From nobody Fri Oct 3 07:42:23 2025 Received: from NAM11-DM6-obe.outbound.protection.outlook.com (mail-dm6nam11on2056.outbound.protection.outlook.com [40.107.223.56]) (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 878B978F43 for ; Thu, 4 Sep 2025 04:18:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.223.56 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756959522; cv=fail; b=cEpo7ZyiumjJxj6uCjfZlEOFqjP91Oey81/XRkviWitmPm6RoWhs7M8hiecZfY5rLih1UzHsZFG1sNxulKvt1nHKg4Fd0SNlJYug3SsVKmyJYsv173zODpQEmMAIVUmgLyFc+W7PN9UrY8L/VeQ+w8SobRIZBAwUn+5cDzLgl60= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756959522; c=relaxed/simple; bh=pJy7wI1F71X+agKOfh19SZeOvb2WnGFidEWwCxybO4U=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=dnFyL62xKd+i8NpZ4jdYkG6rqHAMrA/Ti/5hFad7ZDOLqpKLMEv5I34o6Khh+Z1lC+iJNa6eZWd64tG/Q4ngHM0MLhG6MLErWqnbN+jNOmAjx5CTwjVinLBmobBz50KD+O6iz6gZwSJH+/vpx9DiDQxAF6bIiL6gt4I4lOe9pus= 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=W9K+24vI; arc=fail smtp.client-ip=40.107.223.56 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="W9K+24vI" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=vocmWAJ+YBMuIiRbh84mwhsn4/iqRbAJRtV1iN56bGMWMUQqKpBv6m9pZy/cdtvOiQqFcr4IZeA995gPw3zCXWIGhhAEPm9A120ZY4SJI+nFNxNmBCI+T8loJSdQq8TGWobzwxdB+MWI4kXhZoatXH7MumAQb206rAEOCy2KE5lU73gmXJc6G8a3ts8uEqQMUd/Y9C+LCWesuqQViYnoAaTnvZmlZtg06XT94kjynYsb6eVriiRnrPaIu4KkYjl9iXM2Rp/3U6a3xFZvZZNuRxck3iU4RgsvwbELne9Jbw5JxXmnzacVywGHPrZzn6FOJFAF9aNcKCuth8307xMJEw== 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=RKTbjyymihfZs+a1XKLkRhsraQkuiKw2YH1W29dLrr4=; b=DB8Fv2X5sBA6DZBbYgBxaKxnw7cwj/PKXjiayvAGrZZ1qsmB7UhalHrzLNBk0B+I7+yeUOvdT5BP4VUae43YLiQvTb4IqKFYemGryQmBv6oq+nWsnnJiVdyu1SlWqpOLm6DDZO2nD4a+5nDTTJEGyz008iSSIR3eQkZfvSHMJZH3TfTVqg8H+bhCKGdc0uh+wotPCOXJ46xrvEBE+m1ZKSg7LCxt0dDQBd44DJegDxokRioC3crvYL4kJjWkoMImNZBMVxCK8+gbBuzSH+pnP91Cc82FNipiMrqgdCVti2s6BrkzSD+T9wBsRNc5Q09svy6wAF02YbTMLs1aAEPbKA== 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=RKTbjyymihfZs+a1XKLkRhsraQkuiKw2YH1W29dLrr4=; b=W9K+24vILXz8PYK5+YC/u4V3LbU8fjWHgYZM6HQy7yogZh2arYRY5wLf2G0iG127ncQZDXwRBEU0Z/eZSP7XX/FCLRCcZ0BsbJ6EgfqP6KzywC/jW8BT3Voxt8shE6oRyI20TyGkNmvoksox4/AMu8vJy6rU5QOoLV+tdGP/oXs= Received: from DS7PR03CA0262.namprd03.prod.outlook.com (2603:10b6:5:3b3::27) by DS7PR12MB5837.namprd12.prod.outlook.com (2603:10b6:8:78::6) 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 04:18:36 +0000 Received: from CY4PEPF0000E9D9.namprd05.prod.outlook.com (2603:10b6:5:3b3:cafe::92) by DS7PR03CA0262.outlook.office365.com (2603:10b6:5:3b3::27) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.9094.17 via Frontend Transport; Thu, 4 Sep 2025 04:18:36 +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=SATLEXMB03.amd.com; pr=C Received: from SATLEXMB03.amd.com (165.204.84.17) by CY4PEPF0000E9D9.mail.protection.outlook.com (10.167.241.72) 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 04:18:36 +0000 Received: from Satlexmb09.amd.com (10.181.42.218) by SATLEXMB03.amd.com (10.181.40.144) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Wed, 3 Sep 2025 23:18:35 -0500 Received: from BLRKPRNAYAK.amd.com (10.180.168.240) by satlexmb09.amd.com (10.181.42.218) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.2.1748.10; Wed, 3 Sep 2025 21:18:31 -0700 From: K Prateek Nayak To: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Anna-Maria Behnsen , Frederic Weisbecker , Thomas Gleixner , CC: Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , K Prateek Nayak , "Gautham R. Shenoy" , Swapnil Sapkal Subject: [RFC PATCH 10/19] sched/topology: Introduce "idle_cpus_mask" in sd->shared Date: Thu, 4 Sep 2025 04:15:06 +0000 Message-ID: <20250904041516.3046-11-kprateek.nayak@amd.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250904041516.3046-1-kprateek.nayak@amd.com> References: <20250904041516.3046-1-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: quoted-printable X-ClientProxiedBy: SATLEXMB03.amd.com (10.181.40.144) To satlexmb09.amd.com (10.181.42.218) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CY4PEPF0000E9D9:EE_|DS7PR12MB5837:EE_ X-MS-Office365-Filtering-Correlation-Id: 6544d648-d94e-41a5-2cbb-08ddeb6a1e5a X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|82310400026|1800799024|7416014|376014|36860700013; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?0+Y5DOmsopDjHBf3Zjrip0m08/4MDP/w/gwMz4A2A4I9norcW+hnAKPsdICq?= =?us-ascii?Q?sfyJrWmav5gD///QjSM9cHWafRtZe554CFUgvrLJ/HsNRUQyeEY7zLMEgUMn?= =?us-ascii?Q?M/evHvB2OXdzD/diIq0d1r+hHOF1pEZ2VPlW/c9xlLDzz2N/XnVA8AkQ8ybX?= =?us-ascii?Q?lZ02sle358LtRO6pEPSYzel9U/kX2H1jZ4aih9BrhfUjMV9pJnmQ+dKTR9dT?= =?us-ascii?Q?HOMWnlyzBKMiGofvzKy1rEY+LEjQz+JIi9skaYacrhYV1Tx/R5oqlpxT8nl0?= =?us-ascii?Q?lSz/7SLYe7rIFi63yEjc/WcqXm80aYcoqtT+n8PwX3Tyg7q1Q4EYTVMFvWtQ?= =?us-ascii?Q?tjuCOAMbeGxWsF37Mf9n/EAe1TU2gJBLGWmWB/Oo2pBuu711e4iQcTRIJiFw?= =?us-ascii?Q?oN4vIFg2+FvyvUZ6GrDO4XyNP2TQDRtXjEygqIs7rFexYloPHfS3F/bOeGqC?= =?us-ascii?Q?4bUzIWJXixw1zPR9UtbbwFJcr+QKBKwJw9M0njSn/kNeEmUU2ajJvPedIu8r?= =?us-ascii?Q?KQkZ8bGZ7EuhJcjmTzsOfMhaTdv3VBj86Y0xBwmw1C2DDPZYddmn6TgnE4fe?= =?us-ascii?Q?KmwINQPKlXVInWDk3vUT2xknYtkS8zLutdfiP4ckOTIWYKk/S+l1cFqQ/6jd?= =?us-ascii?Q?JWGA6NZ8TweaJa5tDB+hKSiX+Z3dqYN/NZc/orMZHYuTwnyE4QWILOMZJdS/?= =?us-ascii?Q?z3bGYwxUqbg7jbOf6whq7BAKC4fPSa83UiPl+LWbdaHCp2YCFAZkNfAE4tEp?= =?us-ascii?Q?CC1EG7YntuxsSxmelTX8saP9ohHc7dmafla7ksZuVgsh7WtU0BUp72OKPvsu?= =?us-ascii?Q?R5HNJymopftZqEarP0sMfbEbuZarFFrNoMkwSZ80QAS5fF7gr3R1X/a5Xv9n?= =?us-ascii?Q?6cBhRUhwaGjLq/NOPXGA4emWtDa+iPRzmcMVP7W7BaGgHJ/Di1dPdyHKavdd?= =?us-ascii?Q?V9UVLkwQpwzOM/J5AiAHlA6cz9tou0xtzpuqWwHTRNONaV1/9KTmldK6YJre?= =?us-ascii?Q?xVJagvxP/514v/+JC8hihMNj6PzDUQv79Hhdvzq+QzIwOrIQG2fRPk9r8UM+?= =?us-ascii?Q?FhqIM7sfefEzm7CnNUddIMlGRGyGPjbhF0NFbEcDRgjcKus0/8D5nVLi/v4C?= =?us-ascii?Q?Pd2Sq2DRL+JucPq+iiPLtqV4S3BBpti3dB3xhWtFlVxHCIcWbN+1085BtXrP?= =?us-ascii?Q?8NJwTyl/hafwyla6yWDdM1Wp7muVUEDd7N/8qU4a8vwTUAv/GcTJdnH2RAgA?= =?us-ascii?Q?aOVFYRfBOibPdeS2Zu3IWPt90tiG8n4PsIab8J1dRwXW0JrLbgFqghIBhBH8?= =?us-ascii?Q?0p/xg5cPHH0lvJxrE+rJn4DNzssV4nKjIlVxfSCWR+JDM15wmOHpcq/+Bkbh?= =?us-ascii?Q?Ofp1erFIWf2zrTtTjnGNxwcU4JT/T4nBUTZryuGtM6DcPcKe1quWSFViApcm?= =?us-ascii?Q?a3A3y9+2y3YVDwc9BQsHMpbJlykvOmtu+dMgs8Y8LrOjv9y4hdOymnDkmcUD?= =?us-ascii?Q?+ishk4DyCNx5Do6FG1aXsPRTxR7beyPHWb8d?= X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:SATLEXMB03.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(82310400026)(1800799024)(7416014)(376014)(36860700013);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 04 Sep 2025 04:18:36.3895 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 6544d648-d94e-41a5-2cbb-08ddeb6a1e5a 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=[SATLEXMB03.amd.com] X-MS-Exchange-CrossTenant-AuthSource: CY4PEPF0000E9D9.namprd05.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR12MB5837 Content-Type: text/plain; charset="utf-8" Introduce "idle_cpus_mask" to track idle CPUs within the sd_nohz domains. This mask will eventually replace the need for the global "nohz.idle_cpus" mask for nohz idle balancing. Convert cpu_set_sd_state_*() to set / clear the CPU from the mask when transitioning to / out of nohz idle state. Reviewed-by: Gautham R. Shenoy Signed-off-by: K Prateek Nayak --- include/linux/sched/topology.h | 1 + kernel/sched/fair.c | 2 ++ kernel/sched/topology.c | 48 +++++++++++++++++++++++++++++++--- 3 files changed, 47 insertions(+), 4 deletions(-) diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h index 2f0d8ecea427..6db3448e2f00 100644 --- a/include/linux/sched/topology.h +++ b/include/linux/sched/topology.h @@ -67,6 +67,7 @@ struct sched_domain_shared { atomic_t ref; #ifdef CONFIG_NO_HZ_COMMON atomic_t nr_idle_cpus; + struct cpumask *idle_cpus_mask; #endif int has_idle_cores; int nr_idle_scan; diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 624b3753c818..c8226520758d 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -12458,6 +12458,7 @@ static void set_cpu_sd_state_busy(int cpu) if (!xchg(&sd->nohz_idle, 0)) return; =20 + cpumask_clear_cpu(cpu, sd->shared->idle_cpus_mask); atomic_dec(&sd->shared->nr_idle_cpus); } =20 @@ -12488,6 +12489,7 @@ static void set_cpu_sd_state_idle(int cpu) if (xchg(&sd->nohz_idle, 1)) return; =20 + cpumask_set_cpu(cpu, sd->shared->idle_cpus_mask); atomic_inc(&sd->shared->nr_idle_cpus); } =20 diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index f230892528c7..c2832445c578 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -468,6 +468,24 @@ struct s_data { =20 DEFINE_PER_CPU(struct sched_domain __rcu *, sd_nohz); =20 +static int __sds_nohz_idle_alloc(struct sched_domain_shared *sds, int node) +{ + sds->idle_cpus_mask =3D kzalloc_node(cpumask_size(), GFP_KERNEL, node); + + if (!sds->idle_cpus_mask) + return -ENOMEM; + + return 0; +} + +static void __sds_nohz_idle_free(struct sched_domain_shared *sds) +{ + if (!sds) + return; + + kfree(sds->idle_cpus_mask); +} + static int __fallback_sds_alloc(struct s_data *d, unsigned long *visited_n= odes) { int j; @@ -490,6 +508,9 @@ static int __fallback_sds_alloc(struct s_data *d, unsig= ned long *visited_nodes) return -ENOMEM; =20 d->fallback_nohz_sds[j] =3D sds; + + if (__sds_nohz_idle_alloc(sds, j)) + return -ENOMEM; } =20 return 0; @@ -502,8 +523,10 @@ static void __fallback_sds_free(struct s_data *d) if (!d->fallback_nohz_sds) return; =20 - for (j =3D 0; j < nr_node_ids; ++j) + for (j =3D 0; j < nr_node_ids; ++j) { + __sds_nohz_idle_free(d->fallback_nohz_sds[j]); kfree(d->fallback_nohz_sds[j]); + } =20 kfree(d->fallback_nohz_sds); d->fallback_nohz_sds =3D NULL; @@ -553,6 +576,13 @@ static void update_nohz_domain(int cpu) =20 #else /* !CONFIG_NO_HZ_COMMON */ =20 +static int __sds_nohz_idle_alloc(struct sched_domain_shared *sds, int node) +{ + return 0; +} + +static void __sds_nohz_idle_free(struct sched_domain_shared *sds) { } + static inline int __fallback_sds_alloc(struct s_data *d, unsigned long *vi= sited_nodes) { return 0; @@ -740,8 +770,10 @@ static void destroy_sched_domain(struct sched_domain *= sd) */ free_sched_groups(sd->groups, 1); =20 - if (sd->shared && atomic_dec_and_test(&sd->shared->ref)) + if (sd->shared && atomic_dec_and_test(&sd->shared->ref)) { + __sds_nohz_idle_free(sd->shared); kfree(sd->shared); + } kfree(sd); } =20 @@ -2524,6 +2556,9 @@ static int __sds_alloc(struct s_data *d, const struct= cpumask *cpu_map) =20 bitmap_set(visited_nodes, cpu_to_node(j), 1); *per_cpu_ptr(d->sds, j) =3D sds; + + if (__sds_nohz_idle_alloc(sds, cpu_to_node(j))) + return -ENOMEM; } =20 if (__fallback_sds_alloc(d, visited_nodes)) @@ -2539,8 +2574,13 @@ static void __sds_free(struct s_data *d, const struc= t cpumask *cpu_map) if (!d->sds) return; =20 - for_each_cpu(j, cpu_map) - kfree(*per_cpu_ptr(d->sds, j)); + for_each_cpu(j, cpu_map) { + struct sched_domain_shared *sds; + + sds =3D *per_cpu_ptr(d->sds, j); + __sds_nohz_idle_free(sds); + kfree(sds); + } =20 __fallback_sds_free(d); =20 --=20 2.34.1