From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <michael.qiu@intel.com> Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by dpdk.org (Postfix) with ESMTP id 184D528FD for <dev@dpdk.org>; Wed, 23 Mar 2016 03:47:38 +0100 (CET) Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga103.fm.intel.com with ESMTP; 22 Mar 2016 19:47:38 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,380,1455004800"; d="scan'208";a="674151485" Received: from fmsmsx106.amr.corp.intel.com ([10.18.124.204]) by FMSMGA003.fm.intel.com with ESMTP; 22 Mar 2016 19:47:38 -0700 Received: from fmsmsx156.amr.corp.intel.com (10.18.116.74) by FMSMSX106.amr.corp.intel.com (10.18.124.204) with Microsoft SMTP Server (TLS) id 14.3.248.2; Tue, 22 Mar 2016 19:47:37 -0700 Received: from shsmsx152.ccr.corp.intel.com (10.239.6.52) by fmsmsx156.amr.corp.intel.com (10.18.116.74) with Microsoft SMTP Server (TLS) id 14.3.248.2; Tue, 22 Mar 2016 19:47:37 -0700 Received: from shsmsx101.ccr.corp.intel.com ([169.254.1.136]) by SHSMSX152.ccr.corp.intel.com ([169.254.6.42]) with mapi id 14.03.0248.002; Wed, 23 Mar 2016 10:47:35 +0800 From: "Qiu, Michael" <michael.qiu@intel.com> To: "Richardson, Bruce" <bruce.richardson@intel.com> CC: Kyle Larose <eomereadig@gmail.com>, Thomas Monjalon <thomas.monjalon@6wind.com>, "Zhang, Helin" <helin.zhang@intel.com>, "Stephen Hemminger" <stephen@networkplumber.org>, "dev@dpdk.org" <dev@dpdk.org> Thread-Topic: [dpdk-dev] DPDK and HW offloads Thread-Index: AQHRgrNHrZMwEFSWME2cIx8wAcyncg== Date: Wed, 23 Mar 2016 02:47:35 +0000 Message-ID: <533710CFB86FA344BFBF2D6802E6028622F7208E@SHSMSX101.ccr.corp.intel.com> References: <20160318101611.2df26ef6@xeon-e3> <10753400.05iPBPOT6f@xps13> <F35DEAC7BCE34641BA9FAC6BCA4A12E70A9CD70B@SHSMSX104.ccr.corp.intel.com> <29795767.yLuRT7a5hO@xps13> <20160321145249.GA16732@bricha3-MOBL3> <CAMFWN9=daa-aNdi3+xE=zPt2kndTwgZCZ1YbxnWXyJNpY42EjA@mail.gmail.com> <533710CFB86FA344BFBF2D6802E6028622F70D9D@SHSMSX101.ccr.corp.intel.com> <20160322101941.GB19268@bricha3-MOBL3> 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] DPDK and HW offloads X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK <dev.dpdk.org> List-Unsubscribe: <http://dpdk.org/ml/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://dpdk.org/ml/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <http://dpdk.org/ml/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> X-List-Received-Date: Wed, 23 Mar 2016 02:47:39 -0000 On 3/22/2016 6:20 PM, Richardson, Bruce wrote:=0A= > On Tue, Mar 22, 2016 at 05:50:28AM +0000, Qiu, Michael wrote:=0A= >> On 3/21/2016 11:27 PM, Kyle Larose wrote:=0A= >>> On Mon, Mar 21, 2016 at 10:52 AM, Bruce Richardson=0A= >>> <bruce.richardson@intel.com> wrote:=0A= >>>> On Sun, Mar 20, 2016 at 08:18:57PM +0100, Thomas Monjalon wrote:=0A= >>>>> 2016-03-20 14:17, Zhang, Helin:=0A= >>>>>> From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com]=0A= >>>>>>> 2016-03-18 10:16, Stephen Hemminger:=0A= >>>>>>>> Right now, all those offload features are pretty much unusable in = a=0A= >>>>>>>> real product without lots and lots of extra codes and huge bug=0A= >>>>>>>> surface. It bothers me enough that I would recommend removing much= of the=0A= >>>>>>> filter/offload/ptype stuff from DPDK!=0A= >>>>>>>=0A= >>>>>>> One of the biggest challenge is to think about a good filtering API= .=0A= >>>>>>> The offloading has some interaction with the mbuf struct.=0A= >>>>>>>=0A= >>>>>>> I would like to suggest rewriting ethdev API by keeping it as is fo= r some time for=0A= >>>>>>> compatibility while creating a new one. What about the prefix dpdk_= netdev_ to=0A= >>>>>>> progressively replace rte_eth_dev?=0A= >>>>>> I totally agree with to add new and generic APIs for user applicatio= ns. But I don't=0A= >>>>>> think we need to remove all current APIs. Generic APIs may not suppo= rt all advanced=0A= >>>>>> hardware features, while specific APIs can. Why not support all? One= generic APIs for=0A= >>>>>> common users, and others APIs for advanced users.=0A= >>>>> Yes we cannot access to every features of a device through generic AP= I.=0A= >>>>> Until now we were trying to add an ethdev API for every features even= if it=0A= >>>>> is used by only one driver.=0A= >>>>> I think we should allow a direct access to the driver by the applicat= ions and=0A= >>>>> work on generic API only for common features.=0A= >>>> Definite +1.=0A= >>>> I think that we need to start pushing driver-specific functionality to= get exposed=0A= >>>> via a driver's header files. That allow users who want to extract the = max=0A= >>>> functionality from a particular NIC to do so via those APIs calls, whi= le not=0A= >>>> polluting the generic ethdev layer.=0A= >>>>=0A= >>> What sort of requirements on ABI/API compatibility would this place on= =0A= >>> the drivers? I would hope that it would be treated like any other=0A= >>> public API within DPDK. I don't think this would be too onerous, but=0A= >>> it would require that the drivers be designed to deal with it. (I.e.=0A= >>> don't just expose any old internal driver function).=0A= >> Why not to implement one simple API with variable arguments, just like= =0A= >> syscall ioctl() does. And drivers implement it's specific hardware=0A= >> features with a feature bit param, and other needed variable arguments.= =0A= >>=0A= >> Thanks,=0A= >> Michael=0A= > A very much dislike that idea. =0A= > * It makes the code much harder to read as you have to closely examine al= l the=0A= > parameters to work out what a function call is actually meant to do.=0A= =0A= It's not a big deal, if we have a document.=0A= =0A= > * It makes it much harder to see that you have an implicit dependency on = a=0A= > specific device. Having to include a driver specific header file e.g. i= 40e.h,=0A= > and call a function named e.g. i40e_do_magic_stuff(), makes it pretty e= xplicit=0A= > that you have a dependency on i40e-based hardware=0A= =0A= Software does not want to bind to specific hardware I think, what about=0A= the transportability?=0A= =0A= > * It prevents the compiler from doing type-checking on parameters and inf= orming=0A= > you of little inconsistencies.=0A= =0A= Maybe, we could do self-check for the parameters I think.=0A= =0A= >=0A= > For all these reasons, I prefer the device-specific functions option. How= ever,=0A= > at the same time, we also need to ensure we have a reasonable set of gene= ric=0A= > APIs so that the cases where users are forced to drop down to the lower-l= evel=0A= > device-specific primitives are reduced.=0A= =0A= For software, it do not care which hardware it is, it only cares about=0A= what ability you have.=0A= =0A= Thanks,=0A= Michael=0A= =0A= > Regards,=0A= > /Bruce=0A= >=0A= >>>> On the other hand, I don't like the idea of dpdk_netdev. I think we ca= n work=0A= >>>> within the existing rte_eth_dev framework.=0A= >>>>=0A= >>>> /Bruce=0A= >>>>=0A= >>=0A= =0A=