From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from YT6PR01CU002.outbound.protection.outlook.com (mail-canadacentralazon11022086.outbound.protection.outlook.com [40.107.193.86]) (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 30E8233A024 for ; Tue, 28 Oct 2025 16:14:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.193.86 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761668053; cv=fail; b=pe71JJZw4p99JPxKWPMP/Bs9Q1WZFJpDAsjDDTydPBM8MRkOL0nzI2Mb1OL7kU+ahrDdHQfdhnwmYC/oUTBlR+TpW9ynoNSLSWLtrSyqSiw1O7o7GRIjqSiOGqxbtI0jKI9UT4mGt58J/CYH88Nz06IC2AAPYkCKfZ3OryUwGhM= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761668053; c=relaxed/simple; bh=47b3v2tqWJ2LEiwoLMVq3eErD8s3Jx/gAYKrr5pnI0g=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=d0t5jveRENwuKEbMIJ/LmUdsBn6hVZhaO4rI9eUF4Tpz6BJi6XRYSd88oIjCiz+3kqgPfMe87hzQ+VLs9Yi91vKjh2AAcxMIfig+nBFNTCGlGKAWH+ftiDGBwivugyh3A8YWm2+5ky2qyU4X615mImN+tbfDri1LfHO8WfyMos8= 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=qouoAfNW; arc=fail smtp.client-ip=40.107.193.86 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="qouoAfNW" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=MUMcA3W8usG1PFRQvsB0HNJSW/rlfEsgn6hPknFn/44d18/JK8YkkO55zbENaWTdwZ/7uyRGtotbC+hsJg0dykuhIzLDxpkzZYcBCor2YOaRZ7jCX8Ew0HTJY3uu3mUevKUQRaZ9cl2GlvFkNFcygXti67wgw+mX3kU5ufw5xUyhL3S3IMv0M+0t2QLMowx3fIAsnOIoADCNsbG53/0XNzix/SYflRUzwa0caTpT4TXbb31WgLel9uJXQdsqeEc/eff3TNu9uizlq/QsPc/boSjoYye7VOASA+p/W706efTisgRY78vcMGGYCeqDfBNFIXp2gn0c6hZT27WSLG6Bww== 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=yxOeVLFtqedJI9ndHyyAZA/XqMwRg6VRPs++u2BLYKE=; b=FJJSyeI0WYPCDbJrnzhi30HDF8V5Jr+fIrlfyMiw9WgoRtMd/n8pbSWYMwV7kqakFuZmL3fgcLl7hxuMce90dUJvXwPT37G12xhWIRRrili0VmAdUPpM7RZMajD0lFJPVvdqcdOUiGp/RH4wvjaze7Kc3/5OfdF3crCgL8bHb6nSUayvOeaKbujJBAF1Xmia3DhV9798w3mwOh1VHxLrH3h7scyyFXJmtRt2RDxwrqJd0YAbRJE3QI6vbuFU57H/bW9xTKASIPCAvkdMlqKLKvgi9PqkeXWjDdW4LCFdStoaHM/HA9NROpUe1kWXSlpdwEBS2KpXIOW8d/m1rN6UCg== 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=yxOeVLFtqedJI9ndHyyAZA/XqMwRg6VRPs++u2BLYKE=; b=qouoAfNWyo/Pg82NnbRnlo5L6YuqbiXhKv3UhmWL/55/erYrAqsV7UPrlgnQb7KTmk5GeQqjjNCvHMV8ZA+CnckzpvpVHXjD7P28UF/AjiSHAsOcW4vqgF/z+16KCGwj2r9n4Xc9UIBSciP60f8M5VEIUDgm3yTxlov3gHYNsNnMjd8lMb6rNPB9778tZV+sPvsRDoeSf/46QwNOftc/CioGZGHdpypy+gyVkVl9L+ZYedE8bBtrl+2ydgwJOFUi1Dsiva0vYWpIVsM8njHBY57wBLt3K4c5fCUpcuNHFOQMGNdxh/awzRh8lLQEniapEP2LrJ8LwX7ol3e0eaEHnw== 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 YT3PR01MB8356.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:9d::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9253.19; Tue, 28 Oct 2025 16:14:08 +0000 Received: from YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM ([fe80::50f1:2e3f:a5dd:5b4]) by YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM ([fe80::50f1:2e3f:a5dd:5b4%2]) with mapi id 15.20.9275.013; Tue, 28 Oct 2025 16:14:08 +0000 Message-ID: Date: Tue, 28 Oct 2025 12:14:06 -0400 User-Agent: Mozilla Thunderbird Subject: Re: [patch V6 28/31] rseq: Switch to fast path processing on exit to user To: Thomas Gleixner , LKML Cc: Michael Jeanson , Jens Axboe , Peter Zijlstra , "Paul E. McKenney" , x86@kernel.org, Sean Christopherson , Wei Liu References: <20251027084220.785525188@linutronix.de> <20251027084307.701201365@linutronix.de> From: Mathieu Desnoyers Content-Language: en-US In-Reply-To: <20251027084307.701201365@linutronix.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: YQBPR01CA0013.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:c01::21) 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_|YT3PR01MB8356:EE_ X-MS-Office365-Filtering-Correlation-Id: 053c006c-7739-42ac-53e9-08de163d0584 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|366016|1800799024; X-Microsoft-Antispam-Message-Info: =?utf-8?B?Mnl4TjNXS1JKbFRrMnpURjRlOVYrZ0Y4eDJJMk9IQW91OUJuMmtmK3VmZ05V?= =?utf-8?B?bG43T2R1SEVndjFjTWc5ZjVkeUQ0L0w5Wm90OXVxTGx5Rk5yWG80VTd3dHZy?= =?utf-8?B?V3h4eWdHTXZ2dDY5bVlMT0Fpak1JRUpUZCtJWHhFdGF4RlUxaXRJK2t3UGNX?= =?utf-8?B?NGFGNEM4bnRjaWFPblRFcVFQcUxYTUFkb3J2cXVycVdIVTZoTE01SUxoeHA2?= =?utf-8?B?NFNadUtmZDN2N09LcnpVcEk3UjN5ajB6Y2FsVnV5RE92ZlhKMk9vTUZ1b2x6?= =?utf-8?B?SHNLcy9yK3JjdmNRcDVqT2p4UkxYTDFLVFVXaFo0ZUQvcjBaR2FUTzJoQWNC?= =?utf-8?B?RlBSOFQ1M21ZK0RTek42R2JmczlVZVNyaFd0Y0lrbDNqVHd6eHdIbVFPMVJ4?= =?utf-8?B?VzdXcStlNXVXYW96MEhBN0JMK2tmM20vZHRlb2IzQjEyYWR3eGZtYWhvQ1ZX?= =?utf-8?B?dlpmblR6dGczNUlOQmNkS1AzdUNRdUVzY3R1TG45b0pGOTErOTFkSlFYK0ZI?= =?utf-8?B?aTNRWGNnNFRqVHhDcFpvczgxSStBcm5HZWV0TnhrcG5xWDZyYVUxMDJNd2to?= =?utf-8?B?KzU1U1hSdUhSYkRtZmtFbVArU0ZyMUZadFRiOTZSVzNzVWlIdHFuclZET3M2?= =?utf-8?B?dXE0OVBZa25IYzdOTkgwNmlNUUNKSkg5K3ZQanI2VXh2TlI3ZHNGYndIL2Vi?= =?utf-8?B?RDBwSFJkTjBJdjJlYTZwcFk4bVVWbGZwc1F3d01MKzZHa3ZoaEk2cFpaV0Zq?= =?utf-8?B?MnFWc1BLaFpQUkpqcUZUMlIzRHNRejZEUjROSUd1YklVMXkwU0VSRXhRWllw?= =?utf-8?B?YnNmRFFGSTV4QWhuQXZWVGRESGRrRU8rR3hwcnBaaU4wT29uT0szYnpLYjhW?= =?utf-8?B?SDJZWDFzUS9LRjNUek9QNUoyYWpobEZnYTNGMGlQd08zbGdvSXB1ZlFObXJv?= =?utf-8?B?Skl4UVp2MDhlWnJmanJmcDU3NlJxMTFXallJTC9FUUcyNk5QbWdNeDc2clU3?= =?utf-8?B?MHZOZ3J6VkxqeU1MQUxEOXlDdnBNR0dBZmhwS2NXbkI5cHJJeVRpSk5IRGx2?= =?utf-8?B?MmNzRVJSN0M3NHhIS3g1SWFYYVZFaW1BM2xFSXpFTTJNV2xpUFFua2xTMlht?= =?utf-8?B?YzZpUFVmTTBSWFMwYUYrL1hHQ0JodmxKRHdzQzJTcjhvZk1jLzJVZk00ZTA2?= =?utf-8?B?dTQ0bG1DcExvWFhoUGthcDQ3Mmh2cWdva2pNVmg0TlRFR2VJUzIzK0E3eFRv?= =?utf-8?B?WWM5LzAwOS9BeW9mNnNOOFhSUEZRWG1XMmtYRmtSamJRUExGQXJIeks4VlYz?= =?utf-8?B?N0FpdGxRSlNuL3FUNGRGN1ptTkZUKzMweXpkWTJ1ZW5VT0JEYmlyNFVWaTRk?= =?utf-8?B?VnV1RVJodFgyZjh3elpZT0g3RmZ1U3pUU2dFWXpkeU9PUnBKd1Z4emNibHF5?= =?utf-8?B?RkFJVmUvUFlML0FhcVhlZEdhc1N1U2xmcSsvdkQvK0ttZHNCZjZnd1lYbVZY?= =?utf-8?B?MldFWlVRbTl3dzVleEYxQkFlaWhHZGVQQzUzRGhIZ2VYSGdEbkUyMGhHMkZL?= =?utf-8?B?NDVhdDN1ODZLTTFKWWFIMjJXZWdsRWdWTXFQM2F3L0FWY1JYd1ZkWEc3djN6?= =?utf-8?B?dnVGTHZhdnpJeFZ1QWNDQzFIbTl3TlBnYlVZbTVueDJ6ZmxJemZIejBYK0JM?= =?utf-8?B?TVFNVm9aSjcxNWtJQTFYZVJ4T3hma01ucHJhUE52dzFjbWFhQkxraENCK25F?= =?utf-8?B?UVNsQlA0MDFyTmdxcmtySU9MY1VrS0kwZmNFVWx5clpicE0wMmUwRUQ0K2lG?= =?utf-8?B?QVBabjN3NFBJWnZwcHppSmM4NjlOYld4cUdWQ2VpQXlISENPR1ZzekpTTWFV?= =?utf-8?B?dEdSVm40SmRHVFArakkyS2lpdFVib25SVWtzTmRmQzBDQlE9PQ==?= 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)(366016)(1800799024);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?Y2lianFFNWkrUVNaMUh4TllpRnZETjBNbDBNcGF1RHZpRXZ3ajV1NzZ2TWFN?= =?utf-8?B?M2t0SkNZcTJrb1R5RTJoMVBVNFo0TUdLdnptWVhNcWJGVTI5dTEyblkyc1Bt?= =?utf-8?B?TS83ekVsbmRzeWJDajZ2ajZ3Q2prcXJCcDl1azYvOURFTkt6OXdJTmk1OXJF?= =?utf-8?B?MDhlNzdYVEpiL2lRRkxoVVBPVXhEWmQxSTRKWU5kK0Q1NG4xTDhKM2ZVcGpz?= =?utf-8?B?Zktha3N2VVBiZmZNNkUxRmRZU1NrV3FMeUhuZ1JuUnlnTDg2R1EySUdHVEFQ?= =?utf-8?B?M29TN3Vudm4zOVVQY2pRUDB6NFArRTVpM0s0MzVXaHl1VW9FZWtwR09jQW9P?= =?utf-8?B?dU5uTlh4K1U0RlJOSHlFTE4vUVZzcENLNFA3MTVCR0ZSdnZYYXlEZjNtMTBn?= =?utf-8?B?UFVURFg0VXZuUUdNajJxalUrSW9MSVk2bHVwT0NVYlhUSmVIU1Z2TGt5Z2Zv?= =?utf-8?B?dVV3QzBSSU51Q1lqeXNrSEdiOGx1cTU1NzNpNzVJMHRXMlpvNkt5U2RNYldO?= =?utf-8?B?M0JLVGJlczJ3SmxPZ282T2htc3ZJdU4zUHBHZTI1dWlyWGtCaUJxVCtmTm84?= =?utf-8?B?VFhab1E2eGVScU1BdWZZVFVIaUhCbzhQMzd5cHQ2RXlibURzMkwzN2Ftdk9k?= =?utf-8?B?UUt5Zkl5MDlQM1ZIcXFQbEhkSlE0c0dIOTg5Y2hPMXJub2hGVWZLTmpJeW41?= =?utf-8?B?NVlJanVCb0ZlMEovRTByc3MwRFQvcE9mTlJuMmJaZ1RXdlo4Q0JycWp5YXh0?= =?utf-8?B?RnpMMFhNZlZhMDlNMHlCQ0dqUCtvQ2dPSDltN2VhckIvaWdPTThtTDFZTmhh?= =?utf-8?B?d0RCV0lkbCtuZS9zbE5GYU10SmtLWWNWeG9yamJXRDVZelRFaHFsY2hwNzQ5?= =?utf-8?B?bUpLajQycmJDanhBYnE0VHJNNTZ4WUV4YysyTTJyeGxTR25oRE1kOStNYkZI?= =?utf-8?B?ZlZJamwvdU9FQysvZ3E2U09FaVROWVpBZUwxbXdmaDNuVVQzYmNEakduZmxo?= =?utf-8?B?bnREM0tRcVFDRng1ci9Gb3dsWWNtc3Z3cUpWc25rcE5MOUVpQ2QvZ3QyMDE0?= =?utf-8?B?cVg5ei9aeTh6TW5GVmdIYnQyM0ZzQ0NDTG9SRGlQN1loMml1NmdMVHQ0ZTlQ?= =?utf-8?B?d2d4R2Y3TTZrZ3c0b3hYL1RmcDYzcDM4dFRvWVYraG8xNmErN3VsR3IyR2xw?= =?utf-8?B?Y3lNUVl4SFFOV25CTFhiZHNCOERjN2ZMc3dnb1pueE0xRENOT2ErdjZKNlo1?= =?utf-8?B?Q243eEt4dUtTMzg1bk5pWE1uam5FVm81SFRFNlhBUGZVTzI0MEdpK0pRNlRr?= =?utf-8?B?aSsySUxQWnJHa0w5akdZcmtmejJSZmdUdXV6UDFtamZMd1g4YkIyZy9pVlRw?= =?utf-8?B?cDc4dVlQMjdBaUw1Q1Fab21NQktjTmMzQXNDakszck5EUXhnZ3JPZHVmUDV0?= =?utf-8?B?dU5oM2pudTd0WUN6TklnMTFqU0IxUkhtbXdtQ25jeFdVMXI4NnRPeWxLRGxp?= =?utf-8?B?V1RTdi9DK3MrSkNna0hpbkRsVHJ2bXVkbVBlWFdVYTVoVVR5UUY3V0RzcXRZ?= =?utf-8?B?UVBZYWkvVFlhU3h1bTR1N2ZEbHF2N2M3Zm8rYUtMSmY2ck5Zbksvc2IvSEpJ?= =?utf-8?B?TmRmNzZubnBaYjMrYnRFQmpqNnFGaU1mUnVtTDlvQ3hYbUZKMTRuNlhYdnBj?= =?utf-8?B?ZzZiMXc2M09rZ1M2QWpTdXFFOEU1emhkSE85d1ZRY0J4NEJtaVVYdythUVpr?= =?utf-8?B?bEIrNUJxbGhPRy93M25YZ0twUFVEMnZ4aGZjaUVlWENXeWZkMW1icm9RdTVa?= =?utf-8?B?S2NqK2lOMkdTUFJDMnI2U0RQVWp6eTg1a2J3bnArRHQyNUgwdXhDSkxvNnFW?= =?utf-8?B?MXZERlVoOUlrUzBxZTJwbUQrSFU4aEFCSmt5TjFuMzR0S1QzVVRhLzNZU2dF?= =?utf-8?B?UjVxZks5emxha3lTZHQ5Yk1PREhVUFdQc3d4aEM0d0l1ZU9uR2d5MGVsRUZL?= =?utf-8?B?TUxGTHI3RnN4WXZRaE8yWXFGT3dPV1R3NHpZamhtUUpKOWEyU25KSjYzOFBL?= =?utf-8?B?cUFJWFEzbnNHMjZBUElFQTJXbTMydE9QZHRJWUxod25JNC9iRHd5MzNOMXAw?= =?utf-8?B?bWFuOVQrSDgwQ0d3eVVqeXI3cDRVeG9FU2tsNTlCL3hIZlNHWVJ0VEd5TDMr?= =?utf-8?Q?IKf6ShuPJF4vEeUDh2bH35A=3D?= X-OriginatorOrg: efficios.com X-MS-Exchange-CrossTenant-Network-Message-Id: 053c006c-7739-42ac-53e9-08de163d0584 X-MS-Exchange-CrossTenant-AuthSource: YT2PR01MB9175.CANPRD01.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 Oct 2025 16:14:08.0894 (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: IESJqEeyjTLXK2xkPcDOo9Un0mHIwYS2Xq0akuGzxw8O35jePEpb9B5p8jg0E5iJPWd3RlZwTHsidnuc3yMz7I2DB1+mzpB4cptImXxnB/U= X-MS-Exchange-Transport-CrossTenantHeadersStamped: YT3PR01MB8356 On 2025-10-27 04:45, Thomas Gleixner wrote: > This results in the following improvements: Awesome! :-) Reviewed-by: Mathieu Desnoyers -- Mathieu Desnoyers EfficiOS Inc. https://www.efficios.com