[dpdk-users] Tx burst and ordered packets

[Van Haaren, Harry]

> -----Original Message-----
> From: users <users-bounces at dpdk.org> On Behalf Of Stephen Hemminger
> Sent: Thursday, June 10, 2021 5:29 PM
> To: Alan Arondel <Alan.Arondel at enea.com>
> Cc: users at dpdk.org
> Subject: Re: [dpdk-users] Tx burst and ordered packets
> 
> Are you using RSS on the receiver.
> Packets sent in one burst should go out in order (if not it is a Intel
> driver bug)

[Sidenote: its best practice to reply inline when answering questions on mailing lists.]


> On Mon, Jun 7, 2021 at 3:09 PM Alan Arondel <Alan.Arondel at enea.com> wrote:
> 
> > Hello everyone,
> >
> > I just wanted to know if a burst of packets using rte_eth_tx_burst are
> > send in the same order of the parameter struct rte_mbuf ** tx_pkts ?
> > I tried the skeleton sample which use this api and can confirm that the
> > received packets are not in the right order. Probably I'm doing something
> > wrong somewhere.

Stephen is correct in that the rte_mbuf **tx_pkts order is the order packets
should be sent on the wire. Indeed if they are not, it is a driver bug, and should
be fixed.

Before we jump to that conclusion, can I suggest we look at how packet ordering
is being measured? Keep in mind packets could be dropped along the way, so
if we count (N) and (N+1) on the next packet, and then validate ordering by ensuring
the received packets are exactly (N, N+1), then a drop would suggest re-ordering issues...

> > I use the driver net_i40e.
> > Dpdk version 20.11.1
> > Compilation withtout any specifique parameters (meson
> > configure/ninja/ninja install)
> > I cannot find any discussion or information about this.

I expect that would work correctly.


> > Thank you for any reply.
> >
> > Regards,
> > Alan.

Regards, -Harry

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