From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM02-SN1-obe.outbound.protection.outlook.com (mail-sn1nam02on2079.outbound.protection.outlook.com [40.107.96.79]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B8E81253B74; Fri, 21 Feb 2025 23:43:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.96.79 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740181386; cv=fail; b=JtEtRgNW5JMQndyT7PqIAFruP/iAcH7H8cuBjQiVCQ84sZsFxl6gm7gYTCJMy52yCwrJK45vv4cU7iTUQnNijgPLRRZTnz7OATUsYEWs85TbSSrO5x/Eazt36Y+5OZVFhwyw5ZZB7SWX7iGmZebtdI+RktdXONH/3J/oKsARu8s= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740181386; c=relaxed/simple; bh=q+5GEhu6m7Jy8MAoH+BJNvIdkABvvzLtLLLbyiL0xfc=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=N/M6Nm30MlBR5FxjNqt+uu/Sf2Pj1bi1J2SPg3Nuz43GLqmX7CUwnOJdpWWZ099pyCyqaV4CUJPzaHVXTgoP9QExsBDbs0dRGq40lMS9fYomArSsHRcfdyGZOfbbd2/zKpQe7cS+9BZgAX3XQnE+dD8kbc3zPpGAGako2nNEEXo= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=4PYVuhF9; arc=fail smtp.client-ip=40.107.96.79 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="4PYVuhF9" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=xj/Hf/iCjw7CetpMgTvVkYhEn0nip03lVD5597VJZZmbw9dCRcOKaBi6pQH6NUnUpHlpNt/GpZ+98SroVqMKwXPHC1UI/XH85p6kTut64QsqluwDboInrSjW36esXP+Y2SjnXrT04W/TjE+HKj3LNsVqj3C/V4xG4ophFXhpjylp0/h/+8WmSGIzfwkiouaDq1ulsuNKRpBHqNxA/d3R/qJg8iGcLizCMnjdDB2lRyg1YjFv7zdJZUbwiZ6XG2un9l7UjA6rAU2GmMm+665QzMvnYLbZPUBqI7BQ8kDsOs8FxlQzrMjCnhY3o3VPA1WKbdmRT1Ap+8CAGbApRZKWKQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; 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=wmhj/E/cAVMvlVcjDwyJKTE5EDGwbB0/YbKy0CIN2hU=; b=P32YqLwegz28YzwsQkDlrlA89xIqQ/Uaey/ZXyrj54yPwPzbxPUHp2RdUV9um1v8yTS4qH42vtJ+PpoI0Bp/40bypfMlZfcx7L6vjhQWs2rPxOvNpsOQ0PegBFRoYt563GXTUF1KZOVy1YzHuwQ5KU4whWytK5ATENg4FVWs0aP+y/4VI8iF1sSqNOrCcj+mbN9pZwDcNGAemU4fSYuPUmzNPLn5NDz5ebG6TPYJ0iNhsXPMs7cFOp9n1mUL9651agtmKKhRHCW/SLi99YMrjlv/Y2+ekOgknnwlYVSwYDMF7yfNf9E+Fqt0go1/fl7vVyGG9h081Cz/oZpSveT2jQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=wmhj/E/cAVMvlVcjDwyJKTE5EDGwbB0/YbKy0CIN2hU=; b=4PYVuhF9nT1+MzOS8DBbqQp2ziy8b++k6Qtw7f7a/EyKolHVPYPb7lRRnhqnDVVd93lXhJqmmVdWTjVe4+NM0NONrMjmE1OpufQQS6P/jzm9IXU9jl3s1UED/aL4G6WzfRdyvFdiJ6kQTBplnBj8758zRCVMhmnmGxJMbFScTeU= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from MW3PR12MB4553.namprd12.prod.outlook.com (2603:10b6:303:2c::19) by DS0PR12MB6391.namprd12.prod.outlook.com (2603:10b6:8:cd::16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8466.16; Fri, 21 Feb 2025 23:43:02 +0000 Received: from MW3PR12MB4553.namprd12.prod.outlook.com ([fe80::b0ef:2936:fec1:3a87]) by MW3PR12MB4553.namprd12.prod.outlook.com ([fe80::b0ef:2936:fec1:3a87%4]) with mapi id 15.20.8466.015; Fri, 21 Feb 2025 23:43:01 +0000 Message-ID: Date: Fri, 21 Feb 2025 17:42:57 -0600 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v11 17/23] x86/resctrl: Auto assign/unassign counters when mbm_cntr_assign is enabled To: Reinette Chatre , Dave Martin Cc: Peter Newman , Babu Moger , corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, tony.luck@intel.com, x86@kernel.org, hpa@zytor.com, paulmck@kernel.org, akpm@linux-foundation.org, thuth@redhat.com, rostedt@goodmis.org, xiongwei.song@windriver.com, pawan.kumar.gupta@linux.intel.com, daniel.sneddon@linux.intel.com, jpoimboe@kernel.org, perry.yuan@amd.com, sandipan.das@amd.com, kai.huang@intel.com, xiaoyao.li@intel.com, seanjc@google.com, xin3.li@intel.com, andrew.cooper3@citrix.com, ebiggers@google.com, mario.limonciello@amd.com, james.morse@arm.com, tan.shaopeng@fujitsu.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, maciej.wieczor-retman@intel.com, eranian@google.com References: <2119b76ef8be21b1d8b2deedfab23e8e33ba724c.1737577229.git.babu.moger@amd.com> <2889da50-b654-403c-910e-13b9144596fd@intel.com> <5f651b5a-3470-4ca8-80dd-4593acef6df4@amd.com> <84e31944-39a2-4e15-9772-56f82e70fbe6@intel.com> Content-Language: en-US From: "Moger, Babu" In-Reply-To: <84e31944-39a2-4e15-9772-56f82e70fbe6@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: SA9PR13CA0008.namprd13.prod.outlook.com (2603:10b6:806:21::13) To MW3PR12MB4553.namprd12.prod.outlook.com (2603:10b6:303:2c::19) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: MW3PR12MB4553:EE_|DS0PR12MB6391:EE_ X-MS-Office365-Filtering-Correlation-Id: 3541c659-6584-4f82-8881-08dd52d17aac X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|376014|7416014|7053199007; X-Microsoft-Antispam-Message-Info: =?utf-8?B?d1g4dU5TOXkyTXhKTHNidXpod2lVZDhDZTNnQ2hzbFBVVHZIOE0vTGczNHJM?= =?utf-8?B?NjlwTldYM0I3MjdGZjNiL05BU3NwMXRyYmNXakpqMjVlNVdpQmdpREQ0WVRw?= =?utf-8?B?N0lhdTdXWEdiU05rTmNSVkVuK0ZTaXpUc1VGSGdrYlEvbVdEWVV5RVFtc3Rm?= =?utf-8?B?SkRNUEhTTVZqc2E4NGRESHYxUUZ6aGYxOG1qZjhNb0NURTZmcGQxU0hNTkJ3?= =?utf-8?B?L0tlQWZnNno2bG9PTkp6VHJ5djR4T3RRTHU3WVhsS3hJNWx2ZGxXYSt1Kzd3?= =?utf-8?B?OXhUU2JObHFEdEVEZVJTcnNmS2t0UGQ0dkY1RDVndnNCOUNCUzVDTXNLRXB0?= =?utf-8?B?QWlXalZkeHhOeGVvdWkxdkIwa3Z0eG45N2wwUlVjcEptQWZ0Q1BWVFViTWNZ?= =?utf-8?B?ZjA5d1dRd1pxM0w1bC9CNHZNbExkZ3B3dE5QMGQxVzFTYWlUYXF6NmlpZ01h?= =?utf-8?B?cStUVWd5aC9hU0RQcVBteGg2ek81S0tJNmQ4dkdBWmIrMTM1bXhYL0RYYlRa?= =?utf-8?B?WnJLV0FUUFI3dDZxMlhKbk9iT3RCSlcvdWZwWUhvWDkyT09SdU1EdG1WZHgv?= =?utf-8?B?QVFlaUFjWTByZnZ4RmNwc2t1NDg2OTBOYjRweVc4SXJTZExka3FlSHhJM2l1?= =?utf-8?B?K1F5b3d4Y0lMbk91ZTd5bjZyYThaT3lwZG1aWEdrcWRjZFlDTmJEZVB5bkRW?= =?utf-8?B?Q3ByNWlsS09KM3BnSXdxaHRjOUgwOW5qODA2NWJucTJuR01YbEJ1Ky9YMkRp?= =?utf-8?B?MUNmZ1ZqM1hNVENCVysrZm9mcm16QkRkMkhLVHg1TkdWTGFoTkd5cU4waUhu?= =?utf-8?B?cmtqSEVTTzVuTkVvSzlRYXdidTFiUXl4dEtubnZibTBDVFlDQUZXMlNodjBC?= =?utf-8?B?ZzJOZy9HaDVSN2lyc0ViaG1hSEkxNlJVSFBxdFVlYTNsWXhjVWNzakpLVk44?= =?utf-8?B?bUtXSjlLajhVL2RCMTBOOU9rZi96UkZhdG9UdUFhRTJ5NnJiTGROamFVZU4z?= =?utf-8?B?d2txTTFjNDlzVFVUOUsreEppNGlaWG5Ha0hRWGJqNURFclAzVGZEWEVTTGRr?= =?utf-8?B?RlpOYXRuTEZvUVl2aWMzc3FSdW1qRDIyMVpvY2FkZGNmK045YjkycGRSNWhV?= =?utf-8?B?ei9NYklZbzBHc0pHcFptSE5ZY2xGdzQxSDYvNDBSMXhxY2dQbWtiMnRqSkFH?= =?utf-8?B?WHh6c2RKYkpGNjFPN2d1bG4xbk5VdTcyaTBkWXdTSWRKZ3RUTCtaNDU3UGpY?= =?utf-8?B?ekJJUEZXeW9QWi9tSXpEWTFsWUZlM1lFNkNWQTZQU3c1VFF5ak1td1N3UDY4?= =?utf-8?B?S3g1QUdWeTJuenUvNWRPektMMHA0bVBwaldmNkl4aG9nTmJrSUxPKzBNYWFl?= =?utf-8?B?dWgzbENtT2loaWZCSzBLNEpzTWsrTHFOblEvMmNtQzZKYXZNbXlWeUtHZHNG?= =?utf-8?B?eWZoQ2hGdmhPbmZNdjhyRXJaaE9kc0pyeFptVG94ZkJpL3FEbzJ1bkhOWDNi?= =?utf-8?B?ZFVEaFBkWUNkY2FNVDJmTmJ1SVF0S3gyM1pVekh0cVJxbjAycWplUDRteUU4?= =?utf-8?B?SEk4YkJTQzYwQzFHS252WmszcXJSRVExY0hubFB6VEgzdmZsSFU3MkRlUjJV?= =?utf-8?B?eVcrZU1ZdWpsdDk0ejBOWGRoRXFOcytPRStDY2RCK3QrdFRRV2F5Wk5wbnh0?= =?utf-8?B?YmVLNW9JUWUxcEFmQU5oK1J4YW41MjdMVmtWZTRMZXlleU8rSjRiaVMzYUky?= =?utf-8?B?RGpwc3lhWjdMbDM0UHFZMjNaWWYzUWFLSFBCaDNSalpWRnhoVDhYWGxraXps?= =?utf-8?B?RXNYdEp3RHl5QXVndDBLd1hrWHhGb2JjVzhhTzFmTFNoRk5CaEtqNW9tYlly?= =?utf-8?Q?w1UkQkTMECupL?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:MW3PR12MB4553.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(366016)(376014)(7416014)(7053199007);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?VERkd3Z6UmVEc01VVmZ6eHowbGtlcm9uV3NpV2QzbHpyNVQ0SjRUaHN2blE5?= =?utf-8?B?QWgrTVJTUXR3WFdLV3FFUE1wRDBEUHJmOEtibEozeTFPNWQrdXdzbnkwcnBH?= =?utf-8?B?bjRpYzAydktGT2g4aE9sWHZVbFBwK0NXUTFHbDh6b3NPc1haWi9KNVVBM0o2?= =?utf-8?B?ZW9rYmlKTHdtRTl2NUVIcG1KazZvSHZMOGV0N1FBd0doZWdoYWgyQzhlZXBr?= =?utf-8?B?R0ZmNmN2a0ptbUJTQUN4UXB4U2Z1TUVvZU1QRnYrL3pvSUp1NWk3ekNNZXBY?= =?utf-8?B?VDNFcWZ6MlNFcFBJVU1MVituR0dpbUozb002Z2pPQTZEQm5CUWtoWVd5R2dN?= =?utf-8?B?bzN1TEFxNEZlSHBDWUdkYk16TTFpcE90aEtDMkhSQ2xsUXNyTlNPY0NwdWZW?= =?utf-8?B?a1BhUG5wRmpKUDhESTRnWWtmS1JkVmJNZ1R6NmZvUWxmREZZQVJjMHZ4dDVx?= =?utf-8?B?TENVdHkwbGc5cDYrN3p4MldkYmNSaGVVNWJiekR3TG42RUdrZDZBb1daNjJw?= =?utf-8?B?dkt3SlVQSVpxSVppUkMzMzRLaWxRZmU4NHhleHBPL1BnVnlnVFdibzJOc0k1?= =?utf-8?B?aG44VTkwSmRJU2ttWlphZnR4ZUdZUGtZd2FHaUxwMTJodDlKR3hNOERxWVVq?= =?utf-8?B?WkpyWVZnRkJqVFhYQlJWUms2dnBORFZHRUxjeHhoNWNOR1BUK3VmT25XWGEz?= =?utf-8?B?aU5rU0c5SVg0N0h3TmhuN0JYdUcyRFpxOHlTSTh4QlpZSjM3Smg0VmJWSGtx?= =?utf-8?B?VWdTK3J6UzFGSm9ublZjVUs1T3NMdHFFaHd1TDVxOGQrQ0ZXeWNZNkFoUWVR?= =?utf-8?B?bExOL1YydFZ6NG4wdFBtWnI0Y2hWTUU0QlIvMW5xM28za3ZWTk1JbVVqZE04?= =?utf-8?B?dUZ1di9WZVFrY1JhOUVSYnprQUxjWlVvWUlibFI4OWQ5cW16TTlPSXhWdWtW?= =?utf-8?B?M3A5S09DQTVXSGJEUFBDYkptUE14R1dQcVdLMUh1UHlHNDZEOFA0WDJWSnp3?= =?utf-8?B?cTk1QlorMmZKNFl4bTVXb09zVDdOZndibm5raWRQaXBXOUJhUHlmalpPVW1C?= =?utf-8?B?UjF4RWV5ZlIyVXh5ZlAwdTZCQjhzUm5YdmZ3b3hIc09qbFo1aTYzeWt5SzM1?= =?utf-8?B?SldJWVFSMVM1Z1dhTUlaZFVUZDdsTlVDSEVielpEakpmZEJDU1ZBbjBxcmRq?= =?utf-8?B?WnBQdHY5WWMrYVEwMmhKbzgxSTlrUlZQOGN6OXUxVU5jbCtMaFBUYjJ3cGMw?= =?utf-8?B?NHBib2Z0Vm5OMlhnSnhjdzRISnFKeDYxcGEwaXRhKzh5Tzk5UUNGOFRVcno3?= =?utf-8?B?MUlCc0J1dnZiU3J4UHA3K28wV3VZbXhaaG40V01iWmszN3FTZGk4bjFOR0J3?= =?utf-8?B?L04wQXhXQi9aQnJLNlR6bFlUR3JmR2dkSUg3TWl1blFFZlB6Q3JWSUh6Ritv?= =?utf-8?B?aDE2WDRaajhIV3Z5UFp0U1pwaXhUUVc5L1ZmeDZBZkQxeWNtRjlMUFNWRFVz?= =?utf-8?B?cHJSbk1nV2FyZDBjOUxldlFaQ2JqZ2RXT3NmR1pHWXZlbDRtcTFlb3Z1Ukdp?= =?utf-8?B?a29XOWtxVCtGbjBxOEhJRld3aHBRckNVZDFQdTUvZEt6RXAwM3kwWjUzV2lH?= =?utf-8?B?OTNHVnVzWTlCNFI4bWlUNEFPTXRpdndGWisxdm8wbXdkRGltejhXZDVCRjBt?= =?utf-8?B?Y1BaMldXMVAxcmVQZFJ3VjlVZ0p2ZU1MWDAvL213aDBQTnU0dDYvTzRJVVVp?= =?utf-8?B?ZHc3UUNublJtWlQ1ZkZ5eGtTN09HSEcwNWpsL1NzMjQ2UkZmOXQrbU5UeEc4?= =?utf-8?B?Q1grY0NxTEJVNzUvY3Y5ZjJqKzNWR3BoSDZ2SCt0cTg0Z0o5R1pTQWZwQjBH?= =?utf-8?B?VGg4ZldtUUhTSkpOdDlDbld4S0sybHNPd2xJQUV0NURrd1NEY1V3VHdjVnEx?= =?utf-8?B?elVpZFI0OWwyQ0NyT054NTd1alpNS0FCOVhTNEZOOHJTVld5ZHFYMVFSOTJX?= =?utf-8?B?bDhyUlk4OEpJWVBIS2hwRUhaZUZSM0lnVERhL3l2ck0vaFJVVHlDdEZIbXlh?= =?utf-8?B?c0VuV0Rzd01vK3VaR1RDdTcyQW55b2oyVHpzdUwyYjdTV080QndFOFFzMkRi?= =?utf-8?Q?XD8M=3D?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 3541c659-6584-4f82-8881-08dd52d17aac X-MS-Exchange-CrossTenant-AuthSource: MW3PR12MB4553.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Feb 2025 23:43:01.9189 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: YwKK56ZwOts9jLJpWU83cBuULkN8SZrOc+x700Fg0AxRcjGw24W6VILjwqTetTzm X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS0PR12MB6391 Hi Reinette, On 2/21/2025 4:48 PM, Reinette Chatre wrote: > Hi Babu, > > On 2/21/25 10:23 AM, Moger, Babu wrote: >> Hi All, >> >> On 2/21/2025 11:14 AM, Dave Martin wrote: >>> Hi, >>> >>> On Thu, Feb 20, 2025 at 09:08:17AM -0800, Reinette Chatre wrote: >>>> Hi Dave, >>>> >>>> On 2/20/25 5:40 AM, Dave Martin wrote: >>>>> On Thu, Feb 20, 2025 at 11:35:56AM +0100, Peter Newman wrote: >>>>>> Hi Reinette, >>>>>> >>>>>> On Wed, Feb 19, 2025 at 6:55 PM Reinette Chatre >>>>>> wrote: >>> >>> [...] >>> >>>>>>> Could you please remind me how a user will set this flag? >>>>>> >>>>>> Quoting my original suggestion[1]: >>>>>> >>>>>>   "info/L3_MON/mbm_assign_on_mkdir? >>>>>> >>>>>>    boolean (parsed with kstrtobool()), defaulting to true?" >>>>>> >>>>>> After mount, any groups that got counters on creation would have to be >>>>>> cleaned up, but at least that can be done with forward progress once >>>>>> the flag is cleared. >>>>>> >>>>>> I was able to live with that as long as there aren't users polling for >>>>>> resctrl to be mounted and immediately creating groups. For us, a >>>>>> single container manager service manages resctrl. >>> >>> [...] >>> >>>>> +1 >>>>> >>>>> That's basically my position -- the auto-assignment feels like a >>>>> _potential_ nuisance for ABMC-aware users, but it depends on what they >>>>> are trying to do.  Migration of non-ABMC-aware users will be easier for >>>>> basic use cases if auto-assignment occurs by default (as in this >>>>> series). >>>>> >>>>> Having an explicit way to turn this off seems perfectly reasonable >>>>> (and could be added later on, if not provided in this series). >>>>> >>>>> >>>>> What about the question re whether turning mbm_cntr_assign mode on >>>>> should trigger auto-assignment? >>>>> >>>>> Currently turning this mode off and then on again has the effect of >>>>> removing all automatic assignments for extant groups.  This feels >>>>> surprising and/or unintentional (?) >>>> >>>> Connecting to what you start off by saying I also see auto-assignment >>>> as the way to provide a smooth transition for "non-ABMC-aware" users. >>> >>> I agree, and having this on by default also helps non-ABMC-aware users. >>> >>>> To me a user that turns this mode off and then on again can be >>>> considered as a user that is "ABMC-aware" and turning it "off and then >>>> on again" seems like an intuitive way to get to a "clean slate" >>>> wrt counter assignments. This may also be a convenient way for >>>> an "ABMC-aware" user space to unassign all counters and thus also >>>> helpful if resctrl supports the flag that Peter proposed. The flag >>>> seems to already keep something like this in its context with >>>> a name of "mbm_assign_on_mkdir" that could be interpreted as >>>> "only auto assign on mkdir"? >>> >>> Yes, that's reasonable.  It could be a good idea to document this >>> behaviour of switching the mbm_cntr_assign mode, if we think it is >>> useful and people are likely to rely on it. >>> >>> Since mkdir is an implementation detail of the resctrl interface, I'd >>> be tempted to go for a more generic name, say, >>> "mbm_assign_new_mon_groups".  But that's just bikeshedding. >>> The proposed behaviour seems fine. >>> >>> Either way, if this is not included in this series, it could be added >>> later without breaking anything. >> >> How about more generic "mbm_cntr_assign_auto" ? > > I would like to be careful to not make it _too_ generic. Dave already pointed > out that users may be surprised that counters are not auto-assigned when switching > between the different modes so using the the name to help highlight when this > auto-assignment can be expected to happen seems very useful. In that case "mbm_assign_on_mkdir" seems on point and precise. Thanks Babu