From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 48C38CA0FFE for ; Tue, 2 Sep 2025 13:42:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A29128E0010; Tue, 2 Sep 2025 09:42:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9D9378E0002; Tue, 2 Sep 2025 09:42:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 879EB8E0010; Tue, 2 Sep 2025 09:42:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 7133B8E0002 for ; Tue, 2 Sep 2025 09:42:13 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 1E27A1184AE for ; Tue, 2 Sep 2025 13:42:13 +0000 (UTC) X-FDA: 83844424146.01.067C743 Received: from NAM04-BN8-obe.outbound.protection.outlook.com (mail-bn8nam04on2058.outbound.protection.outlook.com [40.107.100.58]) by imf12.hostedemail.com (Postfix) with ESMTP id 6CE2E40003 for ; Tue, 2 Sep 2025 13:42:10 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b="i/4ammBC"; spf=pass (imf12.hostedemail.com: domain of jgg@nvidia.com designates 40.107.100.58 as permitted sender) smtp.mailfrom=jgg@nvidia.com; dmarc=pass (policy=reject) header.from=nvidia.com; arc=pass ("microsoft.com:s=arcselector10001:i=1") ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1756820530; a=rsa-sha256; cv=pass; b=ElmJzzJr2R20/vJwQS8VqAC+2zHuMGdcMAFBKRr06dCIwvgX/LNHWN8MXZAnkGymprZLQa WORBWR9vKTwtcoyXAOFkj6MKk6UTuf0EtUd93xLZHkJDCfyKg0koE3gLyyW7StE9Htdwdk PVi7BcpwLw6DN4eaIxEdSRFoL2yfOuE= ARC-Authentication-Results: i=2; imf12.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b="i/4ammBC"; spf=pass (imf12.hostedemail.com: domain of jgg@nvidia.com designates 40.107.100.58 as permitted sender) smtp.mailfrom=jgg@nvidia.com; dmarc=pass (policy=reject) header.from=nvidia.com; arc=pass ("microsoft.com:s=arcselector10001:i=1") ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1756820530; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=sEybjIT39tfAtWyDWxHX2hIEW4WjU+uiXdQ+aAhfJdQ=; b=VHp9MM4C+l7sH4/jMwDgUqtzPtUNIwTpb45ZDu3QB3c98+8yfsWKfaYvg4xTCsTPqqNp9G H7gU9+JNGZceXX++pFGGem27F12Ld2gQGCpJu/rWuVUicIS5PyTXx0mf4tOvCjB0hMGFo1 vEyzO/dKhg7RY8EH1gNzFmJf/cAUIrM= ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=nnW8n3rLPvPGL9BcHZcpBj6vgZ4/3OyweZYcfHE6/gmH0nGwODp9dHLKMBhIqZ61NTIc7lezIrAIJ++uetdlOA2GT+6LT1qUV0aftXlmNZqXkemVulZbwftKDQ7uovweuOPRjEMTJ0mHcgUK7RgNka5PEYkD2OgftjgSDguWHFpIo5ZfrU1c9IcCZVT0Tx/Max35H3On6NXWMVv6ZJP5pOisMoOc7yAaebJTD0gPdhfF33eNpKkoKK64UNYyV8Z7TPLJzR9SgBY2SKKkVH2A2Ux6m8p0u+meKkgemrVk1cgPc9tL/8sOJHR3LL3qSme/1WGv8mDW1jwPNe06yP5Ndw== 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=sEybjIT39tfAtWyDWxHX2hIEW4WjU+uiXdQ+aAhfJdQ=; b=niIAe8UK5GocQkAv/8UZNHIaxc5ImaMtRxlx9CY056LnYJy4RY5qGODCKRhDsMR7RnJI+W62Z0oZy8uU2ZtgigVYC5GGiiA/1puCFQ5ziiNx6bWf/FxlrdGASpgPO/RMydWdf5yYjpHiaQJ7G5TbFcS6HqIo/rjVXejza1wghmJ3MFBIj4/r9Cx6zPw2Q8hY6zOzagWufFylHJbODjgm7rVwR6UGzdeQr8Rl4jQemPaCpJfIX5J5IvcNRZyTPCOUZvQEJjrm2tgiGmjLO5hyNQeUtBJjW1PKTnITB8eOeQtNozZd1y/iTnqlUUiezP3unRekukmS/IF+iK+0IYkHww== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=sEybjIT39tfAtWyDWxHX2hIEW4WjU+uiXdQ+aAhfJdQ=; b=i/4ammBChnBbQXtOn0lrXvWcMtGUS1zrL7gjwANl67rCPhjkMvHUMPisFIjttKLK9eAauFH8r2Rng6glCW7f6aOb5c/hSgSCFb8i5XFeUNJs/Mlh3eUrasZ8RzgbND8IEIRW76Zf6FP4ObgqmfTAP+91RLnkxOZogxMiebDrIBmetzjyhWrYq318lTxv2lW76lVavoC+EQgT5FWEewI5KhJ7ukMkLtBA0WYQFck1ihUmeXjzf1S7j5aqnw1ZxAb+7TdcsznjTL8QkUNw4ep8S1hTCAJJH14aI7CpR1pTVs6yZgIKpDs9Fse85/X+bC4vx8MIRJVEPjjk9dDf31XTOw== Received: from CH3PR12MB8659.namprd12.prod.outlook.com (2603:10b6:610:17c::13) by SJ0PR12MB7007.namprd12.prod.outlook.com (2603:10b6:a03:486::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9073.27; Tue, 2 Sep 2025 13:41:57 +0000 Received: from CH3PR12MB8659.namprd12.prod.outlook.com ([fe80::6eb6:7d37:7b4b:1732]) by CH3PR12MB8659.namprd12.prod.outlook.com ([fe80::6eb6:7d37:7b4b:1732%4]) with mapi id 15.20.9073.026; Tue, 2 Sep 2025 13:41:57 +0000 Date: Tue, 2 Sep 2025 10:41:56 -0300 From: Jason Gunthorpe To: Chris Li Cc: Pasha Tatashin , pratyush@kernel.org, jasonmiu@google.com, graf@amazon.com, changyuanl@google.com, rppt@kernel.org, dmatlack@google.com, rientjes@google.com, corbet@lwn.net, rdunlap@infradead.org, ilpo.jarvinen@linux.intel.com, kanie@linux.alibaba.com, ojeda@kernel.org, aliceryhl@google.com, masahiroy@kernel.org, akpm@linux-foundation.org, tj@kernel.org, yoann.congal@smile.fr, mmaurer@google.com, roman.gushchin@linux.dev, chenridong@huawei.com, axboe@kernel.dk, mark.rutland@arm.com, jannh@google.com, vincent.guittot@linaro.org, hannes@cmpxchg.org, dan.j.williams@intel.com, david@redhat.com, joel.granados@kernel.org, rostedt@goodmis.org, anna.schumaker@oracle.com, song@kernel.org, zhangguopeng@kylinos.cn, linux@weissschuh.net, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, gregkh@linuxfoundation.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, rafael@kernel.org, dakr@kernel.org, bartosz.golaszewski@linaro.org, cw00.choi@samsung.com, myungjoo.ham@samsung.com, yesanishhere@gmail.com, Jonathan.Cameron@huawei.com, quic_zijuhu@quicinc.com, aleksander.lobakin@intel.com, ira.weiny@intel.com, andriy.shevchenko@linux.intel.com, leon@kernel.org, lukas@wunner.de, bhelgaas@google.com, wagi@kernel.org, djeffery@redhat.com, stuart.w.hayes@gmail.com, ptyadav@amazon.de, lennart@poettering.net, brauner@kernel.org, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, saeedm@nvidia.com, ajayachandra@nvidia.com, parav@nvidia.com, leonro@nvidia.com, witu@nvidia.com Subject: Re: [PATCH v3 29/30] luo: allow preserving memfd Message-ID: <20250902134156.GM186519@nvidia.com> References: <20250807014442.3829950-1-pasha.tatashin@soleen.com> <20250807014442.3829950-30-pasha.tatashin@soleen.com> <20250826162019.GD2130239@nvidia.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: YT4PR01CA0178.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b01:110::22) To CH3PR12MB8659.namprd12.prod.outlook.com (2603:10b6:610:17c::13) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH3PR12MB8659:EE_|SJ0PR12MB7007:EE_ X-MS-Office365-Filtering-Correlation-Id: 6f298804-37d7-4bab-18a5-08ddea267c28 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|366016|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?5JxLcpjwR6GyS0yueaHCQW0qPezbGnIap2B3D175k2kiiFXO2F1cQk2lecM4?= =?us-ascii?Q?chETL4PPcJWU+Et1rsOMO0WMR2u3iVjQt/2o9wzZH7tsgy81Ia4ZAGQ8Q8AS?= =?us-ascii?Q?/HwvVLeJhCBr2mCOHuSRJdXWekJV+2GG+aL9gXgg3jroQ/18hNu/dqQSbNLz?= =?us-ascii?Q?TgHwGNegSOJKHij8wJ6OTehszTLgCWg0PqbYXYxS/c/naF6UplgCubcd8vPc?= =?us-ascii?Q?PxSSp8NgPG9iXloSEIuqHH/6wSySxHLn2dxRRk70t5U1u3wVUre8sVLIhZTP?= =?us-ascii?Q?w2HfDVp5d6oC9mIbNUmbWyj0Bgn0kVPWZ7akKiBrJf/SgIL8I+F7ASzVr+La?= =?us-ascii?Q?tGIzCkKxwgc6m3izmOjxpZqU33MLHhvFA3ZPy6Uxq5F5Q6++/rpCaomcZXWz?= =?us-ascii?Q?oUmoTOvRx0R00ir0bm+gU7ai9ZN7PBcvblORGM4efPT3jmWq2bBSUG44eijo?= =?us-ascii?Q?fZgBAvTqsLWuoijkiNll+D/rMKpd7lu7L7BqQckvSUsnCXqY6tI0nMWDkSKN?= =?us-ascii?Q?ndjASN1LlE1KV5tzhxY9Qqvg6dhzV0fbbyxRDB5qsfR7bYt8UOXT/+3mqNMz?= =?us-ascii?Q?0A3482g6m8hPVngZbGCHulF593p1qSXOLXnYIqNhTtlq+7mI4ef5b+8eYYg4?= =?us-ascii?Q?xrB3yxfWYpqlZPd3DcWuGVU8h8igp0S/seKqIxR+C5c+VJev+49NG3XgeS83?= =?us-ascii?Q?tnyEVgW89mRY10cU3LugbOPNGIMjJpUSgNjYmkCV5SP899vFThyKNG+P+B7S?= =?us-ascii?Q?OfIvmqbulb34UGq2f1pqHO4SIROrHey/2RCkW82gePJzQQdt9kjrrWEVQY36?= =?us-ascii?Q?bB5tt5J8JWh86lcN4J20ddfq/8map3wdEFebuUVZxFPWDjEwymn30xLh/0xo?= =?us-ascii?Q?RnSAJYT81s6g8JRXjn+Q/LXHR0UlHzibxOce+Dzbz/rdvrXa1uIPtGQ5Y0Xq?= =?us-ascii?Q?G68/DSwOJtKt1aNRfA4O7Y2lyyrM79cPynkxoF2amWa52ENdoqln1AhEOZ6A?= =?us-ascii?Q?qXCUoY7CCnPLVU7fi/6TFhAVhLGIugBajEaY0pOymmersXdZYFGIJ/EfV+NR?= =?us-ascii?Q?wJnxw5M1rTp1/4i7D4BrrX/UP/nKi4/SQwmBP2bHEbz/SgiNKjpP4J5xK04p?= =?us-ascii?Q?cTOeD5WVHVT2S5YfqhE31Hwh5z0IcgpszB4LQVRYL1d3Q+Ast2yBxXrDfhc6?= =?us-ascii?Q?A1trDAofxtRe6HctLvTop6jZass9xdr3Eik50mlTeQfUQtNAwdZyoAzAlvRL?= =?us-ascii?Q?0rbrG3FaD2M3/80FiYmX0/+53RdJCpYfJ+5Yl7sMSQ7lcP3QSIlXj6OqKOpx?= =?us-ascii?Q?0frXUSYHy7aUkhwRra0BuQcA2WuB402QyPioQXThBqQC5aUU3BHlcVCFKqS9?= =?us-ascii?Q?x/3scpVpe5cWdMdRPxqFnK3mHQ4DLXVOcB8Tbz7i7wYi1GpVyXvorFaHhVBx?= =?us-ascii?Q?KeeSt1DZQ3E=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CH3PR12MB8659.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(366016)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?2jL1gIG+SvQNrr2tnbrZBk8GSdHeAcsd1gUKaeUARZ9PMUpQbmqlih4k8c2d?= =?us-ascii?Q?lQRbmlioWdzOugdIWYTSkfkZanUHD4MrO9XW6H4bh60n4jI3hNCWLLRizKHA?= =?us-ascii?Q?6AAJrdUJJ9PkBgAdIur6deOijCEVTRbhbgOZ369wdAl8Nag85wQVRc0x2Btx?= =?us-ascii?Q?+/tqkLeSwvTdMI2bdJu/MjxbZp3ZL6K6nIpebZkkzfZ15eDJ9DnWf/SNmejA?= =?us-ascii?Q?CtJDahXG/8AZTZlsQGNkfQvHSJvJXcz//4TQwL8OfhQoYjWZ0BTfX8AsO04M?= =?us-ascii?Q?nMjrY0HU02azXT9PkluPxWXZUieSb0Sl2NB3T7NpWNddvcRKxzpwFHvIHUqN?= =?us-ascii?Q?viaaMdRrq87x5Q3HQ5nWQXs4Ho0dNjereAg2Yq5zDRxokJjy6D2OBCE6+QbL?= =?us-ascii?Q?VlL9lknVjiOjPsyVq2UsLwZz0x0RIIBwJwqZiEbwPOeZYQ4AooVrXhm56vcz?= =?us-ascii?Q?2fysy+MPdIU2pt3x0axP9mAKSwVwGPptG4WOF7gaaJxgvP5lruGga7NJK5/A?= =?us-ascii?Q?TqP7f30tHcBffq2BkVR9wOWxPYhIClaViLST2RSOYcJYgjKMyG+uwg6zzCWf?= =?us-ascii?Q?pgFk+tYpzwl7maZbEFCdQIp8bbKd/oCVSFpPSA0JF9AFIpRa5DTF8d/TeUNd?= =?us-ascii?Q?eAgjalFRV6PK+Z7jOE7R2Be6bIxU4+H4X/4KT2moRfQ3mlkprKmugN9hZM7E?= =?us-ascii?Q?zwweDtAkzH61Mmg3NxXSpKJMLu3K5R2IyUL6ECoHWaVkOTVQVMUaL+MY+Ru0?= =?us-ascii?Q?fU7wS8fgG1IiAnJ2IrUFJ5wClV8lXEnjj1LcxBC+xK9AFLM/w/XU810dLXpE?= =?us-ascii?Q?4pXG4KJmamFlQnhb8HVtNsNXk+0JTfsgpGfbCFP65MEHDNGsyidNTasN9s7K?= =?us-ascii?Q?JawU++gJAdP7SsUkIKrj42ZpAMpEqpToPttt5BVWw7Wyagcl5W0A+cpSTmNB?= =?us-ascii?Q?auBQgFqq7+v8lPSd2+i8/ZEya1bFhwD4ap8SHCQwupNcnzZ2bnukOhmwx4es?= =?us-ascii?Q?YbrGTtpHUOyFBTbzs7+YGCYeQoTNI3Xie/T99KNqfatcxcaUrYNLLA0kPmPv?= =?us-ascii?Q?bwTPPgll/aISdZApdb1z/lromtAFjaGUe83JMjgnWzHTQysTxnk42lC2zuKl?= =?us-ascii?Q?fuPnqGdHBVZc8AmsKHBBu2OCUoXFOMy3v0ZSHntiC3tjtYjI2Lu0Ip7xcECL?= =?us-ascii?Q?CE9f7mQpFNgE1NffMLJn3bSluRjXoEff7ndlYLWHFZQDZq4cZj+x3D+xgCpN?= =?us-ascii?Q?CZW48MdJsCOUERGu1s6dJu7AbN4gndKxULQcu7g3en73Dpq61vMnUs5Onsf2?= =?us-ascii?Q?hAIKxVRMSOGuGYVqjIXBqcSKj/8eZ6V9wpsQG8Rwr/42kJz9cQcQvQ39ZlKg?= =?us-ascii?Q?VChKfCOU16dvQ9G8BTBKjuIL0ryuFoVJaPhlWSBKH/SI2dJqcOQsds8IwqtS?= =?us-ascii?Q?LvTvj+YeIlJ+J7oTn9W3eY/cTc6nBuUTqGqo8Ypxi0LuewCcqI4ztA1LhItQ?= =?us-ascii?Q?UmE+vQeBH4s9KE1ybbMflrocdZmTHcTMcvoMNc2dva+lFg1bkUo2HbpBEKqn?= =?us-ascii?Q?e/E14UaTejfS0KaqPv4=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 6f298804-37d7-4bab-18a5-08ddea267c28 X-MS-Exchange-CrossTenant-AuthSource: CH3PR12MB8659.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Sep 2025 13:41:57.1851 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 0+EziM7yE+WN5x5MIDcTALvON33cmOgQN5RzZGpzsS8mNN4G8gW+Gqc7PmrfPJYD X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR12MB7007 X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 6CE2E40003 X-Stat-Signature: 55czdc7jog4xjy4qxxd7qxw6ahu16mzi X-Rspam-User: X-HE-Tag: 1756820530-27314 X-HE-Meta: U2FsdGVkX1+7GSYyX2B99xo5u7RKWRubNcDqnNKKCOtAQCS/ejcq1SWtO7WsoFFJiE8FgmsJcUt513ty7J8PpvLliaV/C1NIOe+RiiyU9XCpz93r95qc8fOUQDJx1AAF7XERxgQRe3CzbRJU878S7NrGor4hAxjSHkR5MMi2ZcpbVYa45cmUJUMjcoGreD11Fc2lbciKhXAC0vs/H1Cbj8cHQLjahSaTwoCYUDA7kjV1ftgFyQj7stcR4l5csRTjtyY+xZFQIUJvBGVrdFfTVLqdz3fj/kbNbWo+1CrJCJZ2CvYvjbXCJbmrUk82uK5OJRQM0V4HwviHhWWw7sUbD171D2yOQqW/ViG3wCl2HxclKbK3ZTrtE+CysVVPV2wwifQqFC3HqRRaXl4QU2ghYlzkcq/Zj5C3bOeE8BONT3+/Gf0Tha9er618JO+N0gcMgMeK0UKdUZFVKR5dfIhD+l9HAE+kWGZ5TONSWgrKyktHq+nXYHYqTSuf0LQ/YGBk4OkIf0t8JG4SaImYQdTFv6oA2S2VKN89C/DytTEvUQeJoF5/iCzZKnRtpx+pLDfUr4aBi1BzMF8ZIJ8xzOt137PnmKlXk5/f6Yelag5Q7aEAqCpqAxgvZks7moA086tzVJJkmsdHMSeOqfduCQEvzpng/5zgvPI3vz3f2Hb5xmJTjY2WEon6Mifqc2bHBB1Q/XDxd6t1Ekpp+UnO6DT1Mn7xALReTFAPxPHXv3GTBS+lNUurk06PcRCV13bqGgx5JJJ0DoXOPMbMFT76FBp7Xl0Uin9vWosH4nOEcmFPzUA4Asd1pr8Chr7f+x5nvixEkT6mJcRHzQDSsWqnjxh5ZAEKKyMQx1pfTvS5lhi6e78HyvFrhEp6rlQQcqafrQtGQKXAodpjjdgT5/q/ELwe/J58QTqaoyZmHixhSDNZZYORRP4asyN5vGcp7xcNZxgCAlJpGcKxLvXxO8w1xrX /63uXF0C uilxZeDozdyTX9OWSDEXbZCU8i1VjjCJonX/z X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Fri, Aug 29, 2025 at 12:18:43PM -0700, Chris Li wrote: > Another idea is that having a middle layer manages the life cycle of > the reserved memory for you. Kind of like a slab allocator for the > preserved memory. If you want a slab allocator then I think you should make slab preservable.. Don't need more allocators :\ > Question: Do we have a matching FDT node to match the memfd C > structure hierarchy? Otherwise all the C struct will lump into one FDT > node. Maybe one FDT node for all C struct is fine. Then there is a > risk of overflowing the 4K buffer limit on the FDT node. I thought you were getting rid of FDT? My suggestion was to be taken as a FDT replacement.. You need some kind of hierarchy of identifiers, things like memfd should chain off some higher level luo object for a file descriptor. PCI should be the same, but not fd based. It may be that luo maintains some flat dictionary of string -> [object type, version, u64 ptr]* And if you want to serialize that the optimal path would be to have a vmalloc of all the strings and a vmalloc of the [] data, sort of like the kho array idea. > At this stage, do you see that exploring such a machine idea can be > beneficial or harmful to the project? If such an idea is considered > harmful, we should stop discussing such an idea at all. Go back to > building more batches of hand crafted screws, which are waiting by the > next critical component. I haven't heard a compelling idea that will obviously make things better.. Adding more layers and complexity is not better. Your BTF proposal doesn't seem to benifit memfd at all, it was focused on extracting data directly from an existing struct which I feel very strongly we should never do. The above dictionary, I also don't see how BTF helps. It is such a special encoding. Yes you could make some elaborate serialization infrastructure, like FDT, but we have all been saying FDT is too hard to use and too much code. I'm not sure I'm convinced there is really a better middle ground :\ IMHO if there is some way to improve this it still yet to be found, and I think we don't well understand what we need to serialize just yet. Smaller ideas like preserve the vmalloc will make big improvement already. Lets not race ahead until we understand the actual problem properly. Jason