From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by dpdk.org (Postfix) with ESMTP id 78CE41F28 for ; Tue, 20 Nov 2018 17:41:03 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Nov 2018 08:41:02 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,257,1539673200"; d="scan'208";a="90792020" Received: from irsmsx151.ger.corp.intel.com ([163.33.192.59]) by orsmga007.jf.intel.com with ESMTP; 20 Nov 2018 08:41:00 -0800 Received: from irsmsx101.ger.corp.intel.com ([169.254.1.134]) by IRSMSX151.ger.corp.intel.com ([169.254.4.122]) with mapi id 14.03.0415.000; Tue, 20 Nov 2018 16:40:59 +0000 From: "Trahe, Fiona" To: "Verma, Shally" , "dev@dpdk.org" CC: "akhil.goyal@nxp.com" , "Jozwiak, TomaszX" , "Gupta, Ashish" , "Daly, Lee" , "Trahe, Fiona" Thread-Topic: [PATCH] compressdev: add feature flag to specify where processing is done Thread-Index: AQHUgHH0iBHC0Frsi0+jiJBhoUExD6VYH7qAgAC65MA= Date: Tue, 20 Nov 2018 16:40:59 +0000 Message-ID: <348A99DA5F5B7549AA880327E580B4358967C891@IRSMSX101.ger.corp.intel.com> References: <1542677988-3876-1-git-send-email-fiona.trahe@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: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiYjhmMGNhNjMtMWZjZi00NjE4LWE3YWQtNGViNDcyYTEyN2U3IiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE3LjEwLjE4MDQuNDkiLCJUcnVzdGVkTGFiZWxIYXNoIjoiZHVXOUJRaTNjTkhHRFwvUE5GXC9vSUF0bmRYa3ZSRWFPZjhyZ1pISlwveUZzUzZ5UXBZaGdjNFhFdEp0ZkNGaU5EdSJ9 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: Tue, 20 Nov 2018 16:41:04 -0000 Hi Shally, > -----Original Message----- > From: Verma, Shally [mailto:Shally.Verma@cavium.com] > Sent: Monday, November 19, 2018 10:17 PM > To: Trahe, Fiona ; dev@dpdk.org > Cc: akhil.goyal@nxp.com; Jozwiak, TomaszX ; Gu= pta, Ashish > ; Daly, Lee > Subject: RE: [PATCH] compressdev: add feature flag to specify where proce= ssing is done >=20 > HI Fiona >=20 > >-----Original Message----- > >From: Fiona Trahe > >Sent: 20 November 2018 07:10 > >To: dev@dpdk.org > >Cc: akhil.goyal@nxp.com; tomaszx.jozwiak@intel.com; Verma, Shally ; > Gupta, Ashish > >; lee.daly@intel.com; fiona.trahe@intel.com > >Subject: [PATCH] compressdev: add feature flag to specify where processi= ng is done > > > >External Email > > > >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. >=20 > Help me understand a bit , so how does it work when: > 1. PMD do ops processing only at enqueue , will not set this flag? > 2. PMD do ops processing only at dequeue, then? > 3. PMD can do op processing both at enqueue and dequeue and in such case,= can set this flag to indicate > this support? So that app can choose? [Fiona] Both sw PMDs already upstreamed do the bulk of the work on the enqu= eue. So no need to set the flag. It doesn't seem likely that PMDs will split the workload between enqueue an= d dequeue, if they do for some reason, thy can set whichever makes most sen= se. It's like a hint, similar to the HW flag - to help an application to tune -= applications don't have to use it if they don't want to. I'm planning to send same patch for cryptodev - there two PMDs do all the w= ork on dequeue, the rest do it on enqueue. Our Storage team asked for this = as they changed some polling timings once they understood where the work was done. =20 > if supported then app set this feature flag on PMD and PMD take it as a h= int to know application > preference of processing point or PMD always do bulk processing at chosen= point? [Fiona] No, it's the opposite - the PMD reports the capabilities to the app= l. >=20 > And why specific to SW PMD, I see HW PMD can do use this feature flag?! [Fiona] HW is not using CPU cycle as the work is offloaded, so I don't see = how it can apply there. >=20 > Thanks > Shally