From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from CO1PR03CU002.outbound.protection.outlook.com (mail-westus2azon11010039.outbound.protection.outlook.com [52.101.46.39]) (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 9090737FF6F for ; Thu, 25 Jun 2026 07:37:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.46.39 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782373077; cv=fail; b=teP95gRayAihyR1O3nKDkplr2Sda1KKMU5LXdIURuREccjl1tZO9+JzL7ssbZkFKw7oQ/eZOsxoStYJHw2DW6IlF+HTsxzGomrvXTBEoXLVcuMhBdzA0CFwwXbDZuv4QuMCUn9QdEbC26aXmFLhm9KKj+O94aoUdDXpzAUr9n1U= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782373077; c=relaxed/simple; bh=fwT6CIZk16v2Uh1/6Tn3VECaCEeDsQJPifG+p9g+uJQ=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=X8PRhx4NoRiIEQHrfM1U5jfRtP7rIkk9spZ9FAQN8sVYDlE8iR53aPoIPA6j2IufRtSHpQy00855kySeGRnW3X3+4a/rpgc5njd0DF3f9mRBMVnPbCH58Hq/uvhZro8sOX9nrTlKuSK/PFPC+Bk2InDgFrQtXzo0Js0Po5IQM8Q= 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=eZabZTAU; arc=fail smtp.client-ip=52.101.46.39 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="eZabZTAU" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=DKxNvnM6TBnVMNFCYLXVXgLx8tbxun4h7wFYs+vA0YnU/l1TTFvQtXYlBGnYOkagCzrUQZ8IQTRn993BSE3RN+VZbP2+x5MMkqeE+YrCT7Dzp0yz4E0gGT8FPqH+gQyP4fh/TVtBwadeqACVMPBU2sbdqr+6PzY9g+QnEhyC1/9h+8QGFRjPzUKWtn45SFsJlXDVVd0EsIEJOMsq6f7HMl52nA+MeEIQM+/AoJVNLKfJ8f+Mq1TQN41mLeRdl+OPTTCVbuZxA3MoXWQ5X+pKsa1Nr1bekP0HCx5WtX3c6L6JQszebAK5Ey+UynIKGTSVb5Eda8OZpAhreSTVTvjZTQ== 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=r7OrMKoORi3fG/O0cCba3pbCdhXGx5g4ZoP1SlaLz4o=; b=ZF5mJ1VRy+Yi8syimjC+7yWfoiua2Q0o1xAKErwjsSI30MVLIaL0U3EEO8JU1qDdJiaKMUeGN+eq14yXuVz4nU/Ywfe6xi5aj1F7HzpwCrdk4q0IAPbGtrzQwzho8EXL3iWTUsD6UCyXVthKLrJ10ehMJ1LW0dV5swOaEU0UAtXUIQLL2z+jkhe5Tb9UcUIND6OOsFSIzgr4OyUGDsAC60rH/t9ouAahJx4F6LW5T/4UxmYlexrv+63chbBP2vTG259XZj8nJFX6i2unaJNHt6lMNggz2oO1aNSBdE++pQtpB4InYmnP8fW7l5d11P5HbxriyYRfNiMoRAeUwOBFVw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=linaro.org 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=r7OrMKoORi3fG/O0cCba3pbCdhXGx5g4ZoP1SlaLz4o=; b=eZabZTAUrnmK9P4yR/vTH1r8/T343DZlaG236LqqWSQ935IDQ1AYLyiEJW6TaoIsU96zQfLXllTLFEFcjfZHFwSwI+NmCYBf/7YLBltPWAKSmutDLrMgbwVQQh2BHRpOrpR5QKAIBFZaJQcG2QJT4gN9inGGDNh9+g0Moi2CwEs= Received: from MW4P220CA0028.NAMP220.PROD.OUTLOOK.COM (2603:10b6:303:115::33) by SA1PR12MB8642.namprd12.prod.outlook.com (2603:10b6:806:383::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.139.20; Thu, 25 Jun 2026 07:37:52 +0000 Received: from MWH0EPF000C6193.namprd02.prod.outlook.com (2603:10b6:303:115:cafe::51) by MW4P220CA0028.outlook.office365.com (2603:10b6:303:115::33) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.21.159.14 via Frontend Transport; Thu, 25 Jun 2026 07:37:52 +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=satlexmb08.amd.com; pr=C Received: from satlexmb08.amd.com (165.204.84.17) by MWH0EPF000C6193.mail.protection.outlook.com (10.167.249.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.181.6 via Frontend Transport; Thu, 25 Jun 2026 07:37:52 +0000 Received: from satlexmb10.amd.com (10.181.42.219) by satlexmb08.amd.com (10.181.42.217) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.41; Thu, 25 Jun 2026 02:37:52 -0500 Received: from satlexmb08.amd.com (10.181.42.217) by satlexmb10.amd.com (10.181.42.219) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.41; Thu, 25 Jun 2026 02:37:52 -0500 Received: from [10.136.35.225] (10.180.168.240) by satlexmb08.amd.com (10.181.42.217) with Microsoft SMTP Server id 15.2.2562.41 via Frontend Transport; Thu, 25 Jun 2026 02:37:49 -0500 Message-ID: <613c1bde-4152-493f-b103-f1fda035b4af@amd.com> Date: Thu, 25 Jun 2026 13:07:43 +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 6/6 v3] sched/eevdf: Speedup short slice task scheduling To: Vincent Guittot , , , , , , , , , , References: <20260624151229.1710703-1-vincent.guittot@linaro.org> <20260624151229.1710703-7-vincent.guittot@linaro.org> Content-Language: en-US From: K Prateek Nayak In-Reply-To: <20260624151229.1710703-7-vincent.guittot@linaro.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: MWH0EPF000C6193:EE_|SA1PR12MB8642:EE_ X-MS-Office365-Filtering-Correlation-Id: 96d9af58-7550-40f4-7323-08ded28caa26 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|82310400026|376014|7416014|1800799024|36860700016|23010399003|22082099003|18002099003|921020|4143699003|11063799006|56012099006; X-Microsoft-Antispam-Message-Info: pjTyx2kPfZ68nuODdLWT7pcqKym725dHg0z4ulEYbh8h+rTS5GebZh29Qv01SyUoPUVk0IIuHGCKm2neOohPD8v40wAOyomdInNsdP4UTGcS875R50AyFqIddJCmUQK7tWbRfo2mYA6jHLkUFX5PnQ3tvuXA3nn2HacyxUbOdR46RQz30bbSdDNbuzr+Ptv106HpT8vSGqS7rJnpGEeB+Yyx4pgmeq6oFmaWQ0RJzAHlBdS1+EOIDD54fE9xJTpAMYyiKHhFhwFdUc3B64vVO5edhUxNDXI74GkHq0mAfH79EVuDc7B0JWABTYLbT0uvWaya9rPdaZDSKwK7IkLJo7yXu19er4jbUMPK7droRzMfnKkyHoPJVmHYHdRhwynzWVkxTOHuzvu3J4YiJJWp8IMsg7/D8bDXxSwQX0xyRIsmVXYqxKHgTM/J5dd8gLr+7vP40FsA8wvXTO9Gqn4/Viv/fPoyGaHNjLtxRwlFT8j/GYRT0sVd7G+cMM64Sjj/ci3wRWYJE/Vgk1vEKJpmTxD6t0Bl6qm+587Oy38GJ9XN2gy2suwl0caQod01K8EHDIzjXhbtjzoxMyNVEy3BzVVr5Ye5uTeToGEr2NZGA0t0MylPbADCeWB2/iTXHrXy0IDk7gsjfOuuN6M29rips3fV6tN4HiWzrqanHbXkIOCqSIW6O5818KwdfFNTw5pIEYBq2yo6JdEJZoAyzIAW7klDqVvRXyijziegAwTLl6iWxT3PIMUTFAk/sXkcRQ/t X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:satlexmb08.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(82310400026)(376014)(7416014)(1800799024)(36860700016)(23010399003)(22082099003)(18002099003)(921020)(4143699003)(11063799006)(56012099006);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: 7R/g27rEwcPDY9dIEHZWfDnZEAB1eJA00xVPpDa3Qdepl8ND0KVU03g+VFfxtx/P+Rg1uY9YOTG4vvCzxhZadRAiFiu9kUSOv/MFzL4e+wGKYzuF7BZZaEoKb68ZVVRC0KAeL+K4pRGQCSHE7F8y3fVfZHMq3aYwKbziLqGh9vOE3XCN+79jm0fgHmpWLyBnYt/cV/nWdMB1ZAMFK9VaoW1rSl0mCfjzuuzFQf4Zi9L31Tkg7xAuKVmi5MuJzq/kmkAr3rskK5cVHpNBqZHlavP2/4TFivp0PoK6KPAQqTRgIyN5amY6BYsGjfAIfqMmQWKaQLmD3SQLEfqLVIidww6z+BH4PyoMGg/FZM8UJ3rNjQU6yseH3kkCYrdFndVA04NEYQIG2A3CXSav9UQNlb/RhNI5T56BFbv6fdXFPgjFun793r7GVtp16zlau6Ni X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 25 Jun 2026 07:37:52.4343 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 96d9af58-7550-40f4-7323-08ded28caa26 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: MWH0EPF000C6193.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA1PR12MB8642 Hello Vincent, On 6/24/2026 8:42 PM, Vincent Guittot wrote: > +/* > + * Compute the vruntime until which the entity remains eligible when it runs > + * or is about to run on the CPU. We use this value to set vprot to the min > + * value until which other entities would not be picked anyway. > + * \Sum (v_i - v0)*w_i > + * V = ------------------- + v0 > + * \Sum w_i > + * > + * We want V' for (v_se - v0) == 0. Previous entity has already been enqueued > + * in the rb tree and next is already dequeued so > + * > + * cfs_rq->sum_w_vruntime > + * V' = ------------------------- + v0 > + * cfs_rq->sum_weight + w_se > + nit. ^ is that a stray line or a Missing * at the beginning of the comment line? > + */ > +static u64 eligible_vruntime(struct cfs_rq *cfs_rq, struct sched_entity *se) > +{ > + struct sched_entity *curr = cfs_rq->curr; curr seems to be unused here and is NULL anyways when set_protect_slice() is called ;-) > + long weight = cfs_rq->sum_weight; > + s64 delta = 0; > + > + if (weight) { > + s64 runtime = cfs_rq->sum_w_vruntime; > + > + weight += avg_vruntime_weight(cfs_rq, se->load.weight); > + > + /* sign flips effective floor / ceiling */ > + if (runtime < 0) > + runtime -= (weight - 1); > + > + delta = div64_long(runtime, weight); > + } else {> + /* > + * When there is but one element, it is the average. > + */ > + delta = 0; Even with a single entity, the se->vruntime can still diverge from cfs_rq->zero_vruntime Last avg_vruntime() call for cfs_rq was at update_entity_lag() during last dequeue while se->on_rq was still set for the dequeuing entity. Should this be entity_key(cfs_rq, se) instead? > + } > + > + return cfs_rq->zero_vruntime + delta + 1; > +} > + > static inline u64 cfs_rq_max_slice(struct cfs_rq *cfs_rq); > > /* -- Thanks and Regards, Prateek