Or if the ring is only used for queueing packets originally received (at a
> > physical port) by the enqueueing core, why not keep the mbuf->port value
> > from the original reception?
> 
> In my case the enqueuing application originates the flow from SW, so the
> rte_mbuf does not come from a NIC.

Thank you for the explanation.

Acked-by: Morten Brørup <mb@smartsharesystems.com>

> 
> >
> > >
> > > Please advise if this change is something that can be upstreamed.
> > >
> > > Signed-off-by: Sriram Yagnaraman <sriram.yagnaraman@ericsson.com>