From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.14]) (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 3EDD63E51D6 for ; Mon, 8 Jun 2026 15:10:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=192.198.163.14 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780931421; cv=fail; b=EQaR619hAIRy+DIOwb+RzwsonlJIS8VqAzNjnQXpP6yqPYlvi6eBmkfv6YHgjhhWwYo+eMJp6PeokodhIJXwjirkW6KSy4WjQveZ8JXVQxLxiOcfoJV6oD806AG0MqT/qMoz1BWbPkgdmYLB9gLnLWlNxuToPcT/r9/suqT7xiY= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780931421; c=relaxed/simple; bh=9ARfUQnuMjc5AIzdUsiQ9RHBK7X4XDL7/MIrZlcZ04A=; h=Message-ID:Date:Subject:To:CC:References:From:In-Reply-To: Content-Type:MIME-Version; b=R/dpjA9vlu7ewGJM9k/KplzrgRBNSpMijNp2UPBM5RRSFjczx8oJTQ1Q9UkkYs52rBJES05wl5TtvT+Yao00CXGgbtRT8Oy8dCGy9lfCibacPzOLw+ARzvmHzt5JBPZ9sc5+R7awpiVsMbwc0dXnhPwu5Pl428GuUbK0rzp90dM= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Dt5ig/Fz; arc=fail smtp.client-ip=192.198.163.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Dt5ig/Fz" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1780931420; x=1812467420; h=message-id:date:subject:to:cc:references:from: in-reply-to:content-transfer-encoding:mime-version; bh=9ARfUQnuMjc5AIzdUsiQ9RHBK7X4XDL7/MIrZlcZ04A=; b=Dt5ig/Fzfcf/VKEMT9hfNaYeJVYvM+iS/v5tkD6XvwMLDhrsyuktF2xT 2c2hxM2slUlBBlkljvUpO9UDLTQ9qunoWm6abQ2bQf2rjEa3fZCAfajxT AedJkfyBX0NDKK6cA6hFexDxyJHxvG4SlfCMSLP7E5WaFBX6Fq3RRv2wS bULCutBFHwT2UgXwWo1H6GmR8sI22ZbIBqYY+8NEV0sY8i/orvtgTMVYo aotAEIq3VNlCsMWOiuo25jGDs22nBGsTIu6JEr+9UZa8fft7R4s3H32J4 TpLp0LahDtsbqybJfGU9mlaIDplLDNrVMqIr7IiSKtam12khEe5LN7/qJ w==; X-CSE-ConnectionGUID: 2Fh5ICM5Rtug1OJxB4UFvg== X-CSE-MsgGUID: db4Gofn2SFmsP/R3ZzpoeA== X-IronPort-AV: E=McAfee;i="6800,10657,11811"; a="81715717" X-IronPort-AV: E=Sophos;i="6.24,194,1774335600"; d="scan'208";a="81715717" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by fmvoesa108.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jun 2026 08:10:20 -0700 X-CSE-ConnectionGUID: legoScNoTLuvb4ZeaWUwaw== X-CSE-MsgGUID: gkyHgsCnR1GFJ2+XuZgs5g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.24,194,1774335600"; d="scan'208";a="244720505" Received: from orsmsx902.amr.corp.intel.com ([10.22.229.24]) by orviesa010.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jun 2026 08:10:19 -0700 Received: from ORSMSX903.amr.corp.intel.com (10.22.229.25) by ORSMSX902.amr.corp.intel.com (10.22.229.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.37; Mon, 8 Jun 2026 08:10:18 -0700 Received: from ORSEDG903.ED.cps.intel.com (10.7.248.13) by ORSMSX903.amr.corp.intel.com (10.22.229.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.37 via Frontend Transport; Mon, 8 Jun 2026 08:10:18 -0700 Received: from CO1PR03CU002.outbound.protection.outlook.com (52.101.46.62) by edgegateway.intel.com (134.134.137.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.37; Mon, 8 Jun 2026 08:10:16 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=IXxr8sM+60U66794dzZikOjoAHBx6cmH2mhQNKMfH/dZC//oex0dsbptvAH2TJNAIfxTwIxLDb/oX4Evx1oO4sdTjW3EmjuRgjw0FKHjIj535Cqiu4Z0leL+xtNph0W3jdod6E2Ti6qd9KgOmM8HxGRIY964HF8N7vJtj4o9FbMgDShQKmJm+sJdFdkD09/JW/h5/N52BNDvoxDit8cAIRC90Ay0O8nGWmYIUIKuR+XnvTEqkthBHBC1gk+1ha/vdciRvs4mCDVBQ5EH15AoXt8EwNFj+/AAsIcArqF19CcuD8QRBC2LcaPk9eh0tRcPJ2oilrAxIouwqFFgkIeWMw== 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=4ZLZWroo73WFkMs42B4+Kh/mZM/L6FUu9n+CFb1VgXE=; b=e4Hzj/ZIXMo5rXjS73rBnW4ni04eX3ssIQV1SWDi78YrmwhtWZDDZSSE/atutQXIVoesztU3EjUQdoNOXQbq//q9vFh3ZG9iNiFgIJUStrqaHFmrOrG7aiaIt24+m3oGFPjFQ9incPiRsYXHkrcd6wEHtNeqnn/6ML24PXHudZWYSJxt3L4Th4/1xUjKLlDvitlC+GjSqVUaZSDQCeWmzDT2q/sFYKJkVmd/D4hZEguPL6oMbYA6I77L8AO5dOoPP+n9cAP0nN/7m3UuZ/4XgAn12UaXQxd6MJp7osMvEqEir3P/cAVW8yQUGSsHez+k0B0kO4uA/c7ajjvs+64gCA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=intel.com; Received: from SJ2PR11MB8370.namprd11.prod.outlook.com (2603:10b6:a03:540::20) by SABPR11MB9961.namprd11.prod.outlook.com (2603:10b6:806:50b::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.92.13; Mon, 8 Jun 2026 15:10:12 +0000 Received: from SJ2PR11MB8370.namprd11.prod.outlook.com ([fe80::b6cf:ce77:3cdf:7cc]) by SJ2PR11MB8370.namprd11.prod.outlook.com ([fe80::b6cf:ce77:3cdf:7cc%4]) with mapi id 15.21.0092.011; Mon, 8 Jun 2026 15:10:12 +0000 Message-ID: <7bb16cf1-567f-4a08-b399-d6069023a02b@intel.com> Date: Mon, 8 Jun 2026 08:10:09 -0700 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 5/6] fs/resctrl: Do not invoke smp_processor_id() in preemptible context To: "Chen, Yu C" , Thomas Gleixner CC: , , , , , , , , , , , References: <87v7bt4ee7.ffs@fw13> Content-Language: en-US From: Reinette Chatre In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: MW4PR03CA0100.namprd03.prod.outlook.com (2603:10b6:303:b7::15) To SJ2PR11MB8370.namprd11.prod.outlook.com (2603:10b6:a03:540::20) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ2PR11MB8370:EE_|SABPR11MB9961:EE_ X-MS-Office365-Filtering-Correlation-Id: 6e20fd64-dec1-49e2-29fa-08dec570094e X-LD-Processed: 46c98d88-e344-4ed4-8496-4ed7712e255d,ExtAddr X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|366016|1800799024|11063799006|56012099006|4143699003|6133799003|18002099003|22082099003; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:SJ2PR11MB8370.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(7416014)(376014)(366016)(1800799024)(11063799006)(56012099006)(4143699003)(6133799003)(18002099003)(22082099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?MlU5N1czVFpyRm11YUh2RkVEYlJZTVhSV1RURkh5SHhQTHZMcHlVYzhIQ0RR?= =?utf-8?B?Nm0zdjVDTGdLQjlyNklGeEd6YlIzbmlrNzRqb3VCNFdid0pNeHF5cGZQbHVQ?= =?utf-8?B?NmNBRS9YVms3eU9jOExaYWx3elBUSldpajJWUGhaT3RJK3cxUURsdkdkN250?= =?utf-8?B?L016SjkzUnNwZE1ZY0dIWjgrWnlhSWNsNGU4b21QcU0vL3JyNWlBN1JRdDBE?= =?utf-8?B?REQ5Sm1WZWFzVlQyV2VaNFZLU3dhMnk3ZEwwUlQvOEQwZDlmN1pJaDZtWXR1?= =?utf-8?B?bGtVSWJ3QWFremlDOXNqSzF6MnZUaVI4Uis3VDdrVGhGTUVrSjg4VTRHYXA2?= =?utf-8?B?MmZ1blpiL1I2c0hDVHo2Z0JneDhFYzhYeEllZjFlZHdVZ09tRFg2SkRoaWFV?= =?utf-8?B?bXhhK3ZRNElHNHJDWTRzc29mTWVPTG9TRkdFOVlSQkIreEhyeHhSMWZ6b2NK?= =?utf-8?B?azNheDlKdEw0NTFQUTFKeG90YTlMYlJlaFFwVm8wR3BHNWpPS2Fva2tMUDk5?= =?utf-8?B?SHE2Qk0yWEVhRFI2WlVnRFl5YVhONUdBMHhrN0NqM2puUXlGcmFCV0wwMFk0?= =?utf-8?B?SXFpQmo4UFJ6bG9FaEFNdjQ0ZldhT0IxZUNEaVdvcWU0NVBXS2Y0eWtkMko0?= =?utf-8?B?eTNEVkJBSllWc1dLMzE0OGoxQWd1Rlp3cDR6dFJONnVqQjBjQTBUcFNXUHBw?= =?utf-8?B?L3dwYVd6ZjhkL0p5bHhjZnJMU2JwVmFWRXUwUHdMcTB1cFo5Q3ROWVl3aE41?= =?utf-8?B?Ymo4VmRjTlEvS0Q2ZFlpQWtoOHRTSW5SbWtTMXpsc1V6SDJIUWVMNjEvMEQ0?= =?utf-8?B?SjNCTnZUMTR1Ym1VOVhHVWxxVlhDcnIwYTRZUU5MOWdzLzZieG5JZ2NGeWlK?= =?utf-8?B?YUc3S3l2R24veFc1QlFSVTZNU0JLKzFpN04xQVdNcmtpc2MwdHMzeE1GVjZX?= =?utf-8?B?VWd4NEdVTldYSTQxaUwrZ1ZYeUFONzkwRE01aFhWZ3RlMGVxRldZNGtBRVlp?= =?utf-8?B?T3kwSHQxdzFqQWJrTTJTQlpkZ1pHZEsva3BOazlQL3dXRHowenkra0NPcXc2?= =?utf-8?B?TTZ5OGdBRUpvUnlvYjdKZnJyNHdhNHd0eGN5dTM2MU5vR3BoR2pZYnNMTkpx?= =?utf-8?B?SFRhTTNESlplRVFMamxWWW9RcUc5dHhkZkd2MG9PV2JLeEUvckdEa2tFM3dB?= =?utf-8?B?NjRYK0xIR0ozZzF0cWZXRGtXcWpsMkRYOFpKZEt1amtoS3VZa2I1NVBTU1pw?= =?utf-8?B?VUZ6SzlNMjdaaS9tS0lyOTdoSzQrM1RXYmNuOTV1UGNIYjVFcjJveUg3Y0tj?= =?utf-8?B?RHJrYjhrWW9tcFNySGJLTEFwdjQyUHVsR2s4bFdTa3JBSzJhcVZ6OE8vc0JN?= =?utf-8?B?dndnRS92UzVDZnhmQ1pqWmllRDcvQmZFMk1KNmFuSzM4UW9uK2RnRUFRK1lM?= =?utf-8?B?TVlzVENjTDdJanFjWHk2RWdXMnB6Z05pRHgrTFAwaUpweGRzL1pqcjk2RXZU?= =?utf-8?B?elA2NlVoakd6ZmI4RTZPaUxsak9LWk1WalBTbW4ySE93b3dveXBKeWErSDFK?= =?utf-8?B?V05sSjlUaC9FdFRjUjVNKzZJK0RKVWJpOVFaNVFpaDVGTXJOc2F1S0orYWJV?= =?utf-8?B?b1lOTHJSN1JxMGlYTzNlTXkxV2gzOFZ3cVhQOEdjeGRGTm1hRnlLUGQybnFR?= =?utf-8?B?L0sya1Q1RlpGelpxT3E3NWJMb1RORWVXa1RMdnI0aTRxWFp6TjFZeVd4dVNN?= =?utf-8?B?Y1Z2dUszZEhIUG8xZ2RGYzNDbzlRYTB0QXQ3bkVVU3IxMVh1SUNyVFBULzVa?= =?utf-8?B?TU5uQ1VWNnZza1o2N0J2dGh2eHhhaEJwb1hhUmI2QzJYelNJRmhxQmhRV2xm?= =?utf-8?B?d0VzSnlkWU44ZVcxeWh5b3YzaGN4WjJGdUxwcXNXVVN3Rm9kZjA4QWJHeEVT?= =?utf-8?B?dGdVRUJuRHI4eEhlejlFY1ByRW00MXBvaks4aG1VL3ZSWEtzR2lkNGtqUHhn?= =?utf-8?B?a005d1QvRUwxQkV2K0lWSUZ0RXRmZUZEMzNCVDJHTHZlb2FxN2JDbWRCZVFF?= =?utf-8?B?RVlqZDVEYXVQUjFTSGY1akhyendoKzhvRVlhczlvSjBzSjR1bGtpQUJyaWlS?= =?utf-8?B?NjRGbUNKMWg4eFAzOTdpRVcwZW5sY2hSazBVR0wvRXBqRllBRHgyTWZ0UVdJ?= =?utf-8?B?c0lobWk4bFVpaGc1VTFlKzFTQlpGcERJditXejU0SFQ3RWpXQ0EwbDI2TjBO?= =?utf-8?B?R2ZNbFpySEFHVU91OHFXZjZ0c1NxT05VN1VqdEJJVEpDYmkxWUNNbGo2dFBQ?= =?utf-8?B?Zk5kMDJraTk5dTVVTEkzM1FaM25jSVpsS3JENDhKUFErdDVJZ0dYbnRFVDhi?= =?utf-8?Q?ouPI8yrI+IynY4nA=3D?= X-Exchange-RoutingPolicyChecked: IAiPytw42HH9UdUUjfHENktBPna8u+j4GXugTe+RMnZkA8fwsdM5ZDxwk1qLPAeTfQxAfS5ioLKNwP4ODeRiJ9ozJUfs92weLMtaJi9i1QmTOlYrU59WaJSY8Ffe8LDT+Dj0VDia6re5irpi0Hc+7cw1QhnECvF0h7hTZ1utL8SDcnoxn3+kLzemuzcXQCFNqJlCr68NMOMTn0+NdRmkPu2Q4BOK/VM0sfJSTTYSD8+vLmkejgpdGndHmGvDXn0XYq0OBdgsQL5EKRfK9h+xRFnc92lqN8DflhUXPGQmwLXCX9+LbAi/+fAVM6oIlhWFRzymeyLoOM1s7m5Kcg3xWw== X-MS-Exchange-CrossTenant-Network-Message-Id: 6e20fd64-dec1-49e2-29fa-08dec570094e X-MS-Exchange-CrossTenant-AuthSource: SJ2PR11MB8370.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Jun 2026 15:10:12.2535 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: cfvwwlL7IehkVs+Tupx6KmR4NQIhRRA3U7pHZeZ1v+kHfNSBijboOcF30r3VzZfZkNshE81lUnfVme74/3nYLQLhaScPyzoGGjTdrt48xOU= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SABPR11MB9961 X-OriginatorOrg: intel.com Hi Chenyu, On 6/8/26 4:26 AM, Chen, Yu C wrote: > On 6/8/2026 4:36 PM, Thomas Gleixner wrote: >> On Sat, Jun 06 2026 at 10:38, Chen Yu wrote: >>> From: Tony Luck >>> >>> __l3_mon_event_count() and __l3_mon_event_count_sum() call >>> smp_processor_id() to obtain the current CPU. However, some >>> monitor events can be read from any CPU in task context via >>> mon_event_count(); in that case the calling context is >>> preemptible and smp_processor_id() triggers a debug warning. >> >> Is this new with this MMIO stuff or is this an existing issue? If the >> latter then this patch should be in front of the series and get a fixes >> tag. If not the change log should explain it. >> > > It is an existing issue. I'll adjust the sequence and provide a fixes tag. > Thanks! Could you please elaborate how this is an existing issue? At this point in implementation mon_evt::any_cpu is and can only be false for all events associated with resource RDT_RESOURCE_L3. This is highlighted by the existing splat that will be triggered by the WARN_ON_ONCE(rr->evt->any_cpu); that is removed by this patch. It is this series that makes it possible to read L3 cache occupancy from any CPU. This is only done in the following patch (6/6) that makes mon_evt::any_cpu for L3 cache occupancy be conditional on MMIO support enabled by this series. This patch (5/6) replaces the above mentioned splat with a subtler check since it is about to become possible for L3 cache occupancy events to be read from any CPU. I thus do not see this as an existing issue needing fixing but instead a necessary part of this series that is specifically a preparatory patch for the final MMIO based event enabling done in patch 6/6. Reinette