From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by dpdk.org (Postfix) with ESMTP id 834201B14C for ; Wed, 19 Dec 2018 18:09:49 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Dec 2018 09:09:47 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,373,1539673200"; d="scan'208";a="119727659" Received: from irsmsx103.ger.corp.intel.com ([163.33.3.157]) by FMSMGA003.fm.intel.com with ESMTP; 19 Dec 2018 09:09:45 -0800 Received: from irsmsx101.ger.corp.intel.com ([169.254.1.237]) by IRSMSX103.ger.corp.intel.com ([169.254.3.157]) with mapi id 14.03.0415.000; Wed, 19 Dec 2018 17:09:44 +0000 From: "Trahe, Fiona" To: "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: AQHUgHH0iBHC0Frsi0+jiJBhoUExD6VX5t6AgADy5OCAAB0HgIArxwTwgAD9/YCAALx38A== Date: Wed, 19 Dec 2018 17:09:43 +0000 Message-ID: <348A99DA5F5B7549AA880327E580B435896A5DB3@IRSMSX101.ger.corp.intel.com> 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> 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: 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: Wed, 19 Dec 2018 17:09:50 -0000 Hi Shally, > -----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, P= aul E > > Subject: RE: [dpdk-dev] [PATCH] compressdev: add feature flag to specify = where processing is done >=20 >=20 >=20 > >-----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 s= pecify 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 to= o :) > >> > Would you prefer I removed that line? > >> > >> Hopefully, there would be one or more open source projects using the A= PI. > >> I just did a survey of DPDK an 1/3 of it is never used by any open sou= rce > >> project. Hate to see more dead code and special cases created. > >> > >> At least, some example code in examples would help. Something like a s= imple > >> 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 integr= ating > >compressdev and intend to push a patch to SPDK - a storage open-source p= roject - 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 specific. [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 back = to the op. The work is done by the HW accelerator, in between those 2 API calls, not u= sing any CPU cycles. So what would it mean for HW to set OP_DONE_IN_DEQUEUE? =20 > Thanks > Shally