From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <dev-bounces@dpdk.org> Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 55C2AA034F; Wed, 10 Nov 2021 15:00:28 +0100 (CET) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 49AAA4113E; Wed, 10 Nov 2021 15:00:28 +0100 (CET) Received: from na01-obe.outbound.protection.outlook.com (mail-cusazon11020021.outbound.protection.outlook.com [52.101.61.21]) by mails.dpdk.org (Postfix) with ESMTP id E380B40142 for <dev@dpdk.org>; Wed, 10 Nov 2021 05:20:56 +0100 (CET) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=VrCSCXeO8tYyjfsiVgPaU9GHoDdo0n/dfNADSJPobexSCZGt6t6wmSgKw0IQutVA7s+HDTY6kTDPGgX3kIy/VPJoaeXyHsrwkRBL8GU5J4bY03wxCvm+YXOxeYzbJ1byLT7fYkkVhG8c0hxdTTwJ23XIuicqF3+rQRExHUR0qOUzfBaMof/9erBRwmctzC/0GuidWa3vOZH/Ul9V/3vLVCCwIWKmrOTiYs9/cjsN9teK9aCA+epwzNatikWCqdxWfRzZ80qQ1/SifzNuL/55oDliM8oCz5XQ2YAabh26DYceMmxv8Mznyhs8m9+ccY1tcs92WWrKfrpaUEVfNbGVcg== 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=RsiAncHIUdAyzse95tPDEDWjkc+6X0xK9IfsafCa20M=; b=drWvL6dG+lmtYgzbZBv8/wnL4LFBch2+wt1vZfuxJoEOw1OK8JacuJcyZfggm1IZgYaIcms4uySTEFu/VxG+57vxulrbOtxljE9MI1XdU+g3PK32K8qyQXMQ47NBy//7O33/LpB/GP4vimLNpJTYpdp9Z+2PqUFRiRBHVDL7gBPC9h9PEyeWrIm+tWBBwbWRA9j/QgbWrq7JE6SlzIAI2UUnBLOq4ocIahqloMEHR7n1loLGIPI+W8Xb5tkbRmTwmn0xIxRJ0wppQEkk6rpktK7QQ+LaRmtvJ4ZrMVhvulc03RryUy82gqzY0FXSGVXjhbe4ejr/2jtwPPocU45OOw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=microsoft.com; dmarc=pass action=none header.from=microsoft.com; dkim=pass header.d=microsoft.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=RsiAncHIUdAyzse95tPDEDWjkc+6X0xK9IfsafCa20M=; b=LTgwvnYL37JBNunoPRxcb6vkkMc+y5TNbjL9DVqBYIrcS/ot9XC55LZy9Am7ng0bB8NEG1p1h+sJOAG9Mz7s7Stt8zBjMRvMvR4clo0SifhoLXfeBoI25bJVuuN+6u2spkILO08gEbwM97pmDLVUM0yEXYgAxreyfrDPrz6e31w= Received: from SJ0PR21MB1312.namprd21.prod.outlook.com (2603:10b6:a03:3fe::19) by SJ0PR21MB1887.namprd21.prod.outlook.com (2603:10b6:a03:2a0::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4713.3; Wed, 10 Nov 2021 04:20:53 +0000 Received: from SJ0PR21MB1312.namprd21.prod.outlook.com ([fe80::c4a6:46f1:a4dc:30e1]) by SJ0PR21MB1312.namprd21.prod.outlook.com ([fe80::c4a6:46f1:a4dc:30e1%4]) with mapi id 15.20.4713.005; Wed, 10 Nov 2021 04:20:53 +0000 From: Tyler Retzlaff <roretzla@microsoft.com> To: Stephen Hemminger <stephen@networkplumber.org>, Narcisa Ana Maria Vasile <navasile@linux.microsoft.com> CC: thomas <thomas@monjalon.net>, "dev@dpdk.org" <dev@dpdk.org>, Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>, Khoa To <khot@microsoft.com>, Dmitry Malloy <dmitrym@microsoft.com>, talshn <talshn@mellanox.com>, Omar Cardona <ocardona@microsoft.com>, "bruce.richardson@intel.com" <bruce.richardson@intel.com>, "david.marchand@redhat.com" <david.marchand@redhat.com>, "Kadam, Pallavi" <pallavi.kadam@intel.com> Subject: RE: [EXTERNAL] Re: [dpdk-dev] [PATCH v16 2/9] eal: add thread attributes Thread-Topic: [EXTERNAL] Re: [dpdk-dev] [PATCH v16 2/9] eal: add thread attributes Thread-Index: AQHX1d+qNDlXNk5crkyb5wSg6TDHlqv8IvuAgAADZhA= Date: Wed, 10 Nov 2021 04:20:52 +0000 Message-ID: <SJ0PR21MB1312004596300D8A45096BEEC8939@SJ0PR21MB1312.namprd21.prod.outlook.com> References: <1633732841-17873-1-git-send-email-navasile@linux.microsoft.com> <11591275.oo6G3FHbOz@thomas> <20211109015923.GB12569@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net> <6965604.4qUlQkvJ3b@thomas> <20211110030417.GA7558@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net> <20211109195931.2c26f51e@hermes.local> In-Reply-To: <20211109195931.2c26f51e@hermes.local> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: msip_labels: MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_ActionId=954d1389-9ef5-4d44-aed5-6855f4dd69cf; MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_ContentBits=0; MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_Enabled=true; MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_Method=Standard; MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_Name=Internal; MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_SetDate=2021-11-10T04:11:40Z; MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_SiteId=72f988bf-86f1-41af-91ab-2d7cd011db47; authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=microsoft.com; x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: 2538fe6c-6cfc-4c63-a27c-08d9a4017c0a x-ms-traffictypediagnostic: SJ0PR21MB1887: x-ld-processed: 72f988bf-86f1-41af-91ab-2d7cd011db47,ExtAddr x-microsoft-antispam-prvs: <SJ0PR21MB1887CA4227D3DBF27D3072A3C8939@SJ0PR21MB1887.namprd21.prod.outlook.com> x-ms-oob-tlc-oobclassifiers: OLM:5797; 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:SJ0PR21MB1312.namprd21.prod.outlook.com; PTR:; CAT:NONE; SFS:(13230001)(4636009)(366004)(66946007)(10290500003)(53546011)(83380400001)(508600001)(8676002)(64756008)(2906002)(8936002)(66556008)(76116006)(82960400001)(33656002)(8990500004)(4326008)(66476007)(6506007)(38100700002)(82950400001)(38070700005)(71200400001)(9686003)(86362001)(7696005)(54906003)(52536014)(122000001)(26005)(110136005)(316002)(186003)(5660300002)(66446008); DIR:OUT; SFP:1102; x-ms-exchange-antispam-messagedata-chunkcount: 1 x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?E1iEM00Y8RViB9M9/lQ1yrYBGg3tqwhGF364PMLvRAVoxGaReqFGH9F8bOvd?= =?us-ascii?Q?FKuUVxeG6vMymrBdqhkZ7gasel1eUzg7NS3Zy4CTXSMJRMEGh5ruiQlsTSZg?= =?us-ascii?Q?gxokjk2o5s/Hvad6k4iF3onWZQylFeR1Z6rlRqoJUfXTYuP0tgfGFQ3os9RM?= =?us-ascii?Q?1z0fVhcll+5suNkqyYNEWI5yd9q/l974BvOTUaqQrLkkmOP1xfdSBmc77I0x?= =?us-ascii?Q?KSN+IcuAqyl95bmMuIAjHcPfyU1GpoHVHHnSIDPmlXHOkTALg0SyyzshM2R6?= =?us-ascii?Q?E19bGLlkNXN4zGAt6V+OCfRsTZS78PBT5/zfHnvmR2ObokQVrsA+8OkPubuM?= =?us-ascii?Q?e1bStupXNiMJN3THt2J2V/ZA/adoeusGSWcsBDw/OEEv7bV18gUbjwZg5lSk?= =?us-ascii?Q?ieKD47EJ/m0rIqsX1ouW/MWL7k+XYPy4MFyQp8nX/D3C1St7bvc1lCOV8xrf?= =?us-ascii?Q?koB1odb7KqWEvacqJ5T/LxiuWV7QgMN8SjQKeHVg9lBD5Jq9VurU7cR5ccDq?= =?us-ascii?Q?dc+chKa5CtEp/XpjofZIsjVZyF9UrhJkljREtxCAWdhY8Bvb6ZUFGUUNY1n2?= =?us-ascii?Q?9YAFyTVy/Mj/ECcLlCEmRw5JNe+8dXgO6z0kLg5ZeveC59zJIkDM2Q1rwzK+?= =?us-ascii?Q?bNjTZccDZwyYeqp2TVb5nomTO1nwGRecFI6o8eQ/OZ8c7iVE5DvwhcNKYz17?= =?us-ascii?Q?fRzSApMDGKWOTL34NZSJxxrFNJsIXnD2praBsIdMIMUmsccLXk5X57+VVIJq?= =?us-ascii?Q?NB/rt89iNNNtulNbHG9BxsvSaPeTx4KJrRlzYgqOQUgHwPvzriYjD75uHczL?= =?us-ascii?Q?H4wwrDDcImrJKZaMxeASLhSl3Bxun/ObfaZ/Q1BAdf/RhjzioIVkJlB8UBMZ?= =?us-ascii?Q?qkEt9088sBTvjeuJ8NFvPTcwxXoygK5z33idGnsuyjBhYyuIlZgNqXbfNjrS?= =?us-ascii?Q?rCZhXtKBQ6sLJ1r8qyZn7Nc4YESpJBigVQ4c8l/fX2nRm3zcXnRvQGJfXuQ9?= =?us-ascii?Q?a7cCQH0s1tz+yM+h2Tw054d2/UlRyF8Iz1sXWWB5P/IAq5BfwyMmIjdLHKm5?= =?us-ascii?Q?p5yZtf79IX1pVVBG9Z0hBvQyA1ZP7g92Qwy1wKfLMbUqX9D8JMtjriYblbXT?= =?us-ascii?Q?sXWgzev9y8K7whHQm9w86gzcsjKzbIscGtFu9kpRZd0gZVA1hxkVZgHeNP9u?= =?us-ascii?Q?JbwzSh5LmJeVcnMGCuYBg281jSAGy/Cc34McgrPK4M4e9naWSHM7WTSe6npH?= =?us-ascii?Q?K8D72Lwcc4Gn1Si02DwN5zttafUgPa0SJBMkXx3cQf+VVmHeMgBrhVBfVYa8?= =?us-ascii?Q?BL/vnESa6/ouY8eoknGzQQu/OI308ikdCJqmoDmyXRqans2ZoLJIJUwVjw/P?= =?us-ascii?Q?adRxqNDlFeyAzu7s5l5W8AsXrVI8vvnlpBWJ+pH8agWFOjwRu7Kw1Hvp7NAQ?= =?us-ascii?Q?gtvq371/+j++qdj4Y4wNA+R96jjRM5taapMRVZX5TYpSg2h3Idf5Bi2wZm4Q?= =?us-ascii?Q?aJOjNkxHqVnZUPiysgNMARWn+ImuU879vm4eTYBkdk2CBzAyoHZmnc1xBLTl?= =?us-ascii?Q?CbuMuPfhSfvJXO1Vp6/AwwsoCzIcp66KS4H/7GpAaN9e2+OPOyRT+pf6jgA0?= =?us-ascii?Q?CaU74QM6H7aP1pzBeHv5Kis=3D?= Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: microsoft.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: SJ0PR21MB1312.namprd21.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 2538fe6c-6cfc-4c63-a27c-08d9a4017c0a X-MS-Exchange-CrossTenant-originalarrivaltime: 10 Nov 2021 04:20:52.9882 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: h0gKFAu5hOkbGLfFc4e0Y6zpTiyIQ3JoU4mToQkouC8UDcEFf/PqLXLX8CYui6gJV088hb9gyQEnF9fBp48WfQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR21MB1887 X-Mailman-Approved-At: Wed, 10 Nov 2021 15:00:26 +0100 X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions <dev.dpdk.org> List-Unsubscribe: <https://mails.dpdk.org/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://mails.dpdk.org/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <https://mails.dpdk.org/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> Errors-To: dev-bounces@dpdk.org -----Original Message----- From: Stephen Hemminger <stephen@networkplumber.org>=20 Sent: Tuesday, November 9, 2021 8:00 PM To: Narcisa Ana Maria Vasile <navasile@linux.microsoft.com> Cc: thomas <thomas@monjalon.net>; dev@dpdk.org; Dmitry Kozlyuk <dmitry.kozl= iuk@gmail.com>; Khoa To <khot@microsoft.com>; Dmitry Malloy <dmitrym@micros= oft.com>; Tyler Retzlaff <roretzla@microsoft.com>; talshn <talshn@mellanox.= com>; Omar Cardona <ocardona@microsoft.com>; bruce.richardson@intel.com; da= vid.marchand@redhat.com; Kadam, Pallavi <pallavi.kadam@intel.com> Subject: [EXTERNAL] Re: [dpdk-dev] [PATCH v16 2/9] eal: add thread attribut= es On Tue, 9 Nov 2021 19:04:17 -0800 Narcisa Ana Maria Vasile <navasile@linux.microsoft.com> wrote: > > > > I'll send a new version with a better commit message. > > > > Thread priorities on both Linux-based and Windows platforms are s= imilarly > > > > constructed from a class/policy + priority value. Currently in DP= DK, most threads > > > > operate at the OS-default priority level but there are cases when= increasing the > > > > priority is useful. For example, the Mellanox data path accelerat= ion driver requires > > > > realtime thread priority. Similarly, some Windows applications wi= ll require elevated > > > > priority. =20 > > >=20 > > > It should not. We should not use realtime priority. =20 > > > > Thomas, can you join the community sync tomorrow? I'll bring this up to= discuss. > > > > High performance applications benefit from an option to raise the=20 > > priority of their threads to avoid being preemted by other threads on=20 > > the system. If there are issues with realtime priority on some of the=20 > > platforms, maybe we can add a warning for the user to make them aware=20 > > of possible crashes as Stephen H. suggested some time ago. Note that=20 > > this patch doesn't change the priority of EAL threads, enabling the hig= her priority will be done through a command line option when starting the a= pplication. > > Maybe we can explore raising the priority but not to the realtime level= . > Let me put it more succulently. > Almost all DPDK applications have threads that are a 100% CPU doing polli= ng. > Putting those thread as real-time thread breaks Linux badly because the k= ernel can and will try and run work on those CPU's and the system is broken= /unstable/dead at that point. The suggestion is that when running on Windows it should be possible for th= e application to be configured to use real-time threads, there is no implic= ation that it will force real-time priority on Linux. If it doesn't make s= ense for it to be configured on Linux then don't configure it. But saying = it shall not be configurable for any platform just because one platform can= 't make use of the configuration and those platforms have to run compromise= d makes little sense. Linux administrators are (or should be) knowledgeabl= e enough to know what configuration to use. > > This is a case of different definitions and expectations of real-time i= n Linux and Windows. Linux definition of real-time priority is for well be= haved and time critical applications. It expects RT applications to run, th= en sleep.