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emacs 29.1 From: Alistair Popple To: Dan Williams Cc: linux-mm@kvack.org, vishal.l.verma@intel.com, dave.jiang@intel.com, logang@deltatee.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 11:17:20 +1100 In-reply-to: <66ef6c41eeb4f_10422294fb@dwillia2-mobl3.amr.corp.intel.com.notmuch> Message-ID: <87y12vxzh1.fsf@nvdebian.thelocal> Content-Type: text/plain X-ClientProxiedBy: SY0PR01CA0009.ausprd01.prod.outlook.com (2603:10c6:10:1bb::10) To DS0PR12MB7726.namprd12.prod.outlook.com (2603:10b6:8:130::6) Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS0PR12MB7726:EE_|SJ0PR12MB6829:EE_ X-MS-Office365-Filtering-Correlation-Id: 72b6c5b2-29a2-4966-f1f8-08dce98a7168 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|376014|7416014|366016; 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>> folio->page.pgmap->ops->page_free(folio_page(folio, 0)); >> >> - if (folio->page.pgmap->type != MEMORY_DEVICE_PRIVATE && >> - folio->page.pgmap->type != MEMORY_DEVICE_COHERENT) >> + switch (folio->page.pgmap->type) { >> + case MEMORY_DEVICE_PRIVATE: >> + case MEMORY_DEVICE_COHERENT: >> + put_dev_pagemap(folio->page.pgmap); >> + break; >> + >> + case MEMORY_DEVICE_FS_DAX: >> + case MEMORY_DEVICE_GENERIC: >> /* >> * Reset the refcount to 1 to prepare for handing out the page >> * again. >> */ >> folio_set_count(folio, 1); >> - else >> - put_dev_pagemap(folio->page.pgmap); >> + break; >> + >> + case MEMORY_DEVICE_PCI_P2PDMA: >> + break; > > A follow on cleanup is that either all implementations should be > put_dev_pagemap(), or none of them. Put the onus on the implementation > to track how many pages it has handed out in the implementation > allocator. Agreed. I've ignored the get/put_dev_pagemap() calls for this clean up but am planning to do a follow up to clean those up too, probably by removing them entirely as you suggest. [...] > For this one: > > Reviewed-by: Dan Williams Thanks.