From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by dpdk.org (Postfix) with ESMTP id 3DF8495AD for ; Thu, 7 Jan 2016 09:48:10 +0100 (CET) Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga104.fm.intel.com with ESMTP; 07 Jan 2016 00:48:08 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,532,1444719600"; d="scan'208";a="721904698" Received: from fmsmsx104.amr.corp.intel.com ([10.18.124.202]) by orsmga003.jf.intel.com with ESMTP; 07 Jan 2016 00:48:08 -0800 Received: from fmsmsx115.amr.corp.intel.com (10.18.116.19) by fmsmsx104.amr.corp.intel.com (10.18.124.202) with Microsoft SMTP Server (TLS) id 14.3.248.2; Thu, 7 Jan 2016 00:48:08 -0800 Received: from shsmsx104.ccr.corp.intel.com (10.239.4.70) by fmsmsx115.amr.corp.intel.com (10.18.116.19) with Microsoft SMTP Server (TLS) id 14.3.248.2; Thu, 7 Jan 2016 00:48:08 -0800 Received: from shsmsx103.ccr.corp.intel.com ([169.254.4.220]) by SHSMSX104.ccr.corp.intel.com ([169.254.5.183]) with mapi id 14.03.0248.002; Thu, 7 Jan 2016 16:48:06 +0800 From: "Tan, Jianfeng" To: "Dey, Souvik" , "dev@dpdk.org" Thread-Topic: tx_burst errors seen with virtual pmds Thread-Index: AdFJEroo/Pehexp0S+W2DmX07vcsDQAFJJZw Date: Thu, 7 Jan 2016 08:48:05 +0000 Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] tx_burst errors seen with virtual pmds 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: Thu, 07 Jan 2016 08:48:10 -0000 Hi Souvik, > -----Original Message----- > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Dey, Souvik > Sent: Thursday, January 7, 2016 2:15 PM > To: dev@dpdk.org > Subject: [dpdk-dev] tx_burst errors seen with virtual pmds >=20 > Hi All, > While trying call load with virtio_pmd/vmxnet3_pmd , I am= seeing > that at around 100Mbps, we are having tx_burst errors. We are currently > using DPDK 2.1 and send 1 packet at a time. When we try the same with > ixgbe_vf we are not seeing similar drops. Is there any issues with the vi= rtual > pmds which is causing this tx drops. We are using tx descriptor as 1024 = and 1 > tx queue to send out packets. >=20 > -- > Regards, > Souvik IMO, for virtio and vmxnet3, there's a frontend in guest and a backend in h= ost. And mostly, backend driver does the data copies, which spends more CPU than frontend. So the tx descriptor queue could be always full, which leads to t= x error. Thanks, Jianfeng