From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) (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 2FA86380161 for ; Tue, 6 Jan 2026 18:06:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=205.220.165.32 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767722765; cv=fail; b=pmXq27NltUrSLtLLqMfXwaqHs7ewyTs6fEcDjnPfay54RelP+o3Br4hZzdlJSbQNgjNQLeO2M1RRTd7963dChzRyvaIqZepcTWarMXmWZItLd32rExgWWecyUzSVtQBnOBX02xPygXxFoieM0WOoDkg9R/YytPccXUhtX7U3uFY= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767722765; c=relaxed/simple; bh=vLC2CjZqEoFwxtw8RneoqKDNt8yILU6NhYOSAKLOhtw=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=IGQEu5kjxA99iDAOivfuyiE/+6z4CCkg+kBnE8lba2qZswr21SqeIpE5BXaDkN+VAgiw3+L93psU+b8aSQGXFWNHVN3MjdXrFgcUu9OHWNiTHJdWNxHWIv3IRQk4XFiDx5Ojj0G6TWm44t+H9tsD1ZEKYHrhM+pDlGmW94WYc8g= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com; spf=pass smtp.mailfrom=oracle.com; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b=Ln+JalJS; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b=RGcluPQm; arc=fail smtp.client-ip=205.220.165.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oracle.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="Ln+JalJS"; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b="RGcluPQm" Received: from pps.filterd (m0246627.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 606HpOQP4066373; Tue, 6 Jan 2026 18:05:32 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-type:date:from:in-reply-to:message-id:mime-version :references:subject:to; s=corp-2025-04-25; bh=ApJz7CTW1ATTAHXh1p VzDWlv2PcLueoc71CPqWVG19c=; b=Ln+JalJSW6XFdfe4Fvls38hkVxRfcuccbG YCk5S2wVWTxGdxKTRwOiwPBacNP2b0ibT5oqdK7a6rc1+ny5LpITx247mPtGmJPf Mkqts1IRLkf6yXal1VC73kwHRyHhSnNlG7PCOgcpsqD0R2dWNNW/OO6XPyyBEuSV 7N2AqZewSXMJ1jh8yBVLasJhsoo4rp/7E+f6mPVBtPYWL0pDaQr2l18b0UE1rgUj 0ZqeqGFLnBTzZVyRBWm62QT/zQQBN1rzek8ZeozO8IepxgXVGArKeGd8FFIttM2Z QYRKlrukqEKbY/1xaERwRelwKK8s4KZO1GUtUeCUeVgRZG/Ck+3w== Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.appoci.oracle.com [147.154.18.20]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 4bh75h810v-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 06 Jan 2026 18:05:32 +0000 (GMT) Received: from pps.filterd (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 606Gnna3030764; Tue, 6 Jan 2026 18:05:31 GMT Received: from co1pr03cu002.outbound.protection.outlook.com (mail-westus2azon11010010.outbound.protection.outlook.com [52.101.46.10]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 4besjcww20-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 06 Jan 2026 18:05:31 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=xkyIEUFEO+OfqUCOzM1aBHlDh4J+mJgFuwHuTsP5X+kP1vjfNUREHjsHNVfYwn4/fU9R0kA/CoXsKCgK2o0Pl3/3FpgTeRGEAj47yeS5j/QuGhCMfxJrL4QXlQtNBZ9RxF8yIgsVmShdz4BillFrvYUvyNAHp5sRzVF/OObJCBgeuR1cbm2s9zoLsfUKVq061//W2uVbuH/zodNzS5AEfa+dSmYWtRMlZMOYsrdLM+pVfKTuutf9EYRQ+wm110MLRuu5cEZLV0GpBxM/nQuUKEDgGZ6gwGuNWe+unhsIMXfAPbZZFooHRJkICcg9tCzDQXt52CrT/ZFk6MiKLQtc+A== 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=ApJz7CTW1ATTAHXh1pVzDWlv2PcLueoc71CPqWVG19c=; b=kmoJBUCLdRWM5+s7TehrxW0YING3Z5nbcLbqZxb54nsurh70uUQg5Z6J2IsWYg1LQqEEbxqpZk3xo6iBzGGxHgXSblYA4AmAqiqz4cSo6KljNhUjC5k1Vmzjaq3I2azA+M0sqWa4YOSKCQnRxRIW6zjyBXSE3imNf9taRxqstmJKMwcxF7ca/PZciXuf9GQAi90KgXhZ6HEnIy8HqR5t4bAhAI5qgRhlOerddYkl3pmmFpXwsn3peMfPqQNTXPOYk3aormryVJBUeK4o0s3/1knU4Ec4GI0sSWHD6HuuvvWD/NCNN6ol+sj669hyL8PDBGMg2K0DcSobeLZ3WWVBpA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=ApJz7CTW1ATTAHXh1pVzDWlv2PcLueoc71CPqWVG19c=; b=RGcluPQmpaY3xDWEAj0vHjaJylny0oBByv1WwJjvEi3AS8JerMledQQy5CwiBOTbhsSs7KXhvUpEwdBJGpzeRKNCgoN5ISP0I/gjsEJLqB0rneT2KCuvQtFOB/suDmAxS2BK3a9OLyGIVPUTlmW3Bywby6f3pinzMQG6SozLJ2U= Received: from DM4PR10MB8218.namprd10.prod.outlook.com (2603:10b6:8:1cc::16) by SJ0PR10MB4782.namprd10.prod.outlook.com (2603:10b6:a03:2dc::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9499.2; Tue, 6 Jan 2026 18:05:26 +0000 Received: from DM4PR10MB8218.namprd10.prod.outlook.com ([fe80::f3ea:674e:7f2e:b711]) by DM4PR10MB8218.namprd10.prod.outlook.com ([fe80::f3ea:674e:7f2e:b711%6]) with mapi id 15.20.9478.004; Tue, 6 Jan 2026 18:05:26 +0000 Date: Tue, 6 Jan 2026 18:05:28 +0000 From: Lorenzo Stoakes To: "Paul E. McKenney" Cc: Gabriele Paoloni , Steven Rostedt , Kate Stewart , Chuck Wolber , "Julia.Lawall@inria.fr" , Dmitry Vyukov , Mark Rutland , Thomas Gleixner , Shuah Khan , linux-kernel@vger.kernel.org Subject: Re: Follow-up on Linux-kernel code accessibility Message-ID: References: <90d56d30-232d-4930-ad9f-5aebade7cdf2@paulmck-laptop> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <90d56d30-232d-4930-ad9f-5aebade7cdf2@paulmck-laptop> X-ClientProxiedBy: LO4P265CA0067.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:2af::17) To DM4PR10MB8218.namprd10.prod.outlook.com (2603:10b6:8:1cc::16) 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: DM4PR10MB8218:EE_|SJ0PR10MB4782:EE_ X-MS-Office365-Filtering-Correlation-Id: 177ee27a-be12-489a-ff6d-08de4d4e2b40 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|7416014|376014|366016; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?Y9/ER7GP0XO7mQpSACg0vTWGbxpQcHu0clbLkGYbR4Hx6Gho5pwWNcog/tB+?= =?us-ascii?Q?X3L8LkVByocpAnzrRlMLvXt7pWrtmWAbxXrafpAREcaDNOL4X+AjxS75t4aS?= =?us-ascii?Q?RHUCcZl2Qi5dEB7ZLh5lAuXaHEOEqKSI+D5XJLETkWiMkw38GHrwaAEo4vS7?= =?us-ascii?Q?5gG0+UKBpmxZ8UBQnysZ8RgQ9c63mx/vI56m4X6vnFdGkWQ6IT2l3iJip86F?= =?us-ascii?Q?ZkjeZllDUAZyxjeD7PZDcuLlKR3WpgDbjE/kOzi7MsRW7FS//mkpnTwx59md?= =?us-ascii?Q?zVxFrUmz5FHUUdtod8AQlUOmhPujcPN8gRPQw1iAODAqhxVhgegpRzVuVY6S?= =?us-ascii?Q?bB12Ipe0V7DSD3P7Cy62+XqNRvKbv3Y+rMN4iQoDFKKgHZ0UMBlM+RZPVYJM?= =?us-ascii?Q?NYH7mmVOLvzkJ2NC8jjwImHiX0RwdYyczmcWdbPHVJN6qnido1EAdsu56Ytl?= =?us-ascii?Q?LT89IbF34Tv/XCyOSiAXBJ4F6jO985WUEWmk/N2piPXW2ErI9KTPiSEhuqMN?= =?us-ascii?Q?feTV29wphIV0pIaapPi77CXAqC9PozLTTUR2ErYAUCIwr9mFEYv4487xGKB8?= =?us-ascii?Q?ti4a8XInIxaEkWM8xyayeS6QlMR5MpuaeA8ZytgdNHIVxem3/HIJEwRJP7Fl?= =?us-ascii?Q?cQlQd95WgwwC8dZsXXEprlJ3fK+5n30GlGHdBagremd478MAfI8XAOoBMfWL?= =?us-ascii?Q?pnou5bJ0nmKNw1R1x3nN8TJLkN/u33EjzO2AGzmTXlIjYlUvvYqT/1T7JYWu?= =?us-ascii?Q?6f6CkBOhcl2VG7/UGoSRYuWjLCgypyYtYbb1PaaoVKVZimYLwBWR0yxjnBB/?= =?us-ascii?Q?oHzF8bkl4xgVpj75oaLuUb+wkW4NEsHy6HydEOlJIf3/wtWFfloaLqy+hGYk?= =?us-ascii?Q?NZ31nFO7dK5O4DXVYZu/Sj3pypzywBLeZPmaeKjY/PLP99nby72liHfKdpe6?= =?us-ascii?Q?NwX0pmkJl7rO/gIZp8iWHBmA+LxFwjkoBFEJ8jvUYvDflkF7ydFrOGDOIwv7?= =?us-ascii?Q?WcEducVNkEYawp3Lo+VoQ97qSm5JQlaABMIefp5MZEwDXD0AVbXZFi+0PSNe?= =?us-ascii?Q?CR1uak8+6fF3Im3D1min0TgDHXqwn+bLoEvTmsavXFGjyK0O/cikjua873ak?= =?us-ascii?Q?8yPAwmpojNBwKvtVMG0o4GpbnjddgfqMfNJxOazaWA/vekg0nu0B8HiKuV+o?= =?us-ascii?Q?Mj1dh6lNTCVpPfpQz/VU817gCTTV0T7D8fhifgy2RtwIX5oLEuHaraE4Gwge?= =?us-ascii?Q?PLW7Y0wknXx/oPYAKedAyn/7dngKjSjfGS1txBoPrXJJ0dLvLFwXTidnveXJ?= =?us-ascii?Q?s3f2vXJ8yZMkblKTIZtgi0rKBmPYzQUZL2nXsXNv6ZjNSAuZQJ5oinM/zMty?= =?us-ascii?Q?XfJXvfDq3G26UTRs9nvBPhRaWAu1LxJ0X43z66B9iKw3Kie2XudShDKEGpHi?= =?us-ascii?Q?asJqaZTR7I1piORlDiccU3/7CWTjr6j1?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM4PR10MB8218.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(7416014)(376014)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?XVEkTrq3mZ2LbmpzkqrDPoeoaeYtOU90/CvjXg9eOiPvd2Fz8uVYdkWwPhrq?= =?us-ascii?Q?/6a1rrsPCSAxdil5M/ZbTJhyyNz/vO5bOZSq2eJMgOUEWym4kAYvX/133Fj+?= =?us-ascii?Q?DBy8zLN82y6nNK1WchFPAYrKOa7gBHc0n6FIukxEW9eznH1V6UDnmgfQBWJ8?= =?us-ascii?Q?yjL4/ofiBX7eBcRT+upynuwaqq83TMaopcIkelLzraYWwakgOsFcOECJFTSe?= =?us-ascii?Q?GeCWBALO5k5Lq8qffu5yZqd1K1n+sH82uRYZIX1h4AsEoKogT8Buqse20f6z?= =?us-ascii?Q?OEMruRxh8FVL3YWqMNvOwi983jmjq7lxZJLUR+VtDifFNRXTmffT1zRzJQ5k?= =?us-ascii?Q?HHER/SbpjTCok07IGC6g5zAZDiGObJCtKjyfOVoGMFzJbI5ypeDBdpC2hlvl?= =?us-ascii?Q?XXpV93AtlXyivyRfyJNI3TakPBiCiIsv4UKBv0vVe6cgxsRCHidPR4uNW6hT?= =?us-ascii?Q?USigoShsgMyIAhzo9MmiD7s+UB8wPS/ccPhvWYfM/BxYcyJ4b/Kxg/TXIJeh?= =?us-ascii?Q?htzuUzC5mVOffCqG//sfUISSMEB6a7sh6OIT8jLJGBkJi2GxHKIgLAM3lJ4+?= =?us-ascii?Q?DkygEQ/fMTRMr2/W6hAepYa+UIulfqBhy56p6GPjqoeyVtE2g7KtW09YOlhT?= =?us-ascii?Q?TDTs0+yn7V2f1OSS+m/bNdZ6UtS5yEDSrPLRDUKo9jPtxOYdrMvrtVHqtJCr?= =?us-ascii?Q?9rtoPeDCeqWX5ZImIvVhFFS8XJZFJIFHD2r00jEqvHbEDwzI7MguZMtFcJ0G?= =?us-ascii?Q?4Hhr4pLE7QydATzyPqiPzEGcJMUkrsdkoTMyA1WxWmcudqhdEcBrh2FQnuSr?= =?us-ascii?Q?YVhrgJiMchEH4lStTvvgDT7908fGnm3KW8BhEHbrR3wiPad9gwIVEKrvocof?= =?us-ascii?Q?XQO7SiTj+vam3qb8X3ByudyKnry9fZX65vG4L1jparc4GbJ3UxvJ9RpgS/s6?= =?us-ascii?Q?GFN+WfW3DiFF/cZotKL4u7xox53P6OAiv5TER68+J7/LsjpReaYKejoddGS/?= =?us-ascii?Q?ALryLLNMXLLEiJYNRMxIWMQJtw3zWxCJGHYDYswzDDASQx3nSUd09td13yK5?= =?us-ascii?Q?xKw1BCYCjVLFuwzxfsfXJONowHtYG2IU04HGRppeWL0SSfe2tbVWwkc4r0B/?= =?us-ascii?Q?cvNpnKkXINviRS0SX9aL581ADRsxBQw9mf3jUpELdOI+2dlJ+EZoVPim+/wT?= =?us-ascii?Q?nvYUTi8UjHIxRFuoZSgDqo1qUCmF11mj6ZIrTgeUkQIk56x7CtnO0Rv2Ixxy?= =?us-ascii?Q?5snCpaI/JXEjAKn9+rIeUsjc+N9JCQ4LDEZpD+E27BgsPMblJmkwJUjy2hSA?= =?us-ascii?Q?5CIN+pXqDfY6O8VoqS4AMMsyWPPFOXuuJqWjFECRyjsLGsTNu09nPiMCO5iH?= =?us-ascii?Q?K9lyJfS1JG3xksxSwMhGkEKvec+wRnKBQ9YyQY/RurJcFYTW46uxDpVByw8X?= =?us-ascii?Q?gPMWYutfDdMhKuKrQOdg8N4+yngk3ACHohKHn1GQ8P7oAuE5A+l5ise7uZCv?= =?us-ascii?Q?aOXOOwnPsnaeFWmYAiJZ5Sky7ebdtREYtUQJBjELVJNIENCjCSaXM8lBtKHn?= =?us-ascii?Q?CjfkInXK7GxIboHGmLt1ehs+ekb38wf/jiKUqWb5OnnsIgRDR5iu2YEIhZB0?= =?us-ascii?Q?N4PAI/wteGPT19E1UhR7xtSPvl4g0RI2RDR9Qg93Ng2+1uWLWuLT/K2dULp7?= =?us-ascii?Q?e2wyuUlGKei/PtIjMEfywbqWf/NJiIH018b3GU0tHCd9nivUEk6x/7L9dyoz?= =?us-ascii?Q?h2VSVcG2b1FOK4zN3MYhpvqWL8/pyGA=3D?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: Vkk2h0oY43eL7a0wIl7SV+mmOrlzrd4jz6dNVT61Gzf9nutyMY7vgdQ+QPbc5G0g2MnYvlWHkcCucSaAWEnYwDIYbNJwgYDg3HH36FLeO4Lp6/kfc8k5sVDprXpib6tNGdSxzetrrtKvFqW9Tu//ssrHpxSOqaFyv8OgGaHbY7HOacw0OYTugi6HY9qlFG9eF68tpZEFmal5dNNZuEz/GaFlFvJBeSJpTJtuZCb4B3soL3Z4Rim71Ofr/FYsRDFCRDTXOFJmZF906ztVou/55VzFlypOBCtvKviU8Cu92jogh9gl5p7FXF0zhysKbrYazvvMQqW7CCnyQCuBgSvuDS1/w9i5yDfSjfrWDqT+roEmYbAXe7ZwRcv9Ff1RDEh4fYfydPJ2NHd3hW/s54oAOghwBTDy7yUWoBE2FfDxvaZxqU2AMgPRkMyVLO/9dUes8r1HSoHSPRD+eG19hwCNw7wxDnBnK/OgvDy11IvaMqrkkd/pHVzgOPpKvBwIkQiOCi22+MKY2J4wrpmkZli2e9tsw78xLJK68zTCbkBYm12VvV0BdnyuXtqv4emqHz0bUUUyJbEeEnIcQBh2j4Pdg2v/1B8gwkpLHo8Hj5K3TVQ= X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: 177ee27a-be12-489a-ff6d-08de4d4e2b40 X-MS-Exchange-CrossTenant-AuthSource: DM4PR10MB8218.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Jan 2026 18:05:26.2992 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: S9a9G3XOqOx1G3g69XBt7aeNL8aHGKLCk19CdNXZe+7+nQs/rkfC9WR6W26RAAE5+Vd3Ub8VhmFxx3um3fI/DS5Rw3QUovGcqM6eekJW2OM= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR10MB4782 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.9,FMLib:17.12.100.49 definitions=2026-01-06_01,2026-01-06_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 phishscore=0 adultscore=0 malwarescore=0 suspectscore=0 mlxscore=0 spamscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2512120000 definitions=main-2601060157 X-Authority-Analysis: v=2.4 cv=evLSD4pX c=1 sm=1 tr=0 ts=695d4eec b=1 cx=c_pps a=e1sVV491RgrpLwSTMOnk8w==:117 a=e1sVV491RgrpLwSTMOnk8w==:17 a=6eWqkTHjU83fiwn7nKZWdM+Sl24=:19 a=z/mQ4Ysz8XfWz/Q5cLBRGdckG28=:19 a=lCpzRmAYbLLaTzLvsPZ7Mbvzbb8=:19 a=xqWC_Br6kY4A:10 a=kj9zAlcOel0A:10 a=vUbySO9Y5rIA:10 a=GoEa3M9JfhUA:10 a=VkNPw1HP01LnGYTKEx00:22 a=JaRYSSNRvEQmyo3gHpoA:9 a=CjuIK1q_8ugA:10 cc=ntf awl=host:13654 X-Proofpoint-GUID: uB-gUwhewCbSwmL6JkQgMA84gutumTdb X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwMTA2MDE1NyBTYWx0ZWRfXzck5hNjqidoa rMVEnIxgyCV4YpQdJDIuj71Rot5CjD/6u3rMaaaaWVM+RjpmRPawo2/l9/VzsklFGObjVcXB6Yq 1Wimpo79pKmUoZmIAt2PRphfLuPDbITNwvHc3fNlfESKIo3OyZc9gHuRTlAqBrjK1Nyeqi5LXi9 wcx9GzW55bCDbXxw8ZFz4V1CWlrmTqO+Bc0k3loyg7rweoHrw9NFvyhKblFPJMxhQpv1mVhFBZi oyJpGIvrMHOWceJC5M3e4pZr+m37cRbkX0dwRNgSlD4v+wMIGSWYwP9wVZiLBaEs0Vwxa+Zb1Au pGIq44IsAxDyYn1u1bpTofNsAQ9hvOfsyA2Y8RZVAf4+h8S8rLdINzDwRIKhQpGaGstEnn5Io4U a48n5vHdc2dMMoVogwkSOBTgV4kElFOL+1uNwrhliZDmou0whUVYiFvNAqEE+vqyI4XKCO5i5IF O5XRQ5L5Qx+DGQ41JawTZnXC0rmGr9OR4Dawsdow= X-Proofpoint-ORIG-GUID: uB-gUwhewCbSwmL6JkQgMA84gutumTdb Sorry been on leave! Sorry to fork the thread but going to take me a while to catch up with it. On Thu, Dec 18, 2025 at 11:49:21AM -0800, Paul E. McKenney wrote: > Hello! > > Just following up on some Linux Plumbers Conference discussions on the > accessibility of Linux-kernel code to people ranging from novices to > the developers and maintainers of the code in question. I am adding > Lorenze on CC not because he was involved with these discussions (at > least as far as I know), but rather because I am using some of his work > in my follow-up analysis. > > The Linux kernel's mm system weighs in at about 200KLoC, and Lorenzo > wrote a book on its design that weighs in at about 1300 pages, or > about 150 LoC/page. This suggests that the Linux-kernel scheduler, > which weighs in at about 70KLoC and has similar heuristics/workload > challenges as does mm, would require a 430-page textbook to provide a > similar level of design detail. By this methodology, RCU would require > "only" 190 pages, presumably substituting its unfamiliarity for sched's > and mm's deeply heuristic and workload-dependent nature. Well - keep in mind my book explicitly and intentionally excludes a _great deal_ of topics (simply because I didn't have the time or capacity to cover more), and even when exploring the code, I made liberal use of 'X is out of scope' here to a. make it readable without being distracted constantly, and b. again for time/capacity reasons. And of course, I focused on only one architecture for anything arch-specific (x86-64) with similar excuses^Wreasoning so there's that as a multiplier too. Overall I suspect what I cover is really only 10% of mm, as well or not otherwise as I did. So I'd x10 the LoC there ;) > > Sadly, this data does not support the hypothesis that we can create > comments that will provide understanding to people taking random dives > into the Linux kernel's source code. In contrast to code that is closely > associated with a specific type of mechanical device, Linux-kernel > code requires the reader to possess a great deal of abstract and global > conceptual/workload information. > > This is not to say that the Linux kernel's internal documentation > (including its comments) cannot or should not be improved. > They clearly should. It instead means that a necessary part of any > instant-understanding methodology for the Linux kernel include active > software assistance, for example, Anthropic's Claude LLM or IBM's (rather > older but less readily accessible) Analysis and Renovation Catalyst (ARC). > I am not denigrating other options, but rather restricting myself to > tools with which I have personal experience. In my view AI is useful in the hands of an expert who can determine when it tells the truth or not. So you have a catch-22 there that's unresolvable by such tooling in my opinion, and developers relying on that from the start are likely to not have the right mental muscles exercised in my opinion. I think there's definitely a place for AI, but I feel like this is not it. And I think we'd do people a disservice by suggesting it. A big idea in my book is to get people familiar with the concepts and the code presented together so they can end up reading the code and understanding it on the basis of the book having tied the two together and shown 'hey it's not so bad you can extract meaning from this!' That way, they can take the inevitably out of date contents and update to the latest kernel with the skills developed (and of course many of the concepts will remain valid). > > And one reason for continued but reasonable emphasis on internal > documentation, including comments, is that the aforementioned tools > ingest that documentation. ;-) > > Thoughts? > > And in the meantime, happy holidays for those celebrating them! > > Thanx, Paul Cheers, Lorenzo