From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Gospodarek Subject: Re: [PATCH v4 net-next RFC] net: Generic XDP Date: Wed, 19 Apr 2017 16:25:43 -0400 Message-ID: <20170419202543.GL4730@C02RW35GFVH8.dhcp.broadcom.net> References: <20170415005949.GB73685@ast-mbp.thefacebook.com> <20170418190535.GG4730@C02RW35GFVH8.dhcp.broadcom.net> <20170418.150708.1605529107204449972.davem@davemloft.net> <20170418.152916.1361453741909754079.davem@davemloft.net> <20170419142903.GJ4730@C02RW35GFVH8.dhcp.broadcom.net> <20170419171753.GA12838@ast-mbp.thefacebook.com> <58F7A21B.9060309@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Alexei Starovoitov , David Miller , michael.chan@broadcom.com, netdev@vger.kernel.org, xdp-newbies@vger.kernel.org To: John Fastabend Return-path: Received: from mail-yw0-f196.google.com ([209.85.161.196]:36554 "EHLO mail-yw0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S939402AbdDSUZw (ORCPT ); Wed, 19 Apr 2017 16:25:52 -0400 Received: by mail-yw0-f196.google.com with SMTP id 203so3549423ywk.3 for ; Wed, 19 Apr 2017 13:25:52 -0700 (PDT) Content-Disposition: inline In-Reply-To: <58F7A21B.9060309@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Apr 19, 2017 at 10:44:59AM -0700, John Fastabend wrote: > On 17-04-19 10:17 AM, Alexei Starovoitov wrote: > > On Wed, Apr 19, 2017 at 10:29:03AM -0400, Andy Gospodarek wrote: > >> > >> I ran this on top of a card that uses the bnxt_en driver on a desktop > >> class system with an i7-6700 CPU @ 3.40GHz, sending a single stream of > >> UDP traffic with flow control disabled and saw the following (all stats > >> in Million PPS). > >> > >> xdp1 xdp2 xdp_tx_tunnel > >> Generic XDP 7.8 5.5 (1.3 actual) 4.6 (1.1 actual) > >> Optimized XDP 11.7 9.7 4.6 > > > > Nice! Thanks for testing. > > > >> One thing to note is that the Generic XDP case shows some different > >> results for reported by the application vs actual (seen on the wire). I > >> did not debug where the drops are happening and what counter needs to be > >> incremented to note this -- I'll add that to my TODO list. The > >> Optimized XDP case does not have a difference in reported vs actual > >> frames on the wire. > > > > The missed packets are probably due to xmit queue being full. > > We need 'xdp_tx_full' counter in: > > + if (free_skb) { > > + trace_xdp_exception(dev, xdp_prog, XDP_TX); > > + kfree_skb(skb); > > + } > > like in-driver xdp does. > > It's surprising that tx becomes full so often. May be bnxt specific behavior? > > hmm as a data point I get better numbers than 1.3Mpps running through the qdisc > layer with pktgen so seems like something is wrong with the driver perhaps? If I get ~6.5Mpps on a single core with pktgen, so inconclusive for now.... > I get a chance I'll take a look with my setup here, although it likely wont be > until the weekend. I don't think it needs to slow down dropping the RFC tag > and getting the patch applied though. > > > > >> I agree with all those who have asserted that this is great tool for > >> those that want to get started with XDP but do not have hardware, so I'd > >> say it's ready to have the 'RFC' tag dropped. Thanks for pushing this > >> forward, Dave! :-) > > > > +1 > > > > >