From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from PH7PR06CU001.outbound.protection.outlook.com (mail-westus3azon11020083.outbound.protection.outlook.com [52.101.201.83]) (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 D4C5C2FD699 for ; Fri, 28 Nov 2025 13:01:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.201.83 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764334906; cv=fail; b=skkcfX884wpoSAW+lupAwUOWLfJEdZauDPSL6gk5SRDc4KICIMqdezpgt5SUIQ0TtTuBAtx9RUSeWZnAiLzM/3HqkbKaVTj7UnvQm4TY90jLqCmvXJinUnvFhyX2A0pBTJlghAmV8LNksibl2WOmmTb23PjxvfzbRjvfgvW8bsU= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764334906; c=relaxed/simple; bh=dx5+CtJ7hsR99pX+5bUtfIgYvHsroOfm58jgYdsroxs=; h=Message-ID:Date:Subject:From:To:Cc:References:In-Reply-To: Content-Type:MIME-Version; b=osorY9zaWd8MN1fOLFN4lXZoaqpii8ZDomTtPsM3uYYOmOLysbChmbol8W97ShrklfHKj176tfpIDpQUQskZh1ZQgDHg7X7UqQNpnD8VNb99w5QpvLT3maoeu4qwOcvnHWxE0Q1iPGLQfcs+CA7On4Vr24FgDFHAYF+QnNjv3jQ= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=amperemail.onmicrosoft.com; spf=pass smtp.mailfrom=os.amperecomputing.com; dkim=fail (0-bit key) header.d=amperemail.onmicrosoft.com header.i=@amperemail.onmicrosoft.com header.b=Pr1imG7M reason="key not found in DNS"; arc=fail smtp.client-ip=52.101.201.83 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=amperemail.onmicrosoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=os.amperecomputing.com Authentication-Results: smtp.subspace.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=amperemail.onmicrosoft.com header.i=@amperemail.onmicrosoft.com header.b="Pr1imG7M" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=n5Cn1lR/atqczpm0jO4LjmGzrgAHFAoFgCFUV7KW96bH7QrRm8Kx+JYVWThTHZO5fqnpv9r8rSgutmiO+N9FsY39DglaZMmQqVEPGnDz/Wuy9vk6pFGwO+aM4cXwZXu+tBq4XezAy0HwPepx779kK8xAd66JtRQyXlzWRsGPc46VUtzIxC6c6IYabGvcwDu/9B2M9C/JFtOwEFW8FQqK4lHci2T1M5QZGIrf6MOQKbmbF7pi7LQYft62Fc0fn9g/pQxrAAzwJ6FyixYBHIJLT4ULNdVJZXsbS9yt4Yzkeo6+ZaBItyqQBv/o340i8ZlMDAgCZJvXVAkLHhSM9Qgvxw== 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=IS9TPFhuRz7QbWg1tXwpwm7j1SChlkdUe0s54J+Qktc=; b=mRjXpMMVU8OM+l+y/6WYSjo+8l1PUgX9zqQzbJmIMdd660bNwdSIj9JDo7Uf/NwrpyBhIR0xffwAcDbY6d257xsP6fn2MpN18eTokz1rwGvwuuAXkW+F1xJAlPdNnqqIK5UC7DwdbilUoSc3VKWnyy4oqqhdFSSRSfrA9BIy87eZ2WzWfMFtGztPpHgM/OT8CLUu2ZuabOqsZ+JwT35qGsRTG/XlVvEatgvHPh40iqj/FZ8oWL++otkQUFVUedASiBSoyd5CBjLioiLVqkEcd8XjOu1HZ6MU+9HnYO7hMUcXk4QXoH6ER2/l4lbu9qOYy0eCJ4Q7LcgsbMde7kOIdQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=os.amperecomputing.com; dmarc=pass action=none header.from=amperemail.onmicrosoft.com; dkim=pass header.d=amperemail.onmicrosoft.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amperemail.onmicrosoft.com; s=selector1-amperemail-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=IS9TPFhuRz7QbWg1tXwpwm7j1SChlkdUe0s54J+Qktc=; b=Pr1imG7M926kAy9+igtj0lGSYbdEPpZYEBMA5g2y7K2dZXHV1htDrRvd8+dqqeNMYC0CqxjDMxuxzJO+RUCX6pQAzeepmba9LpV56kGYVzTiA6FOVR7H58Ladqey4vC6uAmvlSt2RORiZflHKuHZwBmeMxByaCmda12Lb1ITcRQ= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amperemail.onmicrosoft.com; Received: from PH0PR01MB7975.prod.exchangelabs.com (2603:10b6:510:26d::15) by LV5PR01MB994148.prod.exchangelabs.com (2603:10b6:408:35d::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9343.17; Fri, 28 Nov 2025 13:01:42 +0000 Received: from PH0PR01MB7975.prod.exchangelabs.com ([fe80::6926:a627:118e:8050]) by PH0PR01MB7975.prod.exchangelabs.com ([fe80::6926:a627:118e:8050%4]) with mapi id 15.20.9366.012; Fri, 28 Nov 2025 13:01:42 +0000 Message-ID: <5cde0f5b-b05f-4f89-a202-94b7a63a51b5@amperemail.onmicrosoft.com> Date: Fri, 28 Nov 2025 21:01:24 +0800 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 1/2] sched/fair: set rq->idle_stamp at the end of the sched_balance_newidle Content-Language: en-GB From: Shijie Huang To: Madadi Vineeth Reddy , Huang Shijie Cc: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, patches@amperecomputing.com, cl@linux.com, Shubhang@os.amperecomputing.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, linux-kernel@vger.kernel.org, vschneid@redhat.com, kprateek.nayak@amd.com References: <20251128075454.676765-1-shijie@os.amperecomputing.com> <20251128075454.676765-2-shijie@os.amperecomputing.com> <1b0facef-8d3c-45fa-a490-506204e1395d@linux.ibm.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: SG2PR01CA0113.apcprd01.prod.exchangelabs.com (2603:1096:4:40::17) To SN7PR01MB7969.prod.exchangelabs.com (2603:10b6:806:34a::19) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH0PR01MB7975:EE_|LV5PR01MB994148:EE_ X-MS-Office365-Filtering-Correlation-Id: 717c49d7-63ca-42b7-e0be-08de2e7e4668 X-MS-Exchange-AtpMessageProperties: SA X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|1800799024|366016|7416014; X-Microsoft-Antispam-Message-Info: =?utf-8?B?dVJmdXl6d212QzF5TmJQb1dZQnMzNmVBUFRGNGFYY0VBRVptOUdtRCt0enBX?= =?utf-8?B?TWQ3bi9ZNy9pS1RiSVpjMExOVXlrbEo3S2ZsZU5QSHF5SjZkVFAzWjFxbWlC?= =?utf-8?B?NDNicGdxMVZmblZIVEdQSmpFY0ZMa2M2OWwySWFERWJ1U2xqa1FkSTJUUTJD?= =?utf-8?B?TFJ5S2RmdXRkR2JKTHlsQzUzZXJNRlZuQTRCYWU4Nmx5OE5kUkNFQ2IrMTYy?= =?utf-8?B?T1l1a1BQQVVTVkExVjJxcmg2Y0wzN2srenZaQ21wNnZlZEVudUwzZm5zM3lS?= =?utf-8?B?M1hhS2JndVVjLzVibzE4TWFsb05xOHN1YjBhUmRIL2xvT3lEQ2hTemxES3h1?= =?utf-8?B?OGQrcm1QNy9HUVhFN2RoTzlrQTMxbzE0MWtrcVM2b3JkRU5rdFJmb1Vxd0xa?= =?utf-8?B?dlhXcFl5UHNBTlhCTnVwN3B2bE95OHJ0dlVaTUs0NHBTelVrMW9XTjRJeDFx?= =?utf-8?B?ZjRsVXRvR0ZVSHBWSUg4U1lCWEpqaXBoSzc2ZE05UU1WTktaZ2dwVXZXY0tK?= =?utf-8?B?dzI5Ym9rak83WUdlajNwcWNXdDV6TzBpUklRbERISnRjSXQ1TUNEblZ1NzVz?= =?utf-8?B?dVRaaWMvL3NuY3RwQkZwYm9uSEwvVUdOUVh6UU5wR0diV0E2UVk4dzNyQ3o1?= =?utf-8?B?SVdjRkNVbU5XVVIxVEhZSjBRd3dZcG1iaDREZ3YvbnRrdTNiOVJ6MXdtM2FL?= =?utf-8?B?elkwN0N3WGgvQ1N0ZG9WU09NODZiVGRKTzFwcXJRSzZSRmxmbHg2cElrcVNw?= =?utf-8?B?dW5TeUpIYkZGUEE5SU5yTkZob3Y4OTk0ZnVMYTVwRW44YTNUUnVnUUx1Nnkv?= =?utf-8?B?SnU3a0hpZjdPd3ZmSmNxaWF4dk9nWXFZNUN3b3NKRk1raVF5ZnFIeDlLQzc0?= =?utf-8?B?eExTQW11ekpBUnlmaXRTSHNuTHBzSEh0SitzcjNZTEladXZ1YVFFQkJSeFJF?= =?utf-8?B?U0x5QXQzQkN4eFQwWjN1cWtiQ1k3d1BENWVjanJDcXRSZmJOSjhwQStSSkY1?= =?utf-8?B?dm5MYkRqSG9vZzIwb1EvY1MwRldTVXYvTjFYRDBSamZtTEhwSE8zWHk1OER3?= =?utf-8?B?bkRFNm9mNlpSa1RQODFGT1RLU0tZb3BjMzRpTjJsUTdwTSs3dHdENE9qYUlM?= =?utf-8?B?MkNKeWFZdU9DOE1SbTNvckhLelNRUElCMTBWNmVEUVdIVTY3V0ZuUjJMcEtD?= =?utf-8?B?V1A0RVlZaDI4eHFRTnY0NEx0OUhsKzVVR29OOVU2WXUzV2NFdDlQRzdOelhL?= =?utf-8?B?cW5JN2tyTnArdW5KaGJ3ODFVVVRWOUE5TXNQWlhGaHdrS0dLb21Db3FYcjdv?= =?utf-8?B?aUVINHVkOUtXd1dGNTVETnZ5M29pVklPQ1NubzJUWjZ1SGhibThlODFCTG5H?= =?utf-8?B?bHVmcHBMQ0NtdnczdW1KTU00Z3IzREdLS0YxRDgyclJHOG5hbURiN01Cd0NL?= =?utf-8?B?RXR2dExXQmR5NU5WaVBibE5rdjM1RmhnZENBMzB3akNtNWJzRnV6YnpNYk1j?= =?utf-8?B?RjY1ejM0R3FnQzNGOFk1Z1QrWEYrdlU1VVNhMDZQazVJcnk4YWt0T1Y3YXNF?= =?utf-8?B?RVNWRmpmc3VzTTl4MWd3NFRuRW14Yy8yb1h0RWVmcnQ5RjdSQVh1bGVwZ05w?= =?utf-8?B?bTc1SFcvNVZNbjhmaXRhdDBMYjNXRzJSZXRQdHREZDNtdEVHMjQ1eUtvYnF6?= =?utf-8?B?ZHJnajhKdWdUMkR1UmUraWlHM0owZWN3elBUTDRVSTV3OXAzbkI4bmZPRjZD?= =?utf-8?B?L3Y3SWdCWlZOeDlUcm5FQzJsejUwdUtaSTFyZlhNMkNicVNrekhKWkRFRHJK?= =?utf-8?B?M3BKOHBEV2ttZGFRUzM5NmFKNnpBWDVBQUt0RkVKVk1ET2JHMFNJWXhPRGxM?= =?utf-8?B?dWZHWEdXZGxTYjZiMnc1eW5iSFEyTTlGQlllNVF2QnpMa1I0REtyQkU4VnNx?= =?utf-8?Q?Aqirj1dqr3CryJUiFNNXC4mo8x3tQANK?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PH0PR01MB7975.prod.exchangelabs.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(1800799024)(366016)(7416014);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?SzJQMFhZYmtIejB0VUNCZHJNZHhSdmhHcEh6Q0ZIdjduUmxubTIwODlJOGZK?= =?utf-8?B?TFFpRThnTDZkZy8vQUdheEU4eFA3NzhVSHRvdThxWTlSbXlZM1kwUGRSMVNJ?= =?utf-8?B?Z00xeHZMeHplaG1OQlVEdDQrRDZnMFRmTkNwRW4zK3NHeEhJRWpibDRhQk5I?= =?utf-8?B?NU5oVUxxVXVoU2NxdkVjOFlNN3dCR3ZISmx3dlQ0N2JlWW5MQTEvazNPdjRV?= =?utf-8?B?VlUrYXhTdm9yaThiWWJ0OW9kQjZ4L0tta1JpM2QzYTNhMjV4a3puTFMvajNy?= =?utf-8?B?em4vMHFiaFZSZGJ4VzlTenFLN3QzSEQzUkw4c1EyRVNuQlFPL1RnQXAvZlUy?= =?utf-8?B?MjJCY3RxK3h1YVhUU3FwdlpESWI1ODJKVFF5TksyVVJ2dEQ0aE1BZlZ6MWlW?= =?utf-8?B?eSt4dUlpdjlkUWVJaDNaSnFCVzROSUlPb2JiaGxLRW5XZEpYdlE0RTE5bUJM?= =?utf-8?B?WHZvUEw2L3ozZFVNdkRIQUNMd3JuWmRTUWRXeEhJc0k0dHhpelFFVEowMTdq?= =?utf-8?B?bHZpT0ZJU05PTWF3NUh1M1lWK3psY0tMc2JuWERxSjZwbkdTVWZySGdzYWg3?= =?utf-8?B?NWp5ZCsraUdQTC8zS0Q2R3NySVBJWEpiLy9jamRmVy91TkRhMW5aRUY4MEZK?= =?utf-8?B?dzJDYnlpYzdsTytqc0wxWW8xZ1hCbENEOThHeDdtdzJudDZENTZtcGNZYjF1?= =?utf-8?B?bDBTVXBLaXR0RnJzUVdmdVBBakdlUG1QSEpqV2o0Sng1SnBqWTdUYVkzUlRD?= =?utf-8?B?R0J4eGd1ajQ2K2VlTlBuc2tvZExDaXBheXY4bUIxZ0JBeURyemhHOUx6WURp?= =?utf-8?B?RXdYWlN5SHFDb1NLd3hHdldkaUt4SnhvYmdUS1RxU0VQK1JQZ0s0ci9KUDBV?= =?utf-8?B?ejRSZ01udzVxMHkwT1NlNWw2dmdlZVkrSlNLTHNINnIvd1dMTjc4Z2hKOTB2?= =?utf-8?B?RVJ1UG9XdTFSekZnMHl0T3dxZHMwVTd0RWpidEs5VlZ0TTBVUVorNzhwaE1q?= =?utf-8?B?ZXV1MUVrUUo5M0FQSll5TFhCTitENUlrRzdNcG9VMnYzaHpndWVFMEFGbDN0?= =?utf-8?B?cEdPbm5iR0NUZmZoTUgxUzhvcHdlQUlNMkk3SkMxR0lxRFFNbUE0UzlYdFI1?= =?utf-8?B?NFRCZXNWWWV1RDYyb29QYUpacGh1dkhMQ2NvR0NuUW1ZVjFPQWV2VnhLd1pE?= =?utf-8?B?SFRsMDVOcWFZYnd6OENJSklMQXBjdG91TmJtb1BGa1pQQUlDTU5SMitnaG9v?= =?utf-8?B?V1ZmTWFUSWRmdEVkMXd3TE9ZMm9lWVNRTE5FeE95YlY3SytHVFNmamF2Uzc5?= =?utf-8?B?bmlNVUo0LzQyTjFyY1dnMUNaUytVQ1pja3FIeGc5aXU1VTlQRmZzcnhqRTVC?= =?utf-8?B?amRRc2RHRVBkWHpNc2J4R29FYzloWUZaeGR6Qm9RMldFVGhDenRWVkxveDdj?= =?utf-8?B?ZEtKWUJ0ZlkvZ0ZiRERXM3JIUHphZUI1dFk1cFRIdGlFcUNjNEJrTWRDM2d4?= =?utf-8?B?YTIvYUg0S2kwWFA0L3NmMHNielh0QW9ldzhPS0M2RmVXRnkwZzBJWnNHSWZU?= =?utf-8?B?SUowT05TdmVMOFVoTXd3ZnVUTlpXcTFLUTZpSGFjUUFRVmgwRlM2Q3RaYi9G?= =?utf-8?B?VUhjamM2L1E2SkZQa1g5LzU0RXRIa0srclpyUUhFZkVtcVlkSHZBMGRrdkNH?= =?utf-8?B?WDRtelNKUEFISEZxclhEWGpYaWEydlF6WWdNRlA3MnZCaWRhZ1R6bnh0VTFQ?= =?utf-8?B?UlhZcGZyU0JDK2xNaDNkWVpKL1Q2OFJnK1hYYzhHMWQzN04yWWIyNW9xZkov?= =?utf-8?B?L1M3TDJmRVZXakVUckl6K0hlSmtoR2RTeHVhTHZvMGo0RU9KWmxTMjRrMkFP?= =?utf-8?B?UVV0YS82QkZPMC82ZWd1RmowcEpvU3BXMFlLUnBYSFcvQU9vMUtzWUwwSGd2?= =?utf-8?B?YURQRzNaU1I2VEZZODc2REJyVjlkd1hFTjRydFVPMFBaM2NMZjVleEdmWEVD?= =?utf-8?B?Znc0clYyTld6eWJyalN0K2lqVlR0QXFMbmRnS0VodlltblVqcTFqcnU5b2FF?= =?utf-8?B?ajF3ZkN1UmVRaGV4ZTVORmVBRndUeG1wTFZmNU9mQ1hZaHNiWnBtU3NVYjlv?= =?utf-8?B?TW8yZ1F5aUl4dmpFdFg0U3NDNTRnVkplUUd1bDg1YTh0cVAxT0dsaUVZajhZ?= =?utf-8?Q?wyOJumdr0EZtiocyyHwrs5c=3D?= X-OriginatorOrg: amperemail.onmicrosoft.com X-MS-Exchange-CrossTenant-Network-Message-Id: 717c49d7-63ca-42b7-e0be-08de2e7e4668 X-MS-Exchange-CrossTenant-AuthSource: SN7PR01MB7969.prod.exchangelabs.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 Nov 2025 13:01:42.6087 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3bc2b170-fd94-476d-b0ce-4229bdc904a7 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: AJQ4ES7QbVxOyKFGhdFI8CBnBsqXt9uCVnjWxFhlQeAmvAVwkYOKwSOm80YtYWRWtTuBjtBNYQzCwlfjPe5eqhuJppJ/Tk+xDbgAx6bSPX30b9l8v14Tcb0UEUhd9txN X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV5PR01MB994148 On 28/11/2025 20:54, Shijie Huang wrote: > On 28/11/2025 18:07, Madadi Vineeth Reddy wrote: >>>        */ >>> -    this_rq->idle_stamp = rq_clock(this_rq); >>> +    idle_stamp = rq_clock(this_rq); >>> + >>> +    this_rq->idle_stamp = 0; >> IIUC, by setting this_rq->idle_stamp = 0 at the beginning, any call >> to update_rq_avg_idle() during >> load balancing when tasks are pulled will fail the if >> (rq->idle_stamp) check, preventing the average >> idle time from being updated. > >  1.) For the newidle balance, it is okay to prevent to update the > rq->avg_idle. > >  2.) For the idle balance, the this_rq->idle_stamp is not zero, and it > can update the rq->avg_idle. > >             Can the idle balance and newidle balance run at the same > time? I mean on the same CPU. > > >  3.) For the busy balance, the  this_rq->idle_stamp should be zero, no > need to update the rq->avg_idle. >