From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-out1.informatik.tu-muenchen.de (mail-out1.informatik.tu-muenchen.de [131.159.0.8]) by dpdk.org (Postfix) with ESMTP id DCE34C4A0 for ; Tue, 28 Apr 2015 00:28:37 +0200 (CEST) Received: from charizard-wifi.fritz.box (p5DCD7DC1.dip0.t-ipconnect.de [93.205.125.193]) by mail.net.in.tum.de (Postfix) with ESMTPSA id 0B015188DCBF; Tue, 28 Apr 2015 00:28:34 +0200 (CEST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2098\)) From: Paul Emmerich In-Reply-To: Date: Tue, 28 Apr 2015 00:28:34 +0200 Content-Transfer-Encoding: quoted-printable Message-Id: <23D2CA18-1875-4182-8DEE-9F6393011D2C@net.in.tum.de> References: <6DC6DE50-F94F-419C-98DF-3AD8DCD4F69D@net.in.tum.de> To: "De Lara Guarch, Pablo" X-Mailer: Apple Mail (2.2098) Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] Performance regression in DPDK 1.8/2.0 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: Mon, 27 Apr 2015 22:28:38 -0000 Hi, Pablo : > Could you tell me how you got the L1 cache miss ratio? Perf? perf stat -e L1-dcache-loads,L1-dcache-misses l2fwd ... > Could you provide more information on how you run the l2fwd app, > in order to try to reproduce the issue: > - L2fwd Command line ./build/l2fwd -c 3 -n 2 -- -p 3 -q 2 > - L2fwd initialization (to check memory/CPU/NICs) I unfortunately did not save the output, but I wrote down the important parts: 1.7.1: no output regarding rx/tx code paths as init debug wasn't enabled 1.8.0 and 2.0.0: simple tx code path, vector rx Hardware: CPU: Intel(R) Xeon(R) CPU E3-1230 v2 TurboBoost and HyperThreading disabled. Frequency fixed at 3.30 GHz via acpi_cpufreq. NIC: X540-T2 Memory: Dual Channel DDR3 1333 MHz, 4x 4GB > Did you change the l2fwd app between versions? L2fwd uses simple rx on = 1.7.1, > whereas it uses vector rx on 2.0 (enable IXGBE_DEBUG_INIT to check = it). Yes, I had to update l2fwd when going from 1.7.1 to 1.8.0. However, the changes in the app were minimal. 1.8.0 and 2.0.0 used vector rx. Disabling vector rx via DPDK .config = file causes another 30% performance loss so I kept it enabled. > Which packet format/size did you use? Does your traffic generator take = into account the Inter-packet gap? 64 Byte packets, full line rate on both ports, i.e. 14.88 Mpps per port. The packet's content doesn't matter as l2fwd doesn't look at it, but it = was just some random stuff: EthType 0x1234. Let me know if you need any additional information. I'd also be interested in the configuration that resulted in the 20% = speed- up that was mentioned in the original mbuf patch Paul