From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-0064b401.pphosted.com (mx0a-0064b401.pphosted.com [205.220.166.238]) (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 55FF51C4A0A for ; Tue, 8 Jul 2025 15:30:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=205.220.166.238 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751988611; cv=fail; b=jp8we2ZkhnTJcY2RBkXnjoq06wG/xozLtNv+sPIb7IHtBjHZHkzf5E+5M83OUYQxOI9k00SIsEg4TFWR/4j6aNh+eU3n2fkXibn/VjFNNKjS5EC1pjGchYQiwj1+48wzwJGd4Muwc3EeAdjslVdgCBX6pcyhlwtzeP/sp8Uq0Vs= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751988611; c=relaxed/simple; bh=Z3oNklfSeNNU8WGwYkGOiQl9DNLiuPN8OEb/D6VbDWQ=; h=Message-ID:Date:Subject:To:References:From:In-Reply-To: Content-Type:MIME-Version; b=uLYEe+V7+PRbfnzztrquF0Wg/mgP6tRWSBD/BRBCu2rS67EuJeu92mJ64CFTzVgMfgaPAMcyBxipOsikbdTDsx4iPrBvwZ7MjJMldjuNjCFNvRRf7t9EUUDspn6Jm3Hz4p5al3l1EuXy5M7oDBmpvyk7PzrITbIsWX32T00htkk= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=windriver.com; spf=pass smtp.mailfrom=windriver.com; arc=fail smtp.client-ip=205.220.166.238 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=windriver.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=windriver.com Received: from pps.filterd (m0250810.ppops.net [127.0.0.1]) by mx0a-0064b401.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 568BsZ1n028556; Tue, 8 Jul 2025 07:56:25 -0700 Received: from nam12-mw2-obe.outbound.protection.outlook.com (mail-mw2nam12on2059.outbound.protection.outlook.com [40.107.244.59]) by mx0a-0064b401.pphosted.com (PPS) with ESMTPS id 47pyb5jx5q-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 08 Jul 2025 07:56:24 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=F6He2zsjEvhx+ksd5ZJH56ewa7kZr0OuKb/TBpCuh2unS3NM/e6+zB/Moia8N4oQQ+/RCdBSH1RlNc96trGf/yXt8xTxIZ1OtEmW6/PwuJchhLMKDKs9dcODw/NbnGG2/jz7ejSClj7ihHsGfTKkIXN/dir0eMDl5ay6coVljtmfIt4grYw+EDAzA18RPb7T2PK9dkmKIbZmYxT/JO7jm9TsuOv8VNvfWEzilEga8KB5dZlnfvXxgCJNzZdQu7aAA60jw1GeN2tDWw5LilMQb6yKCgAIEuWL2Nolhpz7qSBZsDLvsy7Cb/7dp9LkWcH6G3JZtAG3R6JcWxR0y7gygA== 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=Ou/Al5n+PVMC2FynHB6awznBNKiddCPg+1Q4vgUEgkk=; b=BDRQ8fUwbAlkyp4xQq9WE8dAp4xzWhU3XXHOHZ9JTIxRM3kJL1IrWCGmXv0FzEY3+7S77mfUlv7Eg28NMiMeFFXM0VkU+AlNUIOOOJhcs0UXg2WsD9Bxvh4RGD0mBtprgVDswuPQphu1P9uBowhcAh/cwkGHN+lLYWOloUfrYEAsEovwgQGo3avoTGOFgaW5/yQleNPBQ5L8qousCa4BeqHtD61fRH6IVv8mYELZmNgjrWU1PdKbL0WU64S1bLQqxORwTxAD2VLA3J0G+vGVU114itD2IsHBrrQkifbCfdNERHPa5CEl9MEqgP6fofLnfoIVsESTfUovFcidGh/7SA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=windriver.com; dmarc=pass action=none header.from=windriver.com; dkim=pass header.d=windriver.com; arc=none Received: from DS7PR11MB8806.namprd11.prod.outlook.com (2603:10b6:8:253::19) by SN7PR11MB8026.namprd11.prod.outlook.com (2603:10b6:806:2dd::16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8901.25; Tue, 8 Jul 2025 14:56:23 +0000 Received: from DS7PR11MB8806.namprd11.prod.outlook.com ([fe80::fd19:2442:ba3c:50c8]) by DS7PR11MB8806.namprd11.prod.outlook.com ([fe80::fd19:2442:ba3c:50c8%5]) with mapi id 15.20.8901.023; Tue, 8 Jul 2025 14:56:22 +0000 Message-ID: Date: Tue, 8 Jul 2025 08:56:04 -0600 User-Agent: Mozilla Thunderbird Subject: Re: question about behaviour of cpuidle on 6.6...seeing *many* missed estimates To: Christian Loehle , daniel.lezcano@linaro.org, kgene@kernel.org, linux-pm@vger.kernel.org References: <0dd1f3be-3bdf-44c9-a6d5-623077714149@windriver.com> <7d43a796-d831-430b-92d9-53b3d8351fb6@arm.com> Content-Language: en-US From: Chris Friesen In-Reply-To: <7d43a796-d831-430b-92d9-53b3d8351fb6@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: MN2PR08CA0027.namprd08.prod.outlook.com (2603:10b6:208:239::32) To DS7PR11MB8806.namprd11.prod.outlook.com (2603:10b6:8:253::19) Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS7PR11MB8806:EE_|SN7PR11MB8026:EE_ X-MS-Office365-Filtering-Correlation-Id: e2f928d0-3fb8-4bb0-a3c6-08ddbe2f99f6 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|376014; X-Microsoft-Antispam-Message-Info: =?utf-8?B?U2RRV0ZTVFN5TWR1QmVKRkNoeWhZSlVGbFFSMUlzK0lZZ1VqUTNkRGJVWUpX?= =?utf-8?B?cnBkT3RzTk0wN2VFa21rdjRMSG5GOVlPQS9xVWp5QXRxMi84ZVBSRHhTZ3BF?= =?utf-8?B?WFVUeSsrTlJZNkVGemxHU0E1VVFZSGh5YTA2SXVHSFZRQ1VsK1pxSjNkM1hz?= =?utf-8?B?MHoyQWJUTVNJR2YrVUhIZldsSVZXYkVXUjIyKzdxbU1XSTVxVysyQWpRN0NQ?= =?utf-8?B?R3RGN3EwWXBBOUozTkY0Zk9GaEVDaFdQV0JiL3pkT0tEUUtVUzRGMU9YcTZP?= =?utf-8?B?aU54THhpVExJdFRTZHp1VWh1bUJ1TjJXVGQydDdWMjVmQjE1Q3VmV3ozSFpl?= =?utf-8?B?WlpHSGNnWjh1YUV2SDZ5T2ltYlFtTzgyUEtCRGZTd3hIK2RNak9odE5IejFJ?= =?utf-8?B?aCtRdS9zMFV4M0k5WDZXM1lPM0hhOVVXdFc5QmJvYWlYT0xiekxFQ09HTU51?= =?utf-8?B?Qmc4Rm54dUlsM29vdVhQZmExMTk3TlU3OXlzTGxoMHN5d1RaOWo4R0Z6NFBW?= =?utf-8?B?UWsySzlQVmo5a3llamNMQmI4Q3ZKU0VVbmVrTDZBZSsvWm5FU0t3YnZxVVNR?= =?utf-8?B?MnQrc3BMNlFBL3ZLSVgwM3dCS1FsWXBWaGFGQ3hFZnhhQmwyc05NUHJqWGRl?= =?utf-8?B?RlV1Ujk2NC9hY2Zxb1MvL1VYZlRCc1JCMWU3Q1I3aGlRaDB2ZDBRTnI5M1lr?= =?utf-8?B?bWZ4UnFTMGcxVGxLejBtZmFmWnJqK1pYd0dqT0UrWGU0b2ptUTRhZlpjOGs2?= =?utf-8?B?bkUrdS9wWWhjVVBYOStiK2g5QWl5RGlvMnMxd09SOFprYk5zMEczY0tzUG9a?= =?utf-8?B?ci9GaEUrbDdGWSttZ0dTVlprQzFoM28vYlRKb0JpS1ZWRHdFb2IzeDZVRTAw?= =?utf-8?B?TlhwS3RMSTZCWXpWdXB6VStXb0J4MXBzQTV2cFk5QmZsK3ZacVRNMDhKME45?= =?utf-8?B?Tk9TMHZ6SzVDckQ1UWFnRHo2Z3ZhSnRSMVN0TFRVb0tFOWpVWXIra1BwWDdU?= =?utf-8?B?M01tQWo5NXdQNzFaQlJwaG8xZExwNEdVUWt1TFFGWHBqd1FPd1BQUWVQZDBE?= =?utf-8?B?NnhzMWVxUE8wU3ZGWG9XS0hnMjZDZExnT3AvMHM0M3YybWxUcHBsb2ZjN0hx?= =?utf-8?B?Qm9MMTNFZEhJR0lkQkhmY3ZyYlliaXVhUHRqRjd2ZDdqUVNVemF1UFRQRXYw?= =?utf-8?B?UFA3UmEvMlYvVGYyY1ptZUFiMllIa2pWSUlXZm53SG96eVFGbWFWa1RvRmFq?= =?utf-8?B?Ykpmb2d6a3J1TFlMRG8wY3R5MUNKM0F2ekVjY285NWZoU0s0azdlV3VLVDMx?= =?utf-8?B?SUhVUnJtQnlyUmNKVzA3aGhMb2V2MDVodGlETytlbDN4a2RUdkE1cTFRa0RE?= =?utf-8?B?OHBtZDh1WjVvczJhRXdObi9uYmJyZGxsd1RnTWl3ZENKaEFkZEc3NDRidXFL?= =?utf-8?B?cWhFWDhBMUFTS2RhQlpjMXBPSmw5SE9NNUJhMUNhYXRaUExPamtHWnplL3NP?= =?utf-8?B?dE5QVTZyeUhURVZ4Z1ZRZkhWajZxWE1BZ3U0bHZSejZGK2dqaTZZam9xVk1C?= =?utf-8?B?QnZNbWhOM1JITVJtbUNuVytPMU1lOTd0RVhabk5aMGpjVHpRalpDZE1rUElX?= =?utf-8?B?a2h6K1B0RU42STFBVXhneTZydHRBSFBvM3ZXVjQ5OUtJR3VSRk5LWVY3YWZ0?= =?utf-8?B?dGt0Ui9leW9LaWJiMEl1cWpObnJ3UkNOYUFIeDNJLy8raDdsVmk2L21ZZEZh?= =?utf-8?B?dTlKRFl5NkdjNXBGWkFnZUl3RXh1YUdkOWxkZld5ZDdPR2dzSnZzcEU4bnB5?= =?utf-8?B?Y25qejAzZWhhT2xjQThJRTU0V2doS3E1MUhNOVU0b2dGZlh0ZUh3YTBiSGZX?= =?utf-8?B?K3VFblQxY3J4K0EyeFlWYXVzWjcyWktGcGdBM3hRc3pWakE9PQ==?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS7PR11MB8806.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(376014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?eEJUNGtBOVJ0MW5oY2l2N2xnUVp5aUpLVEhhOXEvY1NSMjB3alZnTlRNOXlP?= =?utf-8?B?ZlJLeTVZV0kvWXd5b09XOHZMVXVVOU9XQ0FuWkpjL2dIYTByZ05UdnNpWlAw?= =?utf-8?B?clQvc3dPS1hjb2lOODdOTS9mV1M1UHo5Q1lNbG1WSTF3Qmo0RmpVTlBtd202?= =?utf-8?B?cG0vNnREUG9ZSDNtdGYzQjF4SG9xd0Y3cWJpT1FEVDY1d0k3ck0zUTcyVjRD?= =?utf-8?B?cGVVaWg5QlRnQ25kTlpnVG1wR1dTZUdtZnR2MXBrSUNNc1hhZUpxV2V2MWVk?= =?utf-8?B?SG9EVlRmNlVBWXRFelhZeHg1YTFyR1U4NFY3azI1a2dRUk8vTG9NcEQ3U0hy?= =?utf-8?B?dlRUNXhkWGpTYmhXNHFHc01QaVMyZDF5elhkKzZTelNsaW1yMGZGcmZHY1hv?= =?utf-8?B?OHZNdTRXWFZENXNLdlljeFBkcXdlYSt0ZEluZGZzRFZWTXI3cWxhOVQraTl4?= =?utf-8?B?bGNBTTFrUmFJaURGS2VFaWdtNjJXTGhCcUNVT0IzYkJCYVFqWmxpMU5MalZP?= =?utf-8?B?cFZUNjMxYmFIYzM1U29GZDNFZ0E0cHRBRVQ0WjkyKzVyWDI5M2YzUTh0SUZG?= =?utf-8?B?NXhVdTJqRmJoOTJrOVJZbTRWU0RmWnVxVWZXVFdXRHo2VXd6V0FnOUNGelBi?= =?utf-8?B?VUJKMVljSXhMLzh6dDFrck1HMUtscWlZSnFDLzQ2MUN6bG1LbjdmdjVTWDB0?= =?utf-8?B?QlB0Q05BZWdoUml1SFQrRS9PeUFsRUpGNWtzSGU0bEFWL2pKY1FTRWU1Nnht?= =?utf-8?B?TmhxMXJ0NWN1czI1akQ4ek5Sa00rM3lKT1NOSC84UkRqR0R3bTZTeTZESzV5?= =?utf-8?B?YXdtMzdLSTF1cTl3dEhseWpLR0V4M282dVVwd293b052UW5INnYwUEdPWVd4?= =?utf-8?B?OFZxNEpGUVpwbnA3SFNmWCsrWWk1MldDRC9WQ0dtaHJzbW1wckJTVzViREtQ?= =?utf-8?B?WWlUZmFNZzU5SkFndEZ5MDdrZkM3Rll1RmlkUFJIYU93Zkl0c3E4UGJ3bng3?= =?utf-8?B?WDN1R25ZTXhKRkt3dHVERS81clJ4ZkxGN2cvK2VLMHE2VHNBa0NGeFVrSXZG?= =?utf-8?B?WFU3b3NOcnlBTmdVWjN1NHVDbFM2TmV3L3cxd3pqTTBKK2NMN3F3SjhoNDRa?= =?utf-8?B?bTZXY0V5NlZWVzUyeUNMN3ZOVEp5aDFzcjJRZ0tvdVJjMDR0U2t5dktGaE4y?= =?utf-8?B?YkhjNXdCMW45bW05Wm1mTVlMeU1PMVJxQ2ZnbW5JQ2lYUzZKYVU5OCtaVTlt?= =?utf-8?B?UXpjU2ZPQXFCV2o1NSs3aDhSMWZEakJBTU5ZZEJQd2lLN2tlVGRhL09hSUFT?= =?utf-8?B?UlJGQTBFSmpsZkxPc2xhZ1lZYkZkTUM0Wk02N3RWMXhaYjR5bDZ1YXRrVEV4?= =?utf-8?B?RUFxRi9BMERYUFpTUTRkVTc3SCtCZVZnTWNMT05PQmRuWVNnaUZyWG13T0VC?= =?utf-8?B?aldFMTl6Q1ZwbDBjaW9acWZrRG9sVWtXTjlWRW1lWHNlMUZVSjNSdTdlR0xy?= =?utf-8?B?WS8zZjJhRmhPYmhYUzRVeUgxeE80aEZQdkVxVnlXT0xxMHB6L21IVzR6eURs?= =?utf-8?B?dk9yVCtCRnVJTFdtZUVwV0Jid3hTT1hxcTZwd290ai9INVRvVk5MQ2RxZGx0?= =?utf-8?B?VjdyT1g2TExnOEpCMkFXYkNia2IzclM5R0xzNXBwNjd1WitWaTJ6WDlkRVlY?= =?utf-8?B?aXlncm1ZZTd4K20zeHh2OU9SVkxnWWlQL2JrZDY0cTY4MWtpcVI5R3dFMGgy?= =?utf-8?B?TkFNSXJLRDY4ZFErMTNSZHAvMkMyNWZZQXZCZ2xxdUVwampUbkd0YnVtcGZ2?= =?utf-8?B?WGVkNVFnM0FyNFQ5VE1ySWk2eVoyYUdkbkxYQlVTZm5UM2U0M1BGNzVoM05M?= =?utf-8?B?OUt6MGROT0RnQ2ZnejJoR0ViMTBGbVVHRUFqTEVBdlpxamZmNkJoOUd4NUFi?= =?utf-8?B?eVJzWkZZRmEwNXI5NUduVFNMdkM2aWswUmdRaWVsVWQvaGtRQlZIQ1g3OWwr?= =?utf-8?B?TUNiVlN4emx1TUpHZmw4K2tyMkg0b25xaUU4KzNVTjFKMVRFaUNqaU9Sa3Bx?= =?utf-8?B?dUEvR0gwbjBBcXNzOFJZRkNKbjZrVlAzcEdKQmEySW52SUNjZzQ4VWw3V3hJ?= =?utf-8?B?QS9hSjBVblpnbHVLY011SkZCRmFFQjUrejdDeEJhcnFZYlcrS1F2MnBJby9U?= =?utf-8?B?d2c9PQ==?= X-OriginatorOrg: windriver.com X-MS-Exchange-CrossTenant-Network-Message-Id: e2f928d0-3fb8-4bb0-a3c6-08ddbe2f99f6 X-MS-Exchange-CrossTenant-AuthSource: DS7PR11MB8806.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Jul 2025 14:56:22.6653 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 8ddb2873-a1ad-4a18-ae4e-4644631433be X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 5QO1uOAWatqYGsRHhNfnJKn8lK7CuUorcPDHmDynO6OTeTWIs5/vgSzc5shBUjcDqDVpSENecYJCbvQGRx/+h59LZ/XftL41SsOafPwcr6I= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN7PR11MB8026 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwNzA4MDEyNSBTYWx0ZWRfX09d7e4vQ4MNd GBbKuUliIy3YUjsJjTfh8MpxRuF3hKYSsTJUk7wugUa5i2dx8IA2CYZRua66wHT0wvz3BsK2TZ1 Sg0Nw0VphonoPkTPjHKxEyRvr0Xg3bjYOJLFj5tcY/SF5RqNYk+FmqDkNQop0sujJZArlueKM0O QBE1vlnQ1CRd60jxo/hl/4LbVp2jeHx4kImu7Hr8a/udD+0A6uVLoRvdyJhXluqmSiw49o20Co4 THwFLAPV362VQrWLWVSo5jRG8j1VQJVddSv/5n1WjGz2bOekg7vkiah55qCjfw2DEv3tM5LYxvO 9RFD0nCRz27UtaTMZMagIdGzdgQR/ZIFSTiGJkjr0hNEuVIaTUiS1Sw92VYNomIe0c82Gjnc3EP tiwdUwYvHpx+afEtYVQNRcXlnWnIhja7iRZuAzqU6ixmgtla26U4D80Je1uaw8VgHzJO6dzV X-Authority-Analysis: v=2.4 cv=V5590fni c=1 sm=1 tr=0 ts=686d3198 cx=c_pps a=FPEtuPkCzHsnJ8XfbyoA9g==:117 a=6eWqkTHjU83fiwn7nKZWdM+Sl24=:19 a=lCpzRmAYbLLaTzLvsPZ7Mbvzbb8=:19 a=wKuvFiaSGQ0qltdbU6+NXLB8nM8=:19 a=Ol13hO9ccFRV9qXi2t6ftBPywas=:19 a=xqWC_Br6kY4A:10 a=IkcTkHD0fZMA:10 a=Wb1JkmetP80A:10 a=yCOTQmV8_SjKz6MKC4IA:9 a=QEXdDO2ut3YA:10 a=zZCYzV9kfG8A:10 X-Proofpoint-ORIG-GUID: 1GsQ8-EKmn0x_t1h5YwdL76v_oBbDlKp X-Proofpoint-GUID: 1GsQ8-EKmn0x_t1h5YwdL76v_oBbDlKp X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1099,Hydra:6.1.7,FMLib:17.12.80.40 definitions=2025-07-08_04,2025-07-07_01,2025-03-28_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 mlxscore=0 spamscore=0 priorityscore=1501 clxscore=1015 suspectscore=0 adultscore=0 bulkscore=0 malwarescore=0 impostorscore=0 mlxlogscore=999 lowpriorityscore=0 classifier=spam authscore=0 authtc=n/a authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.21.0-2505280000 definitions=main-2507080125 On 6/27/2025 1:49 AM, Christian Loehle wrote: > On 6/26/25 19:26, Chris Friesen wrote: >> Hi, >> >> I've got an Ice Lake server running 6.6 PREEMPT_RT, currently using the acpi_idle cpuidle driver and the "menu" governor. I'm seeing some weird behaviour with cpuidle and C-states and was hoping someone might be able to shed some light on what's happening. > > Does your kernel include > 3cd2aa93674e cpuidle: menu: Avoid discarding useful information > (since v6.6.93)? Finally got around to testing this. It looked promising based on the description, but in our testing this didn't resolve the issue. Still seeing qperf latencies in the 120us range. Can anyone else reproduce what I'm seeing? Should be pretty straightforward to try out. Thanks, Chris