From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from YT6PR01CU002.outbound.protection.outlook.com (mail-canadacentralazon11022112.outbound.protection.outlook.com [40.107.193.112]) (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 D11B933AD8D for ; Fri, 30 Jan 2026 15:38:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.193.112 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769787540; cv=fail; b=ZTU58NPKM5EXbULfjtHZh7+7VzdP+bTMoSaUqM7TvAHTLW7O/tFLT1r+EY9jiLvZLN0BgpMG+aq7Q0ePYOAyzSw9F9pF6Ola1gb1nTVy9DePr8WLSfc2FV/6EyBx63Mo1jo33PKWViacpxtF4FcmUJxnlynedzjX+D9uabVluFc= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769787540; c=relaxed/simple; bh=JmMrKPobTupnJgf84++8Ou3qA+/iDSC6b6MnMXfGQKY=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=i6aLlsav02tjdq8aK9Xx/vlgEc0Ejl6j2x/G+3EF4dLm0a5eQ0VXiSmQFdBMZ4MXtx3AghdHLydqDUBIwNoiKo6yMQ0QdB1C00DQF4Rp90zy9ij+vF/MoamkRtSYzVDDwGQgoDR7d5JWfj4FqvfiT5Vx10S9fY5d7Wql/Uo0mu8= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com; spf=pass smtp.mailfrom=efficios.com; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b=bMAp55AN; arc=fail smtp.client-ip=40.107.193.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=efficios.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b="bMAp55AN" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=ZJZ+ii4iLqCIyUVwjRlE6srdiqN4VqF1behrn8u3ldbLIJ98QAEgn8FDnsWlzDbKhmy2mig/B5uVaTmz3RzpXF8EP2dVXg2iC8KDyimLTEKjRHYmw1fORNIl7ssz1v9GxPZ8GavOw+u7ppdshMVAuqD8HfoZMP7yOQJ1i7FtPI0tpSlbRa278P6AIYp5gnaeoNX4kDudfMkv5+A/FtAOh6gICTAieY27jcqVCZti1gSP6Dt3Ph6fUfHmLb0eA9WEBhHatc7j5YFVqiQ/aKG3bCEp8gRq4oDZFJsDN/l++wIYqQqEm0UcUM27RE8ntrRCnTCq7SXAWLg/Sxa5rxHhRA== 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=8rc7AqG/wit+jlJc+RWN9wK71UShy/Ty2AOClHpQp3Y=; b=r5MYu4xhAsTuLUMPgCxEm42A5b1HcGTpO5ujf7x5UQ+ruLlByhp0eYyHBZp4ZDJpUT9tjIIo0YJvzKmgEJQ7E8jdWESr9q7fnxsHMig4//6YG5PBIxvJ1WSmWT9lwjdaAiHWYEm+zHAbEJOSWUfwX/Y6JpZP8DIqZizWQUmapGqT92/8+8JFDzLrNcad5y08QrYXPiTW8s7TTx/nu3mQV00PxWvBRl62/st1LBxpH+/c8Blcf7nXG9gjb0oxbgJOHEM+nzOo9h/oXN6oZgamfO6+hOf3USvHiCqRhsjBxzbGBOodKK/HR0WsMNOKcNEwDf877zuR8vKq4T0+RtZtXQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=efficios.com; dmarc=pass action=none header.from=efficios.com; dkim=pass header.d=efficios.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=efficios.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=8rc7AqG/wit+jlJc+RWN9wK71UShy/Ty2AOClHpQp3Y=; b=bMAp55ANOjJPckmmY6vRd8Oxk238qM6cAiVGI+tZi00o43bPLbs3+vymaX7FwekCTH8pm1Ro7ftSgN/X9eQtMkxWkgw2nR8lBScfS8HxDVCMlbHmICJ618IBn2+WIKxCS3pNyWff5jZ4SLSTL82TMKB3Orl0EjNpurZPTC3g6PsGcKeQKPrZyxFqL5a9rDT91qQnF7WYo5rT+FDWYJBoQly13hloAv5gv6djQ9eWAMxRnrQ1MG82uGraLi1RiS6z1kjY4kAJwFL/uwZlfupndmnUYlUx+uPZkNHMCW7+zJtC2PDtHL9vD3tL4VeOH6oB+f0HSagdjaWQCEsxzBK+1g== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=efficios.com; Received: from YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:be::5) by YT2PR01MB10732.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:f3::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9564.7; Fri, 30 Jan 2026 15:38:55 +0000 Received: from YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM ([fe80::6004:a862:d45d:90c1]) by YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM ([fe80::6004:a862:d45d:90c1%5]) with mapi id 15.20.9564.010; Fri, 30 Jan 2026 15:38:55 +0000 Message-ID: Date: Fri, 30 Jan 2026 10:38:53 -0500 User-Agent: Mozilla Thunderbird Subject: Re: [patch 3/4] sched/mmcid: Drop per CPU CID immediately when switching to per task mode To: Thomas Gleixner , LKML Cc: Ihor Solodrai , Shrikanth Hegde , Peter Zijlstra , Michael Jeanson References: <20260129210219.452851594@kernel.org> <20260129211557.815063341@kernel.org> From: Mathieu Desnoyers Content-Language: en-US In-Reply-To: <20260129211557.815063341@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: YQBPR0101CA0015.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:c00::28) To YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:be::5) 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: YT2PR01MB9175:EE_|YT2PR01MB10732:EE_ X-MS-Office365-Filtering-Correlation-Id: f0d943e9-f879-41c2-7748-08de6015ad0c X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|1800799024|366016|7053199007; X-Microsoft-Antispam-Message-Info: =?utf-8?B?a3BLUUt1MkxRSzJFT1V2UWtOZFlSa3Y4TDNtK2lVNUJaOGI2ZGo5WDN4bWVj?= =?utf-8?B?aS91MnFtbGFSMGVMZmtkWDN6YVhYSmxsdWcrRldhR0VlQ0tVQy90RmkzMkcv?= =?utf-8?B?bWZJQkIxN3IzNzNZYTZUaXFybDRXamJYQ1Q4QzdMald1aHgvdGlJZisyclNv?= =?utf-8?B?QXc4NlgvOUhBdmJQWnVUY3c3T05hSmFweXNwZEFieis2eWdxajZtL3ZOQmsr?= =?utf-8?B?VENQcUJRLytBT1F2Wnl2aDBaVUdVVXZnbWtBQm5LVmhKSStOckgzRTJ0OHVk?= =?utf-8?B?L1FmRmxHa2dMbFV6NFBxazJRd1Iwd2xSNGdXQ2dLZkNLUXFHS04zM3NTbWxW?= =?utf-8?B?YzJBbDltcThtK1NMQ1RSWUJ4d1ZucTBidDZkQnhoTEgyWnFuZHpMWDFaM1Ru?= =?utf-8?B?WGFNbnp6S0dQNWtPK21ZOWNpVTJybHcwak82VElVSkFKYVcyUy9hUG5PN2Rh?= =?utf-8?B?QlJBUmNqZGVCWE9IcUR5bTN6VGtTSFdLS2JlcC9uZmZHTXlTMEd4Q1dQQUI5?= =?utf-8?B?aEFEbEFvTGxkYjczaGtvU2UyQks2UExITi9vaWFsWGs1bksrVFBHMFZNcXRG?= =?utf-8?B?QXZaL3FVcmJvejF0RllGcDB4dGRka3J6QWZIN3pIZFhRd2UxUU81YlpDVzMw?= =?utf-8?B?aWkwaS9aVUl3QUtta2ZmWjVWSTdqd0Vwb01YRnJxMStHdUJmODZzNjNIZ2ZN?= =?utf-8?B?eEIxSzd2azlsalk3WDhOL0ZZTVhKMkZUclA4bGlYMGdha1h6VVcra2Nmektk?= =?utf-8?B?dDNWbWYwa2YzZ25kdzJnbUVUUWErdkI0cG82WTlONUhiTjVmKzRIWHIvTlZN?= =?utf-8?B?b0RkQ01pOGdXczFoYlBzT3gvOFVZR0dndmhWYXZwb3lBWnptRnVDNU9yRVlV?= =?utf-8?B?STFSeGJZakNnVENGUDhqL05EOThvYjZlS09tZ2NTclpzNWloOG0rTVlmMnFK?= =?utf-8?B?cVMrVkRVRU85SUZqbW5vZVQ2aWdDbTJjWVBhcmtVRVVLNklOTUdORWY2MTlo?= =?utf-8?B?M01YOHpMU2diRW5XK1EwM1RXTTEvK0Q0NE0wZjdtbFA1QTVaWGF4aEhDb1FK?= =?utf-8?B?Tmp2cHhzSzRpY0xGcENUcGVhN2psTjVrdzZBZmpEZGxNdUtWaGI2dk9NMU1P?= =?utf-8?B?UlNkVEtpeGVWeWdlTkdPZkFEMWxCd2NNL0tTZVByNG5yNnRlenpqQzY4QWpv?= =?utf-8?B?bGtTTllXRVFuL0ZwbXAzNndwbHFCNW5rK05STitOaTA5N2ZpQmdRTXAwZ0xO?= =?utf-8?B?SjB0b2VpdGFvdUZxb2xQUVZDUmt5clhwd3FHWGpOL2I5ajdZUFNGNnNWeE9I?= =?utf-8?B?SjExN1ZWTVpzMGJZUW82OGhUdFgwbnR4QUJrMTR6RVI0c2k3aUtNZ3RGQUlE?= =?utf-8?B?bFZwalQ2d1gwQWxPQmRWNDhtandjMVhSbDNNVytIRG5sOG5VVVR1VjZqY3JX?= =?utf-8?B?NGlBOXdKQm9zaElYQ0U3RmxzQm1aR3dDZStqQVNFRG5GN1psV3dBUXJMMlFo?= =?utf-8?B?M2JrV0svYzZHMU53NHJuUTloZmxEanZOSzlyUGtscWRSbjZ0ckliR2VXb25B?= =?utf-8?B?dUEzV3A5dG5PWnV4RFgwUUxSZjlUV2t4RWJ3UkRySGNHNG02RTJuWVpHTnZl?= =?utf-8?B?ejd1YUM3TmJrOWd1WEVpRkN3WEJtWXQ3b1pndzE5QW9ZdkljZVVNbzhJa2VB?= =?utf-8?B?OWQ0NFdNNEZSVVJBSFNOdmZNa29mSldKMGszTG5tMlRGZy95bm9nSmQyZ21s?= =?utf-8?B?M0loVitVMGR6aS9abWsyS25VUGd6M0RtbGowdzdXMXg0czc1dHhFTEM3OGg4?= =?utf-8?B?NmN0bjFMTXNDV3poRmlleTFYSVdUMHArUWhJckhMWHdGVVFWckdqcVhvZmRP?= =?utf-8?B?SkQ2d2pTa0xkaFZFNVVqMElYbHBDSEtjWG5uVVZHTWJMcEo0S3BkLzl6MnlN?= =?utf-8?B?RzYrUUFXTkpoakh1UHF4azRST0pEWDZQRG4zK0NxWDQxcm91RUs2YXQ3UVZr?= =?utf-8?B?TVIrS25zeU01Sm5tK1dranpab1FtN1R6bUpXOXBLTUg5emdTRVZRL2lsWXVR?= =?utf-8?Q?J/2H37?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM;PTR:;CAT:NONE;SFS:(13230040)(376014)(1800799024)(366016)(7053199007);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?RG9lRCt3end2TW9XSTJES2NPREFZWmYxTlY1OVErVElQd0RZNndkRnpJaTl3?= =?utf-8?B?bys0Uk5lTlJseWVHZGRpek1PeXV1WjBnbEJlUVNOOUdPV09SKzB2QVNVbkpo?= =?utf-8?B?a29ORmMraldDMkoza01ITlNzRFBuLzRIMmhmL1RoM2pZM0hsSE9TZXV1aDB0?= =?utf-8?B?WjZtd3lVaG1lR1lWWXdpUVBlaC9mZ09vU0Q0aHRLekRrNUtyUHg5QzBUQUEv?= =?utf-8?B?OFA1YkgxMUU4MkNIc2RTYTRZZ3kvaUJkVG1BU1NDci93QnJWSitMUVRwZjNh?= =?utf-8?B?VVlkcU84K1JaMkNnODZUMm94eUp0MjFydzllcjNOMGNZOWlhRCtaakhPbmFx?= =?utf-8?B?UkdxbjJnSFlhRFJLYnBiOXZEdjY4TXI0ZWFEb2hqK2hHZXgzYXhSWDY3bkRn?= =?utf-8?B?K25SYWFCbU9IUHQxN2FzdGJ1SVBSdzBrYlpLbW9VVkxTTjBSdUxWL3dHTE1z?= =?utf-8?B?VHZsRE1lM3FpelJTWExoSnZkVkQwMDZUQTFFbURDOWtZRUJPRVpDZVhBdDA4?= =?utf-8?B?VG5KTjNGTURGeXdvOTEwRGdudXo5eDdtN1B6RWMxR3UxU0F5Vk5iM2JYQzVn?= =?utf-8?B?R0FWNHBqbnFCekt1d0ZwV2hkQzZJd0JSeWVVNWt1eSszQjBVYlZhUmpqNGRP?= =?utf-8?B?N1F4U0FIcHNsa2w0cXRUZ2o1RDdNYTQrQVBwM0VJTmJGeTZtTHNTRmhMV3FS?= =?utf-8?B?ZWZjY2pUdG1icWsxTmJFNnhwM1E3L2pzbVdKdkRhbkJoS2dyUWhmQ1pmckJT?= =?utf-8?B?WWFNOEFuL2gxTWJFODR5QkhkU25wR1F0YTJzRUU0eG9QSDdlcXgyTWtJcldr?= =?utf-8?B?a0RXTWhOZ2VBVnI0VGhGVkJNT2syNk9mZk8wbDBlUUY3MFJmZ2I5dkhLbEM3?= =?utf-8?B?bE1HbVlXb2cvYlJNdlY2MXk1b1h2UkFWUkhLZS9oMUw4QjRjblZJQ1VReWFC?= =?utf-8?B?MjJaTjJlcy9abk1MaSszdlZmTy9WUFArUlRkSmlhSndiT0hGMG1iZFRVSlFC?= =?utf-8?B?ajlXWk5HMDZDeG9nSm5qcldvQ1ljNXAzdXFtMzliSHNDWnpoMzRDR0todU92?= =?utf-8?B?RFFZb0RVVEJQWVBBaWt1RCtDZUgwRE0vdS9BWDhTdytqRDhUNWdCYzAzZHNJ?= =?utf-8?B?ZlhVelJwa2EwbWkwaFlBcndGaFJ5VUtlR0dRMDkzcW9rMHp5RkJPVlhicG9j?= =?utf-8?B?ZkVTd0tXcm00dzdtWk5SMUZiK1dNNlpzakdKUlpCbXI0ekhsK3U0SmFGUlo4?= =?utf-8?B?M3FJTGI5Ry82RGRETWJDclJ6cFJDQzJHUnZiNmVHaXNEVDczbStDNFBRQ2tL?= =?utf-8?B?Yml0Y0xJaEdxM1doYlh4MFhJaTNBT1drdkc1TEZOd3JTQ1k4OER1TWl3b3V1?= =?utf-8?B?M0NtNi9QajVGNFpEeDVJMlZoenZMMEV3Tm1jY3lueXpCZVVjWUVsaU1oQ0Rz?= =?utf-8?B?TDU2djdjb2svVktkUm9PMEtXVHRiWjE3Sk1YS1ZzbXgzaXhmU1FBYnNiS3Vl?= =?utf-8?B?RG9QeFlUaWNWTmVPSnFRTk9XcDA3V0w0VVlXOXRLbS9venk2Yzl3cE1nWDJr?= =?utf-8?B?Ymx5eHV2N2VyVEZkTW9rNGEvWXFFdnl6SEF1Qlg5QmxjOEVzaXc3bXBmTmt1?= =?utf-8?B?Y0xma2VZUDJEMGp0MVhqZjJ5Ukg3RjFtb24zNXRZSVhIbEtNSHVObXRqd3VJ?= =?utf-8?B?MTNoZ1ZvT0l4UzV2eEZZN0VEeE1ZbVhpYWVLS2d2dm1BS2JXM3JCZFpYMmZ4?= =?utf-8?B?eTFsZUdTbCt5L0lXTWNSQVFLUXlPWVdNeHBxTGpUNFpoOTRpNHE1OFRkdUx6?= =?utf-8?B?a2hhM3QrcFRXTHZDYmkvSldYeS9kRHA0N2JyL2NZdUZkMkpEWVd6eGF6Wm5z?= =?utf-8?B?bHFwZVdKa0U4eExkRGFKKzZuTWdweVFYbDUwNDMrc1dOSGpncDlneS9MZENS?= =?utf-8?B?VmNZS3BSaFZnTzRkMExybDJZb2VYYzF2SjF0Qy9mbUdWMFNPTFc2OWc0cDdJ?= =?utf-8?B?cnRKa0gvOXNpbHEzSWkyN0w3NnB6Q2R4ZjNsb3FtTkxuYk9LVi9xMlEya3Jr?= =?utf-8?B?SVFwTllzZnZxVnFkNFBONjNndThYcGpOWEp1NVBUV0hsU3BiTVBEZFE2d2hN?= =?utf-8?B?QVNETFYxTmFyM2dVN1NIaE1BRmtsK3FnS0RQQXVUMk9yQ3hTRUh1Vmp3UmNL?= =?utf-8?B?aTU1Zk5wYWV5YmpzaTVNSW9pdzZWZnkvZ1cvelRPRDg5WDdvYVdsc1hTdlJX?= =?utf-8?B?R25yZ1lWU1hDQ01ZZkgzMFoxZnRaS2dLWk1oWmtwNVlHQ3NSRGdvcEp4dFE2?= =?utf-8?B?WG1COWZmQ1hvVUxFQUZPWTB6b3FSUEZaU3NkYVlCbytzZCtIa0x5WS85dmVy?= =?utf-8?Q?4CbKvwea5+wUl//M=3D?= X-OriginatorOrg: efficios.com X-MS-Exchange-CrossTenant-Network-Message-Id: f0d943e9-f879-41c2-7748-08de6015ad0c X-MS-Exchange-CrossTenant-AuthSource: YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Jan 2026 15:38:55.0072 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4f278736-4ab6-415c-957e-1f55336bd31e X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: djQY7SLADdI+YdBDxOubjCrJsg2sEdk6Nyz40j1+PfmAyy6RJWKTQIRtmdXLkzBb/p1DfyQO/2p0TfREXmzqBXIde3wka/PxUz5Pu397PXI= X-MS-Exchange-Transport-CrossTenantHeadersStamped: YT2PR01MB10732 On 2026-01-29 16:20, Thomas Gleixner wrote: > When a exiting task initiates the switch from per CPU back to per task > mode, it has already dropped it's CID and marked itself inactive. But a its [...] > > Fixes: fbd0e71dc370 ("sched/mmcid: Provide CID ownership mode fixup functions") > Signed-off-by: Thomas Gleixner Other than the nit above: Reviewed-by: Mathieu Desnoyers -- Mathieu Desnoyers EfficiOS Inc. https://www.efficios.com