From nobody Thu Oct 2 14:25:57 2025 Received: from SN4PR2101CU001.outbound.protection.outlook.com (mail-southcentralusazon11012021.outbound.protection.outlook.com [40.93.195.21]) (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 DB0BA30C365 for ; Tue, 16 Sep 2025 12:22:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.93.195.21 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758025325; cv=fail; b=buKpA7HIo+X6rl8wA5/wfXfDzrmcrWvUGTJYtkKupLIGM3srO8rIyD7XYcVq6BD3k5CGAmqEskkKRCcvu/txoYxSaMJyJih3k3a0i7SZFXqyycbgR5S5zHO17UZCSxZ5nkdgawaKmfmf1/KfRU3b5pcDBPPkDMl0alrE6JvvsVM= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758025325; c=relaxed/simple; bh=/OdFUawXweSzTo7bt8brkYzPLc0Lx9iFgkZRvhb+25I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=jH/iWclHJyCOK5y3LmACn0Lnzh7RW7RH0aD4Sm39ieYzUfC2ygUcnm7bfPq/PnVpxu3IfQ1ppLPfBRKrk8rV6Lp7O+khLCUNyNCWP0We6n+dVOBhi2UpAIjY0aCU1AiFs+6e7L8b9uMpSaBrPMm7lRSmp7RDTnPJAXEAQfTEWPQ= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=TR85zBP+; arc=fail smtp.client-ip=40.93.195.21 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="TR85zBP+" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=KVFzRHyznrvl/W5p1WCC8/XUdGdn2Xt2bZl0UcPHDHjTQqThhTYJOi4zYXBxr4ZYCDToVBTsVPVESK2Ot1Hb3ZUFTMf3jyMBg+4iu4dpIb9FUMj8IOWYlVM4WE1Px2mnSjuTYKbUOBSVdmFULzRkYhxDHE5WLE+DBt8F8kqlVJ/zNX39FajYwc/iV3ohU6g3UN7Rq95vYF3hzk2VvbRfZXcEsPpq2YNA7nbP5YEB7QsDatjmkIupm05dRPqkEzzOjUsKm4KtCS7XXgSUqaExwzEv5bGy2F5POyqnrTxKMRr47UpabEBbRCXEtx6K8zTFRHnq0/IitRjMKeiCdxf4Dw== 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=Lf6Lo4GHmVHv45h8UNJrWYOxsmekted8s+hIRd5zl9Q=; b=MrQFQD/SFJVCG9HbOTE2QLCoARg8PXa6VOX1f+U2VEpv4mhw0bptnpkVtTd3kFMnGD4Hkn19awO9ntKxvuKbjCqG6EpiMgCAw0GFt1HVq1sTL1GY4WSgBzkS178O0d5DX6pDAZVYqRwLAcKBPJO3gkS51jLL2oIG8ho9JVIlvrlIQQiyPWtK3K+p5BGH/11m2fZcLzKHJiL7TEgyCUtvobFy+7FlPc6Q8WaG/kbWaL41W8xRVmzZkG/G5nQYDbnyhlWVAlqQl5uPO5fS97vZcObcACESZMJXOCMrcZilvTBNhcMEMkJbbxmE4EYqGg6XBEOH2qM6Rg76PDjX4fGeow== 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=Lf6Lo4GHmVHv45h8UNJrWYOxsmekted8s+hIRd5zl9Q=; b=TR85zBP+eHrteiL4u6IywoPq8iSeYxUp7eHuvoToTGx1/hU3pCzGzdQXRXfQkC67fLOJaXKCwaGDkluUz50xoD2/stYOlM2Bezvzor8ocnN6GINehKsZ90HrpVC7g/L1oPQFZ9uJWahKLRtur1X2oNE0ZGvpHTTw92VWURHtMNupUQmE3fyu9D+92W+JNFRwG0RsjsPBv8UuGrlNH2TiZzaDfRV+VxR1Ud4Pe8RqVup1oxn1/G7Nulqu3ER8FOsqDitTEh+ISYO/2bUdxX5BMZMlb+PcZI9wIVon9hEaR/UdvUQoRXv4f+p71iS4y/cAAxJLy3fxfNqUGI9EnmsIKw== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from PH8PR12MB7277.namprd12.prod.outlook.com (2603:10b6:510:223::13) by PH8PR12MB7373.namprd12.prod.outlook.com (2603:10b6:510:217::16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9094.22; Tue, 16 Sep 2025 12:21:56 +0000 Received: from PH8PR12MB7277.namprd12.prod.outlook.com ([fe80::3a4:70ea:ff05:1251]) by PH8PR12MB7277.namprd12.prod.outlook.com ([fe80::3a4:70ea:ff05:1251%7]) with mapi id 15.20.9115.018; Tue, 16 Sep 2025 12:21:56 +0000 From: Balbir Singh To: linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: damon@lists.linux.dev, dri-devel@lists.freedesktop.org, Balbir Singh , David Hildenbrand , Zi Yan , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Oscar Salvador , Lorenzo Stoakes , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lyude Paul , Danilo Krummrich , David Airlie , Simona Vetter , Ralph Campbell , =?UTF-8?q?Mika=20Penttil=C3=A4?= , Matthew Brost , Francois Dugast Subject: [v6 06/15] mm/migrate_device: implement THP migration of zone device pages Date: Tue, 16 Sep 2025 22:21:19 +1000 Message-ID: <20250916122128.2098535-7-balbirs@nvidia.com> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250916122128.2098535-1-balbirs@nvidia.com> References: <20250916122128.2098535-1-balbirs@nvidia.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: SJ0PR13CA0098.namprd13.prod.outlook.com (2603:10b6:a03:2c5::13) To PH8PR12MB7277.namprd12.prod.outlook.com (2603:10b6:510:223::13) 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: PH8PR12MB7277:EE_|PH8PR12MB7373:EE_ X-MS-Office365-Filtering-Correlation-Id: 238cf21b-67fd-4b43-5b55-08ddf51ba05f X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|376014|7416014|10070799003|366016; X-Microsoft-Antispam-Message-Info: =?utf-8?B?b2piVGx6aytDSE9jaExBSXpyUG1oMFVHdWc0WkVIZEJwZzR4VDhzSFVheC93?= =?utf-8?B?TjVDZnVPOGplcXdVYVBwMDZxZ1dadDNVeElaS0l3cUZnMndLRlZNa1cwc0Fo?= =?utf-8?B?UDFTeGJFTnc5Q2lKcnMyMzhVZEt1MFdOdG1JUzJjQ2lhSmwza0kyaytwT1lo?= =?utf-8?B?RGsrOGVuVHZ6b3Y3bjJKTWtzcVB4QUYrV0p5TXovNkl5cmxkSWRUUEhNZk1l?= =?utf-8?B?Y0xmVTQ1S0ZZWVVxZUZvRU00NlExUGZ1S1c1bVB4Y2FlMTBLTkp5WlV1aWFP?= =?utf-8?B?TndBclJsUjMvLzJuUlV2TlZVS3M0N0ZVUGdhN0RUWGpwU2EreWlGTGdDOVoy?= =?utf-8?B?VklGZzVLYlJIZVRsV04razZRWnkzUzJRSStGc1U3Ri9MQWF0WlY4LzN6MjQx?= =?utf-8?B?bnFRVFdXaHdvWEJSanVtbnZLWXozQ1FFK2dWdDY0NHFRcTBYYTVaakZ0UmUz?= =?utf-8?B?bWdLaVlkMi9QOExTQ21sUzA0cmJvT2l0UjBtbkV5MnpocUNZZFA1azBzcUN5?= =?utf-8?B?Zi81RFA4QmQ3b3g1QjRMKzhkcW9EK2VKcDF4L0p3NDJuVmF3VFoweWsvV0Qv?= =?utf-8?B?Sko2UzNBeHlTMmtmMCtHQkQvSUN3eFNpZzJSck1KUEs4UHhHVUwyUzVheHBy?= =?utf-8?B?eDRXZFFBQXVTSHNEQitjcHo5WmYweDd2b3RmdjVMS0swSTMwYW5iTjU3Ymh5?= =?utf-8?B?bW5xQVpnNTZ0SXBMNC94TU1uMDVsZlpSdWhNM2Q1NGdGT0M0VE1IckREMWgv?= =?utf-8?B?UkU4MDJoLzJiNXlCbFVrSHU5amt5M2I4WjFCOXJUTWdOYjQ4dGZLdnN0VUNY?= =?utf-8?B?R0t2Mitpank2RXdxNTFqYjRHa3dseWNJajVqQkhrcjZtTjBHTDF4am1yTjJU?= =?utf-8?B?RDkxSnhlcmhzOWJNem1odHhER1dBNWYxU1BWZnlpVXJBa01MM3UyZGtidUF6?= =?utf-8?B?RXZsWmtqU1VsWTdJcmdlZVFnL3ZqK0RyaldSZ3ZYTUUyaE44UHlEdk8rdHI3?= =?utf-8?B?T3BqS2NTeEQ5QlpRV1p2R0dDQ2VNclFMMVRtaXhkVGhhN3ZCa3poU3BHRFh5?= =?utf-8?B?THBmMjUzUHczS2g1cVpuMU5acDZHWUJKakxjMTYwa0Rja0FnM2RvWFYyY0t1?= =?utf-8?B?MzViVmFSdTI1TVg3N1JqQXBqbFJ0M2NRcVpGSXBuNDNPcWhaM2JWSEl1OTBa?= =?utf-8?B?REpzWlliSnZGV1JkRzJYNEI1ZytTMUJOUmUxcjJuNWF2aWtWb3U0ak5DWXRH?= =?utf-8?B?Vm85M1UxaHplYkdET0VNZTl4d25WSkRJR3N4WjdxdjZsd293bnVkcW5qR3FC?= =?utf-8?B?SVA0ZHpmYWU1NWZnUm94WmY5a0hnNCt3MFY3WEIrS3RWRjMyWnJtL3g5azFY?= =?utf-8?B?bysxVUZjYXExSHh2QzdoVXU5NnFYd2xQKzNjQ1MyajFOalczK0ZzSVJ2T0tp?= =?utf-8?B?UWpzQm9wclU4UkdwdGs2SG9xQ2hpUEFzd1dXQ0NjeEY1MTRaRHpNT1BSay8r?= =?utf-8?B?UDJlTEU5R1J5S2hyTk5KTTJQL3hYbFZxR3ozU3Z3SWhsTzlxY3ZJUjQvNlJo?= =?utf-8?B?TTE0ZGNXRlVLRzFhYzdBdVM4b3FTVU5wb090cUpIM2FCU3pYUy9mOUFGenhX?= =?utf-8?B?ZnFWQkJ5Q3FEaWhYei9iRnV5YXM1ZWRLdHBvWTZzTnJXQm1vS2o1anlPTTFv?= =?utf-8?B?bTVRZzVDdjFsaU5oQmdUTEM4VVVoZGJDL3Z3SlQ2dXhDeXZMaWNMNm5tZDNp?= =?utf-8?B?bW1NMWk2ZFdJU0oyZGFMN1FidWJlcDdrbEJQcEp3dkJYQXREM3pTQndFY0Ro?= =?utf-8?B?TEd4bW9ZVk8xajFRWGkyRkRsbU1FOXdRUndwRjlLd21SMVJ4STJxdTZxWWhP?= =?utf-8?B?NHFvOFUvSE4yakNqckdMeElVbEQzQTRmOFhpWHVsaEVzbFZNY3VZa2hyUWNH?= =?utf-8?Q?wvJf78G4jzc=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PH8PR12MB7277.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(376014)(7416014)(10070799003)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?RHJpUUt3eCtGRnBEN0U5V3NJbHZWOFFrdUNZaDBjUkE2enhCM2duR1pKTlNh?= =?utf-8?B?ZkNLSHcrTVlKSkJsUVhoamxTRE9VL2NsWnMrNDhmNnIrV0hvc0svejNBeWdq?= =?utf-8?B?OFFxMHh0K3pvaXRTZVpRc3M5dWVnR2JwUmlYUW56NlJUeWhnV2pUa3l4QTFu?= =?utf-8?B?ZWRUR3VvSko2UmN4bThZSjBvL1p5cFdSYkpUVzFBbmh2UFo5K1ZmbTdwVzcv?= =?utf-8?B?SUdhVm80OHA4QzZtR0VzcUsrUjlMUFJuTG5LNFhIY25PNkJPMDRDVGhEbEpG?= =?utf-8?B?UDNMSzlyUTcxc2c3a3lkSXljRHYyeUtJS1RtSEJrWUI0SWZUMWpOWmFsa0Fq?= =?utf-8?B?bHMzUmluMEtpMFRrNm1TelhOZHUwY2d2bkxHbU40UnRod0I3TUMxakIycGUz?= =?utf-8?B?SkdoTkNLcVF2dmo1M0k2dGJYTUdUWTcvK2tiVkRuKzFKRlRDR05qUVBaODYv?= =?utf-8?B?cGdNSzQ0ZEpmZVNlN3FNTUU3UDVaMzN1RGRxUTdHazhqSFcvRWZoZ2V6Qmw4?= =?utf-8?B?aVhTODJRMXN6d1F3NTBzUmF6Z2ZQN1RqaWIraDUzWnVyN0VUUzFRSGJHcXl5?= =?utf-8?B?QWhrMG9vVWlrNFhLb2M0ZklHZElZR1VkbUxBaEJsRk9hTVN5S1h3MFBqblZY?= =?utf-8?B?RjFsOERubTRHbkN1SzA2RWZSZzkxZVRqc0s2Um40Y1BrOEQ0M2xBZTArR3ht?= =?utf-8?B?N1YzdGlFUTlKWVZxM2tWdDliV21xUWpFNEFncjVweUlEdTY2UW5BRmpkcnBS?= =?utf-8?B?OW90TUszTWdNYVUvMlBFdjcxV29rbGRWdnQ3a2pHc1dlOEJYbWhnb0s0UFIx?= =?utf-8?B?em1yYmphQytubnhiL3ArOGJJTFFnVlhydFdvc1BnNUw2RUh3dHRmS1FJSWpt?= =?utf-8?B?cGNNcnNLcmRVL3VCUTVVMitMc2dYa3ZKWm9lRmoxNDQ2dGtoUmREZW5nVmhT?= =?utf-8?B?RHRYNE5tYXlENHkyUmhLTUVLTFMyUnVZd3NVaDBvVGFXaDdTeVkydGJhNEV0?= =?utf-8?B?d0lzemdpY1J5QWpSc2pNOHdlV1U5YXYzV0hjV0luUWU3K2Y4R0JoSG5LSXNN?= =?utf-8?B?U2Y3T2hsYkU2UXhLY28rT0FaTmxOdExtQzNqQVd4K1RXZ2d2d3dxTi9CbE1F?= =?utf-8?B?YlFLMTFmRlFsWUJZbzdBNHlYTWtZenhSZ0xXeFYvNDRYS1ZEUlZnckUxZHFx?= =?utf-8?B?dWVpVmdxUFFKZ0NzYWtrb0xxaU5hbytmeEpnSHU4N3hJRTRpZWlFN1FFOFU0?= =?utf-8?B?SlpWV0ljMzF2Um9zSlp2TVdsYXJKeTZKd0Fpd243anQ0a3lBZkJPanJXcFRl?= =?utf-8?B?T29zUXJsbm1rVVdjTTMvOHJGRE9CS25wR2RLRGN3SmlHWFF6SFFEU3dkVElr?= =?utf-8?B?WkhlRE1OTHBrMGp3ZkVSWjBHbGRxQ3pjdzZ0V0poODl2SUlqaW9qSTBNM05t?= =?utf-8?B?Nks0WHJ3RGc4VEdlVGRINzYxR05ONUpYbVZpbWNwZmZQektXc0xsbWhvSVFp?= =?utf-8?B?WnJCK0hhb0ZEdGVQU21zUlF0M1Q5bHVTa1BVOGJUM1dVVFh6T3hqa1U4T2RC?= =?utf-8?B?NGhXRkVkNUlKSEtwdWpSbWUrdmhOV2N5VWt1Y3Q0VERSbExnRjFtMWpLSWxx?= =?utf-8?B?ZXBjK1hmc3NDWVpibTYwVnlKSGk3T2RiN1pUYzNFcmVIaTFRR2hlKzdNMlo1?= =?utf-8?B?RnkxMkdKK0xUcnpaTmdna2U3bXJaOE9tMDVSeTZRSEtIc0pwSUp1ZUduaVJC?= =?utf-8?B?cndSTDlycWtDWGlKcU5PdXVabW82UmFWSDk4OUhVM3lndU9jYkFzWFBWdkNM?= =?utf-8?B?ZUQranJ6TWdkM1ZxWS9zWVBXMHJXM1hFeWJHWlhkMU5aMGJyZjQvRjE2a2k4?= =?utf-8?B?ODVPRzVSSHhGMGsyVEFrVW1wOGQzQmltb3hqOWxJWVFMdmdsSFpKdzhBRmg3?= =?utf-8?B?K1J0YzNvM1ZETWducXNMSDl3c3dMTk9wU21GSDlSYm1IUUdaK0xMZTJPNmNp?= =?utf-8?B?M3hVSDU1UTdXUG54bkpQZ1ozQUYxRjZUNVB5Uy9uWXZKZHBzNFc4Z1QzNjZa?= =?utf-8?B?WkEyTFN1cW4xSW45OERDZlA2OEdLVjZXc1BGUWZKQWtVRVFYV0E1NHd4Y1Y0?= =?utf-8?B?aGNidVRJR1FHK0Z1eWlIdWtGeENpbFRnTVdkaHpEL3Y1cnhkb1VyMlNMZFND?= =?utf-8?B?WlE9PQ==?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 238cf21b-67fd-4b43-5b55-08ddf51ba05f X-MS-Exchange-CrossTenant-AuthSource: PH8PR12MB7277.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 16 Sep 2025 12:21:56.2641 (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: kxKKAwUl+gJ/Jbrb6ulnZTEqRh6j6CaShc88ctTta4rr4krJ5cmGETMuxOqWJGACqQ4G8Nykf0UlcY9TlaJbkA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH8PR12MB7373 MIGRATE_VMA_SELECT_COMPOUND will be used to select THP pages during migrate_vma_setup() and MIGRATE_PFN_COMPOUND will make migrating device pages as compound pages during device pfn migration. migrate_device code paths go through the collect, setup and finalize phases of migration. The entries in src and dst arrays passed to these functions still remain at a PAGE_SIZE granularity. When a compound page is passed, the first entry has the PFN along with MIGRATE_PFN_COMPOUND and other flags set (MIGRATE_PFN_MIGRATE, MIGRATE_PFN_VALID), the remaining entries (HPAGE_PMD_NR - 1) are filled with 0's. This representation allows for the compound page to be split into smaller page sizes. migrate_vma_collect_hole(), migrate_vma_collect_pmd() are now THP page aware. Two new helper functions migrate_vma_collect_huge_pmd() and migrate_vma_insert_huge_pmd_page() have been added. migrate_vma_collect_huge_pmd() can collect THP pages, but if for some reason this fails, there is fallback support to split the folio and migrate it. migrate_vma_insert_huge_pmd_page() closely follows the logic of migrate_vma_insert_page() Support for splitting pages as needed for migration will follow in later patches in this series. Signed-off-by: Balbir Singh Cc: David Hildenbrand Cc: Zi Yan Cc: Joshua Hahn Cc: Rakie Kim Cc: Byungchul Park Cc: Gregory Price Cc: Ying Huang Cc: Alistair Popple Cc: Oscar Salvador Cc: Lorenzo Stoakes Cc: Baolin Wang Cc: "Liam R. Howlett" Cc: Nico Pache Cc: Ryan Roberts Cc: Dev Jain Cc: Barry Song Cc: Lyude Paul Cc: Danilo Krummrich Cc: David Airlie Cc: Simona Vetter Cc: Ralph Campbell Cc: Mika Penttil=C3=A4 Cc: Matthew Brost Cc: Francois Dugast --- include/linux/migrate.h | 2 + mm/migrate_device.c | 468 ++++++++++++++++++++++++++++++++++------ 2 files changed, 407 insertions(+), 63 deletions(-) diff --git a/include/linux/migrate.h b/include/linux/migrate.h index 1f0ac122c3bf..41b4cc05a450 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -125,6 +125,7 @@ static inline int migrate_misplaced_folio(struct folio = *folio, int node) #define MIGRATE_PFN_VALID (1UL << 0) #define MIGRATE_PFN_MIGRATE (1UL << 1) #define MIGRATE_PFN_WRITE (1UL << 3) +#define MIGRATE_PFN_COMPOUND (1UL << 4) #define MIGRATE_PFN_SHIFT 6 =20 static inline struct page *migrate_pfn_to_page(unsigned long mpfn) @@ -143,6 +144,7 @@ enum migrate_vma_direction { MIGRATE_VMA_SELECT_SYSTEM =3D 1 << 0, MIGRATE_VMA_SELECT_DEVICE_PRIVATE =3D 1 << 1, MIGRATE_VMA_SELECT_DEVICE_COHERENT =3D 1 << 2, + MIGRATE_VMA_SELECT_COMPOUND =3D 1 << 3, }; =20 struct migrate_vma { diff --git a/mm/migrate_device.c b/mm/migrate_device.c index 70c0601f70ea..1663ce553184 100644 --- a/mm/migrate_device.c +++ b/mm/migrate_device.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include "internal.h" =20 @@ -44,6 +45,23 @@ static int migrate_vma_collect_hole(unsigned long start, if (!vma_is_anonymous(walk->vma)) return migrate_vma_collect_skip(start, end, walk); =20 + if (thp_migration_supported() && + (migrate->flags & MIGRATE_VMA_SELECT_COMPOUND) && + (IS_ALIGNED(start, HPAGE_PMD_SIZE) && + IS_ALIGNED(end, HPAGE_PMD_SIZE))) { + migrate->src[migrate->npages] =3D MIGRATE_PFN_MIGRATE | + MIGRATE_PFN_COMPOUND; + migrate->dst[migrate->npages] =3D 0; + migrate->npages++; + migrate->cpages++; + + /* + * Collect the remaining entries as holes, in case we + * need to split later + */ + return migrate_vma_collect_skip(start + PAGE_SIZE, end, walk); + } + for (addr =3D start; addr < end; addr +=3D PAGE_SIZE) { migrate->src[migrate->npages] =3D MIGRATE_PFN_MIGRATE; migrate->dst[migrate->npages] =3D 0; @@ -101,57 +119,150 @@ static int migrate_vma_split_folio(struct folio *fol= io, return 0; } =20 -static int migrate_vma_collect_pmd(pmd_t *pmdp, - unsigned long start, - unsigned long end, - struct mm_walk *walk) +/** migrate_vma_collect_huge_pmd - collect THP pages without splitting the + * folio for device private pages. + * @pmdp: pointer to pmd entry + * @start: start address of the range for migration + * @end: end address of the range for migration + * @walk: mm_walk callback structure + * + * Collect the huge pmd entry at @pmdp for migration and set the + * MIGRATE_PFN_COMPOUND flag in the migrate src entry to indicate that + * migration will occur at HPAGE_PMD granularity + */ +static int migrate_vma_collect_huge_pmd(pmd_t *pmdp, unsigned long start, + unsigned long end, struct mm_walk *walk, + struct folio *fault_folio) { + struct mm_struct *mm =3D walk->mm; + struct folio *folio; struct migrate_vma *migrate =3D walk->private; - struct folio *fault_folio =3D migrate->fault_page ? - page_folio(migrate->fault_page) : NULL; - struct vm_area_struct *vma =3D walk->vma; - struct mm_struct *mm =3D vma->vm_mm; - unsigned long addr =3D start, unmapped =3D 0; spinlock_t *ptl; - pte_t *ptep; + swp_entry_t entry; + int ret; + unsigned long write =3D 0; =20 -again: - if (pmd_none(*pmdp)) + ptl =3D pmd_lock(mm, pmdp); + if (pmd_none(*pmdp)) { + spin_unlock(ptl); return migrate_vma_collect_hole(start, end, -1, walk); + } =20 if (pmd_trans_huge(*pmdp)) { - struct folio *folio; - - ptl =3D pmd_lock(mm, pmdp); - if (unlikely(!pmd_trans_huge(*pmdp))) { + if (!(migrate->flags & MIGRATE_VMA_SELECT_SYSTEM)) { spin_unlock(ptl); - goto again; + return migrate_vma_collect_skip(start, end, walk); } =20 folio =3D pmd_folio(*pmdp); if (is_huge_zero_folio(folio)) { spin_unlock(ptl); - split_huge_pmd(vma, pmdp, addr); - } else { - int ret; + return migrate_vma_collect_hole(start, end, -1, walk); + } + if (pmd_write(*pmdp)) + write =3D MIGRATE_PFN_WRITE; + } else if (!pmd_present(*pmdp)) { + entry =3D pmd_to_swp_entry(*pmdp); + folio =3D pfn_swap_entry_folio(entry); + + if (!is_device_private_entry(entry) || + !(migrate->flags & MIGRATE_VMA_SELECT_DEVICE_PRIVATE) || + (folio->pgmap->owner !=3D migrate->pgmap_owner)) { + spin_unlock(ptl); + return migrate_vma_collect_skip(start, end, walk); + } =20 - folio_get(folio); + if (is_migration_entry(entry)) { + migration_entry_wait_on_locked(entry, ptl); spin_unlock(ptl); - /* FIXME: we don't expect THP for fault_folio */ - if (WARN_ON_ONCE(fault_folio =3D=3D folio)) - return migrate_vma_collect_skip(start, end, - walk); - if (unlikely(!folio_trylock(folio))) - return migrate_vma_collect_skip(start, end, - walk); - ret =3D split_folio(folio); - if (fault_folio !=3D folio) - folio_unlock(folio); - folio_put(folio); - if (ret) - return migrate_vma_collect_skip(start, end, - walk); + return -EAGAIN; + } + + if (is_writable_device_private_entry(entry)) + write =3D MIGRATE_PFN_WRITE; + } else { + spin_unlock(ptl); + return -EAGAIN; + } + + folio_get(folio); + if (folio !=3D fault_folio && unlikely(!folio_trylock(folio))) { + spin_unlock(ptl); + folio_put(folio); + return migrate_vma_collect_skip(start, end, walk); + } + + if (thp_migration_supported() && + (migrate->flags & MIGRATE_VMA_SELECT_COMPOUND) && + (IS_ALIGNED(start, HPAGE_PMD_SIZE) && + IS_ALIGNED(end, HPAGE_PMD_SIZE))) { + + struct page_vma_mapped_walk pvmw =3D { + .ptl =3D ptl, + .address =3D start, + .pmd =3D pmdp, + .vma =3D walk->vma, + }; + + unsigned long pfn =3D page_to_pfn(folio_page(folio, 0)); + + migrate->src[migrate->npages] =3D migrate_pfn(pfn) | write + | MIGRATE_PFN_MIGRATE + | MIGRATE_PFN_COMPOUND; + migrate->dst[migrate->npages++] =3D 0; + migrate->cpages++; + ret =3D set_pmd_migration_entry(&pvmw, folio_page(folio, 0)); + if (ret) { + migrate->npages--; + migrate->cpages--; + migrate->src[migrate->npages] =3D 0; + migrate->dst[migrate->npages] =3D 0; + goto fallback; } + migrate_vma_collect_skip(start + PAGE_SIZE, end, walk); + spin_unlock(ptl); + return 0; + } + +fallback: + spin_unlock(ptl); + if (!folio_test_large(folio)) + goto done; + ret =3D split_folio(folio); + if (fault_folio !=3D folio) + folio_unlock(folio); + folio_put(folio); + if (ret) + return migrate_vma_collect_skip(start, end, walk); + if (pmd_none(pmdp_get_lockless(pmdp))) + return migrate_vma_collect_hole(start, end, -1, walk); + +done: + return -ENOENT; +} + +static int migrate_vma_collect_pmd(pmd_t *pmdp, + unsigned long start, + unsigned long end, + struct mm_walk *walk) +{ + struct migrate_vma *migrate =3D walk->private; + struct vm_area_struct *vma =3D walk->vma; + struct mm_struct *mm =3D vma->vm_mm; + unsigned long addr =3D start, unmapped =3D 0; + spinlock_t *ptl; + struct folio *fault_folio =3D migrate->fault_page ? + page_folio(migrate->fault_page) : NULL; + pte_t *ptep; + +again: + if (pmd_trans_huge(*pmdp) || !pmd_present(*pmdp)) { + int ret =3D migrate_vma_collect_huge_pmd(pmdp, start, end, walk, fault_f= olio); + + if (ret =3D=3D -EAGAIN) + goto again; + if (ret =3D=3D 0) + return 0; } =20 ptep =3D pte_offset_map_lock(mm, pmdp, addr, &ptl); @@ -257,8 +368,7 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp, mpfn |=3D pte_write(pte) ? MIGRATE_PFN_WRITE : 0; } =20 - /* FIXME support THP */ - if (!page || !page->mapping || PageTransCompound(page)) { + if (!page || !page->mapping) { mpfn =3D 0; goto next; } @@ -429,14 +539,6 @@ static bool migrate_vma_check_page(struct page *page, = struct page *fault_page) */ int extra =3D 1 + (page =3D=3D fault_page); =20 - /* - * FIXME support THP (transparent huge page), it is bit more complex to - * check them than regular pages, because they can be mapped with a pmd - * or with a pte (split pte mapping). - */ - if (folio_test_large(folio)) - return false; - /* Page from ZONE_DEVICE have one extra reference */ if (folio_is_zone_device(folio)) extra++; @@ -467,17 +569,24 @@ static unsigned long migrate_device_unmap(unsigned lo= ng *src_pfns, =20 lru_add_drain(); =20 - for (i =3D 0; i < npages; i++) { + for (i =3D 0; i < npages; ) { struct page *page =3D migrate_pfn_to_page(src_pfns[i]); struct folio *folio; + unsigned int nr =3D 1; =20 if (!page) { if (src_pfns[i] & MIGRATE_PFN_MIGRATE) unmapped++; - continue; + goto next; } =20 folio =3D page_folio(page); + nr =3D folio_nr_pages(folio); + + if (nr > 1) + src_pfns[i] |=3D MIGRATE_PFN_COMPOUND; + + /* ZONE_DEVICE folios are not on LRU */ if (!folio_is_zone_device(folio)) { if (!folio_test_lru(folio) && allow_drain) { @@ -489,7 +598,7 @@ static unsigned long migrate_device_unmap(unsigned long= *src_pfns, if (!folio_isolate_lru(folio)) { src_pfns[i] &=3D ~MIGRATE_PFN_MIGRATE; restore++; - continue; + goto next; } =20 /* Drop the reference we took in collect */ @@ -508,10 +617,12 @@ static unsigned long migrate_device_unmap(unsigned lo= ng *src_pfns, =20 src_pfns[i] &=3D ~MIGRATE_PFN_MIGRATE; restore++; - continue; + goto next; } =20 unmapped++; +next: + i +=3D nr; } =20 for (i =3D 0; i < npages && restore; i++) { @@ -657,6 +768,160 @@ int migrate_vma_setup(struct migrate_vma *args) } EXPORT_SYMBOL(migrate_vma_setup); =20 +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION +/** + * migrate_vma_insert_huge_pmd_page: Insert a huge folio into @migrate->vm= a->vm_mm + * at @addr. folio is already allocated as a part of the migration process= with + * large page. + * + * @page needs to be initialized and setup after it's allocated. The code = bits + * here follow closely the code in __do_huge_pmd_anonymous_page(). This AP= I does + * not support THP zero pages. + * + * @migrate: migrate_vma arguments + * @addr: address where the folio will be inserted + * @page: page to be inserted at @addr + * @src: src pfn which is being migrated + * @pmdp: pointer to the pmd + */ +static int migrate_vma_insert_huge_pmd_page(struct migrate_vma *migrate, + unsigned long addr, + struct page *page, + unsigned long *src, + pmd_t *pmdp) +{ + struct vm_area_struct *vma =3D migrate->vma; + gfp_t gfp =3D vma_thp_gfp_mask(vma); + struct folio *folio =3D page_folio(page); + int ret; + vm_fault_t csa_ret; + spinlock_t *ptl; + pgtable_t pgtable; + pmd_t entry; + bool flush =3D false; + unsigned long i; + + VM_WARN_ON_FOLIO(!folio, folio); + VM_WARN_ON_ONCE(!pmd_none(*pmdp) && !is_huge_zero_pmd(*pmdp)); + + if (!thp_vma_suitable_order(vma, addr, HPAGE_PMD_ORDER)) + return -EINVAL; + + ret =3D anon_vma_prepare(vma); + if (ret) + return ret; + + folio_set_order(folio, HPAGE_PMD_ORDER); + folio_set_large_rmappable(folio); + + if (mem_cgroup_charge(folio, migrate->vma->vm_mm, gfp)) { + count_vm_event(THP_FAULT_FALLBACK); + count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE); + ret =3D -ENOMEM; + goto abort; + } + + __folio_mark_uptodate(folio); + + pgtable =3D pte_alloc_one(vma->vm_mm); + if (unlikely(!pgtable)) + goto abort; + + if (folio_is_device_private(folio)) { + swp_entry_t swp_entry; + + if (vma->vm_flags & VM_WRITE) + swp_entry =3D make_writable_device_private_entry( + page_to_pfn(page)); + else + swp_entry =3D make_readable_device_private_entry( + page_to_pfn(page)); + entry =3D swp_entry_to_pmd(swp_entry); + } else { + if (folio_is_zone_device(folio) && + !folio_is_device_coherent(folio)) { + goto abort; + } + entry =3D folio_mk_pmd(folio, vma->vm_page_prot); + if (vma->vm_flags & VM_WRITE) + entry =3D pmd_mkwrite(pmd_mkdirty(entry), vma); + } + + ptl =3D pmd_lock(vma->vm_mm, pmdp); + csa_ret =3D check_stable_address_space(vma->vm_mm); + if (csa_ret) + goto abort; + + /* + * Check for userfaultfd but do not deliver the fault. Instead, + * just back off. + */ + if (userfaultfd_missing(vma)) + goto unlock_abort; + + if (!pmd_none(*pmdp)) { + if (!is_huge_zero_pmd(*pmdp)) + goto unlock_abort; + flush =3D true; + } else if (!pmd_none(*pmdp)) + goto unlock_abort; + + add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR); + folio_add_new_anon_rmap(folio, vma, addr, RMAP_EXCLUSIVE); + if (!folio_is_zone_device(folio)) + folio_add_lru_vma(folio, vma); + folio_get(folio); + + if (flush) { + pte_free(vma->vm_mm, pgtable); + flush_cache_page(vma, addr, addr + HPAGE_PMD_SIZE); + pmdp_invalidate(vma, addr, pmdp); + } else { + pgtable_trans_huge_deposit(vma->vm_mm, pmdp, pgtable); + mm_inc_nr_ptes(vma->vm_mm); + } + set_pmd_at(vma->vm_mm, addr, pmdp, entry); + update_mmu_cache_pmd(vma, addr, pmdp); + + spin_unlock(ptl); + + count_vm_event(THP_FAULT_ALLOC); + count_mthp_stat(HPAGE_PMD_ORDER, MTHP_STAT_ANON_FAULT_ALLOC); + count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC); + + return 0; + +unlock_abort: + spin_unlock(ptl); +abort: + for (i =3D 0; i < HPAGE_PMD_NR; i++) + src[i] &=3D ~MIGRATE_PFN_MIGRATE; + return 0; +} +#else /* !CONFIG_ARCH_ENABLE_THP_MIGRATION */ +static int migrate_vma_insert_huge_pmd_page(struct migrate_vma *migrate, + unsigned long addr, + struct page *page, + unsigned long *src, + pmd_t *pmdp) +{ + return 0; +} +#endif + +static unsigned long migrate_vma_nr_pages(unsigned long *src) +{ + unsigned long nr =3D 1; +#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION + if (*src & MIGRATE_PFN_COMPOUND) + nr =3D HPAGE_PMD_NR; +#else + if (*src & MIGRATE_PFN_COMPOUND) + VM_WARN_ON_ONCE(true); +#endif + return nr; +} + /* * This code closely matches the code in: * __handle_mm_fault() @@ -667,9 +932,10 @@ EXPORT_SYMBOL(migrate_vma_setup); */ static void migrate_vma_insert_page(struct migrate_vma *migrate, unsigned long addr, - struct page *page, + unsigned long *dst, unsigned long *src) { + struct page *page =3D migrate_pfn_to_page(*dst); struct folio *folio =3D page_folio(page); struct vm_area_struct *vma =3D migrate->vma; struct mm_struct *mm =3D vma->vm_mm; @@ -697,8 +963,24 @@ static void migrate_vma_insert_page(struct migrate_vma= *migrate, pmdp =3D pmd_alloc(mm, pudp, addr); if (!pmdp) goto abort; - if (pmd_trans_huge(*pmdp)) - goto abort; + + if (thp_migration_supported() && (*dst & MIGRATE_PFN_COMPOUND)) { + int ret =3D migrate_vma_insert_huge_pmd_page(migrate, addr, page, + src, pmdp); + if (ret) + goto abort; + return; + } + + if (!pmd_none(*pmdp)) { + if (pmd_trans_huge(*pmdp)) { + if (!is_huge_zero_pmd(*pmdp)) + goto abort; + split_huge_pmd(vma, pmdp, addr); + } else if (pmd_leaf(*pmdp)) + goto abort; + } + if (pte_alloc(mm, pmdp)) goto abort; if (unlikely(anon_vma_prepare(vma))) @@ -789,23 +1071,24 @@ static void __migrate_device_pages(unsigned long *sr= c_pfns, unsigned long i; bool notified =3D false; =20 - for (i =3D 0; i < npages; i++) { + for (i =3D 0; i < npages; ) { struct page *newpage =3D migrate_pfn_to_page(dst_pfns[i]); struct page *page =3D migrate_pfn_to_page(src_pfns[i]); struct address_space *mapping; struct folio *newfolio, *folio; int r, extra_cnt =3D 0; + unsigned long nr =3D 1; =20 if (!newpage) { src_pfns[i] &=3D ~MIGRATE_PFN_MIGRATE; - continue; + goto next; } =20 if (!page) { unsigned long addr; =20 if (!(src_pfns[i] & MIGRATE_PFN_MIGRATE)) - continue; + goto next; =20 /* * The only time there is no vma is when called from @@ -823,15 +1106,47 @@ static void __migrate_device_pages(unsigned long *sr= c_pfns, migrate->pgmap_owner); mmu_notifier_invalidate_range_start(&range); } - migrate_vma_insert_page(migrate, addr, newpage, + + if ((src_pfns[i] & MIGRATE_PFN_COMPOUND) && + (!(dst_pfns[i] & MIGRATE_PFN_COMPOUND))) { + nr =3D migrate_vma_nr_pages(&src_pfns[i]); + src_pfns[i] &=3D ~MIGRATE_PFN_COMPOUND; + src_pfns[i] &=3D ~MIGRATE_PFN_MIGRATE; + goto next; + } + + migrate_vma_insert_page(migrate, addr, &dst_pfns[i], &src_pfns[i]); - continue; + goto next; } =20 newfolio =3D page_folio(newpage); folio =3D page_folio(page); mapping =3D folio_mapping(folio); =20 + /* + * If THP migration is enabled, check if both src and dst + * can migrate large pages + */ + if (thp_migration_supported()) { + if ((src_pfns[i] & MIGRATE_PFN_MIGRATE) && + (src_pfns[i] & MIGRATE_PFN_COMPOUND) && + !(dst_pfns[i] & MIGRATE_PFN_COMPOUND)) { + + if (!migrate) { + src_pfns[i] &=3D ~(MIGRATE_PFN_MIGRATE | + MIGRATE_PFN_COMPOUND); + goto next; + } + src_pfns[i] &=3D ~MIGRATE_PFN_MIGRATE; + } else if ((src_pfns[i] & MIGRATE_PFN_MIGRATE) && + (dst_pfns[i] & MIGRATE_PFN_COMPOUND) && + !(src_pfns[i] & MIGRATE_PFN_COMPOUND)) { + src_pfns[i] &=3D ~MIGRATE_PFN_MIGRATE; + } + } + + if (folio_is_device_private(newfolio) || folio_is_device_coherent(newfolio)) { if (mapping) { @@ -844,7 +1159,7 @@ static void __migrate_device_pages(unsigned long *src_= pfns, if (!folio_test_anon(folio) || !folio_free_swap(folio)) { src_pfns[i] &=3D ~MIGRATE_PFN_MIGRATE; - continue; + goto next; } } } else if (folio_is_zone_device(newfolio)) { @@ -852,7 +1167,7 @@ static void __migrate_device_pages(unsigned long *src_= pfns, * Other types of ZONE_DEVICE page are not supported. */ src_pfns[i] &=3D ~MIGRATE_PFN_MIGRATE; - continue; + goto next; } =20 BUG_ON(folio_test_writeback(folio)); @@ -864,6 +1179,8 @@ static void __migrate_device_pages(unsigned long *src_= pfns, src_pfns[i] &=3D ~MIGRATE_PFN_MIGRATE; else folio_migrate_flags(newfolio, folio); +next: + i +=3D nr; } =20 if (notified) @@ -1025,10 +1342,23 @@ static unsigned long migrate_device_pfn_lock(unsign= ed long pfn) int migrate_device_range(unsigned long *src_pfns, unsigned long start, unsigned long npages) { - unsigned long i, pfn; + unsigned long i, j, pfn; + + for (pfn =3D start, i =3D 0; i < npages; pfn++, i++) { + struct page *page =3D pfn_to_page(pfn); + struct folio *folio =3D page_folio(page); + unsigned int nr =3D 1; =20 - for (pfn =3D start, i =3D 0; i < npages; pfn++, i++) src_pfns[i] =3D migrate_device_pfn_lock(pfn); + nr =3D folio_nr_pages(folio); + if (nr > 1) { + src_pfns[i] |=3D MIGRATE_PFN_COMPOUND; + for (j =3D 1; j < nr; j++) + src_pfns[i+j] =3D 0; + i +=3D j - 1; + pfn +=3D j - 1; + } + } =20 migrate_device_unmap(src_pfns, npages, NULL); =20 @@ -1046,10 +1376,22 @@ EXPORT_SYMBOL(migrate_device_range); */ int migrate_device_pfns(unsigned long *src_pfns, unsigned long npages) { - unsigned long i; + unsigned long i, j; + + for (i =3D 0; i < npages; i++) { + struct page *page =3D pfn_to_page(src_pfns[i]); + struct folio *folio =3D page_folio(page); + unsigned int nr =3D 1; =20 - for (i =3D 0; i < npages; i++) src_pfns[i] =3D migrate_device_pfn_lock(src_pfns[i]); + nr =3D folio_nr_pages(folio); + if (nr > 1) { + src_pfns[i] |=3D MIGRATE_PFN_COMPOUND; + for (j =3D 1; j < nr; j++) + src_pfns[i+j] =3D 0; + i +=3D j - 1; + } + } =20 migrate_device_unmap(src_pfns, npages, NULL); =20 --=20 2.50.1