From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id AA2F8137D for ; Thu, 10 Jan 2019 07:23:18 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Jan 2019 22:23:17 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,460,1539673200"; d="scan'208";a="113592423" Received: from orsmsx105.amr.corp.intel.com ([10.22.225.132]) by fmsmga007.fm.intel.com with ESMTP; 09 Jan 2019 22:23:17 -0800 Received: from orsmsx157.amr.corp.intel.com (10.22.240.23) by ORSMSX105.amr.corp.intel.com (10.22.225.132) with Microsoft SMTP Server (TLS) id 14.3.408.0; Wed, 9 Jan 2019 22:23:17 -0800 Received: from orsmsx122.amr.corp.intel.com ([169.254.11.231]) by ORSMSX157.amr.corp.intel.com ([169.254.9.157]) with mapi id 14.03.0415.000; Wed, 9 Jan 2019 22:23:17 -0800 From: "Rao, Nikhil" To: Stephen Hemminger CC: "Dumitrescu, Cristian" , "Singh, Jasvinder" , "dev@dpdk.org" Thread-Topic: [dpdk-dev] [PATCH] ethdev: support double precision RED queue weight Thread-Index: AQHUh6hGZNKORyos/kqiWAO0xdfBoqVmy+KAgBCunFCAAT9ugIAvirqw Date: Thu, 10 Jan 2019 06:23:16 +0000 Message-ID: <1F668163772FA946975B9466A9DFF729EDDA4F7C@ORSMSX122.amr.corp.intel.com> References: <1543470882-145287-1-git-send-email-nikhil.rao@intel.com> <20181128221245.017eadcf@xeon-e3> <1F668163772FA946975B9466A9DFF729ED3AF9EF@ORSMSX110.amr.corp.intel.com> <20181210080109.617902f1@xeon-e3> In-Reply-To: <20181210080109.617902f1@xeon-e3> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiYjc5ODdlNjItYTVmMC00YjYyLTkyZWMtM2JjM2E0YmRkNDVhIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE3LjEwLjE4MDQuNDkiLCJUcnVzdGVkTGFiZWxIYXNoIjoiZVh4UUdWUUw3ZURjaDlwemd2V0ZYWHh6b3UzYzlXdjFGWWdROFY2R245cERSV1ZQamtZaGxNb0JWck5NUGxzcCJ9 x-ctpclassification: CTP_NT dlp-product: dlpe-windows dlp-version: 11.0.400.15 dlp-reaction: no-action x-originating-ip: [10.22.254.138] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] [PATCH] ethdev: support double precision RED queue weight 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 06:23:19 -0000 > -----Original Message----- > From: Stephen Hemminger [mailto:stephen@networkplumber.org] > Sent: Monday, December 10, 2018 9:31 PM Hi Stephen, > To: Rao, Nikhil > Cc: Dumitrescu, Cristian ; Singh, Jasvinde= r > ; dev@dpdk.org > Subject: Re: [dpdk-dev] [PATCH] ethdev: support double precision RED queu= e > weight >=20 > On Mon, 10 Dec 2018 05:43:37 +0000 > "Rao, Nikhil" wrote: >=20 > > > -----Original Message----- > > > From: Stephen Hemminger [mailto:stephen@networkplumber.org] > > > Sent: Thursday, November 29, 2018 11:43 AM > > > To: Rao, Nikhil > > > Cc: Dumitrescu, Cristian ; Singh, > > > Jasvinder ; dev@dpdk.org > > > Subject: Re: [dpdk-dev] [PATCH] ethdev: support double precision RED > > > queue weight > > > > > > On Thu, 29 Nov 2018 11:24:42 +0530 > > > Nikhil Rao wrote: > > > > > > > RED queue weight is currently specified as a negated log of 2. > > > > > > > > Add support for RED queue weight to be specified in double > > > > precision and TM capability flags for double precision and negated > > > > log2 RED queue weight support. > > > > > > > > Signed-off-by: Nikhil Rao > > > > > > Since this is an ABI break anyway, why not just commit to the new for= mat? > > > > Hi Stephen, > > > > Can you please provide more detail on your comment ? are you suggestin= g > replacing the wq_log2/wq_dp with a double ? > > > > Thanks, > > Nikhil >=20 >=20 > My comment is that since you are changing a structure layout, which would > break existing users; why not go farther and just fix the API to a better > version. I don't think any projects use this code anyway, see my talk > (https://github.com/shemminger/dpdk-metrics). Sorry for the delay. I don't get your reference to a better version, the = structure supports both formats using a union, similar to how it's done in other DPDK APIs (struct rte_crypto_sym_xform f= or example). If you have a suggestion for a better layout, please let me know. =20 >=20 > Isn't floating point going to be expensive. Or is it only during the setu= p > process, not enqueue/dequeue. Yes, floating point may end up to be more expensive (and the RED computatio= n is invoked at every enqueue) Nikhil