From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vc0-f174.google.com (mail-vc0-f174.google.com [209.85.220.174]) by dpdk.org (Postfix) with ESMTP id 7B9FF5B2D for ; Tue, 27 Jan 2015 08:51:09 +0100 (CET) Received: by mail-vc0-f174.google.com with SMTP id le20so4274225vcb.5 for ; Mon, 26 Jan 2015 23:51:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=g3Yh0YW9eIBY2hxDuGM8m6lLlzxHcmL72auT/AI3lYo=; b=wBlrVDrqzUMTuN0W3lHFey+2C7tGkhjbRRbbsAxlqDfvfeBDHiz3fwU3UKoaCF+SS3 qmBkEsxTYzcbEZ5+yfzGjRfDmKDmp6Xz36cHm5jWyhnYBMIPrCAMvOMpiy5GA/jwY6IG Ty0Y0pnQBVr2/jOeALXl9vVzsKD6iLQpjL3yBfZmMwjtpxF3uu4M9C20ffPZpcwWvCgV gvO0WN+5G60DuQ7KkJ+cKNYuFwSqv61VgXWGN7re1wgNO/x0oAGW6vOEUJUe44+zk8iH m93Vo9lyQnP/YSFiegIOFX3dNIbhCIeRHQZrhXCA2n6bKXMTuHl88LXw/7kJ+Q3U/4o2 Atzg== MIME-Version: 1.0 X-Received: by 10.52.22.9 with SMTP id z9mr11246717vde.87.1422345068478; Mon, 26 Jan 2015 23:51:08 -0800 (PST) Received: by 10.52.116.105 with HTTP; Mon, 26 Jan 2015 23:51:08 -0800 (PST) In-Reply-To: References: Date: Tue, 27 Jan 2015 10:51:08 +0300 Message-ID: From: Alexander Belyakov To: "De Lara Guarch, Pablo" , "dev@dpdk.org" Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: [dpdk-dev] Fwd: DPDK testpmd forwarding performace degradation X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 27 Jan 2015 07:51:10 -0000 Hi Pablo, On Mon, Jan 26, 2015 at 5:22 PM, De Lara Guarch, Pablo < pablo.de.lara.guarch@intel.com> wrote: > Hi Alexander, > > > -----Original Message----- > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Alexander Belyakov > > Sent: Monday, January 26, 2015 10:18 AM > > To: dev@dpdk.org > > Subject: [dpdk-dev] DPDK testpmd forwarding performace degradation > > > > Hello, > > > > recently I have found a case of significant performance degradation for > our > > application (built on top of DPDK, of course). Surprisingly, similar > issue > > is easily reproduced with default testpmd. > > > > To show the case we need simple IPv4 UDP flood with variable UDP payload > > size. Saying "packet length" below I mean: Eth header length (14 bytes) + > > IPv4 header length (20 bytes) + UPD header length (8 bytes) + UDP payload > > length (variable) + CRC (4 bytes). Source IP addresses and ports are > selected > > randomly for each packet. > > > > I have used DPDK with revisions 1.6.0r2 and 1.7.1. Both show the same > issue. > > > > Follow "Quick start" guide (http://dpdk.org/doc/quick-start) to build > and > > run testpmd. Enable testpmd forwarding ("start" command). > > > > Table below shows measured forwarding performance depending on packet > > length: > > > > No. -- UDP payload length (bytes) -- Packet length (bytes) -- Forwarding > > performance (Mpps) -- Expected theoretical performance (Mpps) > > > > 1. 0 -- 64 -- 14.8 -- 14.88 > > 2. 34 -- 80 -- 12.4 -- 12.5 > > 3. 35 -- 81 -- 6.2 -- 12.38 (!) > > 4. 40 -- 86 -- 6.6 -- 11.79 > > 5. 49 -- 95 -- 7.6 -- 10.87 > > 6. 50 -- 96 -- 10.7 -- 10.78 (!) > > 7. 60 -- 106 -- 9.4 -- 9.92 > > > > At line number 3 we have added 1 byte of UDP payload (comparing to > > previous > > line) and got forwarding performance halved! 6.2 Mpps against 12.38 Mpps > > of > > expected theoretical maximum for this packet size. > > > > That is the issue. > > > > Significant performance degradation exists up to 50 bytes of UDP payload > > (96 bytes packet length), where it jumps back to theoretical maximum. > > > > What is happening between 80 and 96 bytes packet length? > > > > This issue is stable and 100% reproducible. At this point I am not sure > if > > it is DPDK or NIC issue. These tests have been performed on Intel(R) Eth > > Svr Bypass Adapter X520-LR2 (X520LR2BP). > > > > Is anyone aware of such strange behavior? > > I cannot reproduce the issue using two ports on two different 82599EB > NICs, using 1.7.1 and 1.8.0. > I always get either same or better linerate as I increase the packet size. > Thank you for trying to reproduce the issue. > Actually, have you tried using 1.8.0? > I feel 1.8.0 is little bit immature and might require some post-release patching. Even tespmd from this release is not forwarding packets properly on my setup. It is up and running without visible errors/warnings, TX/RX counters are ticking but I can not see any packets at the output. Please note, both 1.6.0r2 and 1.7.1 releases work (on the same setup) out-of-the-box just fine with only exception of this mysterious performance drop. So it will take some time to figure out what is wrong with dpdk-1.8.0. Meanwhile we could focus on stable dpdk-1.7.1. As for X520-LR2 NIC - it is dual port bypass adapter with device id 155d. I believe it should be treated as 82599EB except bypass feature. I put bypass mode to "normal" in those tests. Alexander > > Pablo > > > > Regards, > > Alexander Belyakov >