[dpdk-dev] KNI performance is not what is claimed

[Wang, Zhihong]

> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Jay Rolette
> Sent: Friday, September 21, 2018 5:39 AM
> To: Stephen Hemminger <stephen at networkplumber.org>
> Cc: DPDK <dev at dpdk.org>
> Subject: Re: [dpdk-dev] KNI performance is not what is claimed
> 
> On Thu, Sep 20, 2018 at 3:16 PM Stephen Hemminger <
> stephen at networkplumber.org> wrote:
> 
> > On Thu, 20 Sep 2018 15:02:53 -0500
> > Jay Rolette <rolette at infinite.io> wrote:
> >
> > > On Thu, Sep 20, 2018 at 1:11 PM Stephen Hemminger <
> > > stephen at networkplumber.org> wrote:
> > >
> > > > I wonder if KNI is claiming performance that was never measured on
> > current
> > > > CPU, OS, DPDK.
> > > >
> > > > With single stream and TCP testing on IXGBE (DPDK), I see lowest
> > > > performance with KNI.
> > > >
> > > >                 Rx              Tx
> > > >         KNI     3.2 Gbit/sec    1.3 Gbit/sec
> > > >         TAP     4.9             4.7
> > > >         Virtio  5.6             8.6
> > > >
> > > > Perhaps for 18.11 we should change documentation to remove
> language
> > > > claiming
> > > > better performance with KNI, and then plan for future deprecation?
> > > >
> > >
> > > Do TAP and Virtio provide equivalent function to KNI? I can't speak for
> > any
> > > other products, but ours is dependent on KNI. The ability for control
> > plane
> > > applications to use normal Linux sockets with DPDK is key even if it
> > isn't
> > > performant.
> > >
> > > Hopefully the answer is "yes", in which case I'll happily port over to
> > > using one of the faster mechanisms.
> > >
> > > Thanks,
> > > Jay
> >
> > See:
> >
> > https://doc.dpdk.org/guides-
> 17.11/howto/virtio_user_as_exceptional_path.html
> 
> 
> Thanks. Looks like it's time to run some experiments again.

To do the test with the latest DPDK 17.11 LTS, you'll need the below
one-line fix (which was missed during backporting) to enable the
offloads:
https://git.dpdk.org/dpdk/commit/?id=bce7e9050f9b

You can also refer to this paper for more details:
https://dl.acm.org/citation.cfm?id=3098586

-Zhihong

> 
> Jay