From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from YQZPR01CU011.outbound.protection.outlook.com (mail-canadaeastazon11020105.outbound.protection.outlook.com [52.101.191.105]) (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 087493559F3; Tue, 16 Dec 2025 15:13:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.191.105 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765897995; cv=fail; b=rmmNe14G2gOX73mDcVxJkdgyrTOhZ5uHowhrvzt13TEDgx8CfiSO+k8eyGOsl++xBoSJrUkdIy6VB20T+/yon69w+6YxyXoRl+MBgI6gde6A1RG2MBtASaBGyqZT6kKS0EBSkFpdnlWPHTEWboUYSQJZlxouVPxxeRXTE4LihBs= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765897995; c=relaxed/simple; bh=q4YM/LgXoNB2Uu3wmzdNvSfa0976RgI/xiwurydaokA=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=pbRIFUKdZcr8OpSTdJx+6LT7x1MUdW/lbfcFNZwrXLKXQiT1M10bc4rSNV71pBHzR6loUaetG8FujSZJ5yQ2jwgzKfo6yHBiHAVaHi68ejr6f8dOHZRn9MltMiKo84vSpftXmS9CGCJ3FsyIU3XzmW+ZtgXsAEu/fOygszVLTXQ= 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=LvbbGV4+; arc=fail smtp.client-ip=52.101.191.105 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="LvbbGV4+" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=qdioFrFOkXiT2ifR2jStdK9t1F/U1UPb357Uoqu3ZSrtjjayf27sk/5Q6OtpwKQUrQpL8t88qGFlw8k7o0v3branOFSZFHwatS9ZGVDQDBFXdFgTqxtfJ8Fq+0fvOk883fu7Y1s18TfJLxQ7kMaH63aOZ35GacqfsJGDJLdmvoiMWhLK0bUO8iIGLLmQvMG/Qc+r3k5fcObl9iVL4AccyssNQG71niz68EYHDlKa5kGnJfOyXO5eNk4xI9U6GZifIccgPYWchHmbQywUmphIYm3lHwjoUV8uewRJoL3wYOKyiEu2O8aHWYgaTa9cYxdWgkdvM5mInjAVtEFGZdON4g== 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=4DzyLg23i5xqOkC+BnS1ugv3ZM1462ETWewrrFM1tYU=; b=v99xj179B7jrfXVDH/Iy6OvOcRZo15cOyQkU8JyK2T5oMJo4FPuKm839ssVxSMH8HhAOxhiNX82eO8pCnXWCFONjpBXNSwhMNpne3eRhrnUgU7DJfLCm/vYmVV9oP2VUg15OYerNXlJS3PmMgNKg6XZbIHp7Gf4PBg+teq8AzL2iB3rFvmCeNavSAfn2wgwQAaKygO4pSEOZ4rr4jPH+sR0IsavumpgWNh2DVfCPb4n56D/+9qfua2oSVkz7Why+ZupGk+wNFHPRRe5Z8TFCxpHlFhlblqWKx2bwvrAIh1pPTAHo6ywlgHEWSZMz3kdb913KLGgF/CWcsVgp3ZchJA== 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=4DzyLg23i5xqOkC+BnS1ugv3ZM1462ETWewrrFM1tYU=; b=LvbbGV4+932HrBCP9hw6N1Rmn2dIuDrq2YJ+fiPJSwh6S55ynUdLhW82gl2MrG1llmkd7DstzdcKsxATMrdBaZNNIewJQRL0kbiKx4ah+Nec7UIBS5U6FVCXmSoDHbV4zq0UUAAQJFnjfET/pWYNR0OBVWUvzmtIfr+pzAQ390eXwEM8cUGEQir5Z8FxzDtgNVO5wKO1cWBJ4IOSLEbKA+nwNWWnbx637rf7GUp83IdtVIWecjLJE85i6VJoXlaJeo3CREx55iBVEjnlT5T1q5SSc2YjK5Pcg8qMXll9H14bhdn3IMh3O/fozJSk4giGi8vuKDi4m5VvtxOh/OGiuA== 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 YT4PR01MB10389.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:e1::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9434.6; Tue, 16 Dec 2025 15:13:08 +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 15.20.9434.001; Tue, 16 Dec 2025 15:13:08 +0000 Message-ID: Date: Tue, 16 Dec 2025 10:13:05 -0500 User-Agent: Mozilla Thunderbird Subject: Re: [patch V6 07/11] rseq: Implement time slice extension enforcement timer To: Thomas Gleixner , LKML Cc: "Paul E. McKenney" , Boqun Feng , Jonathan Corbet , Prakash Sangappa , Madadi Vineeth Reddy , K Prateek Nayak , Steven Rostedt , Sebastian Andrzej Siewior , Arnd Bergmann , linux-arch@vger.kernel.org, Randy Dunlap , Peter Zijlstra , Ron Geva , Waiman Long References: <20251215155615.870031952@linutronix.de> <20251215155709.068329497@linutronix.de> From: Mathieu Desnoyers Content-Language: en-US In-Reply-To: <20251215155709.068329497@linutronix.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: YQBPR01CA0165.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:c01:7e::22) To YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:be::5) Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: YT2PR01MB9175:EE_|YT4PR01MB10389:EE_ X-MS-Office365-Filtering-Correlation-Id: 5c262e72-0408-4491-4b13-08de3cb59ec2 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|7416014|376014|1800799024; X-Microsoft-Antispam-Message-Info: =?utf-8?B?WWVtWUt5QTAwczdiMnluZFdsRGpldGUzbTJ1RWJNWFB3RzFQYmNyckk5NUpw?= =?utf-8?B?YklOZVJoTTNmZHlsbWkvek5Yc2N5eklUTGtRRTJsdXdqT2pLQ3g0ak5vcEVj?= =?utf-8?B?MnZ1WDNLQnRCZWpwYUlRanF1RVV6aTJDYktVdHBnRGt2V2pWenFkRGowTk4r?= =?utf-8?B?b01xMHV3d3VrNEdGdHMvaHdiQWRibzIvejN6YzAvamsvTEM4VUY4bGhDc1pK?= =?utf-8?B?ZVlCNS9OYkUzQnRETHhkd1VPazQrK0NlbzJDNVVMamJxQ2d0TWgrNitQU3ZV?= =?utf-8?B?S0VWblh3c05rNmJTcjd6RHl3YUwvbGIvcktYVDUwSlVUY2lBcVZUWGc0ZkVt?= =?utf-8?B?U0tZV0RDOWxwcTd6TzhoSnJCNTdackRTYS9pYXZwVW9ZWWM5cjQ5U1FGS3Ba?= =?utf-8?B?blQxZzBpYVdwd25kNTZCS3d0V0tBUDFRVTNuWWJuSS9lNW9vOTh1b2FCeTRj?= =?utf-8?B?NktQWlhpNFBXNGtiVEhhK0MyUGliOVZ0S2I4aVFrZzI0cTh0dEpJcEkrNmJi?= =?utf-8?B?a3ZCSVlXWUZUYjRJMXUrcEg4dVZQRzVRSzdrdG9yUGRMUDRLTVFsckpmWFZF?= =?utf-8?B?Rkx6cXNWdyt1UzlNb04wUEJpMUR1dk80OUNUcE9JR2hVOG1iZU1pL2JrMlNj?= =?utf-8?B?Q3RTQm1QT1NoUkV4eWxuWWpiTzRQMDZtZkNZa3Z0VU1GaWM3VWR1YnY2dFVq?= =?utf-8?B?TlpuekhZdWZORHI0RkE2Rkd6akJPa0JYTDE4a3gzNEQ4b0FRSlExK253Y0pr?= =?utf-8?B?TlFnVTZncWRva2VROWVzem51WXhoUjFyaXV3dEhZMm1FV1hKYnZXb2lsVFRs?= =?utf-8?B?TVhkSFkwVnhtMkdRVG9EeHA3czc0N1JJRVhJWUtQdDhobXg1QmN2a3dBZjR6?= =?utf-8?B?VjViQ0RDV2VDNFlCNFRCYnZHSGpVWEN4eEd5Y0k0Yk5oZ1c3RXRjdVhQUE9W?= =?utf-8?B?b3d0MkdlYThwRnZRTnF5NUxnc0xac2s4RXlYanR2TXRCQ0lHY2V0NFZzVVhJ?= =?utf-8?B?NGg5b3A4OW5OWnZsZlQwQWw5RitRYWhMR29zS1ZNdXdOSjcwK2lZWUc3VTZB?= =?utf-8?B?dFpSdzNrcjI4VWgvaTlBL2FPL05jQWtZQUx2STBUT3F4eE5wclZEakM3dE9C?= =?utf-8?B?amtxeEZ1a2t1Wnp4OXJWRkgzaGNnRExsNGFROHMvcXJEV0FRQ1ZjMWpJRGQ3?= =?utf-8?B?NjRPanY5bFVFbjZBL2V6cWVGZFNZTk8wQ29wdlBCVlhYTTRPRlpXVXlyNTB0?= =?utf-8?B?czh3cjVrTFgwWlRsOHRuUEtLSlV2RDVvcUYxNnZzZnhvZklNSlZCMkplU05U?= =?utf-8?B?RGJNWnN4eXc4NitOaEVjNjBBRWFtNzFYRnhuTS9DOXlaa0V2SCt4L0hzQms3?= =?utf-8?B?SGdSVlZtRUlKb00rRy9wOXdBZDFsZXQwbkk1SXAxNTd4YnVidENBbGhhZEFo?= =?utf-8?B?K24xUlBucWJnaWExWFhEb2xWYWlIemVBdlFyaTdGamhKaUZvd1hTazdZbkZE?= =?utf-8?B?Vk53cWdvYXZHMTJPcUxCTk84RWZxSFo3RVVjZGpCZkg1UXd5WkRDdjVOVnkz?= =?utf-8?B?TXNvUGlxcm51Z3hVdk1EWG1YMnlGeFRRZDlpOVowRkJHZ3k3RkFaWU90bGZB?= =?utf-8?B?aWg2dEFGa0RhQUttVm9Db1l1R2VubXdCWHFkS2g3WFJPZFYwNzFMdm5STzhU?= =?utf-8?B?N3c5R0w5QTZUZDdnK1Exb3JFdCtQQ1NVNkNRUDJXNnhMQ3d5NzI3QkxEL0Jw?= =?utf-8?B?RFFKZ0IvRU11TStZU29nYU9RNUppODBXVjk4emg4ZkpjbUlrQmd6a1R2SEFi?= =?utf-8?B?Ylpjb1h2a1pzZ2x5UHRLMVUrcjNoT0ZKUndEOU02ekZNejU1dElYaE9zRjFI?= =?utf-8?B?c3pIN0l6RHFVckZuWHRucU1SYkpraGVsTWUrR3d6dk84M2c9PQ==?= 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)(366016)(7416014)(376014)(1800799024);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?eE4zQVh5cFB4SC9FbkNPVVNEMXJKZzF5TTg4dXJkSGVnZm5LUWY3RExGWkk2?= =?utf-8?B?Y1lzSXVDdkowTjdHU1dlZnlSRlluYUZORU96STZaMjRtanBrZUZXL1lNUEhY?= =?utf-8?B?akdaRHJIM3p5MDJjelVTY3htSXNRcngzSHhqeU5rWEV6TGJWWWtDUXVVSkt0?= =?utf-8?B?MGxsaGpoaHVobEk5bkloaEVJWEJrb2YxekJXK2E4OHNiMSsrOU15T0ZmWnk0?= =?utf-8?B?UmkzcnlicHk5cEE3SEFsUDZ1TTl5ZnlTMlhvbnRkcEozbTA5MlJvNlJhRFBM?= =?utf-8?B?N1dkWTZwLy9VTjRxYWpmYXdFZHMzM2xyQmZac1FZV2ZIcCtNNWlRKy8vQzRq?= =?utf-8?B?NnJpcURESU5KV0U3c1dacS9jbFNGcGl6bERFZTNKeGpaUnVwbDU3RFBuV2Z5?= =?utf-8?B?YUorWEtQZVFwenVmTWhGZFdJSjJOQmFwNEdQREJVR0hPUUJ6QkxscDlQNE1F?= =?utf-8?B?a2NEUjFTUldzZzBzK0VBUXlpUnA0bVdTTTE5b2VpMHJnTEdseUpsWlRuNFp5?= =?utf-8?B?YjZvM3ErRTFtYVB4bTRtdGhiT2lCL1IxUml2OTV1dTFyK2FmV1J4OFZxZHls?= =?utf-8?B?VHR5NnozdUR5OTlkMDZNMmdrU2xPWjVoR2ZFQUhGeXhwdWx5MXgyczgyWU9i?= =?utf-8?B?N1ZZdTcvK0NFemNTcVN6WVZ3eUlHRTBqS2w4VnVVVUdueEJpRllUdTlhd2tC?= =?utf-8?B?VW53THY2ek9zWmdVa2tMbjZrYndmeVVhUW91YWlVVCtOMFE5WmR6RlZMRUNv?= =?utf-8?B?WGl2TVpjYTJCaGRhQkFEd29OWUpBOER2UU5RdDN5MTNsYmZpRlRMTmduU0Y3?= =?utf-8?B?SGYrd2pVaTlVN2wzbFN0cUpxVWlxcVlIYk14dXgvN0FIWmJJVVhQU001Si83?= =?utf-8?B?Tnl3dGZaZ2dxQzd3K283S2lyQ0hCaDg1U0d4TVc1KzZ1c29scEdvejc4dXNu?= =?utf-8?B?V3FxZmpiRnpzV1RnRUxDTGdQWUUyQTJaWUNVYlJRU21VUDRaKy92WmNpaEdT?= =?utf-8?B?eFZ3K0QvbjE3cjJISGNPaDlpNkJLSkJPRUViRFE0Z1BqVW1vNHdUZm1PRUtx?= =?utf-8?B?c0FyeUFyYnAxSDZKdXd6TzdRdGRxYmZWMy9JYStIMkZRb1NBT013Nmk1RXJD?= =?utf-8?B?QU5aOHB2TEhMTWhwK3ZyUjFUK0g5dm5vK3JuTUNaZGlBRGU3MFlrem5jU3pW?= =?utf-8?B?Z2lBRkYyejFuTHNTUDVBL1dXVnEwRkdFL0ZVL21rYkltTVRSbGVSOVJRRFRW?= =?utf-8?B?M3FXMXlRT0dINWFCdzNFeEdvZkVZWmw5SnFVZnhkQW1CTTRxekFYejNrTWpo?= =?utf-8?B?N1NtcFhjRFVZNEREWlVNT3hKU2F6NWsraEFVQWV6VHVodFAvM2dnRmxWN0dL?= =?utf-8?B?VzgzU1ZMWWtnN1c1Y0J6cDlYU0dZcnVDbExhcTBqbWpaUGpOYzZ0MUtYeGxB?= =?utf-8?B?SlRST3BVOFNySDRpenliTU9VNXlGZGpSZzIxNWk4cmpZanVTOE13aVhtSnVq?= =?utf-8?B?ZWRoZmtkNG10NXN0YVNpZ2FNQ0dsN0gzQjNyeE9LY0ZidEVTTEZvL0kvYm5k?= =?utf-8?B?VnJ2UmZHQlZGQXpKWjVQNFVSWFFWT2ltcDJLalIzUjBNS1QrN1lmNllrb0hW?= =?utf-8?B?aE9ZVXdWQmJZbU43ZG9UclJJak9XbXpwcUdpRy9QMUJ5OGY3Smh2RTVRclNx?= =?utf-8?B?aVNybHkyOXBCS3oxSUZxN3Z5R0xMUDJGa014c21GaU5CWjNZWjE2NTQrbjFR?= =?utf-8?B?T1VqWUl4Kzkyd2JFaDlNMmt1dy9Bb0hKQS9HQ29mSVRlcHNRc0Q0UHU0M1kv?= =?utf-8?B?akJRRzhFNXp5YUJUK2pFSW90d2FlZFNYRVp6c3dMV2liVEU4UXhIeEtFVVNB?= =?utf-8?B?TmxWVmdzZDB2WTdvajFQTHZoSDNVaTdKUVBCRHpGWHNwWUdCc2YwYVJvNHRW?= =?utf-8?B?V1VoK0l2QzVCYThBRTZrTTBtTWhtdGRWRFJsN2plYmtJT0dZZ0UvdFkvSDN2?= =?utf-8?B?a1NvUG5Qamh5b004RlZoaUJrdDFDYkRQeTZ2dkZja0w4aEJOL21hZTFXcjJH?= =?utf-8?B?d3Y2RUo3RHdvaExzaERJc1pmS2xIR1NFdDA4Y21PbVdZM3BqOTdES3M2b1or?= =?utf-8?B?cllKYU52am1GWC9lWHBMVU96eFZCY1JHajZSN3V6a0VKRm5CdnFuUkNtSHl6?= =?utf-8?Q?va58KE2LoGwXaYxahKnMaCI=3D?= X-OriginatorOrg: efficios.com X-MS-Exchange-CrossTenant-Network-Message-Id: 5c262e72-0408-4491-4b13-08de3cb59ec2 X-MS-Exchange-CrossTenant-AuthSource: YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 16 Dec 2025 15:13:08.5260 (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: czjz6NbnDuawl/63kpM2ZYtvC1sE78sgyuiP/r8hreH1pXXoq8BCISM/Ap1uyIB/Q3JSVp3+AIt2bEbe2iHu4I/TiX5uo6hdah6pKIDat2k= X-MS-Exchange-Transport-CrossTenantHeadersStamped: YT4PR01MB10389 On 2025-12-15 13:24, Thomas Gleixner wrote: > If a time slice extension is granted and the reschedule delayed, the kernel > has to ensure that user space cannot abuse the extension and exceed the > maximum granted time. Reviewed-by: Mathieu Desnoyers -- Mathieu Desnoyers EfficiOS Inc. https://www.efficios.com