From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id A5FCEA04A6; Wed, 9 Feb 2022 08:59:01 +0100 (CET) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 67A14410FD; Wed, 9 Feb 2022 08:59:01 +0100 (CET) Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by mails.dpdk.org (Postfix) with ESMTP id 34F3D410F3 for ; Wed, 9 Feb 2022 08:58:58 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1644393539; x=1675929539; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-transfer-encoding:mime-version; bh=9GBDqn7lffuTVOYR0C3JwXkxkklpXntFeYVhTZfEYXY=; b=MXtDyRXskUb0R2NSuF9rP3RzYKxoUDG7zTE/fJg8lUSbUwgFhbAMmdJz Lhn23hXCDhEJPb7C4YSWGnolDJoCt4wigVGkgdcNkt3gt5uz8yO5tJ0YI sWgWFZkWGZ6hEj2eqvYn8D51qTKDT/TaVLpabk4sOdQiXPPZCleIOuUWV Gqdx7r1BAt9T0mJOPfzBzLxb+CIxRdrxjhaIh0f+XQDDygn2EI1fYd80m ZFay4iaQPbTmglyFa/nMRxm1ReAdIBrezAU0E4V6vEqlTJNxhydJy5KZF FX8Zc0U9IYMyxROq2D7XceNZGPBs4AYHV8DIQIxq8sTb182qk4B7zs6l2 g==; X-IronPort-AV: E=McAfee;i="6200,9189,10252"; a="249356270" X-IronPort-AV: E=Sophos;i="5.88,355,1635231600"; d="scan'208";a="249356270" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Feb 2022 23:58:58 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,355,1635231600"; d="scan'208";a="771262464" Received: from orsmsx603.amr.corp.intel.com ([10.22.229.16]) by fmsmga006.fm.intel.com with ESMTP; 08 Feb 2022 23:58:57 -0800 Received: from orsmsx612.amr.corp.intel.com (10.22.229.25) by ORSMSX603.amr.corp.intel.com (10.22.229.16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Tue, 8 Feb 2022 23:58:57 -0800 Received: from orsmsx603.amr.corp.intel.com (10.22.229.16) by ORSMSX612.amr.corp.intel.com (10.22.229.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Tue, 8 Feb 2022 23:58:56 -0800 Received: from ORSEDG602.ED.cps.intel.com (10.7.248.7) by orsmsx603.amr.corp.intel.com (10.22.229.16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20 via Frontend Transport; Tue, 8 Feb 2022 23:58:56 -0800 Received: from NAM12-MW2-obe.outbound.protection.outlook.com (104.47.66.47) by edgegateway.intel.com (134.134.137.103) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2308.20; Tue, 8 Feb 2022 23:58:56 -0800 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=kkPgW8muPPMgdJyUtEEXr5MQmXvNXZKxbL8nGf4KsQP9ZuJZju9h2Pr6Ula2Mc0gyZceicw1/B7iEWHiqKmonW5pRJUgDRNN+NWsMCOctz5wTGZnTJeBs2fmKhvcbAvsJPTBDlFRe0hCwMPKwohGIb3PdEqsKTb5AyoxkoM2nh88Ii+Y6vXtgPcxhTeLeAHH1Oph2SfQnhPb5XjOSsU8Ss1ooKKg3xf8ecf5PerCb8SCAwy8n6nfJrTiLC0f30t+oWbvOP89RcwDLbZF8Mbd+LDXuk4U7NfQQjRWC3k3p4wCzukuHQ6dEJQonHLTeiEWRLOvyKO0oL0eKll1jChmDg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=xUaff0MSbKMaoCndXNjdkI71lt4sdulO3WnItllnzd8=; b=CbI1CkVPyD8wurSMTrQF2DnGABZwqYDHtA9nFSbhXIsPouj9uyytOlZnnOYXhyvo7k6wAFJ4GanXLfr0/8TV/QQ2xl3TikdtjdR3H68KYhLit3FzdzALhM4L7hIgwRDckXuCXo+zXyGlEvNd7Jx0C5UmZVwzjK7eRHpkineTB7AtJ9bRZm5FWdymzQLZHukRv3b7np+3oYJuQtJzaZUPpreOtlblBz6GL5wCYq7E+yL7ojfBVDjIxFB1SKo441KLDeYggKy/RI0R4bf7X7BiEDSQWkP2R8z7pgpScJRpsP/2pG4Ldw5TFAaf5udGmo/ZtNfsQW3RfJ+L07i+x5Q2yw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=none; dmarc=none; dkim=none; arc=none Received: from DM6PR11MB3098.namprd11.prod.outlook.com (2603:10b6:5:70::11) by MWHPR11MB1407.namprd11.prod.outlook.com (2603:10b6:300:26::17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4951.14; Wed, 9 Feb 2022 07:58:53 +0000 Received: from DM6PR11MB3098.namprd11.prod.outlook.com ([fe80::4c15:87ef:5338:e0fa]) by DM6PR11MB3098.namprd11.prod.outlook.com ([fe80::4c15:87ef:5338:e0fa%4]) with mapi id 15.20.4951.019; Wed, 9 Feb 2022 07:58:53 +0000 From: "Xing, Beilei" To: Honnappa Nagarahalli , "dev@dpdk.org" CC: Feifei Wang , Ruifeng Wang , "Yigit, Ferruh" , "Richardson, Bruce" , nd , nd Subject: RE: Questions on i40e TX path Thread-Topic: Questions on i40e TX path Thread-Index: AdgdbGSND9JeH63pReG8SPoILQbVuQAGlTqg Date: Wed, 9 Feb 2022 07:58:53 +0000 Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=intel.com; x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: 56ad9df9-3ce4-4f76-daf9-08d9eba203ed x-ms-traffictypediagnostic: MWHPR11MB1407:EE_ x-ld-processed: 46c98d88-e344-4ed4-8496-4ed7712e255d,ExtAddr x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:9508; x-ms-exchange-senderadcheck: 1 x-ms-exchange-antispam-relay: 0 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: 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 x-forefront-antispam-report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:DM6PR11MB3098.namprd11.prod.outlook.com; PTR:; CAT:NONE; SFS:(13230001)(366004)(5660300002)(38100700002)(122000001)(71200400001)(4326008)(86362001)(53546011)(6506007)(38070700005)(508600001)(7696005)(55016003)(8676002)(8936002)(64756008)(82960400001)(2906002)(110136005)(52536014)(186003)(83380400001)(54906003)(66946007)(76116006)(33656002)(66556008)(66476007)(66446008)(316002)(26005)(9686003); DIR:OUT; SFP:1102; x-ms-exchange-antispam-messagedata-chunkcount: 1 x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?lvUbPr/ncsHmId7mzZiBoidagV3VUE+Y6N7FkryXbmctTk+F4oqdKwYehbSq?= =?us-ascii?Q?9mux9AjUSa9+OZ0ar1LK47P++nqVBT90ttuFzMV6lXW735pYBl56QnBblmn+?= =?us-ascii?Q?a57y50s4YBnM+1APUqVZLlDz2SgWU+wEh+OptAzwM4+q55kFXfgZrQyEUhzN?= =?us-ascii?Q?Q3l0hVqzMohPsJ86Z7ireF5rbpYnBDdEOxrjtA7wX7OH/18oVChra8KIv/pZ?= =?us-ascii?Q?zUGJfEtupNA4pYCYpP4ZKrIBZHOBLEjWh6N2/tv7wQZz2Zwp5pW+uIK8uKaM?= =?us-ascii?Q?wZik0fu5zUBrVikWmfTN2iVGUiFCMbOakUzicgD2ES40nMUV1Kkjb/X1vPHg?= =?us-ascii?Q?7MpIpErQ9igt1aL1BMDklNUJmv1IqbFPi42a3JDGhs5e5u7tWqqq14DgJ0c6?= =?us-ascii?Q?t5FMEkq4UpHiCSrhosfTo6RsySV1FbMoHEvIgpNyaXzO4kfK/M6JoXXmE8GN?= =?us-ascii?Q?lIAC6dERTEId4Ovz9E+fX93CyigZZjDeBEvMEHhdJQ9mICkz310DGjHf0JGK?= =?us-ascii?Q?EqHkGtAhfSG+zyi9bfxTk1sqsqmzk89Z+PMkBmreD6sjE45EsiSKOz7o0eTp?= =?us-ascii?Q?N2Rf5jdaALIAcdb9+OzJ6hy2oyPLQsJzIX4g934sTJA+vBSphq+4IIUmhLB8?= =?us-ascii?Q?nkYBT0V5ootwwBa1FQMn/no/XA8fd5xofrmSb2BV/27K19wOJzlDZ3iDlbz1?= =?us-ascii?Q?iZ0waVkKYSxug+Xy06S5968i/TQsz4vQvyQrMR5R5VLrnVLn5/VUHZfDuefG?= =?us-ascii?Q?OO52eh+esWnlsINs8xKrWSKslW1MnNwfBvzCZuLp85DSYMFSBd0koAx5fvez?= =?us-ascii?Q?PXCvTFpldH7UDZtAoPYAczo//hTmB9go2P3HMWgiVCFEhwmlm/m+hWAHuDIl?= =?us-ascii?Q?LDrhPOkfOcL+ZuR5EcAt0NvY+W2pwbGiXQLHpX8RSbi/De5qYAr4Fdkm0kXV?= =?us-ascii?Q?Yz/TIQ5mP+dJuYdQI4oOdRGj8dLEABCDx5FJlZe8aXVzpa2leLS8DzJOnL0+?= =?us-ascii?Q?d7zlLxjudW7CIRZ9R7mg9R7fmQyv1PpjXOG3N/rn8YAK4zgbERAp6slLu9SN?= =?us-ascii?Q?niw7zm0DeQDOOJlrX8Tt9cFPsE3UviPJihtA0kp0rsQKEYdeEkZpA64agNr9?= =?us-ascii?Q?S6YZ/gaUPsQJgYS2sLbVVTKqB7Qvn4bB2PA99omqsR4uLhLRXIwyCvZKb0DJ?= =?us-ascii?Q?fUnCZ6eVD4WTPoNqPSg2CVbub0kkBTAHE8yO8stUFLRcxaBMILsV8lQiRvmu?= =?us-ascii?Q?bFSwHMQrIJ60bPDKc02Ri+g/ERpuCbGKSGLP6BHCqKeKm1bHCgyjjYhlUCb0?= =?us-ascii?Q?9TD0E98ggRfTEL3/OJ3drGMuRkIm2C/cm87c3ibdVvnVnokx3GKMEveJkkaL?= =?us-ascii?Q?465GmYa8ZtXQBMkaCaaOaMWU3W9o97sRcdU8l8Trp2WGTdGVtnRe0dAS85do?= =?us-ascii?Q?jBl2IghmEpm29+GpdaDd9rv9pIojAezhhLCT70jJHFAEITlv/5ikg8naYjHx?= =?us-ascii?Q?OwFzxRK1GfHzH68bTg5PephOg+gtqYOMphpuGQD7jRc5cVQ/VDbQSegsvSxt?= =?us-ascii?Q?pqK1GqgoArP3i6N2E4UiP9m0suvFicMz/+cv26PRxpLgCp/ussTCXy9KDbaW?= =?us-ascii?Q?Jw=3D=3D?= Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: DM6PR11MB3098.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 56ad9df9-3ce4-4f76-daf9-08d9eba203ed X-MS-Exchange-CrossTenant-originalarrivaltime: 09 Feb 2022 07:58:53.1847 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: 3VUTYS9QYBjLFmPrKGDs4XrTdNknGlsjZmEWFX8aa9CQZxTUCKMsOaH/f11Fiu6nQLcN0K7Mku9QefNP+2kisQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR11MB1407 X-OriginatorOrg: intel.com X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Hi Honnappa, > -----Original Message----- > From: Honnappa Nagarahalli > Sent: Wednesday, February 9, 2022 12:36 PM > To: Xing, Beilei ; dev@dpdk.org > Cc: Feifei Wang ; Ruifeng Wang > ; Yigit, Ferruh ; Richardso= n, > Bruce ; nd ; nd > Subject: Questions on i40e TX path >=20 > Hi Beilei, > I want to make sure my understanding of the TX path is correct. > Following is my understanding. >=20 > 1) The RS bit must be set in the TX descriptors to ask the NIC to report = back the > send status. Not for each Tx descriptor. According to the datasheet, " The RS flag can be set only on a last Transmi= t Data Descriptor of a packet or last Transmit Data Descriptor of a TSO or last Tr= ansmit Data Descriptor of a filter."=20 > 2) The NIC reports the send completion by setting the DTYPE field to 0xf.= This > also indicates that all the earlier descriptors are also done sending the= packets. Yes. > 3) The check "if (txq->nb_tx_free < txq->tx_free_thresh)" is mainly to en= sure that > we do not check the "descriptor done" status too often. This condition is to ensure there're enough free descriptors for Tx, avoid = Tx ring full. >=20 > Is my understanding correct? >=20 > Thank you, > Honnappa