From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from NAM11-DM6-obe.outbound.protection.outlook.com (mail-dm6nam11on2057.outbound.protection.outlook.com [40.107.223.57]) (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 A66597081F for ; Thu, 4 Sep 2025 09:51:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.223.57 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756979479; cv=fail; b=cLpsu42cL/u8nCYnRPqnDmOU7A5WEKexDZ0aHjsKZEnH4i2LNG8v4LGWbLbX0qU7REdva3/TV25vV7AcoMsV7Xfh6NxnyD3MEw0Ephvtdq2abx9GbIlOcNgMKKqLFd0LcR4FIBbMQkAu2sxnpcCcvisO6Nwt4yZCktoR0XWfdQI= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756979479; c=relaxed/simple; bh=DTanzjedMQvq7HJUvPKrJbQbFUza0xc1VkAr4ZhZctM=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=CLc1upfkY47Zmr+923WlxnbfWaTdtMcdzdZDl64LdBNQ9kjfYDDCAW/N1ddeFTCGXxPtw3+axhzOW6UUELMqA8lYDcYHTZj1z0XntyLC8ctzRYsbmCoStklD1fMnnMf4T4emLkerueOVncbmQShpyLHk4cBUYu8B2kCumrNBjPs= 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=XeJuNlAQ; arc=fail smtp.client-ip=40.107.223.57 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="XeJuNlAQ" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=gMFtuxIP3mweqAApXKnz42w7pQZEPoCdKSGOgV+jvuqdHldOMNntbHyOMasXFRbAVUtsz7Zk63ZTjqMTj52Pd/gBVEnDTUinby/LJWJF2osic8mOCAQbQNy2FI2hHuTjVDAjH5nXJxntufcBuUZcAACKkj59SYmWqS9b09BPLMEoJMs3Hs9ZmG1mGXHXdfJHaQCrFdEjgiPc4mNE9HSkdW46kbuXiN4CtVtBOELgArelf7j+X9GdEZ9CG5IyfJjP052po1rrVTlYtNlkF+jBTwSn+F8BA7IFvA46yeMy8ueOhQ7n1RyLrIU8zE617xjUk7kFGDx2hHsl8MxbAXLXnA== 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=hSGevmBJrEhMxXi7RXKCig6pCt1smPNNkXynHlCG1Gw=; b=OvhlLHTu15HZLum/N9jgHudp3NsEikL3HVlhUDDEMI6oRMLDa3ys4ce/smcwh7dFXDa4A/Q37DOQQIgfT+lgAO+eYfkZ74ROkx5/foVchrb7W49z8owPvgAmaReF3WcL5851vm7UKvYX+uLk0VUPt5CJSSQGbv5SjtzMFVsuCoXU6Jmy16vXldlex3AJ3PmUUD1gSjgSt1yLI43rtEtSIjwVHPHEjLdWoBEsWqaiH5v59fHMvfLK23Hc81M12dfAaHPPqXw/bssBfYJ6cI1TtqF2sEQbITBKzz74T6cwvvavc0pbMKLtdV49QdttJYpCBG5gd/y0PVu0U7ceKx+i2g== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=bytedance.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=hSGevmBJrEhMxXi7RXKCig6pCt1smPNNkXynHlCG1Gw=; b=XeJuNlAQfjLIwdtXHvNEPcTp/0uthfKP9bsyAJHKO42XKz76BW6CIkAr9oCNWhhHOi9ZhOhgE4i/sLNTCgWKhjiNawRXmXXljcNq3dmBHrzHSlwUXMRzYCBpc6jI0NzpFOEpL9ucGAI4Z3z/Z5SIxcywbVqipUdHM6NZcs/sKyo= Received: from BYAPR05CA0003.namprd05.prod.outlook.com (2603:10b6:a03:c0::16) by BY5PR12MB4036.namprd12.prod.outlook.com (2603:10b6:a03:210::16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9073.27; Thu, 4 Sep 2025 09:51:13 +0000 Received: from SJ1PEPF000023D0.namprd02.prod.outlook.com (2603:10b6:a03:c0:cafe::b6) by BYAPR05CA0003.outlook.office365.com (2603:10b6:a03:c0::16) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.9115.7 via Frontend Transport; Thu, 4 Sep 2025 09:51:13 +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=SATLEXMB04.amd.com; pr=C Received: from SATLEXMB04.amd.com (165.204.84.17) by SJ1PEPF000023D0.mail.protection.outlook.com (10.167.244.4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.9094.14 via Frontend Transport; Thu, 4 Sep 2025 09:51:13 +0000 Received: from satlexmb10.amd.com (10.181.42.219) by SATLEXMB04.amd.com (10.181.40.145) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Thu, 4 Sep 2025 04:51:12 -0500 Received: from SATLEXMB04.amd.com (10.181.40.145) by satlexmb10.amd.com (10.181.42.219) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.2.1748.10; Thu, 4 Sep 2025 02:51:12 -0700 Received: from [10.85.34.65] (10.180.168.240) by SATLEXMB04.amd.com (10.181.40.145) with Microsoft SMTP Server id 15.1.2507.39 via Frontend Transport; Thu, 4 Sep 2025 04:51:07 -0500 Message-ID: Date: Thu, 4 Sep 2025 15:21:06 +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: [PATCH v4 3/5] sched/fair: Switch to task based throttle model To: Aaron Lu , Benjamin Segall CC: Peter Zijlstra , Valentin Schneider , Chengming Zhou , Josh Don , Ingo Molnar , Vincent Guittot , Xi Wang , , Juri Lelli , "Dietmar Eggemann" , Steven Rostedt , Mel Gorman , Chuyi Zhou , "Jan Kiszka" , Florian Bezdeka , Songtang Liu , "Chen Yu" , Matteo Martelli , Michal Koutn?? , Sebastian Andrzej Siewior References: <20250829081120.806-1-ziqianlu@bytedance.com> <20250829081120.806-4-ziqianlu@bytedance.com> <20250903145124.GM4067720@noisy.programming.kicks-ass.net> <14be66aa-e088-4267-ac10-d04d600b1294@amd.com> <20250904081611.GE42@bytedance> Content-Language: en-US From: K Prateek Nayak In-Reply-To: <20250904081611.GE42@bytedance> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ1PEPF000023D0:EE_|BY5PR12MB4036:EE_ X-MS-Office365-Filtering-Correlation-Id: 8b38e332-be12-494e-7f55-08ddeb98957a X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|1800799024|82310400026|36860700013; X-Microsoft-Antispam-Message-Info: =?utf-8?B?UWlpcUlvMlpoTUJMNVRpVy9DNFNrZyt5cWhvQ1ZtZWNFRExGdmRWZzloMXE2?= =?utf-8?B?Nm1XNDZ5REgzNVRTOHpPalBWOUJiZzJhR0R2T1ZrOFlYcWd6anlXdW5remps?= =?utf-8?B?Tmk0amNHS3JlTDYwQU1xSkh5VVlRbXFzcWg3cENCRWJkTzlDSy9hODM5a1FW?= =?utf-8?B?S1RDdm1LeWdTL2NUTzNSVlpta2RRdW9VOE9Kdm1yZlM2MmtWRVM4SnIxSXRL?= =?utf-8?B?V1BEekdJTlZITzhmaStYYUZoRjN6b0dWaHZJYlJzdSt0aTh1bEwrd0NSNnBy?= =?utf-8?B?SVFjNlc4TC9wYm1UdDhRMElLdnVITnVVUlN2Q0RBQ3NTTDFSVnBSUmUrTTAz?= =?utf-8?B?M3ZkV3g1TFh2S2YycFc3K1hpd0JYaXZJek80NERBT05Qd2pGRXE4emFCZjRn?= =?utf-8?B?Y1ZBRG9laEtiOXJObnhNbXViRHg3WWU0aVJrbUF2dmxmUkw0dnFkSkVMcnRS?= =?utf-8?B?S0RQK282Wkg4elpoUFA4ckhDaE1xR25pc1VqT0hsSlNGSDN6aUJVVWR0TVJQ?= =?utf-8?B?c2NCR3I5R3o1RFcwcDJLUlFadDZRTVpkZkg4Nkg4cmpVbG4rSFQzcFN6V1U4?= =?utf-8?B?ODk0Nk1RdFlaSGlHakd6N3JTTkk0T01FL1V2emFuUnd6eWRTV2tJNzBHY0RD?= =?utf-8?B?V0QxRjc2Um1xU3Q3L0JzQk9MNkkzTTAzQW9nSWhDUFpxV2N2MHZiVVhPV3BD?= =?utf-8?B?SEZFc2swb29wcGwzS1lNWVpwb0lyaW5XdDlGTjNHOW4yN0N6d1gxUEFlZDQ4?= =?utf-8?B?M0M1bUFVaTQvbXZQK0l2NkRQaVJXVmxEOTZwWEZvK2dGQ2MvQjhMLzNXK1pI?= =?utf-8?B?THBtaGNnVEkreVpMWjk2RHVpb04wSDN6M3pyT281MDNvdmNPeEJwaXdoaElL?= =?utf-8?B?Nm11Z0w1OVFteG13WlkrQXA3bkZuRlhVaWdJOGxRcHFSTzBGTjZ1SmNRL3VF?= =?utf-8?B?UGpMWERKWVUvY0FiWFRoMFZEWUJKZGU1VFUvaHN4dUpmaENya0VVREtTQVJn?= =?utf-8?B?dXgzUjhuRTRKcnBOaDJmNTdtVzBnZ2ZRUTV2UzR3L3RiUFA1eEwvUG5NczE2?= =?utf-8?B?b1JmWWlpM3lnYVFudFB6QXN3SHRpMG1pSWVwQ0UwTEdmRXhqNVRqNUFPb1ZY?= =?utf-8?B?N1MrNVIwdml0UEZXR0FuU0ZueVRjQ0lNaUlRVUtFeVBvK293MGx1N1V2YmlP?= =?utf-8?B?bnc1d2dKNCtZdE5lTnhJWE1wcVRHWUF4cUEvV2UvalQ1Z3p3VEl5cHl5aW1U?= =?utf-8?B?bnBSd1NhNmh1OCtObGhWdjhnM2dvUDhwdmpsSlprS29uSVY3ei9uQTJFTUk4?= =?utf-8?B?TGRDMUpncnR6WDc0d2lxNlV5TDFiOXRESFduN0JnK3p1OWNmQ0xYYXNwSGlJ?= =?utf-8?B?cDVRaVN0K3VZNGtlTUkrSHdIMnYxT09QK3FlVkNnUWxLMitxaURNeUFRaVJQ?= =?utf-8?B?SysyUVBQVlFRdEhZZGdxc2tncEtKVTJmU2pZZUVlRk40dzdiSytlYXEvSHJQ?= =?utf-8?B?bUFrWjA3RzE4cFFmYk1mM2NyYzJiL1pWVGJvaWhkem5oSnhQT2V2R1hiL0p0?= =?utf-8?B?RDgvU09vbFM4dkJpaHp3eGlwVVJRYXo3Y3lpU0x6Z3Z3VXJXWFVDNU41VjZ6?= =?utf-8?B?SVRrYnhSZ3htd28wdTIvOC8zK3lZWE10S1ZwdDNTdkQ2d3NHMWVwN1RNUmxD?= =?utf-8?B?ZGx3Z1VaaDE3SUFOdTlhQVc0enkzMmhRdFVDRVpXSWk0azRlMzhFVXppZGhF?= =?utf-8?B?YVQvZTV4ejg1NXBnemEvdGxWeVFsSGpYa210NmxIbkZjdFA5czJBYTlUZnpj?= =?utf-8?B?RXFvQmFGZFhHanBsNktXMVNPNCtNdFgycW1EcWxUaldmREVmcUlRK09ERVJG?= =?utf-8?B?SlJmNW9YMkhtb0lyZEpScXR6VDhhcWhCN0tWeW1zSmJBTUVoRVFBSTM2ODEw?= =?utf-8?B?bEd5VnJiZ1hqS1IwU1Z2blcwOEhhVWFUODlmQ0NyZGRtSFg0WFlVRGgwWnBs?= =?utf-8?B?YU45MldvOXlDNkIxRWpHSFp2MnZmTWpkdVRNaXByZ3lQODhQdHBjMlBZZjJM?= =?utf-8?Q?CMQedJ?= X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:SATLEXMB04.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(7416014)(376014)(1800799024)(82310400026)(36860700013);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 04 Sep 2025 09:51:13.0586 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 8b38e332-be12-494e-7f55-08ddeb98957a 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=[SATLEXMB04.amd.com] X-MS-Exchange-CrossTenant-AuthSource: SJ1PEPF000023D0.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: BY5PR12MB4036 Hello Aaron, On 9/4/2025 1:46 PM, Aaron Lu wrote: > @@ -8722,15 +8730,6 @@ static void check_preempt_wakeup_fair(struct rq *rq, struct task_struct *p, int > if (unlikely(se == pse)) > return; > > - /* > - * This is possible from callers such as attach_tasks(), in which we > - * unconditionally wakeup_preempt() after an enqueue (which may have > - * lead to a throttle). This both saves work and prevents false > - * next-buddy nomination below. > - */ > - if (unlikely(throttled_hierarchy(cfs_rq_of(pse)))) > - return; I think we should have a: if (task_is_throttled(p)) return; here. I can see at least one possibility via prio_changed_fair() where a throttled task might reach here. Rest looks good. I'll still wait on Ben for the update_cfs_group() bits :) > - > if (sched_feat(NEXT_BUDDY) && !(wake_flags & WF_FORK) && !pse->sched_delayed) { > set_next_buddy(pse); > } -- Thanks and Regards, Prateek