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 148B3D2444F for ; Fri, 11 Oct 2024 00:21:10 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6B9F16B0083; Thu, 10 Oct 2024 20:21:10 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 66B206B0088; Thu, 10 Oct 2024 20:21:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4E43D6B0089; Thu, 10 Oct 2024 20:21:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 2C35A6B0083 for ; Thu, 10 Oct 2024 20:21:10 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 9482BA058A for ; Fri, 11 Oct 2024 00:21:02 +0000 (UTC) X-FDA: 82659416616.26.2F3FA6B Received: from NAM11-DM6-obe.outbound.protection.outlook.com (mail-dm6nam11on2063.outbound.protection.outlook.com [40.107.223.63]) by imf30.hostedemail.com (Postfix) with ESMTP id DB7158000B for ; Fri, 11 Oct 2024 00:21:03 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=Lxcv5cg6; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf30.hostedemail.com: domain of apopple@nvidia.com designates 40.107.223.63 as permitted sender) smtp.mailfrom=apopple@nvidia.com; dmarc=pass (policy=reject) header.from=nvidia.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1728605928; 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=pDe4Gg0Ncrhhdu95WT6ZItmrm5Cnmkgs4KZzgV8WFQY=; b=PrBP3Hvf/1fEfrDOEfYEt+CQL/IeQZfT9x5hIerbc0BXoV0U83KOaDBnebIPkUorkl3jGG ckgWgYlrDMVEJpnj0Bbmx2FY1gUs/IfgcK3ktjaiukeNs0r8UpYz/KPmJsYcLpn54Z278i liBt45DcK0vKw9D/KaIn/dX81cg5bvk= ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1728605928; a=rsa-sha256; cv=pass; b=X67qX2V4dWYPSAQD8xBz8JhZhL5seONG4z2gD/jrU9Q+IJq70JzVM2QJh8zBUmRlxnkBVq +JU2gCvkA2qCC3Fjb+iJ6tEEsU08N8JoClGLU5ub0kIxwQbu6RVZSU7437XOH3Z6f54rWw Hpkjc/5Y4PNwjeGUxt9wVu7DtcLndYc= ARC-Authentication-Results: i=2; imf30.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=Lxcv5cg6; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf30.hostedemail.com: domain of apopple@nvidia.com designates 40.107.223.63 as permitted sender) smtp.mailfrom=apopple@nvidia.com; dmarc=pass (policy=reject) header.from=nvidia.com ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=XasFqBX8WysBi/Y07/QLUk02TKPgSVzrjkisYJo5Mo2dchJtuJzsaLkOWHSo/C3K1yjJktjbUdqo7z9Y9xSLbiMpUVIoMT4mfNSkf/P7tQmSWwHXOINE4bRCd1uvY8/Gw70S8uLFWaUG/TPQCOA2OjbU0kNWUyfsMikgCE9hh4J5BW1+s0YPzwfT0OW9rW7s0wdjNq/wW5zT152OQsZiITD6WURF5ZJ5ef2UHotImiCtVX6MIw+vCNZIuMlASz+pURE8owyjxrrIl5QwanDVXH7eHS/bbYxh4lnom8lUX4K7/m8/QoFIreGt5Ej6rVqS7eekXlvCJG39Sh4cBDuKmw== 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=pDe4Gg0Ncrhhdu95WT6ZItmrm5Cnmkgs4KZzgV8WFQY=; b=Df71QhfDcMlLYGSimOao8P45MRFQTJttsajMuUj+rVzyCcVrEbt2s0Y2RXput/RdnLS0+5KeNnvtuWv/zJMShg9xHT+CQfyBWMywptcfOoiWJPtbA25ywvhakfdYtOomnjqWGgfuv8yi8NixcWQBhXVy/xQ08sGMwHWgjZvqVYgkV431/tuvbvL1INe3ueiuh0QM2TlMHUWm4ZT3+LW30m8xWIgflABE35SxE6/xR/OUSPDZy7cW9xNzw8ISzhNcP9PCI4xzAjVSUxkZGcNC1vh7kaq7It1lsB7Hp+8Hc8YBSFHAscZaeQtyJJP89QZU9xfBYKQ3ZRH1Gsy2e9ZlFg== 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=pDe4Gg0Ncrhhdu95WT6ZItmrm5Cnmkgs4KZzgV8WFQY=; b=Lxcv5cg6Qw1FfahyZ97zVDm978KO0DtPRdqjCjceFFgpFImoqgkTGr2Y2BxeDd8Gu7vQJwrrGP/FUdrQTXhQBQLOrlQ/yOMqQ3cVubkDvobPYHPfouPS3/4FVCvC5Wd4rywVbwc/CZZPOHrOemN4KrhUwQVpBFhEVdeX3N3TFgcKooQHokYVv2H02DTI600LPmHF1mPLgK1E/YPCa02651ELtlvEE2fQUCqAFkYNV3fZ4aOxUTKTfDY97rnkEPK9afEak0DcKYDEPeaUJaO3Uipk1N1DbXWgSGcXAoJzDS9+s1w2dZSBqVLT4xqn0i72gxmtttT/NejzvBYpZ/GZgQ== Received: from DS0PR12MB7726.namprd12.prod.outlook.com (2603:10b6:8:130::6) by SJ0PR12MB6829.namprd12.prod.outlook.com (2603:10b6:a03:47b::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8048.16; Fri, 11 Oct 2024 00:21:03 +0000 Received: from DS0PR12MB7726.namprd12.prod.outlook.com ([fe80::953f:2f80:90c5:67fe]) by DS0PR12MB7726.namprd12.prod.outlook.com ([fe80::953f:2f80:90c5:67fe%3]) with mapi id 15.20.8048.017; Fri, 11 Oct 2024 00:21:03 +0000 References: <4f8326d9d9e81f1cb893c2bd6f17878b138cf93d.1725941415.git-series.apopple@nvidia.com> <6f3402ae-01ad-4764-8941-f88bc77f5227@deltatee.com> User-agent: mu4e 1.10.8; emacs 29.1 From: Alistair Popple To: Logan Gunthorpe Cc: dan.j.williams@intel.com, linux-mm@kvack.org, vishal.l.verma@intel.com, dave.jiang@intel.com, bhelgaas@google.com, jack@suse.cz, jgg@ziepe.ca, catalin.marinas@arm.com, will@kernel.org, mpe@ellerman.id.au, npiggin@gmail.com, dave.hansen@linux.intel.com, ira.weiny@intel.com, willy@infradead.org, djwong@kernel.org, tytso@mit.edu, linmiaohe@huawei.com, david@redhat.com, peterx@redhat.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, jhubbard@nvidia.com, hch@lst.de, david@fromorbit.com Subject: Re: [PATCH 02/12] pci/p2pdma: Don't initialise page refcount to one Date: Fri, 11 Oct 2024 11:20:03 +1100 In-reply-to: <6f3402ae-01ad-4764-8941-f88bc77f5227@deltatee.com> Message-ID: <87ttdjxzf9.fsf@nvdebian.thelocal> Content-Type: text/plain X-ClientProxiedBy: SY5PR01CA0084.ausprd01.prod.outlook.com (2603:10c6:10:1f5::14) To DS0PR12MB7726.namprd12.prod.outlook.com (2603:10b6:8:130::6) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS0PR12MB7726:EE_|SJ0PR12MB6829:EE_ X-MS-Office365-Filtering-Correlation-Id: c91e47eb-77ab-4ac0-7062-08dce98a9732 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|376014|7416014|366016; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?o+4UJ73iqY5GCP1+7egAxS3C14Jrwhpfx7towZ47gP/FTrfZFvdkMXRrf7w4?= =?us-ascii?Q?Q2Z+N+RqwrE1HEUrDhWk0wb/Yx3I4n7kszFIKcEyHc3Jq00m1Kngquzqqmsl?= =?us-ascii?Q?FqWqbOrYtA4GymeOqqSEPeFKwa223eY55iROTdP8S5TTXCVdILQBUDrNWU1z?= =?us-ascii?Q?gCYmWWKmZIMmyhhoiBLkO9APlXJLtgkeczdZvFnnnzQ8glsIob4xVRY6aOLi?= =?us-ascii?Q?DqCnKDs3tpp96Nh8VjlFfIwR7grnxjuWhvaVBVsQdcvSi78JnBpxL4ejrdfD?= =?us-ascii?Q?krrGtQC2mZ2K25Flu8sGwVAa/ZwfHQfmBshf2vxYVhn3055Xa8bMXmYJ1/DI?= =?us-ascii?Q?6dBTUvzXarDerrmgRSHOrjU2PzWVbOUCx8/cnX7lZ7a3m0LQAcs7CsPObNcF?= =?us-ascii?Q?0fOUbE1vztWFOP8P0NEjh0CwJ75Zfyt76KvdImVjoJyYT8py2YLR2dNdRd4R?= =?us-ascii?Q?fAUl6DcEZO61BTRiSEXxqslhgyFbFEWUieQlOqE2ZW+HHAo3FZnlP1s8E1cx?= =?us-ascii?Q?XfvIqVlJ5/RvXRM8g5QByNaoTWXy9mpC2btPU3lh4lsYgei/itavnDRJ8WH/?= =?us-ascii?Q?Ce20EgTBYZRcDPghAw49gx6ImcYdUlFb/5YnD782zEAefr+GAZCdWhVU/ZdS?= =?us-ascii?Q?G09tULESRQnkmA4YRV1xbJJgDRfvc0muaZdQaQKMnCcAU9ehQUyZWDHi4Zat?= =?us-ascii?Q?0IlGGv4Ejf5D9CTylyHjfMEp3YDEXvpex7YctMwI52awZTtspDuVkKPQ8zIr?= =?us-ascii?Q?f3XuC4iLTSpz9s3HDNx9iVkVoTrIG6g324eJIl3xnnMSfEgme1/QTxo4gZMI?= =?us-ascii?Q?8+J1qPbN4/zwyOFJhEyVUypvGIEK+cOBQLc8caIuLqCPwz63sH5xhmrDo2fF?= =?us-ascii?Q?VDZ9eIsX1+Afw3hg6JloRm8GEnhcd2GM+Z1ix+GOb8bLsH5Y1ApZ48qoIoTQ?= =?us-ascii?Q?GnAYa/A7VqHht8v3TbpN4p4AAFBpT4KJfbvu6At+NjXkf5GvgBmYlyI4O2tC?= =?us-ascii?Q?qsf0U/K8qmPsQo18x+phTFvt5tB+6nwg389CgSwYWNrBeuVcErEtLdNMECkL?= =?us-ascii?Q?2yS0MguThCSzUodGEZ7Wvdmu0r0mdhuLaAhNqPRRKDQMB8oIlBP7LNzKP1AF?= =?us-ascii?Q?S2n/Y2RnfdlED2VjueJ/R160MitGtqEj7nbDdJCpO+0I6fawdFJoXJwE4D39?= =?us-ascii?Q?IfjaQrL2jhYK9cCK7WWdKFKQ0WCAEvS6bnpRyc2eTDfOKRZV1Rws0C1WGF7e?= =?us-ascii?Q?IIy9ubmQ7qPD2zzdzp+euEzP5s0TuIk26uGGBe5iKA=3D=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS0PR12MB7726.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(376014)(7416014)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?JLAmfjGU8ICnI9TPxyjltd84Iu/es1D59C8h3GhKCCPu30NJGyxrzzJeUPPZ?= =?us-ascii?Q?KeE7U6etMbXXDO09lij/fk5qAAYz8/mXxHr0+KPDl6xMaQGJDv+G3oTAHAIW?= =?us-ascii?Q?NTuxkQgufD6T1tRW1PEwjWQN63foAM5y9UCWtfrWrh/Zjd4CM35oVEfJm/0x?= =?us-ascii?Q?jnUVd2dIDVihjE/HLK6O7nZUm8qudG+TsOX2ViabF5jbOqIpDI2WlufR0cfC?= =?us-ascii?Q?VNOZJ5ZYGPXqedZQVsnnrwLXd0YUeRt5IUprC/r8j59CmgK6GJ9JXBPxoqJ6?= =?us-ascii?Q?1ZiIe0RMLuSAuBqNDuOAAlfISCeAaA9nvY2zlpN9qRh0SIR0/zcn7kktX8WW?= =?us-ascii?Q?YrEE99hbzkCB345nZq1E8gAM9NcdHZWHEU/VWpZBQ+jNUe8Xy4n3yXnxZHjU?= =?us-ascii?Q?eLJcdpOEuVqdlHSCAGi18HptKGFsRPG8ZkG/im3UsnmzvUl5iM6FxGfi5MMb?= =?us-ascii?Q?7BGbXkWN6sAjtIbMvXn62FJIeV0grvEjbWO0vIJjWtQic4FWm/M7LeUB7fDj?= =?us-ascii?Q?sZz3ovBimeBNsYG4QgLUSEnCemuvrnTypFOJTHgeX8SiD0RFznBm6DaByJy5?= =?us-ascii?Q?mNHKBVtj9lEUm3QqYZDC+7mQ8SZRYKlbVUNr2kAVIS61h18OFexvnQZbpVCw?= =?us-ascii?Q?ent33hoiEXUyDgqlCL3pscTyL01Ke5xj1oNPjI6nHG1gWDqkubp4howAKOq5?= =?us-ascii?Q?XeZHgaWyyEiikkr2IzQR3gRTp6gTNOm0vIOX6gRtxMJ4DVjMbUDC/CMIOvCc?= =?us-ascii?Q?/pUjIftBIdbsEQ44uQQmxz8tWbnBkMe6ooP2R/Mp7YQUrf2Bg4BhGISje0C2?= =?us-ascii?Q?k9darQ7xW5Xu+5fGIQvilhmkHT3jtbijRWav6kzEZPfLVoSBKhwXifn3n6pV?= =?us-ascii?Q?H+N7CpAN7aXOV3SZs9oWOAougtTkUZe5ay8lQm6/4eIEE6QjJql8ORmINAsq?= =?us-ascii?Q?RWzXSa/KXk2+fpMVw6IGoTpI7sCCesOR7cyNBh35KSJ9b4TB69th2fLI5UYP?= =?us-ascii?Q?6m9/YmO/0Jf/pNkPq1f3oHWJe8OC1jhbfjybe5rQSSoR2o2MwvqGA29nkWPS?= =?us-ascii?Q?6RFJwDO0HXpQDqL3MLdeKWP5YeQt4fzb9r5umIHXD69+hTwtXxvHrFR9cBza?= =?us-ascii?Q?LyCAweagAH4m1K7togLykg3C5sqPMcgudvPWyGomxRu/BDpSWwYjQwbdi2pQ?= =?us-ascii?Q?lQzCvtIhvrWZcyYgR3C4RzwygxENwgfPUNhnD4jwqUmqhWrVz0agHWjT7jAU?= =?us-ascii?Q?MGe0h8oOEjIpFEXHPoCRgvvcu0ju1EpMJsHeR29hE1itA685NvQeg/t/gYiv?= =?us-ascii?Q?qNtt8ltpogKESNka0SJqxWs23fOjaHmoSas07KStBWTkv+j46E9Q1S+P2LPg?= =?us-ascii?Q?qFZr7t4LWxzxV76UardcWXPfTbp3NzSdlSU4W72FgrU9hWktPQGqWF8CkLoX?= =?us-ascii?Q?76kvCl2fo2LLxdRGT2brQlhiLuXGTonzH4aW0zk5ygV7PtM7R9k+eBz1hcOD?= =?us-ascii?Q?dP9t05ZGtn5RPXTe8TfJ/jSLKeVz7DSBZUMBo+GZojj/41eK9cobyg/fdFDG?= =?us-ascii?Q?qg/uHG+unqbKoZ7ebWDaq2MaXBvIWnySRQkiVbKQ?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: c91e47eb-77ab-4ac0-7062-08dce98a9732 X-MS-Exchange-CrossTenant-AuthSource: DS0PR12MB7726.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 11 Oct 2024 00:21:03.2194 (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: KS4EGb1kQUqN5jHM+VhpV7qHMZN8MrIjIFw/WeYMaU5pIteO/QKr6p0HAm14hxmCTGyvuslaUGzOQjD73uVWNQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR12MB6829 X-Stat-Signature: i1sf1dgotb6hn1ni51q6r6ob7kuq6yke X-Rspamd-Queue-Id: DB7158000B X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1728606063-869009 X-HE-Meta: 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 SlONh81r 9As8TY20TVRDP0ayEAYrNbZ1xp/rRK3eiaxOGUPLWtzPG2/C9wxJCMJm2hnDzaXGj8wIJqGfI+ryQgdDtLHxscCv+v4DZ2/AQKaUSnHgQhzBIgQFhdTv66i7suEdA4C1KMM5GQHvsS3CIPNUx1V50ERJ9ZU9h7qLE/dy5ybPyuq2KVc3Pcu/ekBswVeRzQc8mJrkbRswGKp974t/uQiyGrZvbNia9AcYuyy08c8cnTIfYrx1vrlHyBi8UuQWLgH3vnmo+iAleKLlSn+ipevb54oM2HQ== 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: Logan Gunthorpe writes: > On 2024-09-09 22:14, Alistair Popple wrote: >> The reference counts for ZONE_DEVICE private pages should be >> initialised by the driver when the page is actually allocated by the >> driver allocator, not when they are first created. This is currently >> the case for MEMORY_DEVICE_PRIVATE and MEMORY_DEVICE_COHERENT pages >> but not MEMORY_DEVICE_PCI_P2PDMA pages so fix that up. >> >> Signed-off-by: Alistair Popple >> --- >> drivers/pci/p2pdma.c | 6 ++++++ >> mm/memremap.c | 17 +++++++++++++---- >> mm/mm_init.c | 22 ++++++++++++++++++---- >> 3 files changed, 37 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c >> index 4f47a13..210b9f4 100644 >> --- a/drivers/pci/p2pdma.c >> +++ b/drivers/pci/p2pdma.c >> @@ -129,6 +129,12 @@ static int p2pmem_alloc_mmap(struct file *filp, struct kobject *kobj, >> } >> >> /* >> + * Initialise the refcount for the freshly allocated page. As we have >> + * just allocated the page no one else should be using it. >> + */ >> + set_page_count(virt_to_page(kaddr), 1); >> + >> + /* >> * vm_insert_page() can sleep, so a reference is taken to mapping >> * such that rcu_read_unlock() can be done before inserting the >> * pages > This seems to only set reference count to the first page, when there can > be more than one page referenced by kaddr. Good point. > I suspect the page count adjustment should be done in the for loop > that's a few lines lower than this. Have moved it there for the next version, thanks! > I think a similar mistake was made by other recent changes. > > Thanks, > > Logan