From patchwork Mon Oct 21 05:51:53 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Nikunj A. Dadhania" X-Patchwork-Id: 13843592 Received: from NAM04-MW2-obe.outbound.protection.outlook.com (mail-mw2nam04on2086.outbound.protection.outlook.com [40.107.101.86]) (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 B2DE622315; Mon, 21 Oct 2024 05:59:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.101.86 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729490342; cv=fail; b=Z9ix05s8M6HMhj2/Q3lp18HSx3iOQ6JbOSDm5AcMECA79pV2CuHWvLWod2B2Xnn9z6mOQ1Ri2uuGQEUovcadL5WsSmZ4dLLB5B4MHEpnE6iMUrMmF4vN3HwvoSk/QSuwmhTJyjetVWHwCZaPXTpyZ/SCSflYQZqugtHGzi8pHM4= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729490342; c=relaxed/simple; bh=RC1ceEsd4TJKbZnbyiivDykW162VzJKHcT21cOWHsM0=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=tlnwNKN2WMF0vSNNZdwjPQ94KzxDtL9B7iMY9xwTZjiN4bHsXH1bRvoKN8ywOXgwjtSEQYvvTG5AvsxzmjAQgIJtr1+WvzTZYPp244bZGkkLXIaqlTWyT32ufXUXUAvKi8NIuUzCDGYdHI6MRxrNiUQIGk+c7nXh/GL6GxOrBWk= 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=oTH6QNzJ; arc=fail smtp.client-ip=40.107.101.86 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="oTH6QNzJ" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=qqi3DWHyhnN2RgVVLKkj511BERhqyUhR/eT48rT15acl7/fKrvphCwD0Gtpx3SkqiX0W7Wn9B2oEv9bM9cuyJUjkUbqr1AzYIVsnFU8ie0k/G8ZK4VFLTHozUKRVNhXDmxgOawzGlXIVnKFg1FKWxKrusPBThi0mS/T2bw/qHrBgS23ZkSL3hjg/mrKl5APVU4Ep7s+eTe1stVkepy2RW07ioEuDnryPDqrGh4Wx4fffWjikXlm72AWuVlEGy+Ofxc23r38yaVZ0qf8wPeO7pm7nNxP4C3pZqYDE0KjIPZYUXOwPLV9oplwSCyL12E0UbMrS3JSWJC9m90nmayY2Ug== 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=62zDEoFlkhCEX3fQ9O+YQkWhc8sMjZ5r2L0YtVeQA9Q=; b=WGVLjQaMjIIxuEMga4CzRBOl/lAmtESM3d6u4oROHm9kl+6MJWA7c214MO5lqZ2FMrwHPGC+nBqoF4KBf6n14pRl0gsWLr5bOeeqgbeebksokO+ELovVTpzRMwBX60Ka3/ppT1Of24/WCvfI/C71tNmz3f7p4v8BRCF59MD5ZtYzj7Ym7Zuw0n75NPNXakzYxbnwQpglC9jhr3v6LNHoehTp4t9Ej5lBUBxnd+8svx2Ymmi6D8t5mZNyssFGKle0vQLwikjN0dgl38YoHzLEz+If7z/+n44wc/ZlY4vv6F7uhpOidRbkQrDuBy6C5RQWdkm38aylRub5DyzCnGi7Tw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=vger.kernel.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=62zDEoFlkhCEX3fQ9O+YQkWhc8sMjZ5r2L0YtVeQA9Q=; b=oTH6QNzJtQiSc+rWB57aptM48Ssj/3uipF2inWNn+rbWIZxyVzf/FGp7NwZFCC7lU44CgtoHT/2tMIVxVCCqbsqkmBeIFbxvqZD3gy3A16lU5b3bINQgjR9mucIuFrUsdqybnoszwkr/0xy7C4V57y+jr3SdqEDVIc+j8fqd/tI= Received: from BYAPR08CA0036.namprd08.prod.outlook.com (2603:10b6:a03:100::49) by SA1PR12MB8842.namprd12.prod.outlook.com (2603:10b6:806:378::9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8048.20; Mon, 21 Oct 2024 05:58:57 +0000 Received: from SJ5PEPF000001D1.namprd05.prod.outlook.com (2603:10b6:a03:100:cafe::d2) by BYAPR08CA0036.outlook.office365.com (2603:10b6:a03:100::49) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8069.28 via Frontend Transport; Mon, 21 Oct 2024 05:58:57 +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 SJ5PEPF000001D1.mail.protection.outlook.com (10.167.242.53) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.8093.14 via Frontend Transport; Mon, 21 Oct 2024 05:58:57 +0000 Received: from gomati.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 15.1.2507.39; Mon, 21 Oct 2024 00:58:01 -0500 From: Nikunj A Dadhania To: , , , , CC: , , , , , , , Alexey Makhalov , "Juergen Gross" , Boris Ostrovsky Subject: [PATCH v13 10/13] tsc: Upgrade TSC clocksource rating Date: Mon, 21 Oct 2024 11:21:53 +0530 Message-ID: <20241021055156.2342564-11-nikunj@amd.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241021055156.2342564-1-nikunj@amd.com> References: <20241021055156.2342564-1-nikunj@amd.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: SATLEXMB04.amd.com (10.181.40.145) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ5PEPF000001D1:EE_|SA1PR12MB8842:EE_ X-MS-Office365-Filtering-Correlation-Id: 5e161e39-94b3-4048-566c-08dcf19573c1 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|82310400026|7416014|1800799024|36860700013; X-Microsoft-Antispam-Message-Info: fwOKya3czLfPQPixnwcFbCoUvq48+eVbRPgjThnckel8/r8gWpq30EqSJ7SxZ/UxYCiQvynf5sI0CsXS6nfjDF5EA9UUvktvBD3zJSY5aUA41ngqEMu7HvvgiUjGmrA+HfelbpMkzaO9UKyCI7bBwBiGgnQav7beR1E+rz5WmN/lpXf/AePIzH1Q39fAfjgr6gd8Ss+aGrTz2QmMwSExjkTt+0mGCYd8XulL4Khrj15l+vEkJdsd93LUxJZsGvNwgj2XcZi/AYYLNN6YE3QTjgrg/7vJCcApO11GA34EDY12GnuvNz8dVGLlAHKFeKH718A6ye5tVxrQaLN3JWb8JkOCtZ8orHM6l7ZXQsBSNsdhzygzAcqoclj95F93jjAlgmCHrNoRHzgOYcUmSpU24quya1SK5JkTBPcduHVGPQIEE0vvG2y13hyJMSfyLo/4p54WugByXUHjLgdcFz4/7KJN8OUFIS3R3s0C/EAAfJQ9EL+wc+9oDA2JWOz+dIYCNPCDSavKFGp0cm0jafop0JPt+1C5pHbMI2Zl3xXcOr+ttkAdnjWBkFRpyhaT/6mZQyWTePwO3gkONsbB04cboCypgv3XIDoKivptctcl6WAh6x8WVPAB+vQo+F0uN8FPqTh9W5JshbcHFdowLl6rycUrjRUk4CvWAX2vUfFCu8v+ElrdhYRzLITCCvaMQQGoR/qNeyIybPcZ4BEPiAlsOwWOnF0qv7B1LZi81/y/xl39r6forPRcB4efU3shQdacu59b0jRa7EHk8qyhuGBtX19DFRML8BXobS/Pgbte3+3RR0/xqPNNI8vZxlE/IwUZDgnbe9u2L0Bt/5Mo5TLw8lCaAVDlzhHkE5rEMxAeM+h0jA7xima02K+BVMKpRDOGJv1Y5WwxuSCPqJ0c0HOj1gTjsRk7zIO3f5klrS4643Hrsr5t+m1gmjZLIduo6W8QaK7Jb8BSaHJ3Rqbfa4x0CBmx1y6+5u5jYiMvoWhpP+z1TRmaL08y4gd3/32ZtXGYkSVdD2MznKmnuyxIbytRctm2w/BuZNOo24lk7pdZEh4Y2dGbo5ieMbYZ/JnkXAJwqM7mfWHEig8Jr5C7tbTh6EYRRDArWMlA09o4gHFOIZZfuqvSH/7K/ispf3dd6YtbmjAPVAHSyX7mll+T8UczDqdt2kV+JwwH0ifbcSRvsoaU/7kEk5CturHGm0kbXcnvtx4K/9ZbrOHlyjoNwhJmm5WYJgcLQuNgHv/I67Ua39sqjevFaS7XBCvqk3bXbNKcNR3lwc/NN+8UlSGDWLozsfQxoN6XrgTt/NdME4ZboY16ncp3AoEOOqrySFoWQzASd3b5lSB4tUsvciPs7+K0Q/woOHteuFM2bKEm4ipDLcboKKmbVKlzRw4HaRTDtBQjqTZokRTUT9ellCV/WPR+xg== 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)(376014)(82310400026)(7416014)(1800799024)(36860700013);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Oct 2024 05:58:57.2833 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 5e161e39-94b3-4048-566c-08dcf19573c1 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: SJ5PEPF000001D1.namprd05.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA1PR12MB8842 In virtualized environments running on modern CPUs, the underlying platforms guarantees to have a stable, always running TSC, i.e. that the TSC is a superior timesource as compared to other clock sources (such as kvmclock, HPET, ACPI timer, APIC, etc.). Upgrade the rating of the early and regular clock source to prefer TSC over other clock sources when TSC is invariant, non-stop and stable. Cc: Alexey Makhalov Cc: Juergen Gross Cc: Boris Ostrovsky Suggested-by: Thomas Gleixner Signed-off-by: Nikunj A Dadhania --- arch/x86/kernel/tsc.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index c83f1091bb4f..27faf121fb78 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -1264,6 +1264,21 @@ static void __init check_system_tsc_reliable(void) tsc_disable_clocksource_watchdog(); } +static void __init upgrade_clock_rating(struct clocksource *tsc_early, + struct clocksource *tsc) +{ + /* + * Upgrade the clock rating for TSC early and regular clocksource when + * the underlying platform provides non-stop, invaraint and stable TSC. + */ + if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) && + boot_cpu_has(X86_FEATURE_NONSTOP_TSC) && + !tsc_unstable) { + tsc_early->rating = 449; + tsc->rating = 450; + } +} + /* * Make an educated guess if the TSC is trustworthy and synchronized * over all CPUs. @@ -1565,6 +1580,8 @@ void __init tsc_init(void) if (tsc_clocksource_reliable || no_tsc_watchdog) tsc_disable_clocksource_watchdog(); + upgrade_clock_rating(&clocksource_tsc_early, &clocksource_tsc); + clocksource_register_khz(&clocksource_tsc_early, tsc_khz); detect_art(); }