From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from serv108.segi.ulg.ac.be (serv108.segi.ulg.ac.be [139.165.32.111]) by dpdk.org (Postfix) with ESMTP id 2E0762BE4 for ; Sat, 17 Dec 2016 11:43:26 +0100 (CET) Received: from mbx12-zne.ulg.ac.be (serv470.segi.ulg.ac.be [139.165.32.199]) by serv108.segi.ulg.ac.be (Postfix) with ESMTP id 030DB200BFEC; Sat, 17 Dec 2016 11:43:26 +0100 (CET) Received: from localhost (localhost.localdomain [127.0.0.1]) by mbx12-zne.ulg.ac.be (Postfix) with ESMTP id F002C129E9E0; Sat, 17 Dec 2016 11:43:25 +0100 (CET) Received: from mbx12-zne.ulg.ac.be ([127.0.0.1]) by localhost (mbx12-zne.ulg.ac.be [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id Dm3NRF0R_37g; Sat, 17 Dec 2016 11:43:25 +0100 (CET) Received: from mbx12-zne.ulg.ac.be (mbx12-zne.ulg.ac.be [139.165.32.199]) by mbx12-zne.ulg.ac.be (Postfix) with ESMTP id DAA68129E9DF; Sat, 17 Dec 2016 11:43:25 +0100 (CET) Date: Sat, 17 Dec 2016 11:43:25 +0100 (CET) From: tom.barbette@ulg.ac.be To: Bruce Richardson Cc: dev@dpdk.org Message-ID: <1289578237.19546607.1481971405418.JavaMail.zimbra@ulg.ac.be> In-Reply-To: <20161214165220.GC110884@bricha3-MOBL3.ger.corp.intel.com> References: <415214732.17903310.1481728244157.JavaMail.zimbra@ulg.ac.be> <597694261.17905196.1481728433903.JavaMail.zimbra@ulg.ac.be> <20161214165220.GC110884@bricha3-MOBL3.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [109.88.217.64] X-Mailer: Zimbra 8.0.9_GA_6191 (ZimbraWebClient - GC55 (Win)/8.0.9_GA_6191) Thread-Topic: No packets received if burst is too small in rte_eth_rx_burst Thread-Index: nT1kW5rw9qhuis33dc6Iu8yRI7+2xg== Subject: Re: [dpdk-dev] No packets received if burst is too small in rte_eth_rx_burst X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 17 Dec 2016 10:43:26 -0000 Hi, Your comments made me saw the line "PMD: i40e_set_rx_function(): Vector rx = enabled, please make sure RX burst size no less than 4 (port=3D0)." The problem was probably that I was under this limit... Is there a way to g= et that limit through a function or something?=20 With 16.04 I received sometimes 5 or 7 packets with a burst_size of 4 which= respects this limit. I see that "[dpdk-dev] net/i40e: fix out-of-bounds wr= ites during vector Rx" fixed that, as the limit was in fact 32 no matter th= e message. At the end, what should be the minimal rx burst size? How to find it at run= time for any NIC? I imagine that vector rx will create a problem if I give = a burst size of 1 even with a recent DPDK version, right? Thanks, Tom Tom Barbette=20 PhD Student @ Universit=C3=A9 de Li=C3=A8ge=20 Office 1/13=20 B=C3=A2timent B37=20 Quartier Polytech=20 All=C3=A9e de la d=C3=A9couverte, 12=20 4000 Li=C3=A8ge=20 04/366 91 75=20 0479/60 94 63=20 ----- Mail original ----- De: "Bruce Richardson" =C3=80: "tom barbette" Cc: dev@dpdk.org Envoy=C3=A9: Mercredi 14 D=C3=A9cembre 2016 17:52:21 Objet: Re: [dpdk-dev] No packets received if burst is too small in rte_eth_= rx_burst On Wed, Dec 14, 2016 at 04:13:53PM +0100, tom.barbette@ulg.ac.be wrote: > Hi list, >=20 > Between 2.2.0 and 16.04 (up to at least 16.07.2 if not current), with the= XL710 controller I do not get any packet when calling rte_eth_rx_burst if = nb_pkts is too small. I would say smaller than 32. The input rate is not bi= g, if that helps. But It should definitely get at least one packet per seco= nd. >=20 > Any ideas? Is that a bug or expected behaviour? Could be caused by other = ABI changes? >=20 Does this issue still occur even if you disable the vector driver in your build-time configuration? /Bruce