From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: DPDK testpmd forwarding performace degradation Date: Mon, 26 Jan 2015 17:08:11 +0000 Message-ID: <20150126170811.106aa793@uryu.home.lan> References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: "dev-VfR2kkLFssw@public.gmane.org" To: Alexander Belyakov Return-path: In-Reply-To: List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces-VfR2kkLFssw@public.gmane.org Sender: "dev" On Mon, 26 Jan 2015 13:17:48 +0300 Alexander Belyakov wrote: > 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) Did you try using git bisect to identify the problem.