From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from BL2PR02CU003.outbound.protection.outlook.com (mail-eastusazon11011063.outbound.protection.outlook.com [52.101.52.63]) (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 E4D1F38AC75 for ; Fri, 17 Jul 2026 11:16:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.52.63 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784287019; cv=fail; b=FDmnzy/UPzwHY4brsvIsDDDEGnBi8m5EI3iH6XfSXIu9v0YpvfpkDmxJ5Q+8m3kz2wiiZzlmNovOeprT9vkfo4sP/0oc6S1yZiU0CWxNvfIQpo2QWFrmBGH+R7Pw2dswAZJtcTW3/DSVYFf6lF1uCpDUd3Go+9kc2gc16oAdkKU= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784287019; c=relaxed/simple; bh=DWsM/Vh956eCKK9yVZeJwsMMF/vTb7axoSCyoM9Ot/Y=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=W8IiTK+bq4pNvTWSoiuWprrtFXDpQwDyXV33jTZeuz9Pb8/MSFdJXT+Up6xjf/BYPHmOU3rWOS+YEuJ8ekt45swLsNWMLOgXL27C0Hpv9N69XLY+7+2uLgQpY2duAKpjex0pE6DVpkwfOJ0qg6fvSZlIJzOz5HaK9yh6U8OoVoM= 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=PwTZDwf6; arc=fail smtp.client-ip=52.101.52.63 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="PwTZDwf6" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=KEn3QlXTNt5kwyWjvP25/fPpr8uPeUFoqm7Y04uQ6g1DbOtAkt8hhioDkj5JdJGuVi4lvrirPCV/Z6BoDbNbClJrBUhiayLCBTxLBtcedXVZPVtwkGWy7PDi67zaIkdHlLWa7InZPNWDZ27F6U2TSQ7VxYtdVRCtj31vrPM+FpgSzvn54G5vr1DEq++D/TnWhJhs7+hgY7idHZ8PzqwMHmSYrG5sFeI6WmPHwHvmORnRLa33VtDsVSCqIP/ZYho81KV4K1BvqNBE/ux3MDG5S5QpaI9rorxFcu+/MKWbeYLlwHHJuQ6T8ptg4Xmson14R4K5oqOFAnz4l5iSGjko+A== 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=1/4kLRVGGRJ2QGthgr5yrDLkJ+uRNvjRFsFWoBJHU4w=; b=Ev7oEvl5mAhuPhL/1/nf6Tk9SMib7JXgs0OuxDaF0gnbCQ8vs4dv8CQ9hP4sWANiAr9LASm8iq4y6OMFlPMLsHQS4ytBg/zKwIc/tjuV9TM/5kuHU7rvyu++pQLJb0C5shDYHo6esJRTw2Pgr+BuGsiwudtLOALvXX4jALF5TYdW/au6+6xC/nfkq43K2eu/Sn0e6BFKwX9fyq9Wqsn+3n0pJvcE10TYstUup0ie38ET1zcLYfcIBXPUk2n/irZlLsU7di2iS7txDPk9cKpLnlVF/HdhBdg/Y+5UFBSkujQr4UHLq1Xqf0f6AVAHV1oyGKC5YMWMdpqfbgm8Qu5Ltg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=redhat.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=1/4kLRVGGRJ2QGthgr5yrDLkJ+uRNvjRFsFWoBJHU4w=; b=PwTZDwf6KVzduKr9f9E9GPDCmmBpgfp2jlbVt9oobhxYbV5PHwd+2E4pSUn1uikVG3f4MpUeq7rzmjvQvcX4KhyXR84JIGMeEUEcKT7qMoizpn2pSLaw8heGQG4W1qO+sVBydeM24r0gQ8IEU005kkfuyImZJTP2Lv0TGs4EGjw= Received: from BN0PR10CA0011.namprd10.prod.outlook.com (2603:10b6:408:143::13) by SA0PR12MB7074.namprd12.prod.outlook.com (2603:10b6:806:2d5::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.223.10; Fri, 17 Jul 2026 11:16:45 +0000 Received: from BN2PEPF00004FBE.namprd04.prod.outlook.com (2603:10b6:408:143:cafe::1) by BN0PR10CA0011.outlook.office365.com (2603:10b6:408:143::13) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.21.223.12 via Frontend Transport; Fri, 17 Jul 2026 11:16:45 +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 BN2PEPF00004FBE.mail.protection.outlook.com (10.167.243.184) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.245.5 via Frontend Transport; Fri, 17 Jul 2026 11:16:45 +0000 Received: from BLRKPRNAYAK.amd.com (10.180.168.240) 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 15.2.2562.41; Fri, 17 Jul 2026 06:16:37 -0500 From: K Prateek Nayak To: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , John Stultz , CC: Dietmar Eggemann , Valentin Schneider , Steven Rostedt , Ben Segall , Joel Fernandes , Qais Yousef , Zimuzo Ezeozue , Will Deacon , Waiman Long , Boqun Feng , "Paul E. McKenney" , Metin Kaya , Xuewen Yan , K Prateek Nayak , Thomas Gleixner , "Daniel Lezcano" , Suleiman Souhlal , kuyo chang , hupu , Vasily Gorbik , Subject: [RFC PATCH 1/3] sched/core: Track the core-wide pick leader Date: Fri, 17 Jul 2026 11:15:59 +0000 Message-ID: <20260717111601.6017-2-kprateek.nayak@amd.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260717111601.6017-1-kprateek.nayak@amd.com> References: <20260717111601.6017-1-kprateek.nayak@amd.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: satlexmb07.amd.com (10.181.42.216) To satlexmb07.amd.com (10.181.42.216) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BN2PEPF00004FBE:EE_|SA0PR12MB7074:EE_ X-MS-Office365-Filtering-Correlation-Id: 24b6a22e-fa57-4c17-94fd-08dee3f4e306 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|36860700016|23010399003|82310400026|376014|7416014|22082099003|18002099003|11063799006|4143699003|56012099006|10067099003; X-Microsoft-Antispam-Message-Info: lXPsgS83pL7CvMpUjMp4Ep4HX3fK3iDr/bmLnb9He4mqWhdJeOxAx4Z3Dm0vNJz9L/6x0nwJsbWzfAteLSLP+OJn9nMwD9sxSpJ/4/ZCFowNSAZP1rgZI55N81Y/eRZ7fTUW1IdZPMlUTVLF9+WN95yZ5wF1RoSXt7u3QUKEaHC6YnxYO+Pjr9JwvSewAyaQf+jwy6GL0PRtrFjPhjy/Ek7w+uAZLjSU2bi04zFY4cB1sfb/iBYWiTDGXpr3bJgtRIOn8O3xwYkLuhfDaD9WeEL/d+IvcWOaTNsCbwD/VAJ9VNTmH6Lfl2ZK/mbcBxH5gGc01k/tB+m52jstssEEqetqzX5gghHbEbL6J/oFeZqA46s6QIdgrPacVCoKkRdHt4mwnKn7iKNoAwXvUTpsXycx6qxRR8x+I4nmWRE26zpf7m4mpw7J4B5hJ3MzYdhG/vx2LcmflB9SOtPvqEHWgMQYm4+hH6QxAudsUmp42SlKlwsGNGfVBwjNLkHUqh1FEQN2TcvmVlBWUTKCesAqz7J1RQduxFLUmy90uv4ysE248MdKxWqHH73H43imdf0IlIkpY3YWYAnpQvsUFkfTVjxaH8/7aaEuNjwsW3adL7fVxokwRxjGXNb+9jrR5zVJpBivNgRg1M8dmhOJODHLBQVNOgHik3fLXhqkrAfXGutmnyg3Jb1UhjYsxpmdK/DjkDktYSH90rnW9TiY6ikMAA== 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)(1800799024)(36860700016)(23010399003)(82310400026)(376014)(7416014)(22082099003)(18002099003)(11063799006)(4143699003)(56012099006)(10067099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: gmveSdmwWYFDyMFWGAW8QJV5H7da0Ws2Vj4RE9h8Ak0yfng0bW8VTp/EWHX/QKzniVbwMwbpVltdr0WQj+8Z9N7p0edN0eRFYHvGG4FQAKAqwJpz3O46zztjMnrVq+HwqXTo1IXmtd2VO8h3nQ6ynjjnkvoK5k1Tj/BdQtgYLdr49VWmzLhuUPjFR2qNXjoAQAtxCRqyymfD8Ds1qmOmP9T7MAdNap92MnqrqpaDPnB+rwN5lJoT8zd7sinRBZQ50TY5km9V4n3eLYbLJHps/o/7W8uYXgnYHwIxEGD7DFgjBKjrVpi/n+dlg67MXiUf4mbfB5a7xiYrdQj6xUWidHIGnX2+Ln4QhFOpq5Z75c4UHNrWu4wcsKeNteFzZSQZ8PrUWmlVyMBaB2sFJlAGOZNaw/BW4NmxCG0TrMpL3csCfNufzmXDSvI9oCIFJ9Wx X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 17 Jul 2026 11:16:45.3311 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 24b6a22e-fa57-4c17-94fd-08dee3f4e306 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: BN2PEPF00004FBE.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA0PR12MB7074 Track the rq whose task is dictating the core-wide cookie. If no core-cookie is set (!needs_sync), every rq on the core is considered a pick leader as it can individually try to dictate a core cookie later. This detail will be used in subsequent commits to extend proxy execution to remain compatible with core scheduling. No functional changes intended. Signed-off-by: K Prateek Nayak --- kernel/sched/core.c | 11 +++++++++-- kernel/sched/sched.h | 3 +++ 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 25851bb5489d..31fa6bcee616 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6649,9 +6649,9 @@ pick_next_task(struct rq *rq, struct rq_flags *rf) const struct cpumask *smt_mask; bool fi_before = false; bool core_clock_updated = (rq == rq->core); + struct rq *rq_i, *rq_max; unsigned long cookie; int i, cpu, occ = 0; - struct rq *rq_i; bool need_sync; if (!sched_core_enabled(rq)) @@ -6668,6 +6668,7 @@ pick_next_task(struct rq *rq, struct rq_flags *rf) */ rq->core_pick = NULL; rq->core_dl_server = NULL; + rq->core_pick_leader = true; return __pick_next_task(rq, rf); } @@ -6737,6 +6738,7 @@ pick_next_task(struct rq *rq, struct rq_flags *rf) if (!next->core_cookie) { rq->core_pick = NULL; rq->core_dl_server = NULL; + rq->core_pick_leader = true; /* * For robustness, update the min_vruntime_fi for * unconstrained picks as well. @@ -6755,6 +6757,7 @@ pick_next_task(struct rq *rq, struct rq_flags *rf) */ restart_multi: max = NULL; + rq_max = NULL; for_each_cpu_wrap(i, smt_mask, cpu) { rq_i = cpu_rq(i); @@ -6772,11 +6775,15 @@ pick_next_task(struct rq *rq, struct rq_flags *rf) rq_i->core_pick = p; rq_i->core_dl_server = rq_i->dl_server; + rq_i->core_pick_leader = false; - if (!max || prio_less(max, p, fi_before)) + if (!max || prio_less(max, p, fi_before)) { max = p; + rq_max = rq_i; + } } + rq_max->core_pick_leader = true; cookie = rq->core->core_cookie = max->core_cookie; /* diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 9539867e9e0f..b80a5eb384f0 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1350,6 +1350,9 @@ struct rq { unsigned int core_sched_seq; struct rb_root core_tree; + /* private state for sched_proxy_exec() */ + bool core_pick_leader; + /* shared state -- careful with sched_core_cpu_deactivate() */ unsigned int core_task_seq; unsigned int core_pick_seq; -- 2.43.0