From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id 7ACFA2E7B for ; Wed, 8 Jun 2016 10:22:24 +0200 (CEST) Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga101.fm.intel.com with ESMTP; 08 Jun 2016 01:22:23 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.26,438,1459839600"; d="scan'208";a="715745533" Received: from irsmsx109.ger.corp.intel.com ([163.33.3.23]) by FMSMGA003.fm.intel.com with ESMTP; 08 Jun 2016 01:22:22 -0700 Received: from irsmsx102.ger.corp.intel.com ([169.254.2.10]) by IRSMSX109.ger.corp.intel.com ([169.254.13.193]) with mapi id 14.03.0248.002; Wed, 8 Jun 2016 09:22:21 +0100 From: "Chandran, Sugesh" To: Olivier Matz , "Ananyev, Konstantin" , Stephen Hemminger CC: Yuanhan Liu , "dev@dpdk.org" , "Richardson, Bruce" , Adrien Mazarguil , "Tan, Jianfeng" Thread-Topic: [dpdk-dev] about rx checksum flags Thread-Index: AQHRuoezRmm+fNew7kKI9gqfLUQ5c5/SoZ8AgAC5KoCAABVVAIAACI2AgAAR1oCAALl4AIABiH1ggAHYrACAB6B3AA== Date: Wed, 8 Jun 2016 08:22:20 +0000 Message-ID: <2EF2F5C0CC56984AA024D0B180335FCB13DDC6C0@IRSMSX102.ger.corp.intel.com> References: <574C5B9D.4080006@6wind.com> <20160531080916.GI5641@yliu-dev.sh.intel.com> <574DE1FF.6060402@6wind.com> <20160531132820.4fadfc2e@xeon-e3> <574DFB11.5020701@6wind.com> <20160531150247.15819f1d@xeon-e3> <2601191342CEEE43887BDE71AB97725836B694D3@irsmsx105.ger.corp.intel.com> <2EF2F5C0CC56984AA024D0B180335FCB13DDA800@IRSMSX102.ger.corp.intel.com> <57517B5C.4040206@6wind.com> In-Reply-To: <57517B5C.4040206@6wind.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiYjhjOGY0OTAtMTIxMi00MDliLTkyOWUtOGYwY2NjMjMyNGNhIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX0lDIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE1LjkuNi42IiwiVHJ1c3RlZExhYmVsSGFzaCI6IkxXM3hndjgzXC8yRzRsbXpHb0hCMUxlN1V0UUtZa3B3bXNNcVJ5Nm5aM1BJPSJ9 x-ctpclassification: CTP_IC x-originating-ip: [163.33.239.182] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] about rx checksum flags 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: Wed, 08 Jun 2016 08:22:24 -0000 Regards _Sugesh > -----Original Message----- > From: Olivier Matz [mailto:olivier.matz@6wind.com] > Sent: Friday, June 3, 2016 1:43 PM > To: Chandran, Sugesh ; Ananyev, Konstantin > ; Stephen Hemminger > > Cc: Yuanhan Liu ; dev@dpdk.org; Richardson, > Bruce ; Adrien Mazarguil > ; Tan, Jianfeng > Subject: Re: [dpdk-dev] about rx checksum flags >=20 > Hi, >=20 > On 06/02/2016 09:42 AM, Chandran, Sugesh wrote: > >>>> Do you also suggest to drop IP checksum flags? > >>> > > > >>> > > IP checksum offload is mostly useless. If application needs to > >>> > > look at IP, it can do whole checksum in very few instructions, > >>> > > the whole header is in the same cache line as src/dst so the HW > >>> > > offload is really no > >> > help. > >>> > > > > [Sugesh] The checksum offload can boost the tunneling performance in > OVS. > > I guess the IP checksum also important as L4. In some cases, UDP > > checksum is zero and no need to validate it. But Ip checksum is > > present on all the packets and that must be validated all the time. > > At higher packet rate, the ip checksum offload can offer slight perform= ance > improvement. What do you think?? > > >=20 > Agree, in some situations (and this is even more true with packet types / > smartnics), the application could process without accessing the packet da= ta if > we keep the IP cksum flags. [Sugesh] True, If that's the case, Will you considering to implement IP checksum flags as well along with L4? As you said , this will be useful when we offload packet lookup itself into= the NICs(May be when using Flow director) ?=20 >=20 > Regards, > Olivier