From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mailS.toulouse.viveris.com (mail.toulouse.viveris.com [212.99.125.10]) by dpdk.org (Postfix) with ESMTP id F04E52C2F for ; Wed, 17 May 2017 09:58:13 +0200 (CEST) Received: from webmail.toulouse.viveris.fr (unknown [192.168.4.100]) by mailS.toulouse.viveris.com (Postfix) with ESMTPSA id 9D51ACC0100; Wed, 17 May 2017 09:58:12 +0200 (CEST) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Date: Wed, 17 May 2017 09:53:26 +0200 From: dfernandes@toulouse.viveris.com To: "Wiles, Keith" Cc: users@dpdk.org In-Reply-To: <893EE76D-12F0-4D89-8A4C-D7D41C7C6014@intel.com> References: <8474dba1b5f7aeeba26446b349ddf832@toulouse.viveris.com> <893EE76D-12F0-4D89-8A4C-D7D41C7C6014@intel.com> Message-ID: <5b2e2c4bba0c68b6dbfd50cb6654de9f@toulouse.viveris.com> X-Sender: dfernandes@toulouse.viveris.com User-Agent: Roundcube Webmail/1.1.1 Subject: Re: [dpdk-users] Packet losses using DPDK X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK usage discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 17 May 2017 07:58:14 -0000 Thanks for your response ! I have installed Pktgen and I will perform some tests. So far it seems to work fine. I'll keep you informed. Thanks again. David Le 12.05.2017 18:18, Wiles, Keith a écrit : >> On May 12, 2017, at 10:45 AM, dfernandes@toulouse.viveris.com wrote: >> >> Hi ! >> >> I am working with MoonGen which is a fully scriptable packet generator >> build on DPDK. >> (→ https://github.com/emmericp/MoonGen) >> >> The system on which I perform tests has the following characteristics >> : >> >> CPU : Intel Core i3-⁠⁠6100 (3.70 GHz, 2 cores, 2 threads/⁠⁠core) >> NIC : X540-⁠⁠AT2 with 2x10Gbe ports >> OS : Linux Ubuntu Server 16.04 (kernel 4.4) >> >> I coded a MoonGen script which requests DPDK to transmit packets from >> one physical port and to receive them at the second physical port. The >> 2 physical ports are directly connected with an RJ-45 cat6 cable. >> >> The issue is that I perform the same test with exactly the same script >> and the same parameters several times and the results show a random >> behavior. For most of the tests there is no losses but for some of >> them I observe packet losses. The percentage of lost packets is very >> variable. It happens even when the packet rate is very low. >> >> Some examples of random failed tests : >> >> # 1,000,000 packets sent (packets size = 124 bytes, rate = 76 Mbps) → >> 10170 lost packets >> >> # 3,000,000 packets sent (packets size = 450 bytes, rate = 460 Mbps) → >> ALL packets lost >> >> >> I tested the following system modifications without success : >> >> # BIOS parameters : >> >> Hyperthreading : enable (because the machine has only 2 cores) >> Multi-⁠⁠⁠processor : enable >> Virtualization Technology (VTx) : disable >> Virtualization Technology for Directed I/⁠⁠⁠O (VTd) : disable >> Allow PCIe/⁠⁠⁠PCI SERR# Interrupt (=PCIe System Errors) : disable >> NUMA unavailable >> >> # use of isolcpus in order to isolate the cores which are in charge of >> transmission and reception >> >> # hugepages size = 1048576 kB >> >> # size of buffer descriptors : tried with Tx = 512 descriptors and Rx >> = 128 descriptors and also with Tx = 4096 descriptors and Rx = 4096 >> descriptors >> >> # Tested with 2 different X540-⁠⁠T2 NICs units >> >> # I tested all with a Dell FC430 which has a CPU Intel Xeon E5-2660 v3 >> @ 2.6GHz with 10 Cores and 2threads/Core (tested with and without >> hyper-threading) >> → same results and even worse >> >> >> Remark concerning the NIC stats : >> I used the rte_eth_stats struct in order to get more information >> about the losses and I observed that in some cases, when there is >> packet losses, ierrors value is > 0 and also ierrors + imissed + >> ipackets < opackets. In other cases I get ierrors = 0 and imissed + >> ipackets = opackets which has more sense. >> >> What could be the origin of that erroneous packets counting? >> >> Do you have any explanation about that behaviour ? > > Not knowing MoonGen at all other then a brief look at the source I may > not be much help, but I have a few ideas to help locate the problem. > > Try using testpmd in tx-only mode or try Pktgen to see if you get the > same problem. I hope this would narrow down the problem to a specific > area. As we know DPDK works if correctly coded and testpmd/pktgen > work. > >> >> Thanks in advance. >> >> David > > Regards, > Keith