From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from PH0PR06CU001.outbound.protection.outlook.com (mail-westus3azon11011056.outbound.protection.outlook.com [40.107.208.56]) (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 214C62E1730 for ; Wed, 4 Feb 2026 07:55:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.208.56 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770191707; cv=fail; b=dtBkdyjEvoRo2lJ7l8CL8QPD276lB/3YdDWJxFKDzW0Ju5TPC6N2IrVESa7ZSXSpohDgoF/CPntfKq2p9aRnr9EJyzpCth34xcAbsZxg7EfeoWcFfnpRwhY3rZT6rctfNz+poY5XWuROEHZK+8Ghee6SsQhsKWFuznnDFrEx1+w= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770191707; c=relaxed/simple; bh=y4HuUnhZtcAItymPO+z2qfcCYCYNmKc9wfXbhyLFhHE=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=RQeVnXV5NtWQ93WPKs+D3k5+Issil/FVyrVDUKyzXNdzdiVkGMm25j809nYtGwqnPZUTZONhp3fzudcDgQKOPAsaJ0eMpzbeuugcR/LMvs7UEl3X4Banux1kQ+TALMNja6+qdvx2u1pSlQr0IzHSjGYqbXUuvbUJ76NG/RSlgqk= 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=Ea3muU8V; arc=fail smtp.client-ip=40.107.208.56 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="Ea3muU8V" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=UuebDJ7tykI4M6dgNsVO5wsPMjAbI9DCqYtkgMj4YyN5VLjl9Kx4Ps2sXBIpB9zT+j6JlgrTX+LKdaleJ4MQqMQl5J1ZFdK1K6ipYkbSHFYb1nxDJyoG5RL4CAY9DkJ0iSaEptxAfN9ExCreAe3JePWRTDssyfk7MxgoETEn4ZoiGLljEg3gwAfFOc9mEkMDKGqceBxo09Q7lpqfUgHP7FcttXnNxeEKavEJncBI6FD4J9x+wDzzSvqB7C2EN2vrQwrSFK0M31y97Pwa0cBgCSQUHWEonFt5LZOVj0abj4j6649/UlqPGGhK4KBLH5LBUnePQl77JPNHGyr76yHwuw== 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=3aNRfuLRf+hqb8v9Nd1l+pjbI9qeMJmTzebuAFOtLmw=; b=gcUlkSPXn4ZnElswY7d4hHD6nBKXkfp+acGOnukKUF0Auu4MzctiqJL1BoyM3lYdrSochiVdil59QPLvDWP2mB2hHC08TeWV53VTxCNtYPqDU6fmgjYCUBRzn8Zr3VRUdIzJ6j1zlFYdlf2N8n/h9WS8TUahJlLMmsKh+Zb7LvkbtEMGAdI5gdWsPzjKeVAkePFyd49ltv5y2F1Ldjlv5u0KTIlpTAs+dFvzNJRvRScqTY5kUSYJKI7L8IGHVHds7aVOeVEWPSCaKrtoqTZ454ZxFeWQIab2UUceiDNX1ZPZFoABK10V6AzFf0jfOpIIJSWkcaRl5vVm0VR7a7TpIw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=os.amperecomputing.com smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none (0) 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=3aNRfuLRf+hqb8v9Nd1l+pjbI9qeMJmTzebuAFOtLmw=; b=Ea3muU8Vda1k1fciNABNUJTmTPPRpKw5cexXsvSmLpA0TFmUXQpkCcH6hUFK6vp9X3JkSOxTs2rN6p0zS63qpc0fmkfBWMndLWSuQspDjnBreT/sFqNrSmancDGcgzPBoJ23yFGNxvMOoNjR6Osa6E4Sy39z1Qa6mTkl+Sc+s0U= Received: from BN1PR14CA0018.namprd14.prod.outlook.com (2603:10b6:408:e3::23) by DS7PR12MB6144.namprd12.prod.outlook.com (2603:10b6:8:98::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9587.12; Wed, 4 Feb 2026 07:55:03 +0000 Received: from BN1PEPF00004688.namprd05.prod.outlook.com (2603:10b6:408:e3:cafe::f5) by BN1PR14CA0018.outlook.office365.com (2603:10b6:408:e3::23) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.9587.12 via Frontend Transport; Wed, 4 Feb 2026 07:55:02 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 165.204.84.17) smtp.mailfrom=amd.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=amd.com; Received-SPF: Pass (protection.outlook.com: domain of amd.com designates 165.204.84.17 as permitted sender) receiver=protection.outlook.com; client-ip=165.204.84.17; helo=satlexmb07.amd.com; pr=C Received: from satlexmb07.amd.com (165.204.84.17) by BN1PEPF00004688.mail.protection.outlook.com (10.167.243.133) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9587.10 via Frontend Transport; Wed, 4 Feb 2026 07:55:03 +0000 Received: from satlexmb08.amd.com (10.181.42.217) by satlexmb07.amd.com (10.181.42.216) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.17; Wed, 4 Feb 2026 01:55:02 -0600 Received: from [10.136.38.118] (10.180.168.240) by satlexmb08.amd.com (10.181.42.217) with Microsoft SMTP Server id 15.2.2562.17 via Frontend Transport; Wed, 4 Feb 2026 01:54:59 -0600 Message-ID: <097c6b1a-6b1e-48b9-813f-31de79e883b6@amd.com> Date: Wed, 4 Feb 2026 13:24:58 +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: [PATCHv2] sched/fair: Skip SCHED_IDLE rq for SCHED_IDLE task To: Shubhang Kaushik , Christian Loehle , , , , CC: , , References: <20260203184939.2138022-1-christian.loehle@arm.com> <6895a358-c993-74d5-d804-3b7130ee1559@os.amperecomputing.com> Content-Language: en-US From: K Prateek Nayak In-Reply-To: <6895a358-c993-74d5-d804-3b7130ee1559@os.amperecomputing.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BN1PEPF00004688:EE_|DS7PR12MB6144:EE_ X-MS-Office365-Filtering-Correlation-Id: 5982f77f-2d2f-4a1c-fbe2-08de63c2b42c X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|82310400026|376014|36860700013|1800799024; X-Microsoft-Antispam-Message-Info: =?utf-8?B?K211TGpPUnBRS2V2eW9vb1hHZUxLNTZQOUhoOGJQRGI1cTBsZW1Uek5mL0pD?= =?utf-8?B?Z29ydjV0NXdPYzcvNk9tb2RTY0VCMHh2dmJHZ2NHR1RSSDdJQjZFMktYUVNH?= =?utf-8?B?OW43U2FQcTQwbEdSNTFMLzBydTdYdWp0bDhPekc4S1hpYXR5ZGRNNWk3ZS9T?= =?utf-8?B?K3VGOWVrL0ZJUi82Zkh6LzJYQXZmWlFWK1FFNjI4TnlLNEdqdmZRVVd5SXI4?= =?utf-8?B?c3JOSzduV2dqWXlISm5aL1krSDVpbHByTnZJUFN1dmJ5Y3JEM3ZFcU05dDh6?= =?utf-8?B?RjVGYVpxOW5JV1BpQkFzalBsUk85UUJBRzd3Sm81cS9TVGxTQUphY1l5Tkdj?= =?utf-8?B?Y1VOTm8rU0tNcmEyOHpSQkYybGNKYU84Rkt4bElxckdDSWIyeC8xdlBBNFh6?= =?utf-8?B?Q0llWFplVkxFbkFIT1hjQzQ2b2VsRHA4RytwZGszZ05USzJDbm9vVis3Smli?= =?utf-8?B?REZQUlo4Vm5USnpGMHNvUUdCWnJIL2NIUGk3Z2pCRHBtKyt6c1RtTW42WUk0?= =?utf-8?B?SDROM01rM1hJNTRwcW1IT2dldzdsdldlaVN6RHNEaFRidVY1YnoydkNYRHpx?= =?utf-8?B?VzFWd1ZUTnFIRCtiYXdsbElhbDl2UUFmUDhYSXpmbE1oK01FN0Q0VkNzVkpE?= =?utf-8?B?T0ZsVTUxT1E4YnFmYW94SlVISWZ3cEhHZExJcWFiV3Nwa0tIWHlNWFVXZVk0?= =?utf-8?B?eWl0V2Z2VkFGVG5QOWVNTDNkRS9TMlYyb3U5ekdKS1B4a1NHeDVqbnNjc25N?= =?utf-8?B?cFVXNEdyWmJUNldLWEVEM2lwMWtOS1RqcWpTU082VkxkckpGQ09UVjFjQTcw?= =?utf-8?B?czE0UFI4WWxGdU1tbit5K3hTMWpyTk55MCs2UU54cS9jaFJXYk1kbWt6eW9a?= =?utf-8?B?QzhVcXpDdGpMRTU2T0lFdHhlUkN6cElrdWkvS2QyTXJNZ0hscklxZW9rS2sv?= =?utf-8?B?ZjlDU0tLRmtyQWxqVkhIWnl6Tzg3SEk0TTBuc3lMMDZjemNNV0JRN0pwbGVl?= =?utf-8?B?RkpxaEo4WTE4ZFR1VkQ0czdZbGNQcm55bGFJTzBSMnVIM055QmxOR0NLU3Jw?= =?utf-8?B?cUJCTDRTUUhMWWl5cCtra29SQjhPODcwaExsNmRHcXdOdFdqTzBkKzh2UEZa?= =?utf-8?B?RUlweTUxbUdJa2NlNmZPcndWV3BtQ21NUHQweERPRkErTmNBbFpVNmZMaG1M?= =?utf-8?B?WDlNZ1d1YWNXM04vc01tNXkxVXRvUmVDTnFUNVRVMWp6VVozSVA0dVRtdzZo?= =?utf-8?B?L0piZ0s2VnRzd1lpSk8vTkRKMDRDTUZxQ1RGOFJ3emdTd3kyT1JsNk1aYXhq?= =?utf-8?B?QUtKdGZRdklCZTJuNU0zcWRPVXRqR0pWZTI5SUlhbjR6R2NSMi9JNkV2ejZM?= =?utf-8?B?Ykp2T1BBMUVGbGE1dXFuTmdGRTR5MXU5bk1XZzJ2N3B0d3FJdTFZbkN6SXYz?= =?utf-8?B?VHJzZzI5TGtwMXhjMEk5aFdFSVN5NWZvb01Vc0lJcUp6MFZJT1dmU25kc05x?= =?utf-8?B?dnRQV3p2aTFBb2MxVnNRWXV5YWpvMW5VYTlqZDJCWXkwclJYU2I3WGNVbTRt?= =?utf-8?B?QklLcEVRZVZ1NW5OaXY4OUt1bWZMc3p4dEpqOERtMTY5Mjl4WGV1cm5xckR0?= =?utf-8?B?TFJBWjJOK2c1NXIvSE84UFc5dFRta2tqbHA1OHhmSnlILzdBQVFLcVZUcGcx?= =?utf-8?B?TWRIbzU2dkZTWTUxRENhT1BhRDM4YUZrckh0Y1dFelhWK1pWK3Y5ajdvMjZX?= =?utf-8?B?RkgxUWJxRTJEeCtnVHcvR3hILy85eU9Hem95OFI5dks3UmpEYWRodE13c3c3?= =?utf-8?B?NlJZelQ2QUE5NVFRbFpmQ1pOa2x1TTVzUDhxUzhQY2FGOXVtYXVDWHJDRUhu?= =?utf-8?B?N25JUjlWNllLMkl0bEE0RjlDaC9mS29iQTV5MDg1RG5GekptTFlZYmpOZnE5?= =?utf-8?B?QWZwUlhzQ2RXOE5Wd05hcHFwSmp6RzNGL3JxQlBpT0ZnVzY4RXhSc3ZWZ0RG?= =?utf-8?B?MWdlUFlLQ1JSRXFXNFNYWEhaV1oyRUtZWjBtN2diZFFWTU9KUU5qK3lTZWVD?= =?utf-8?B?VzBxNXl6Z2NvK0J2VkhwWmlnMUlpTW9LWGVMSDdVdGM3cGJSMnVMZ0ZUZklH?= =?utf-8?B?bStFNE8zK2hjdUpldUxNdStTSEZEdGVUUFNoUUF2bndtV3FGNlNtM0hLaDV4?= =?utf-8?B?MWtWcHVwK2trSlZ0M1NkNko2dmlhaUl1WkhncHV4MXp5amRKV0VYS0xwV2li?= =?utf-8?B?Wm1tQkp0VUlpclpuOXZHdVZLcHBRPT0=?= X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:satlexmb07.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(82310400026)(376014)(36860700013)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: UPE7RG+Vj1adE3NE0RcPiQVRAC4/97lln4xbpRvE0XyVbIaUCYvWRI5WbHWW/w+aHkklXk5ocg2LEGu25kq1dXW+6ndbmNHn661qtcxsPN1g7nIu+ZdDr7VODXw1tJHUK/bgo0vpdl7le5M+dVPjzhc7NfRhUfvy5K2c69Y4gb/WCyPGXiECSzbYiZOBCeWJ0SkW404HzVA4v8OyUK8fsC6NKdTD5av/GHKsk3QETsUx1PWVbAhOucPdvIADJGta2rgTQ7hZQec6UMMpNj/v0iAa/S+U3gFOamVYiHegp+E/inEWSIZYIFF7G46ELz0t/fzByclwuyBfm2Q6PBpxc40FbGsqvsA3pkgxuQ2pE3fCX6BEfb/iiOJBh3S49NvoStt/TAMZWfDxDiI5BG3uT2w6hwKJN/g/tQPKvdEeERHEu05+1gHftRp5mO1HmySp X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 04 Feb 2026 07:55:03.0415 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 5982f77f-2d2f-4a1c-fbe2-08de63c2b42c 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=[satlexmb07.amd.com] X-MS-Exchange-CrossTenant-AuthSource: BN1PEPF00004688.namprd05.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR12MB6144 Hello Shubhang, On 2/4/2026 7:38 AM, Shubhang Kaushik wrote: >> @@ -12299,7 +12305,7 @@ static void sched_balance_domains(struct rq *rq, enum cpu_idle_type idle) >>                  * state even if we migrated tasks. Update it. >>                  */ >>                 idle = idle_cpu(cpu); >> -                busy = !idle && !sched_idle_cpu(cpu); >> +                busy = !idle && !sched_idle_rq(rq); > > Usually sched_idle_rqs were treated as not-busy in several balancing decisions to avoid yielding to background load. Does this change alter that interpretation at the domain balancing level ? I don't think anything changes in the load-balancer path since we still check for sched_idle_rq() here. Only the wakeup path will consider both the waking task's policy and whether the CPU is completely idle vs sched_idle_rq(). > >>             } >>             sd->last_balance = jiffies; >>             interval = get_sd_balance_interval(sd, busy); -- Thanks and Regards, Prateek