From patchwork Fri Jan 12 09:25:30 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Meng, Li \(Jassmine\)" X-Patchwork-Id: 762329 Received: from NAM12-MW2-obe.outbound.protection.outlook.com (mail-mw2nam12on2061.outbound.protection.outlook.com [40.107.244.61]) (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 8223857303; Fri, 12 Jan 2024 09:26:32 +0000 (UTC) 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="K+5Bpiqp" ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=GIHW6AZ6rBCBEFRPcl6TksJb2MHD+HiciQp7RUPkSfiaflcUMHZm/xfb6WbGQ8MKT3vdCK0MCWWe72Eg5MovR32tGYQRLmbN9yOAzfPW/2s/BZSCCRdg/SpQPkQhy3unarFcA9ODnRhS3JYjhOpsYXuSBWkPd1ZwrDjxeTAN5pzcj14pyAQGeJ0Ll3MsIAEakxoseEJl7ADMEZaifc1GVltCt7E4Z511NyIiBTeEowXAM4TXoMEQEcefKkmmOohnBOanO3ONUbYrJmXO2mMT3xHez4ADi6Md4e0rQ3QebngNG5sCTfgv8CVrVz5fbIaPdFa2AuoxbvmcXgU+zZuaEA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; 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=CkcLPe+OdQhX1JrIwqUungjFDn7/6QsByHrqLs7zL9M=; b=nq1gWLJHer3ST8UlUgTTHZ3U15YpuZ/OY+SMDwOqCpR/W0tOgDoMRv2K09b2CN1FgIy0r+/t/lZHSNZIRNDTD6iMIWkkKpYUasi1U9SObbVal9D8KnbhsWap7NLSLccpgy9WgjmTwCuhnNDzHcALAvr90Os+ArIyA5ehWF37sL0m6x0HWsSgjbmqQoqxA59F56JIerhXp/Y/uMXH1qLlGPFcXwf8HCpUJLD7vXCUdU5LUXen8M1QU3kIaa35XJQAVKPDOhhlsc3vB0DDTCPvgr31qOkIq2kFOCvFy5bNuVBTqHL+3xR3plA7tNP290AoC35WM6C1fUcUzn3tWHOT7w== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=intel.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=CkcLPe+OdQhX1JrIwqUungjFDn7/6QsByHrqLs7zL9M=; b=K+5Bpiqp06574XeuZN382mJZoXd25R1lGFJHi5MmeE4l6XBx23yLJ9rHswtG6dQQAkIuhKNtgCAg1IM3eWnIQ9YW8GDQSHyuHf/599QDxlOFV2/WbwgPwzqOuL7GqbBEla3/csIXOtGniys3JdpNn+QEHigVCD4OHThmXp/s+yc= Received: from DS7PR03CA0052.namprd03.prod.outlook.com (2603:10b6:5:3b5::27) by DM6PR12MB4404.namprd12.prod.outlook.com (2603:10b6:5:2a7::13) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7181.21; Fri, 12 Jan 2024 09:26:29 +0000 Received: from DS1PEPF00017090.namprd03.prod.outlook.com (2603:10b6:5:3b5:cafe::3) by DS7PR03CA0052.outlook.office365.com (2603:10b6:5:3b5::27) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7181.21 via Frontend Transport; Fri, 12 Jan 2024 09:26:29 +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 DS1PEPF00017090.mail.protection.outlook.com (10.167.17.132) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.7181.14 via Frontend Transport; Fri, 12 Jan 2024 09:26:29 +0000 Received: from jasmine-meng.amd.com (10.180.168.240) 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 15.1.2507.34; Fri, 12 Jan 2024 03:26:16 -0600 From: Meng Li To: "Rafael J . Wysocki" , Borislav Petkov , Huang Rui CC: , , , , Shuah Khan , , "Nathan Fontenot" , Deepak Sharma , Alex Deucher , Mario Limonciello , Shimmer Huang , "Perry Yuan" , Xiaojian Du , Viresh Kumar , Borislav Petkov , "Oleksandr Natalenko" , Meng Li , Wyes Karny , Perry Yuan Subject: [PATCH V13 6/7] Documentation: amd-pstate: introduce amd-pstate preferred core Date: Fri, 12 Jan 2024 17:25:30 +0800 Message-ID: <20240112092531.789841-7-li.meng@amd.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240112092531.789841-1-li.meng@amd.com> References: <20240112092531.789841-1-li.meng@amd.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: SATLEXMB03.amd.com (10.181.40.144) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS1PEPF00017090:EE_|DM6PR12MB4404:EE_ X-MS-Office365-Filtering-Correlation-Id: d3a67854-2250-4fff-f73a-08dc13508f13 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 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:(13230031)(4636009)(346002)(136003)(376002)(39860400002)(396003)(230922051799003)(451199024)(1800799012)(186009)(82310400011)(64100799003)(46966006)(36840700001)(40470700004)(26005)(1076003)(2616005)(426003)(16526019)(336012)(6666004)(7696005)(478600001)(36860700001)(83380400001)(47076005)(5660300002)(7416002)(2906002)(41300700001)(4326008)(70586007)(70206006)(8676002)(8936002)(6636002)(110136005)(54906003)(316002)(356005)(81166007)(86362001)(82740400003)(36756003)(40460700003)(40480700001)(36900700001); DIR:OUT; SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 12 Jan 2024 09:26:29.7435 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: d3a67854-2250-4fff-f73a-08dc13508f13 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: DS1PEPF00017090.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR12MB4404 Introduce amd-pstate preferred core. check preferred core state set by the kernel parameter: $ cat /sys/devices/system/cpu/amd-pstate/prefcore Tested-by: Oleksandr Natalenko Reviewed-by: Wyes Karny Reviewed-by: Mario Limonciello Reviewed-by: Huang Rui Reviewed-by: Perry Yuan Signed-off-by: Meng Li --- Documentation/admin-guide/pm/amd-pstate.rst | 59 ++++++++++++++++++++- 1 file changed, 57 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst index 1cf40f69278c..0b832ff529db 100644 --- a/Documentation/admin-guide/pm/amd-pstate.rst +++ b/Documentation/admin-guide/pm/amd-pstate.rst @@ -300,8 +300,8 @@ platforms. The AMD P-States mechanism is the more performance and energy efficiency frequency management method on AMD processors. -AMD Pstate Driver Operation Modes -================================= +``amd-pstate`` Driver Operation Modes +====================================== ``amd_pstate`` CPPC has 3 operation modes: autonomous (active) mode, non-autonomous (passive) mode and guided autonomous (guided) mode. @@ -353,6 +353,48 @@ is activated. In this mode, driver requests minimum and maximum performance level and the platform autonomously selects a performance level in this range and appropriate to the current workload. +``amd-pstate`` Preferred Core +================================= + +The core frequency is subjected to the process variation in semiconductors. +Not all cores are able to reach the maximum frequency respecting the +infrastructure limits. Consequently, AMD has redefined the concept of +maximum frequency of a part. This means that a fraction of cores can reach +maximum frequency. To find the best process scheduling policy for a given +scenario, OS needs to know the core ordering informed by the platform through +highest performance capability register of the CPPC interface. + +``amd-pstate`` preferred core enables the scheduler to prefer scheduling on +cores that can achieve a higher frequency with lower voltage. The preferred +core rankings can dynamically change based on the workload, platform conditions, +thermals and ageing. + +The priority metric will be initialized by the ``amd-pstate`` driver. The ``amd-pstate`` +driver will also determine whether or not ``amd-pstate`` preferred core is +supported by the platform. + +``amd-pstate`` driver will provide an initial core ordering when the system boots. +The platform uses the CPPC interfaces to communicate the core ranking to the +operating system and scheduler to make sure that OS is choosing the cores +with highest performance firstly for scheduling the process. When ``amd-pstate`` +driver receives a message with the highest performance change, it will +update the core ranking and set the cpu's priority. + +``amd-pstate`` Preferred Core Switch +================================= +Kernel Parameters +----------------- + +``amd-pstate`` peferred core`` has two states: enable and disable. +Enable/disable states can be chosen by different kernel parameters. +Default enable ``amd-pstate`` preferred core. + +``amd_prefcore=disable`` + +For systems that support ``amd-pstate`` preferred core, the core rankings will +always be advertised by the platform. But OS can choose to ignore that via the +kernel parameter ``amd_prefcore=disable``. + User Space Interface in ``sysfs`` - General =========================================== @@ -385,6 +427,19 @@ control its functionality at the system level. They are located in the to the operation mode represented by that string - or to be unregistered in the "disable" case. +``prefcore`` + Preferred core state of the driver: "enabled" or "disabled". + + "enabled" + Enable the ``amd-pstate`` preferred core. + + "disabled" + Disable the ``amd-pstate`` preferred core + + + This attribute is read-only to check the state of preferred core set + by the kernel parameter. + ``cpupower`` tool support for ``amd-pstate`` ===============================================