From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: KNI performance is not what is claimed
Date: Thu, 20 Sep 2018 13:15:49 -0700
Message-ID: <20180920131549.6bc82f36@xeon-e3>
References: <20180920111055.54d32242@xeon-e3>
 <CADNuJVpnzHsq9d9R7buU9Zq43pSAWSa6RPsJ2RczQwgv6nFARw@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Cc: DPDK <dev@dpdk.org>
To: Jay Rolette <rolette@infinite.io>
Return-path: <dev-bounces@dpdk.org>
Received: from mail-pf1-f195.google.com (mail-pf1-f195.google.com
 [209.85.210.195]) by dpdk.org (Postfix) with ESMTP id 507267D52
 for <dev@dpdk.org>; Thu, 20 Sep 2018 22:15:57 +0200 (CEST)
Received: by mail-pf1-f195.google.com with SMTP id b11-v6so4893144pfo.3
 for <dev@dpdk.org>; Thu, 20 Sep 2018 13:15:57 -0700 (PDT)
In-Reply-To: <CADNuJVpnzHsq9d9R7buU9Zq43pSAWSa6RPsJ2RczQwgv6nFARw@mail.gmail.com>
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://mails.dpdk.org/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://mails.dpdk.org/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://mails.dpdk.org/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

On Thu, 20 Sep 2018 15:02:53 -0500
Jay Rolette <rolette@infinite.io> wrote:

> On Thu, Sep 20, 2018 at 1:11 PM Stephen Hemminger <
> stephen@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.

Yes, all are equivalent. KNI was just invented as "faster version of TAP"
but it isn't

> Hopefully the answer is "yes", in which case I'll happily port over to
> using one of the faster mechanisms.
> 
> Thanks,
> Jay