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client-ip=165.204.84.17; helo=satlexmb08.amd.com; pr=C Received: from satlexmb08.amd.com (165.204.84.17) by SN1PEPF0002636B.mail.protection.outlook.com (10.167.241.136) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9137.12 via Frontend Transport; Mon, 22 Sep 2025 05:57:47 +0000 Received: from SATLEXMB05.amd.com (10.181.40.146) by satlexmb08.amd.com (10.181.42.217) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.2.2562.17; Sun, 21 Sep 2025 22:57:47 -0700 Received: from satlexmb07.amd.com (10.181.42.216) by SATLEXMB05.amd.com (10.181.40.146) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.39; Mon, 22 Sep 2025 00:57:47 -0500 Received: from [172.31.184.125] (10.180.168.240) by satlexmb07.amd.com (10.181.42.216) with Microsoft SMTP Server id 15.2.2562.17 via Frontend Transport; Sun, 21 Sep 2025 22:57:43 -0700 Message-ID: <228e2fb7-e141-462c-8796-3cf78aa01902@amd.com> Date: Mon, 22 Sep 2025 11:27:42 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [patch 02/12] rseq: Add fields and constants for time slice extension To: Prakash Sangappa , Thomas Gleixner CC: LKML , Peter Zijlstra , Mathieu Desnoyers , "Paul E. McKenney" , Boqun Feng , Jonathan Corbet , Madadi Vineeth Reddy , Steven Rostedt , "Sebastian Andrzej Siewior" , Arnd Bergmann , "linux-arch@vger.kernel.org" References: <20250908225709.144709889@linutronix.de> <20250908225752.679815003@linutronix.de> <736A5840-3372-453F-8F78-5861AFA0F140@oracle.com> Content-Language: en-US From: K Prateek Nayak In-Reply-To: <736A5840-3372-453F-8F78-5861AFA0F140@oracle.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Received-SPF: None (SATLEXMB05.amd.com: kprateek.nayak@amd.com does not designate permitted sender hosts) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SN1PEPF0002636B:EE_|IA1PR12MB8466:EE_ X-MS-Office365-Filtering-Correlation-Id: 793b8416-e552-4005-7dab-08ddf99cf517 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|36860700013|82310400026|1800799024|376014; X-Microsoft-Antispam-Message-Info: =?utf-8?B?TnZOSFRmak9EVXp2OUdSaCttTXFzOG5QeFI3UlpBODYxTkJsZ0VLbFh6a2NL?= =?utf-8?B?aTkwVHAyNUxjKzRQTC9hUHhmOTdsOGRXN2NhOGxsZXFRWHhwczJxTk5oSmtp?= =?utf-8?B?dm4wYWlaSEVKSE9qMnkyMi9FcHAvejNHbFFQWnRKZUdlR0dzSTNvM2RFMGVZ?= =?utf-8?B?ZWRNV09aOTRtd05mVE1kT3pscGpXVm00TGlOM2JzOEZwUGVwTmprWGE5NEJs?= =?utf-8?B?U2VYQmFHYVVCd3RUVHQ5YXVMcWZJVjcvZDNxdzNGUnAvT0tmU0RBYVVSQUhL?= =?utf-8?B?RitISU5lbytja1hITkJLUlhkbXZ1NVhwTncxd0pFMUx3ZmE5aE56REdVNjUv?= =?utf-8?B?dVhkci84RWFuM0UwbEFsczJrRHBvTWsxZjcyWUlBS0pWdHZIaWY4VkpSWVlT?= =?utf-8?B?RWZYbVEyUGxzbVRxTVppUFc4cFdwM2xacjIrZzdOTGlEdE0zdjdIUzYxMmlp?= =?utf-8?B?QkdYb2tSbmorQWdOMFZUMFB4NTZjVVZtV0RJWjFrQ0ZlbHFsQjhwWVZUT3BS?= =?utf-8?B?NjFFRGFiTDdjOUpUMU5DY1dQNGN4TUNkTVNpeGxPMlNDZ0QrT0Uxa3V0WU5v?= =?utf-8?B?cXdXdDUzSUlSV29FZG9GQUdCZllFZ3c1WnN3YUpDTG9GR1lTSVVITmU3TUVD?= =?utf-8?B?WW9md1kzdVNsQVhZWGtBUFdUTWJlaFJhU0Z0b01jaEd5TkhoQ3R5T2x4UldR?= =?utf-8?B?a3hHK0QyZmFEWFdJejdkLzRtcWE3T0JIdXBQdDFRWjhVWlNic0lZTGxGT1pP?= =?utf-8?B?bkN0VGNoUUgwK1ZUQzByWGN2QU85RHdHMlg3dXUyQnE1NE84ZXNGTk9HYmpq?= =?utf-8?B?TnJQSTF5bVlsVHc2T3VZQm1pWVZpWFkrd3Q2WnE0QS93ZW5yMFFGTlVKTFp1?= =?utf-8?B?WDQ5VENMdktjcHJZOHpTR1dsNUgwdWdxZ0xzczNuRjVWbXlBVmxGRnAvNFhm?= =?utf-8?B?QUhYNWlLbU5haHZxc2RicSsxRFRya2NaWFNIc3F4R1RtajBOSVA5cUU0RVJ4?= =?utf-8?B?ZDJEZTdoU1ZlejFmaDVpS3ZhK3NsU2ZRdlBGUTJ2eklsdjduVmVhdXI0T3Vv?= =?utf-8?B?dkRzYkZEc2JTK2YxL0VPWHoyRXFvQnhyMnIxWGRpVTFJOFlpMC81M0lCTnpT?= =?utf-8?B?c3ZKV1FtRDRJemFpb1MybWw4Zm9nazNYNEpYTFpWemdwSzhWdFhtWGdCS09Q?= =?utf-8?B?Tk1Remk4clNvc04raW0yNTUxbm4xY0VVYjBRcjM0TmVPUU94M0NyRlpEL2ls?= =?utf-8?B?MFRCdlE4bm5wVmtYbG9EbUhUSlR3eVYwL3VweCtrKzFjd0xnTzR4d3k1bS9U?= =?utf-8?B?REx6UmJ1WjRoUG1CS1NLbWRRV3U1NzFHVklUekFVRmxkeWpDOUdUQnlBdjRr?= =?utf-8?B?VE5oNFMvUG84V3QxYjI0ZG9OaWJhZms4L3p3cnAxd3lhdXJSWTBLNHJQb0dm?= =?utf-8?B?c0ZZRlZENXZJU2J0OXNaeWZaZ3k3cFJoblhZcUxrT1dUR2o3a0JWVnFMNTlu?= =?utf-8?B?eFZCNWRONlJLajN1RDZjOEVZa1BDdHU2ZHdUYjN0eXl4Y1UramhaOHBoZzhj?= =?utf-8?B?RnBETHJWdFk0VW1iRE5IK2t5OFU0bTc0NTFINlA3aHNuT2FRdWJkb3oydE9M?= =?utf-8?B?MTl5QzRvNFovb04zV1czRmlxQ1p3RFVQU0ZoN0hxL2xnVVJ2dFN3SEd2R2pq?= =?utf-8?B?R1VKS2t4S3R5MlFsZWdhL09URVQ1RDNESlNDak1lWmYxVWVRNnZmMTR1U1dp?= =?utf-8?B?SXFwNHVhZ0FnSDFzZ1ZmY2YzNjVSeGNiYnRRdkJKd0FMR1hUbkpROXBQMlNt?= =?utf-8?B?UUZTWXphMWtKVEJIMnhKNnVXd3RpWXExKzhGd1lGSi8yZzhLbHhaQjMrSm1J?= =?utf-8?B?NDhOQ3NlaXNZRFhuSFQrd0pLemxhSXhHNWlkd1F6OVJhTGQxWHplQXRHRDRo?= =?utf-8?B?c2V4bDJaMktSVUUyazM2cE1abXdUUVFIOTNWWTBtUFZTS2JPYVVXc3c2aUhy?= =?utf-8?B?dDhzb0hrWEl3WHhjeWlJUEROQWRTUkZ2QlFsNjVDZzdWdzZUT1JJYzdxbzJO?= =?utf-8?Q?ywND5G?= X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:satlexmb08.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(7416014)(36860700013)(82310400026)(1800799024)(376014);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 22 Sep 2025 05:57:47.8036 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 793b8416-e552-4005-7dab-08ddf99cf517 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[satlexmb08.amd.com] X-MS-Exchange-CrossTenant-AuthSource: SN1PEPF0002636B.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR12MB8466 Hello Prakash, On 9/22/2025 10:58 AM, Prakash Sangappa wrote: > With use of a new structure member for slice control, could there be discrepancy > with rseq structure size(older version) registered by libc? In that case the application > may not be able to use slice extension feature unless Libc’s use of rseq is disabled. In this case, wouldn't GLIBC's rseq registration fail if presumed __rseq_size is smaller than the "struct rseq" size? And if it has allocated a large enough area, then the prctl() should help to query the slice extension feature's availability. -- Thanks and Regards, Prateek