From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by dpdk.org (Postfix) with ESMTP id 3F84D1B8B4 for ; Thu, 10 Jan 2019 19:46:41 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Jan 2019 10:46:38 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,462,1539673200"; d="scan'208";a="117135955" Received: from irsmsx105.ger.corp.intel.com ([163.33.3.28]) by orsmga003.jf.intel.com with ESMTP; 10 Jan 2019 10:46:36 -0800 Received: from irsmsx112.ger.corp.intel.com ([169.254.1.84]) by irsmsx105.ger.corp.intel.com ([169.254.7.116]) with mapi id 14.03.0415.000; Thu, 10 Jan 2019 18:46:35 +0000 From: "De Lara Guarch, Pablo" To: "Trahe, Fiona" , "Verma, Shally" , Stephen Hemminger CC: "dev@dpdk.org" , "akhil.goyal@nxp.com" , "Jozwiak, TomaszX" , "Gupta, Ashish" , "Daly, Lee" , "Luse, Paul E" , "Trahe, Fiona" Thread-Topic: [dpdk-dev] [PATCH] compressdev: add feature flag to specify where processing is done Thread-Index: AQHUgHPwFM2x5R1UlUmE3G4iRZr1wqVY2mCAgAAcZYCAK8hOAIAA/LOAgAC+loCAIq284A== Date: Thu, 10 Jan 2019 18:46:35 +0000 Message-ID: References: <1542677988-3876-1-git-send-email-fiona.trahe@intel.com> <20181119175349.2bd2fdd1@xeon-e3> <348A99DA5F5B7549AA880327E580B4358967C84F@IRSMSX101.ger.corp.intel.com> <20181120100703.34c462e9@xeon-e3> <348A99DA5F5B7549AA880327E580B435896A4B55@IRSMSX101.ger.corp.intel.com> <348A99DA5F5B7549AA880327E580B435896A5DB3@IRSMSX101.ger.corp.intel.com> In-Reply-To: <348A99DA5F5B7549AA880327E580B435896A5DB3@IRSMSX101.ger.corp.intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiNWIyZDdkNDEtNmIzMC00ZTE5LWI1ZDktOTg2OTM2YmYwYThlIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE3LjEwLjE4MDQuNDkiLCJUcnVzdGVkTGFiZWxIYXNoIjoiTHFvSU1QalZSaDZVc21cL1ptQ3dKU2R3WTlUZjFRTDc4Z3FUSDJTMXFcLzVWaHEzYnV3WmhwWFlHcDhFR3hiSWVvIn0= x-ctpclassification: CTP_NT dlp-product: dlpe-windows dlp-version: 11.0.400.15 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: add feature flag to specify where processing is done 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, 10 Jan 2019 18:46:41 -0000 Hi Shally, > -----Original Message----- > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Trahe, Fiona > Sent: Wednesday, December 19, 2018 5:10 PM > To: Verma, Shally ; Stephen Hemminger > > Cc: dev@dpdk.org; akhil.goyal@nxp.com; Jozwiak, TomaszX > ; Gupta, Ashish ; > Daly, Lee ; Luse, Paul E ; Tra= he, > Fiona > Subject: Re: [dpdk-dev] [PATCH] compressdev: add feature flag to specify > where processing is done >=20 > Hi Shally, >=20 > > -----Original Message----- > > From: Verma, Shally [mailto:Shally.Verma@cavium.com] > > Sent: Tuesday, December 18, 2018 10:48 PM > > To: Trahe, Fiona ; Stephen Hemminger > > > > Cc: dev@dpdk.org; akhil.goyal@nxp.com; Jozwiak, TomaszX > > ; Gupta, Ashish > ; > > Daly, Lee ; Luse, Paul E > > Subject: RE: [dpdk-dev] [PATCH] compressdev: add feature flag to > > specify where processing is done > > > > > > > > >-----Original Message----- > > >From: Trahe, Fiona > > >Sent: 18 December 2018 20:13 > > >To: Stephen Hemminger > > >Cc: dev@dpdk.org; akhil.goyal@nxp.com; Jozwiak, TomaszX > > >; Verma, > > Shally > > >; Gupta, Ashish > ; > > >Daly, Lee > > ; Luse, Paul E > > >; Trahe, Fiona > > >Subject: RE: [dpdk-dev] [PATCH] compressdev: add feature flag to > > >specify where processing is done > > > > > >External Email > > > > > >Hi Stephen > > > > > >//snip// > > >> > > Subject: Re: [dpdk-dev] [PATCH] compressdev: add feature flag > > >> > > to specify where processing is > > done > > >> > > > > >> > > On Tue, 20 Nov 2018 01:39:48 +0000 Fiona Trahe > > >> > > wrote: > > >> > > > > >> > > > A new device feature flag, > > >> > > > RTE_COMPDEV_FF_SW_OP_DONE_IN_DEQUEUE > > >> > > > is added. A PMD which processes operations using a software > > >> > > > acceleration engine should set this if the bulk of the > > >> > > > processing is done during the dequeue. It should leave it > > >> > > > cleared if the bulk of the processing is done during the > > >> > > > enqueue (default). > > >> > > > An application may find this useful for tuning. > > >> > > > > > >> > > > Signed-off-by: Fiona Trahe > > >> > > > > >> > > What application? or is this "if we build it they will come?" > > >> > [Fiona] Our storage team asked for this, so not quite. > > >> > Seems like it might by generically useful, so a bit of the latter > > >> > too :) Would you prefer I removed that line? > > >> > > >> Hopefully, there would be one or more open source projects using the > API. > > >> I just did a survey of DPDK an 1/3 of it is never used by any open > > >> source project. Hate to see more dead code and special cases create= d. > > >> > > >> At least, some example code in examples would help. Something like > > >> a simple in memory compressed storage server using a network API > > >> (SMB?/SSH?/FTP?) > > >[Fiona] There is no compressdev sample app yet. > > >However I've double-checked with the SPDK team, they're currently > > >integrating compressdev and intend to push a patch to SPDK - a storage > open-source project - using this flag. > > [Shally] Am seeing some of our HW based PMD also leveraging this > > choice. So I would say to make it generic feature flag instead of SW sp= ecific. > [Fiona] I can do but would like to understand this better first. > My understanding of HW offload is that the enqueue is just packaging up > the op and sending to the HW. > And the dequeue is just collecting the result from the HW and passing bac= k > to the op. > The work is done by the HW accelerator, in between those 2 API calls, not > using any CPU cycles. > So what would it mean for HW to set OP_DONE_IN_DEQUEUE? Any comments on this? I agree with Fiona that this flag makes sense on SW o= nly, but it seems that you have another use case. Thanks, Pablo >=20 > > Thanks > > Shally