[dpdk-users] RSS : All fragments to same Recv queue

[dpdk-users] RSS : All fragments to same Recv queue

[Shyam Shrivastav]

Hi

We want to use RSS supported by intel 82599 NIC, with one lcore running on
each processor and handling one receive queue. All fragments of an ipv4
packet need to go to same receive queue and handled by same lcore for
lockless reassembly. Looks like Intel  82599 supports RSS IPv4 hashing
using just source and dest address fields and that should put all fragments
on same queue ( can be enabled by ETH_RSS_IPV4 in rte_eth_rss_conf->rs_hf).
Please let me know whether my understanding is correct.

Thanks
Shyam

Re: [dpdk-users] RSS : All fragments to same Recv queue

[Stephen Hemminger]

On Wed, 8 Mar 2017 21:20:57 +0530
Shyam Shrivastav <shrivastav.shyam@gmail.com> wrote:

> Hi
> 
> We want to use RSS supported by intel 82599 NIC, with one lcore running on
> each processor and handling one receive queue. All fragments of an ipv4
> packet need to go to same receive queue and handled by same lcore for
> lockless reassembly. Looks like Intel  82599 supports RSS IPv4 hashing
> using just source and dest address fields and that should put all fragments
> on same queue ( can be enabled by ETH_RSS_IPV4 in rte_eth_rss_conf->rs_hf).
> Please let me know whether my understanding is correct.
> 
> Thanks
> Shyam

Yes as long as you keep port numbers out of the RSS hash it should work,
but you may have to deal with fragments arriving over different paths.
There is nothing in IP architecture that prevents multi-pathing.

Re: [dpdk-users] RSS : All fragments to same Recv queue

[Shyam Shrivastav]

Thanks, multipath is taken care of by upstream router so that all fragments
of a packet are injected on same interface ...

On Thu, Mar 9, 2017 at 7:48 AM, Stephen Hemminger <
stephen@networkplumber.org> wrote:

> On Wed, 8 Mar 2017 21:20:57 +0530
> Shyam Shrivastav <shrivastav.shyam@gmail.com> wrote:
>
> > Hi
> >
> > We want to use RSS supported by intel 82599 NIC, with one lcore running
> on
> > each processor and handling one receive queue. All fragments of an ipv4
> > packet need to go to same receive queue and handled by same lcore for
> > lockless reassembly. Looks like Intel  82599 supports RSS IPv4 hashing
> > using just source and dest address fields and that should put all
> fragments
> > on same queue ( can be enabled by ETH_RSS_IPV4 in
> rte_eth_rss_conf->rs_hf).
> > Please let me know whether my understanding is correct.
> >
> > Thanks
> > Shyam
>
> Yes as long as you keep port numbers out of the RSS hash it should work,
> but you may have to deal with fragments arriving over different paths.
> There is nothing in IP architecture that prevents multi-pathing.
>