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Received-SPF: TempError (protection.outlook.com: error in processing during lookup of amd.com: DNS Timeout) Received: from satlexmb08.amd.com (165.204.84.17) by SJ1PEPF00002321.mail.protection.outlook.com (10.167.242.91) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9253.7 via Frontend Transport; Fri, 24 Oct 2025 04:00:12 +0000 Received: from SATLEXMB06.amd.com (10.181.40.147) by satlexmb08.amd.com (10.181.42.217) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.2.2562.17; Thu, 23 Oct 2025 21:00:07 -0700 Received: from satlexmb07.amd.com (10.181.42.216) by SATLEXMB06.amd.com (10.181.40.147) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Thu, 23 Oct 2025 23:00:07 -0500 Received: from [10.85.36.188] (10.180.168.240) by satlexmb07.amd.com (10.181.42.216) with Microsoft SMTP Server id 15.2.2562.17 via Frontend Transport; Thu, 23 Oct 2025 21:00:04 -0700 Message-ID: <1fa78304-b194-4d34-888a-c387859ef72d@amd.com> Date: Fri, 24 Oct 2025 09:30:02 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: sched: update_entity_lag does not handle corner case with task in PI chain To: "Luis Claudio R. Goncalves" CC: Peter Zijlstra , Ingo Molnar , Juri Lelli , Phil Auld , "Valentin Schneider" , Steven Rostedt , Vincent Guittot , Dietmar Eggemann , Ben Segall , Mel Gorman , Shizhao Chen , , Omar Sandoval , Xuewen Yan References: <20251018195730.GJ3419281@noisy.programming.kicks-ass.net> Content-Language: en-US From: K Prateek Nayak In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ1PEPF00002321:EE_|CH0PR12MB8461:EE_ X-MS-Office365-Filtering-Correlation-Id: 9f10aa79-3c8a-4dcb-203e-08de12b1d520 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|82310400026|36860700013|7416014|376014|1800799024; X-Microsoft-Antispam-Message-Info: =?utf-8?B?UmVMRmhYdlRtUnZjT0dDY251RzFFQ0ZhTk5yazYrZGx4b1U4Qytub0phSklQ?= =?utf-8?B?OElidVgwVXBUNjB6cWtmSHJLN2lQNkZSVktWSDYvaUNDZ3YvYUdkcDJHd0JW?= =?utf-8?B?ZkdtTTg3WHRDcGJTb3NNQ1NCdHVnaWFOVEFPV3Ura2JlRjBqb1czMkVlVzNH?= =?utf-8?B?cUk2SXVSVTlsRDRMOGRhc1NMdmtXaGR3NkhxSUdxcjJWVnA0NE9KcmUySFk5?= =?utf-8?B?MmxCZldsQS9RYkJ2N3VJemJLU20rRE9ZTExGdEFMbjVSdk4reE8yc1hkYmFN?= =?utf-8?B?QXJ4VDdRN3p5RnU3aHp2RkcxbWl4REhyZW00QndNaVI2dUJvVWovS2NzMEM3?= =?utf-8?B?Y0NQeFUraVRFNkZHQTFlWWFBMEN0WXhzSldoYTFra0l3OUV6cEd2djJ6ZWZ5?= =?utf-8?B?MVNyNEF3dVZCTVIwSzh4ZjBXcTJLR2VDTEo5YzltVzZqV1ZOMTgwNHc2em00?= =?utf-8?B?UGhKRC9tZTNtb1Jkb3huUXdVVU9qQStncGtMa1pJZjkwZEVUYzh4SUNQS1k3?= =?utf-8?B?YTZLWG5XaUlYTlVtOE1hV0FKUlVTNkZrc1ZqMGlxOFVmaXBSdUdlejhIK1NP?= =?utf-8?B?SU1lUE5FL04yZTFydkFkWDhFeWFMMG5JRGVvTEd0WTArMFJVcmpWOHhRYm9p?= =?utf-8?B?cTRrTDd6dmQ4WDE1S0ZFNWJMR2N2VGZIanlQSmJWejRkbStwd3Q0Qm8reGhX?= =?utf-8?B?cG9UeWhSM3ZLQ1JHaVZ4V3NNdDlzQzhNT3E0UllLWlBVK1dZWEpOVTdUVk11?= =?utf-8?B?aHRLV3NicFNmZEtqcDRGRng2NXROaW5jTmd0eGg5NGNTSnFWbWR6aWFld2xY?= =?utf-8?B?YmpNVWxpRFNzakhKb1I3c2p5a3B5TXpWVWF5d01oTVNPR1k4Qmw3SUNkT0dJ?= =?utf-8?B?dDRWYkFLQzBnRkZUWG9SQ2UxZ2ZRUlNXRnd3Tm9aZlEwSjg0Yit5SWh5ZzVt?= =?utf-8?B?R01CVlBneXJUWHhVZnlaT3dQS2NadG1QT1pPOGk1VFF2V2p5NGYxYVhLVUJG?= =?utf-8?B?WEUwbE5CZVZVWU5xZW1wRWlXSkV2MjBENWNnSXJXWEFHT2ZQaFZQOHIzU2Jn?= =?utf-8?B?eUlPN1p2djF0TGZPYVRYaFJpdnl2MXNyS09rY0ZVZGFDc05JZXdnUlFvaWd3?= =?utf-8?B?L2hxNGZkd1BXSkhxYStjekdnUXR4YlVpME15N1crZmdYMG5scE5sMURMVm82?= =?utf-8?B?YkhnSHdiT0xlUlVGRlVESytENk8rbjhUSlcrREFqcTBLMHBUOWJuTWxYYVY2?= =?utf-8?B?alRHUXJ3Z2dKN0dzcFZMWDRQcG1BZ1dURWRhUWIyaFN6T0JRV1NNNTVuT2Vj?= =?utf-8?B?Ny9vNlRGR3ZPdE14SUR6Y3gvK1piRCtYcmJPUmhJaHdHRC9HcllIZzJSVjdF?= =?utf-8?B?ZlRDR0dXaTNBVjdIcmhzQ21aYU8xd0c4OFBCUHM0KzM5UEVxUFZFNXNoRktN?= =?utf-8?B?dTFKYkVNejhHSmVwM0pyWDI4bjJYaUlTWmFtRVJ3QiszaXl4ZTFDTy9YSjQ5?= =?utf-8?B?T1YweSt5TVp0eS8wMVV2RVhXS3ZrdkdiYm5aV3JQU0VNZEt3NkJ4dlkyRmor?= =?utf-8?B?VmtTZGlPQ2UzNENTVE5wNmdyS3RUR0EyQVgrM3MzcFRYTGlSR2lrUUt6Um0z?= =?utf-8?B?bXRHWTJQSXMydWo4NWpkeUU2SzB5NFdISG9MTUN4ZTJNWWdEU1p4bHR2YThh?= =?utf-8?B?YzkxeEF0SkgxcUZ6d0wvOEl2Zy8rTVEzbkUvK1RQbDV5UXA3TWRaWEVOUjdM?= =?utf-8?B?UUlIV2RqSWdSbVM0dzhYbTI1WFR0QTVzejdsVksrVGdhcUUxcFYrTmxPd202?= =?utf-8?B?ZEhBditCWFNLQ3ZqUGhtK241RmR4VzAvOFRHeHV2RjBrd1VwNHBDZUJlV2tL?= =?utf-8?B?bzdVbUZMSjNLalFVbEVUblg1WE1saW9zZXp0R3FtK0JsalVBcG1sUnVrVDd0?= =?utf-8?B?YjFHajZxOHZHcThzWm9wNzNyS1ZJK3AySW0zSHlxZEJtSWMzOFZXcVd4cUdy?= =?utf-8?B?anlFQjkwUllmM1JpZGRGU1g5UE5SZlA1L1N1WFFtYzNFeHpTSTZIV1o1MXR1?= =?utf-8?B?RUhIWEQ0MCtFSmJkOTZSRG5BaGMvU05HdDBGdz09?= X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:satlexmb08.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(82310400026)(36860700013)(7416014)(376014)(1800799024);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 24 Oct 2025 04:00:12.6012 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 9f10aa79-3c8a-4dcb-203e-08de12b1d520 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[satlexmb08.amd.com] X-MS-Exchange-CrossTenant-AuthSource: SJ1PEPF00002321.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH0PR12MB8461 Hello Luis, On 10/22/2025 6:05 AM, Luis Claudio R. Goncalves wrote: >> v6.18 kernels will get rid of this issue as a part of per-task throttle >> feature and stable should pick up the fix for same on the thread soon. > > Thank you! You were right, your patch in that thread seems to have fixed > the issue I reported. > > I read the thread you mentioned, built a test kernel with the patch and have > been running tests for more than 6h now without a single backtrace. As reported > earlier, I was able to hit the bug within 15 minutes without the patch. Thank you for confirming! Greg has picked the patches for both v6.17 stable and v6.12 stable so the upcoming stable releases and the RT releases based on them should solve this issues. Thank you again for testing the fix. -- Thanks and Regards, Prateek