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McKenney" , Boqun Feng , linux-kernel@vger.kernel.org Subject: Re: [PATCH] rseq: fix hard lockup on granted time slice extension Message-ID: References: <20260802124423.51616-1-npressel@ethz.ch> <20260803071940.GX49951@noisy.programming.kicks-ass.net> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260803071940.GX49951@noisy.programming.kicks-ass.net> X-ClientProxiedBy: ZR2P278CA0066.CHEP278.PROD.OUTLOOK.COM (2603:10a6:910:52::20) To ZRAP278MB0079.CHEP278.PROD.OUTLOOK.COM (2603:10a6:910:12::11) 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: ZRAP278MB0079:EE_|ZR0P278MB0990:EE_ X-MS-Office365-Filtering-Correlation-Id: edc08d44-2b77-40b3-ad41-08def20bade5 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|786006|19092799006|1800799024|376014|23010399003|11063799006|4143699003|56012099006|18002099003|22082099003|10067099003; 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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?+hOa+17RE82pMtm5yKloGF8Wuh0j6ghSM12BYrl3iJbvADYWFKIX66tmCd7h?= =?us-ascii?Q?mFYMJT5oIFbvdny7/hvgS8kpwLjC7hkNOO1nqYCRPqMdsEqfRaOYEwpexfp+?= =?us-ascii?Q?8EYmxGYP+sOKYeXdfGmMPcoOtdcFKu7ZiM8RFUXoKdxYfuQG+lgvIaxBYLzY?= =?us-ascii?Q?dVEPYuUBu+pItOsiNv35BmG/QtvPEEfDsq3LY4ZJtl6iOv8pK7d/HZx0CtoI?= =?us-ascii?Q?o9WuSKa4I+puLoaokOGmt2OVrJiMdssnsyjTFDpkZRR/esyDKBxCSwKbwC8o?= =?us-ascii?Q?e+ikn+KVW3nKWDAu7nFz3JrjIV+sZZxBpwA1A8rEkV5CZg7K2iJnX/2djiUT?= =?us-ascii?Q?JjQw/6r4kQ1bejMc4NNI//KZ1kSeZ43DbZLkOg1HJ5uUZ1Tn31XImZ6XpIa3?= =?us-ascii?Q?5MuVE5jUUuPQF/lS4NBKLzYrtiiDqyWdYP2vROt3lerzB6W99xWw9rxFdNVv?= =?us-ascii?Q?nJdfcnKoRUSv4uQOZD2yiUmXpfv2cwnuNvzfHW3ZmjXt4zJjcgBY2MLfbaqg?= =?us-ascii?Q?Q9xSTMr5z/rs6Y1H29laCIpGHBNPu/FcOFNmROhG8+2A3U8ix+5fmNYbFnMm?= =?us-ascii?Q?t6dg0V+eg4+cLFCFwm6fNm0tcSrfIxKqJy9xyiPL2kwMLFCZuCHG15txs2JB?= =?us-ascii?Q?qrWKGxTXmDXzETLMK8T7o1iY4rtyyMohtitthEZNo5G81Qxu2QGLoZFoOaED?= =?us-ascii?Q?5d1a1cbY7o6laHy5MGnZau8n3EIATbySM0cZUv3X4MdBM0C7PEcDQXbxdffn?= =?us-ascii?Q?2zHrQQ8YEhKhEd1YdygYmBhk8Sle7PSH95EUKbihYyzLddPg08Ye3Q4dUevr?= =?us-ascii?Q?yATexRgdJThhSeBxZD4kw22Ke5NiqVrZILcGfIaz2jL72t5Q8JEfE54cN25k?= =?us-ascii?Q?6AcNoZQ/kpo825DIVA0+CKe5slexAiprx7Este+NN1HzoPbbCum2YsalTfG5?= =?us-ascii?Q?7kf1IVDvKNTkUEHKhA7ZG/b3hR4g7vVR27FJRlTgNT7BY/tSKHfqbbnzbzhU?= =?us-ascii?Q?2dAqh2RhVQJzt05YvPfepIFD/xuEmfjao7YJKSmUzhmP7GcKPF/kIU5AyCrm?= =?us-ascii?Q?3GVedwiyCxkP7of5Q6hp7fFZFM+5KonZiA9LnS37JZFFrfWASgzijJPG4lF7?= =?us-ascii?Q?LH1rDBcsLjRs/HN58CMIfVGBDSb27fFoDdnDRmGa0SqGPOoY2U823TdMEenp?= =?us-ascii?Q?gWUAxXFx6Qh/xEvBFvk8yzdIesx0MMABGcGBks1Hb0rnhwFG4u1MvKJfCgDE?= =?us-ascii?Q?nH8RyqwfI7w+q6OLpZJHijlX6w4lJqxSAiSDYoh1KKGfjj4jgO6MVqkztiP6?= =?us-ascii?Q?pToD9GSgFobfpU7PFWQY86KZQz2PuI6pEiUowN/IfNnFgofVU3GwRUnf2ci3?= =?us-ascii?Q?7+DEN8H6b+5brd/JnI0rH0vXo9cwLGo2xob/rH7IND63GXiFCYWogIrSX2jG?= =?us-ascii?Q?SyNZ2cgamBBVlMNv8Od7Yn+ubgpB4ZYXm04OCjnv0qthlRgaQbhdfkxSR4bi?= =?us-ascii?Q?lGh3qVJmBZFpg69H5dktpgX0so+UFEIRJglqZ1n7v69dvGcw975M1MayBJsI?= =?us-ascii?Q?yBuju+JkQjOpga2MJQW72uQE8KVNFLTBV+64K1cwNiLJyzCuL6TU1KExPFzX?= =?us-ascii?Q?QKel8ZmM3C1vqu5bbkEMsn/sxLYut79Euiydt1HSDcfXXhS3OVLqO16KCO8U?= =?us-ascii?Q?U8loLugnPHSh+qn1PB1lOFutjKqa8mKAZ8G2amrTDUtELH+0?= X-OriginatorOrg: ethz.ch X-MS-Exchange-CrossTenant-Network-Message-Id: edc08d44-2b77-40b3-ad41-08def20bade5 X-MS-Exchange-CrossTenant-AuthSource: ZRAP278MB0079.CHEP278.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 04 Aug 2026 09:35:11.0130 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 9634a6ec-a266-45a3-ab14-74c4211fc582 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: U/2yRu4Gy03uFX9Rq4quKxCodA6mR6P1XfsBok50JGW5LnEaXAq7MpPCb37RENw6k9LymQuKrt+k6LR8DQYYdg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: ZR0P278MB0990 On Mon, Aug 03, 2026 at 09:19:40AM +0100, Peter Zijlstra wrote: > And while disabling it will cure the splat, I'm thinking it makes > sense to reflow __exit_to_user_mode_loop() to instead delay enabling > IRQs. Thanks for the input, I agree. Will address this in v2.