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]) by smtp.lore.kernel.org (Postfix) with ESMTP id BCFC5C3DA42 for ; Wed, 10 Jul 2024 14:48:28 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 569916B00A1; Wed, 10 Jul 2024 10:48:28 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 523A36B00A2; Wed, 10 Jul 2024 10:48:28 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 36C076B00A3; Wed, 10 Jul 2024 10:48:28 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 17BA26B00A1 for ; Wed, 10 Jul 2024 10:48:28 -0400 (EDT) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id A27CAC0122 for ; Wed, 10 Jul 2024 14:48:27 +0000 (UTC) X-FDA: 82324123854.20.7D18C17 Received: from NAM12-MW2-obe.outbound.protection.outlook.com (mail-mw2nam12on2075.outbound.protection.outlook.com [40.107.244.75]) by imf25.hostedemail.com (Postfix) with ESMTP id 88E8AA0012 for ; Wed, 10 Jul 2024 14:48:24 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=amd.com header.s=selector1 header.b=bMrRdvzn; spf=pass (imf25.hostedemail.com: domain of Christian.Koenig@amd.com designates 40.107.244.75 as permitted sender) smtp.mailfrom=Christian.Koenig@amd.com; dmarc=pass (policy=quarantine) header.from=amd.com; arc=pass ("microsoft.com:s=arcselector9901:i=1") ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1720622862; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=7CBzI8yAb0Pn8ANnJ7k83L1gWb1Ok+HOBPvyMpbF+Tk=; b=mNOoLbfV4h5Mi3Yo5Ci1+4fO+pzbbqxAuZAjTkeawxy7SNlmd5WZYQiMj81c2a6ndcNKQU vj+ONbO9ghfMSen4pr4XlcjsBM2FOxglhOy8Ry4TIrN2XaTyxYF22yfCpIpMQTsG/nZidX 3iUMG+xYr46jx6nG7VppDG9x/OzDykw= ARC-Authentication-Results: i=2; imf25.hostedemail.com; dkim=pass header.d=amd.com header.s=selector1 header.b=bMrRdvzn; spf=pass (imf25.hostedemail.com: domain of Christian.Koenig@amd.com designates 40.107.244.75 as permitted sender) smtp.mailfrom=Christian.Koenig@amd.com; dmarc=pass (policy=quarantine) header.from=amd.com; arc=pass ("microsoft.com:s=arcselector9901:i=1") ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1720622862; a=rsa-sha256; cv=pass; b=zOPyEvKaqegjWCdk94ou1SmpqDJ18JIA/o9+Dkc4P8mg58hR72m9AxTNIC1Y1S/bawV7i2 HQ2O/wlAeLL5dBS2p690DzYJnN2Pgtufl84B2KMtXs1LWbBiQ1uLXKj0FupnajvVxJ3U3p NlhDTM7dR/XCJQqYXKfVFlrNl3X3fjM= ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=feWMJ0vZJDw4VCcR5wb5ms0E4VTL3qS01aXjZ29nL7qG6W8PRy3xq/cYI/AiajTCXm+Rc8Ir3qLBFLwt9JBNZ7k9HdWaf55nEZN19IXVxPTZbk/TFPUj9oKOVThqtutAxOsWedbDpFvNOlU88oHI3QsLWu8u+QAYzvHsdLOfm3NUfKaacPEsQQqe0cGF78j8z0gL5DAXX4pzSuFYmEMR4oERd9J+ymwjye1KG81SSihe8wYD30Jj9SOx00ieyw6cJR/3a5gk9CmvtIMm7O/MS0JdMR8HF27bVC1ZqCEiM3d0a1vMf7DgYqFhMJR29Mf+7lEnvYbA+qgEgnrZISuk6w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; 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=7CBzI8yAb0Pn8ANnJ7k83L1gWb1Ok+HOBPvyMpbF+Tk=; b=awTFJXgK0EaRpwg1q5g2EKHS7amdiNSq00VgjFq3Ieu1sCyIa4JhHDLzmPkamHQ1M045GLfo7qeEjELHpjQa7rU6KuMzgOqO26OmtDegDiG78prnUuMacpwXh0ntS8Aq+MCTJKvwZpmwacS53+R3gScTAJ0Um8pY/faaVTFCikK9OHykWToiGUUQoXVQ2x6SlXQLZbj0OBxkuY54FaHClXGmkh4dqpnhJgq8P6IZTnX+HFvm56hHSyX1xkaXlRQjHeF+Ql0L7RwgTECn7SFB1yuycGIL2sV5JjZ3oMzYehV7M4WOUyiTGOluOz5rw/lOk3fYWOS5yWPleoIgWkSu0Q== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=7CBzI8yAb0Pn8ANnJ7k83L1gWb1Ok+HOBPvyMpbF+Tk=; b=bMrRdvzndLQS3fqGB+V9FiDetekbdRfPB+N5J8jVHca+BHVYYMWLH3uM9PviDBEZeVrf9yFFod/SSuOXuBDFOGsfROKpSUulilzPCnF98SqaVULCAjjfyVFkt26VRjZhTvViDvPAQYXXzhl0cj4wV8npJ385l1u0yBkwE4IGxqc= Received: from SJ0PR12MB5673.namprd12.prod.outlook.com (2603:10b6:a03:42b::13) by SN7PR12MB6692.namprd12.prod.outlook.com (2603:10b6:806:270::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7741.35; Wed, 10 Jul 2024 14:48:17 +0000 Received: from SJ0PR12MB5673.namprd12.prod.outlook.com ([fe80::ec7a:dd71:9d6c:3062]) by SJ0PR12MB5673.namprd12.prod.outlook.com ([fe80::ec7a:dd71:9d6c:3062%3]) with mapi id 15.20.7741.027; Wed, 10 Jul 2024 14:48:16 +0000 Message-ID: <0393cf47-3fa2-4e32-8b3d-d5d5bdece298@amd.com> Date: Wed, 10 Jul 2024 16:48:07 +0200 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/2] Support direct I/O read and write for memory allocated by dmabuf To: Lei Liu , Sumit Semwal , Benjamin Gaignard , Brian Starkey , John Stultz , "T.J. Mercier" , Andrew Morton , David Hildenbrand , Matthew Wilcox , Muhammad Usama Anjum , Andrei Vagin , Ryan Roberts , Kefeng Wang , linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Daniel Vetter , "Vetter, Daniel" Cc: opensource.kernel@vivo.com References: <20240710135757.25786-1-liulei.rjpt@vivo.com> <5e5ee5d3-8a57-478a-9ce7-b40cab60b67d@amd.com> Content-Language: en-US From: =?UTF-8?Q?Christian_K=C3=B6nig?= In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: FR4P281CA0128.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:b9::17) To SJ0PR12MB5673.namprd12.prod.outlook.com (2603:10b6:a03:42b::13) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ0PR12MB5673:EE_|SN7PR12MB6692:EE_ X-MS-Office365-Filtering-Correlation-Id: 919a9205-e24c-4d81-eae1-08dca0ef553f X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|1800799024|366016|921020; X-Microsoft-Antispam-Message-Info: =?utf-8?B?anpiUmVQbmFJN2NnSG4vQmxBNi9DNWRTbTFrZThLcG5tMndrbEg2dlY0TGVq?= =?utf-8?B?VEt6eU50R1NFV0FYN3dXS3JrdDdUeXNESVN6dzAxNkhuWU9XbmR1dmlNTzNw?= =?utf-8?B?MGV0ckI0ZkJaR2FaRVl5RW9pMDBZZGF6K0hKKzFEaFBUZTBXY1VjekszTFhr?= =?utf-8?B?WlR2eTg5TDltNkJodHgwRXE3MUkza0dBdE1qUm9tSmFSZlp0aStwNGhWZ1Er?= =?utf-8?B?VEdxYVplM1U1cVZiYktQR01TTzNpdGd6bnl4Nk1RQlFSRDVQdlZXd0dEZDVz?= =?utf-8?B?bGRsR2t6RTVSeHJBS01kMGR6cEJWbnNSaUZ5VFZvRkFrUTNRcGlHcFlGNU1z?= =?utf-8?B?UEM2U0ticldUdG13MlB4dkJPZkMvbERUNEdmTWZuZkZiVnIwT1VVeVdTWFhp?= =?utf-8?B?WDIrSlhPQm1XcXl2bnBPWHNjblB2b0pFc2prQ0JnZEovZXhhQkhWcmNiSzVG?= =?utf-8?B?cmRjOE81WURRLy9SWmVNV0Q0RGVIU05aNVM2SDBjNVhvblhqTjJad2xxTkhV?= =?utf-8?B?RjRFSTVJQk4wc1hTTTdSdjRRZlR1WHpmVmY1YUdsRHJ6V2pVWGI0NVVDSHV6?= =?utf-8?B?cm9SNjJISHN3QzJ4YXYxU3BrbzU1RDNEVHhFZWZVMFIweGRkM2pzV1lTYjBX?= =?utf-8?B?d1ZXa3UraUpuZXduczVGZW9PdmpINVBjZ0JuS0ZQd2R1UUNGTTlLNmZ1T1li?= =?utf-8?B?V3E4SUNuTmMrVm44eWhUcjNsMGt2MWZPdkNacUhXUXp4Y2dOWkhZWjd3VEVQ?= =?utf-8?B?SjErSGJzWmVMQkgxTFlabnBZQUhQMUV0anRua2c5bDdKbWFhd290VXE2L0g4?= =?utf-8?B?QVJQdHR3VVkrTGdQRU4rTU9xSGdRRmVweEF1Y0JzdSs1T2diWVNKNHlsL05Z?= =?utf-8?B?Z3Rob09seUhLb2k0UUlMa2lQd3N5anc2VXNBSnczZkNnWTk0WWJoRXR4cncr?= =?utf-8?B?VXdHM0gzZ01KMlhXMjhpQ0JjRzZNZEZMYmZiY1Q4cUJiYmRvM0M4cmw3dE9K?= =?utf-8?B?Nkt2dGdvNXJVRnJ5TXFuSTdTakpMNVRMUHA4a0tmUytKRGNEcmJoUHVIeFMv?= =?utf-8?B?UThjYXIydUozK1RZRVVLMVh5UU4xSFlEVjVpK2ttbFJSTmd6b0d1S2Q0WTU1?= =?utf-8?B?MW9NYmlXYUgrcmROUUhxWk9CcXZPWW1GdWZZTFpoaEtSWGJWQlUrR0tDZHJK?= =?utf-8?B?MzM3LzhrWkkzL3ZVQk9yYVcyK2VsSm9hNGFteENocHFnd3ZHUXJnZDdPamg0?= =?utf-8?B?V0E0R0prLzQ3WHNzeHk0bm5VS3dzWkJKWmtFT1JzODNLTk1ucEFwSVc2UGtM?= =?utf-8?B?VFJjSGUwVWVHV0tpVE1ZbnFZYlorY1N1dXNSZlB3QVArOWxudUQ4MVBjVmNK?= =?utf-8?B?RHE0aDlJam1yQTlxUlk3ekt4TmZ1UWNZajRrUDR3RGpRQlVxNFk3TDJPajhR?= =?utf-8?B?eXhUV21DQkdUMWQ2VHd6T09yY2lZb3VKd1ptNlBMRGc3bjQyeWxsZWJSeVJy?= =?utf-8?B?ZmpCc1hYZHd6bHZGV0RnWFNwZnVUL1I3MWJvL3dqeDV2Y0x5S2Y5T0wyZzNR?= =?utf-8?B?U1VudURxWmRkNnB1eFNoWURCNmlnUlNVbVVpQ2JZUGVvQkhaTTIzbndrTFo4?= =?utf-8?B?TzBZSDBZTUhPNGZtb3pmR2Vsdm1RaE1DejAxdlRwS3AwSWVCVGZXcHd4b0p3?= =?utf-8?B?NkVPN2tqSDN4UVljbi8rUmg4dnhNRTQzTm9GTnJqZFJjWGQxcmtyRVVsU3c2?= =?utf-8?B?UVBjcXJZbGduUWhYSUxINlRsU2ZoR1VVTlQ0SWJMSjQwQnpUbXo4bENlVzZz?= =?utf-8?B?RGsyL1NHMVExY0VqTGhDbzUycXM3dytUT1NaeUxyL0FKeDNzUmJxdXpOY0RF?= =?utf-8?Q?QAqgtY+2W0Zoq?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:SJ0PR12MB5673.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(1800799024)(366016)(921020);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?U1VJRElDNGZHSjdtbUQrQUxNWHpaSlRoL2JBTjE5L2Fla09PRnhPamFDRlZI?= =?utf-8?B?UkwvT2JIMFExemwrOU5KRlUvN1hpSE1rOXc5R1hhZEFGdVV3Wlc1TGxpV0FX?= =?utf-8?B?WmtKaXBoeVRMcVRzTXpySHRabXlYRmFYdTg1MGQ3V1hmVlZNa043VndZN0Vq?= =?utf-8?B?WkczQ1ZUTEJ3Q2lrQ2Q4MW5OelBBUmI4VVJ1NFpCQjFWQXQ3VmRDZ0hrMDNU?= =?utf-8?B?SHM4elUxZmtQVWVLNDIvSk9tS1lodzZjbDFZb3ZXOVI2NzgrODhHeFFDeW1J?= =?utf-8?B?ZG53ZWJRdGdTV3hSTzAyQXJoM3didFV2TzRVT1Z5TzhVOHRsaldYMnBJbWQ3?= =?utf-8?B?ai9ja0FxTXluN0Y4VHpUa2YwalVONVhyWkRuQWdMOVp1cHlsSmVmRjhRUDRZ?= =?utf-8?B?MkFaRDJqZWNtZHZnQlJRMXdHUDV4TTlSd3N5RkFsQmRSb0phNVk0Zzhwa2FE?= =?utf-8?B?a0JmQUI3dlhqQkREMEk5LzNaQVNtaUdUSi9Ba1ZQRjZlR1B2dVNHejh2blVQ?= =?utf-8?B?TW5wSFE5cXpvWmF5ck1KQjVLQnpnMDAyVnFpU0R3bUlRN0tzQWlWNlFicTVQ?= =?utf-8?B?Q0tNOXp1Z2lhRjFMTitRWkpzSGFzMUtQdWtvTDh4aWQ1RnQxa2toUGFxWDJC?= =?utf-8?B?bm5POHdvZmpCNjBoMC94YXdxR3QwSU9tVnFGSHRkUUhibGhjNU1yYXJXdWtp?= =?utf-8?B?eE5pL2pUUVJYR3Vxa2NvbkhJVDZKQnZXQzhvb0lTWDVGRERXSjJvazFwR3FV?= =?utf-8?B?Nkhqd1lIQk0vT2JjT0ZBUFVCSlNvTEtnM0RvY0pHSDRBRnFZOWs4N0kxZlJ2?= =?utf-8?B?OEVjRWpPRnJZcjJ1WldCWkxmN0FVaFdHM3ZwME8vTk4vcU1rdVBucVdFQkdF?= =?utf-8?B?Z0xMZXE0YXBTRVJvZHYxRDVGU0hLQ000cjB6VGsyZHpzL0FIS2ZyWWN0YkQv?= =?utf-8?B?clkyeGIyeWN6WWpYOEZlc1EvYTZsM1V3eTRXdW53NWRPeHBNcUJhQXVaSTVT?= =?utf-8?B?VTR6THBVZi83UWdxSmdQa0l1NHdBRk52OHFnUVVnMktqRW1GTTRGT3dVWnNT?= =?utf-8?B?YlhBR1dFenhSc3hVVnJ1TGkrSVVtRXhBUGdod3E1WFBFeG5lR2dKanZ6R21w?= =?utf-8?B?VmVQb1ZxWHBZeWNhUHZvMW9nTXFwdjV2UDV1ck5Kb1RIQjRRUFAza1pEY1hw?= =?utf-8?B?RVpqMHZVbDZlL1gvaEx1Z0ZGaVpwNHFvTXFpVm1wVkhhSTRrSHF6VkxTSGJv?= =?utf-8?B?UUgwOURJTnY4REhvbEcxcW1RamswcHRzamFHZjJJOEl6WDArVFVqRlQxN3d0?= =?utf-8?B?MGhHMm1zeDZabSthYkFxUEs5STFRL0pCREZMT1JBQWF5OTFncVlra1F4bkdE?= =?utf-8?B?VWQvMzdSSHYvblhqOUtxcEJRS3VjUXlINGtWWlovb1VUZWxIYlk4K3R4TFEr?= =?utf-8?B?bkpIcFZxekExcWk5R2NBQnA3VU92WklMaC91U1pCL3ord0hKRysyTGViMWJo?= =?utf-8?B?WHVRSFpnV2N6L05PaCtlRDYvTDB6SE9GTkMrcWxURmF6aENuUFdUM01RZ0ps?= =?utf-8?B?eStaWjFleXRkcXJyWk1QdEJhNUdIN01iZEN0OER0RWp4OHl0R3pXRUdYWHBk?= =?utf-8?B?VGZKSXdnQ2NobSs5dlNPSXQzNEJEalQ4QnF1Nm1meHJlUS8yUW9wWktXZDFw?= =?utf-8?B?ZmFNL0pleldyUmlKaGxteUVYMGRVeFRiSVJvd3NsdEFlbk54TUlmTXBvMFhv?= =?utf-8?B?RHFobWp1Ni81ME9LL3d2Y05Rd3Q0VWIxcWRFNmlVdGI4WVg2K2l6b1RNa0FV?= =?utf-8?B?a1RiRUVJTnBNdWtJZ3I1UmNPUXJ1TVlFYXFEa0FKRkYzK0krZUVnZXovd1Mz?= =?utf-8?B?STdiOWNKRDV3bUgzaFJJazNha0I2RmlpbnF1aDkvYk5QQm5FOGVic1B2VWY5?= =?utf-8?B?RDhJdVc2VUNtR1AwTms1dEV1QWphNndRMjBLZU9NS3kwSUZQTTV4UWU3Z2dB?= =?utf-8?B?RjRUeEhkSWhtN0NXeENjSmV2T2RsZlZteWQ3TkVWVTJoNzY1SzZwT0J5cGhH?= =?utf-8?B?b2QrTkN0Z3dZQ3lYODJhWlF2NCtBSVg2eTBFK1RoVW84NmtBTzlaUlZVSUV6?= =?utf-8?Q?YavE=3D?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 919a9205-e24c-4d81-eae1-08dca0ef553f X-MS-Exchange-CrossTenant-AuthSource: SJ0PR12MB5673.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Jul 2024 14:48:16.8875 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: vQ/pWqGmU0i8YbcTENfdUQRo92/2Xdfz9Kgpg76Dks/i7Kz/GKXqb6mZIQOprJrR X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN7PR12MB6692 X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 88E8AA0012 X-Stat-Signature: 73s8w4u3z3dy8m1ynwcw1dikdt6gs8nm X-Rspam-User: X-HE-Tag: 1720622904-516118 X-HE-Meta: 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 kbeT+FHs v1ujQgAQUC4wITCO1N/eTiwN7uqzoHtxX3nq/gvn7O4y+VodCK4rw2vpw4dmnxdj4+3n8JD5TsIZXERXNJN/2wMNV9/4j6gSTGAjGCjFM3nXsfeRlrVKbuf7TbzI9vXQTOgSuvX7lK6yrTrd7Y13kRuL+pKvlpnWEImqZynSF2OAsfBXQbqJ+9It1JTqBIQ6OpDY7RJwqx07CJiAdIdMiZFvzTMgp3Hkq8uNzRXTmOBADGpjn1wUxVnpVqxbetGcboimXv05JPABFmHSBbx7QC5YVze+IA1Sd1jl2n7KCnf6mYqo= 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: Am 10.07.24 um 16:35 schrieb Lei Liu: > > 在 2024/7/10 22:14, Christian König 写道: >> Am 10.07.24 um 15:57 schrieb Lei Liu: >>> Use vm_insert_page to establish a mapping for the memory allocated >>> by dmabuf, thus supporting direct I/O read and write; and fix the >>> issue of incorrect memory statistics after mapping dmabuf memory. >> >> Well big NAK to that! Direct I/O is intentionally disabled on DMA-bufs. > > Hello! Could you explain why direct_io is disabled on DMABUF? Is there > any historical reason for this? It's basically one of the most fundamental design decision of DMA-Buf. The attachment/map/fence model DMA-buf uses is not really compatible with direct I/O on the underlying pages. >> >> We already discussed enforcing that in the DMA-buf framework and this >> patch probably means that we should really do that. >> >> Regards, >> Christian. > > Thank you for your response. With the application of AI large model > edgeification, we urgently need support for direct_io on DMABUF to > read some very large files. Do you have any new solutions or plans for > this? We have seen similar projects over the years and all of those turned out to be complete shipwrecks. There is currently a patch set under discussion to give the network subsystem DMA-buf support. If you are interest in network direct I/O that could help. Additional to that a lot of GPU drivers support userptr usages, e.g. to import malloced memory into the GPU driver. You can then also do direct I/O on that malloced memory and the kernel will enforce correct handling with the GPU driver through MMU notifiers. But as far as I know a general DMA-buf based solution isn't possible. Regards, Christian. > > Regards, > Lei Liu. > >> >>> >>> Lei Liu (2): >>>    mm: dmabuf_direct_io: Support direct_io for memory allocated by >>> dmabuf >>>    mm: dmabuf_direct_io: Fix memory statistics error for dmabuf >>> allocated >>>      memory with direct_io support >>> >>>   drivers/dma-buf/heaps/system_heap.c |  5 +++-- >>>   fs/proc/task_mmu.c                  |  8 +++++++- >>>   include/linux/mm.h                  |  1 + >>>   mm/memory.c                         | 15 ++++++++++----- >>>   mm/rmap.c                           |  9 +++++---- >>>   5 files changed, 26 insertions(+), 12 deletions(-) >>> >>