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 DC1CF5F2A for ; Thu, 15 Mar 2018 10:48:59 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Mar 2018 02:48:58 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,310,1517904000"; d="scan'208";a="208443230" Received: from irsmsx153.ger.corp.intel.com ([163.33.192.75]) by orsmga005.jf.intel.com with ESMTP; 15 Mar 2018 02:48:55 -0700 Received: from irsmsx155.ger.corp.intel.com (163.33.192.3) by IRSMSX153.ger.corp.intel.com (163.33.192.75) with Microsoft SMTP Server (TLS) id 14.3.319.2; Thu, 15 Mar 2018 09:48:55 +0000 Received: from irsmsx101.ger.corp.intel.com ([169.254.1.5]) by irsmsx155.ger.corp.intel.com ([169.254.14.21]) with mapi id 14.03.0319.002; Thu, 15 Mar 2018 09:48:54 +0000 From: "Trahe, Fiona" To: "Verma, Shally" , Ahmed Mansour , "dev@dpdk.org" CC: "De Lara Guarch, Pablo" , "Athreya, Narayana Prasad" , "Gupta, Ashish" , "Sahu, Sunila" , "Challa, Mahipal" , "Jain, Deepak K" , Hemant Agrawal , "Roy Pledge" , Youri Querry , "Daly, Lee" , "Jozwiak, TomaszX" , "Trahe, Fiona" , Alok Makhariya , Shreyansh Jain Thread-Topic: [dpdk-dev] [PATCH] compressdev: implement API - mbuf alternative Thread-Index: AdO6FqZGVQESVGJPRLukdFdKpdlnigB+2tOQAAwqzdA= Date: Thu, 15 Mar 2018 09:48:54 +0000 Message-ID: <348A99DA5F5B7549AA880327E580B4358934B669@IRSMSX101.ger.corp.intel.com> References: <348A99DA5F5B7549AA880327E580B435893478BA@IRSMSX101.ger.corp.intel.com> <348A99DA5F5B7549AA880327E580B4358934A600@IRSMSX101.ger.corp.intel.com> <348A99DA5F5B7549AA880327E580B4358934B32C@IRSMSX101.ger.corp.intel.com> In-Reply-To: Accept-Language: en-IE, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiNjVjZTIzYTItOGFiOS00OTFlLWI4MWYtYjAyOTJhNzUxNjU0IiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE2LjUuOS4zIiwiVHJ1c3RlZExhYmVsSGFzaCI6IlVTRGFYaDlnNU92T1wvdDRla1M5ZjBqdEVIU3VOVDR5SjZSK3E4ZGgyWEF3PSJ9 x-ctpclassification: CTP_NT dlp-product: dlpe-windows dlp-version: 11.0.0.116 dlp-reaction: no-action 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] [PATCH] compressdev: implement API - mbuf alternative 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: Thu, 15 Mar 2018 09:49:00 -0000 > -----Original Message----- > From: Verma, Shally [mailto:Shally.Verma@cavium.com] > Sent: Thursday, March 15, 2018 4:12 AM > To: Ahmed Mansour ; Trahe, Fiona ; dev@dpdk.org > Cc: De Lara Guarch, Pablo ; Athreya, Nara= yana Prasad > ; Gupta, Ashish ; Sahu, Sunila > ; Challa, Mahipal ; Ja= in, Deepak K > ; Hemant Agrawal ; Roy P= ledge > ; Youri Querry ; Daly, Lee ; > Jozwiak, TomaszX ; Alok Makhariya ; Shreyansh > Jain > Subject: RE: [dpdk-dev] [PATCH] compressdev: implement API - mbuf alterna= tive >=20 > @Trahe, Fiona>> We're proposing, in the interest of getting the API out i= n 18.05, to stick with mbufs - > acknowledging > >> that they're not optimal for storage and we may propose changes in 18.= 08. > [Shally] Sounds good to us too. >=20 > @Ahmed Mansour . I am assuming that transferring from mbuf to regular buf= fers and back does > >not involve some time consuming work like data copying and such. > [Shally] I too assume copying shouldn't be a need and a big no-no. We nor= mally extract and pass buf_addr > from mbuf as it is to HW. > So implicit assumption is data memory is dma-able to device. [Fiona] agreed >=20 > Thanks > Shally >=20 > >-----Original Message----- > >From: Ahmed Mansour [mailto:ahmed.mansour@nxp.com] > >Sent: 15 March 2018 00:32 > >To: Trahe, Fiona ; Verma, Shally ; dev@dpdk.org > >Cc: De Lara Guarch, Pablo ; Athreya, Nar= ayana Prasad > ; > >Gupta, Ashish ; Sahu, Sunila ; Challa, Mahipal > >; Jain, Deepak K ; H= emant Agrawal > ; Roy > >Pledge ; Youri Querry ; Daly= , Lee > ; Jozwiak, TomaszX > >; Alok Makhariya ; Sh= reyansh Jain > > >Subject: Re: [dpdk-dev] [PATCH] compressdev: implement API - mbuf altern= ative > > > >Hi All, > > > >Sticking with mbufs until at least 1805 works for us. We also see > >storage as the main use case, but ipcomp maybe an important customer use > >case in the future. Nonetheless, I see the mbuf formatting as inherently > >external to the compressdev APIs. An application doing ipcomp should > >just do the mbuf packaging outside of compressdev. At least that is what > >current software implementation of ipcomp do when using zlib.net. I am > >assuming that transferring from mbuf to regular buffers and back does > >not involve some time consuming work like data copying and such. > > > >Thanks, > > > >Ahmed > > > >On 3/14/2018 2:39 PM, Trahe, Fiona wrote: > >> Hi Shally, Ahmed, et al, > >> > >> Following internal and community feedback we've decided that there's s= till too much churn in this. > >> We're proposing, in the interest of getting the API out in 18.05, to s= tick with mbufs - acknowledging > >> that they're not optimal for storage and we may propose changes in 18.= 08. > >> Compressdev will start as an experimental API in 18.05 - we'll POC and= benchmark alternatives > >> or API extensions once we get time to do so. > >> > >> Regards, > >> Fiona > >> > >>> -----Original Message----- > >>> From: Verma, Shally [mailto:Shally.Verma@cavium.com] > >>> Sent: Wednesday, March 14, 2018 12:51 PM > >>> To: Trahe, Fiona ; Ahmed Mansour ; > dev@dpdk.org > >>> Cc: De Lara Guarch, Pablo ; Athreya, = Narayana Prasad > >>> ; Gupta, Ashish ; Sahu, Sunila > >>> ; Challa, Mahipal = ; Jain, Deepak K > >>> ; Hemant Agrawal ; R= oy Pledge > >>> ; Youri Querry ; Daly, Le= e ; > >>> Jozwiak, TomaszX > >>> Subject: RE: [dpdk-dev] [PATCH] compressdev: implement API - mbuf alt= ernative > >>> > >>> > >>> > >>>> -----Original Message----- > >>>> From: Trahe, Fiona [mailto:fiona.trahe@intel.com] > >>>> Sent: 13 March 2018 21:22 > >>>> To: Verma, Shally ; Ahmed Mansour ; > >>> dev@dpdk.org > >>>> Cc: De Lara Guarch, Pablo ; Athreya,= Narayana Prasad > >>> ; > >>>> Gupta, Ashish ; Sahu, Sunila ; Challa, > Mahipal > >>>> ; Jain, Deepak K ; Hemant Agrawal > >>> ; Roy > >>>> Pledge ; Youri Querry ; = Daly, Lee > >>> ; Jozwiak, TomaszX > >>>> ; Trahe, Fiona > >>>> Subject: RE: [dpdk-dev] [PATCH] compressdev: implement API - mbuf al= ternative > >>>> > >>>> Hi Shally, > >>>> > >>>>> -----Original Message----- > >>>>> From: Verma, Shally [mailto:Shally.Verma@cavium.com] > >>>>> Sent: Tuesday, March 13, 2018 8:15 AM > >>>>> To: Trahe, Fiona ; Ahmed Mansour ; > >>> dev@dpdk.org > >>>>> Cc: De Lara Guarch, Pablo ; Athreya= , Narayana Prasad > >>>>> ; Gupta, Ashish ; Sahu, > Sunila > >>>>> ; Challa, Mahipal ; Jain, Deepak K > >>>>> ; Hemant Agrawal ;= Roy Pledge > >>>>> ; Youri Querry ; fiona.= trahe@gmail.com; Daly, > Lee > >>>>> ; Jozwiak, TomaszX > >>>>> Subject: RE: [dpdk-dev] [PATCH] compressdev: implement API - mbuf a= lternative > >>>>> > >>>>> HI Fiona > >>>>> > >>>>> So I understand we're moving away from mbufs because of its size li= mitation (64k) and cacheline > >>> overhead > >>>>> and their more suitability to n/w applications. Given that, I under= stand benefit of having another > >>> structure > >>>>> to input data but then what is proposal for ipcomp like application= where mbuf usage may be a > better > >>>>> option? Should we keep support for both (mbuf and this structure) s= o that apps can use appropriate > >>> data > >>>>> structure depending on their requirement. > >>>> [Fiona] An application can use pass buffers from an mbuf or mbuf cha= in to compressdev by filling in > the > >>>> compressdev struct fields with the mbuf meta-data, using rte_pktmbuf= _data_len(), > >>>> rte_pktmbuf_mtod(), rte_pktmbuf_mtophys(), etc > >>>> For simplicity I'd prefer to offer only 1 rather than 2 data formats= on the API. > >>>> We see storage applications rather than IPComp as the main use-case = for compressdev, so would > prefer > >>>> to optimise for that. > >>>> Do you think otherwise? > >>> [Shally] Yea. We plan to use it for ipcomp and other such possible n/= w apps. So, we envision mbuf > support > >>> as necessary. So, I think we can add two APIs one which process on rt= e_comp_op and other on > rte_mbufs > >>> to make it simpler. > >>> > >>>>> Further comments, on github. > >>>>> > >>>>> Thanks > >>>>> Shally > >>>>> > >>>>>> -----Original Message----- > >>>>>> From: Trahe, Fiona [mailto:fiona.trahe@intel.com] > >>>>>> Sent: 12 March 2018 21:31 > >>>>>> To: Ahmed Mansour ; Verma, Shally ; > >>>>> dev@dpdk.org > >>>>>> Cc: De Lara Guarch, Pablo ; Athrey= a, Narayana Prasad > >>>>> ; > >>>>>> Gupta, Ashish ; Sahu, Sunila ; Challa, > >>> Mahipal > >>>>>> ; Jain, Deepak K ; Hemant Agrawal > >>>>> ; Roy > >>>>>> Pledge ; Youri Querry = ; fiona.trahe@gmail.com; > >>> Daly, > >>>>> Lee ; > >>>>>> Jozwiak, TomaszX > >>>>>> Subject: RE: [dpdk-dev] [PATCH] compressdev: implement API - mbuf = alternative > >>>>>> > >>>>>> Hi Shally, Ahmed, and anyone else interested in compressdev, > >>>>>> > >>>>>> I mentioned last week that we've been exploring using something ot= her than mbufs to pass src/dst > >>>>> buffers to compressdev PMDs. > >>>>>> Reasons: > >>>>>> - mbuf data is limited to 64k-1 in each segment of a chained mbuf.= Data for compression > >>>>>> can be greater and it would add cycles to have to break up into= smaller segments. > >>>>>> - data may originate in mbufs, but is more likely, particularly fo= r storage use-cases, to > >>>>>> originate in other data structures. > >>>>>> - There's a 2 cache-line overhead for every segment in a chain, mo= st of this data > >>>>>> is network-related, not needed by compressdev > >>>>>> So moving to a custom structure would minimise memory overhead, re= move restriction on 64k-1 > size > >>> and > >>>>> give more flexibility if > >>>>>> compressdev ever needs any comp-specific meta-data. > >>>>>> > >>>>>> We've come up with a compressdev-specific structure using the stru= ct iovec from sys/uio.h, which > is > >>>>> commonly used by storage > >>>>>> applications. This would replace the src and dest mbufs in the op= . > >>>>>> I'll not include the code here - Pablo will push that to github sh= ortly and we'd appreciate review > >>>>> comments there. > >>>>>> > https://emea01.safelinks.protection.outlook.com/?url=3Dhttps%3A%2F%2Fgith= ub.com%2Fpablodelara%2Fd > pdk-draft- > >compressdev&data=3D02%7C01%7Cahmed.mansour%40nxp.com%7C6a8977f9b3714d586= 21708d589dae > 567%7C686ea1d3bc2b4c6fa92cd > >99c5c301635%7C0%7C0%7C636566495639618830&sdata=3DwmFrxeUNyXdxI5%2Fp5gCmy= IRfeDnbHebBJ > XbztqdsMrc%3D&reserved=3D0 > >>>>>> Just posting on the mailing list to give a heads-up and ensure thi= s reaches a wider audience than > may > >>> see > >>>>> it on github. > >>>>>> Note : We also considered having no data structures in the op, ins= tead the application > >>>>>> would supply a callback which the PMD would use to retrieve meta-d= ata (virt address, iova, length) > >>>>>> for each next segment as needed. While this is quite flexible and = allow the application > >>>>>> to keep its data in its native structures, it's likely to cost mor= e cycles. > >>>>>> So we're not proposing this at the moment, but hope to benchmark i= t later while the API is still > >>>>> experimental. > >>>>>> General feedback on direction is welcome here on the mailing list. > >>>>>> For feedback on the details of implementation we would appreciate = comments on github. > >>>>>> > >>>>>> Regards, > >>>>>> Fiona. > >