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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3A257C30658 for ; Tue, 2 Jul 2024 07:18:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=jooiWfPemUvMpiImGZEPJDFdWpBVTUluLJM85HVIgf8=; b=dfpSb2N4VT4kHtaG6C2CTxJG59 bLBUdQWd3X8gukR4cvYFUmQNdE8henNU0plgIloB1I9OXpFxch/fsfkRaB3noEk78tfayELTfnvlK K1nfc+TFfm5MY+nUP6ysX4Dtm5ZJJajDirRpWLZXaEVsCs0NqMHXr7IXU6unOWSyOVDFFdp7ZjXIM JsQ29qDGb5cVzeeb+xV+F59xKUeX8RhWJKDp3eLjIAtN71x6xQR2XXhIkWQlYLkVZPSwYd2397tHh JweFCrpVa1pyJb/svDeLfb4CjJYwBEf/rP07yIMofNnplm2NyxEHCzz+z3YgN9LcrayW84E8Eq071 EunveKfA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sOXmr-00000005qOY-14wL; Tue, 02 Jul 2024 07:18:49 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sOXmf-00000005qKv-42FN for linux-arm-kernel@lists.infradead.org; Tue, 02 Jul 2024 07:18:39 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1719904716; h=from:from: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:autocrypt:autocrypt; bh=jooiWfPemUvMpiImGZEPJDFdWpBVTUluLJM85HVIgf8=; b=C2VH50vdNMdh/crCTqqLxCKZVdqSQCcAVlrm/nEN7SfvsNCuHvNBtip3/9HAQwHxJgRmQt zJa/+yVVdnE5uFUXXTUGCxMnplGoZQhTFnp2EaLyk95w5epOEDkAkX8Tea/ex7vFEfkJVR DQvv8BUIQxMjy1jcbIDWuiqBTvTSSc8= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-682-LP1yAQfjMg-3bGIr89FhQA-1; Tue, 02 Jul 2024 03:18:35 -0400 X-MC-Unique: LP1yAQfjMg-3bGIr89FhQA-1 Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-4257f95fe85so13650755e9.1 for ; Tue, 02 Jul 2024 00:18:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1719904714; x=1720509514; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:from:references:cc:to:subject:user-agent :mime-version:date:message-id:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=jooiWfPemUvMpiImGZEPJDFdWpBVTUluLJM85HVIgf8=; b=AiC8JEuCSqa5nkOM3tPb+HaJ8SC8R/Dv82q0RuZfsgHOe16aR6akgs9oc4bGJod/lv iQFRJVilZmbOlz7VrmxCo0Abt+idmDYnffvZG7kQqu5RKXqwD0GCIdcyHppLSlfatGOQ DyZr7dFLSkJL/8QIDaMCMyUpAD5uH/Z8lv3ehWCLEn8/Sq0SG/5o9dKug0FMBo1EMcIX dVJ2oWV6ma88RNOK2vGEVEGfw/FLWqkG0WYgaIjF0HaosbtnMf+Zi+TrmcBx78UpxdhI qCLZZp2iMYC10c9emMl6oPJGIUk7fZE5trJo3vtyCRy4iMZq7XG+q3Q0bWFUEPG6b9fV Mfxg== X-Forwarded-Encrypted: i=1; AJvYcCVT+OMzrwSA9A1lYnk3zDfTUo3E5J0hVWD/NmS/4N3LJ3vpsA0mnPHI42Pla53o/KJWPpwhghjO4UNcPUTMZHLsJWmmw6ewT/AZhamdV1kM8ZydwqA= X-Gm-Message-State: AOJu0YxwcwYkEmQVYDK/8g9+QByHIBVE6pkbSyIHONewd/SdinNFRzM6 1HObXV80CgdgCHXnqpDjMxAeQOsxJ/zGbymMRrf1gwuPDPWZLPkVC5qY+zbRCNc4fRsqNl4J1Rl l26uZTyaKCWaW9bLK7sZEJg0RqPbbzkJN49mwbuW0xrn6jhW9nqkJ+BXmhJqSWjD5T4vhErQW X-Received: by 2002:a05:600c:181b:b0:421:7bed:5274 with SMTP id 5b1f17b1804b1-4257a02f7f0mr56194265e9.10.1719904714138; Tue, 02 Jul 2024 00:18:34 -0700 (PDT) X-Google-Smtp-Source: AGHT+IEzz5o3kOQcATmNnqgXuFo5zFXlMg5tD+q0qWYrXcGunrf20m6/A/WfizHYhPadayXK53FB3w== X-Received: by 2002:a05:600c:181b:b0:421:7bed:5274 with SMTP id 5b1f17b1804b1-4257a02f7f0mr56193815e9.10.1719904713708; Tue, 02 Jul 2024 00:18:33 -0700 (PDT) Received: from ?IPV6:2003:cb:c739:2400:78ac:64bb:a39e:2578? (p200300cbc739240078ac64bba39e2578.dip0.t-ipconnect.de. [2003:cb:c739:2400:78ac:64bb:a39e:2578]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-42578578b69sm133608745e9.42.2024.07.02.00.18.32 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 02 Jul 2024 00:18:33 -0700 (PDT) Message-ID: Date: Tue, 2 Jul 2024 09:18:31 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 06/13] mm/memory: Add dax_insert_pfn To: Alistair Popple , dan.j.williams@intel.com, vishal.l.verma@intel.com, dave.jiang@intel.com, logang@deltatee.com, bhelgaas@google.com, jack@suse.cz, jgg@ziepe.ca Cc: 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, 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-mm@kvack.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, jhubbard@nvidia.com, hch@lst.de, david@fromorbit.com References: <50013c1ee52b5bb1213571bff66780568455f54c.1719386613.git-series.apopple@nvidia.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl8Ox4kFCRKpKXgACgkQTd4Q 9wD/g1oHcA//a6Tj7SBNjFNM1iNhWUo1lxAja0lpSodSnB2g4FCZ4R61SBR4l/psBL73xktp rDHrx4aSpwkRP6Epu6mLvhlfjmkRG4OynJ5HG1gfv7RJJfnUdUM1z5kdS8JBrOhMJS2c/gPf wv1TGRq2XdMPnfY2o0CxRqpcLkx4vBODvJGl2mQyJF/gPepdDfcT8/PY9BJ7FL6Hrq1gnAo4 3Iv9qV0JiT2wmZciNyYQhmA1V6dyTRiQ4YAc31zOo2IM+xisPzeSHgw3ONY/XhYvfZ9r7W1l pNQdc2G+o4Di9NPFHQQhDw3YTRR1opJaTlRDzxYxzU6ZnUUBghxt9cwUWTpfCktkMZiPSDGd KgQBjnweV2jw9UOTxjb4LXqDjmSNkjDdQUOU69jGMUXgihvo4zhYcMX8F5gWdRtMR7DzW/YE BgVcyxNkMIXoY1aYj6npHYiNQesQlqjU6azjbH70/SXKM5tNRplgW8TNprMDuntdvV9wNkFs 9TyM02V5aWxFfI42+aivc4KEw69SE9KXwC7FSf5wXzuTot97N9Phj/Z3+jx443jo2NR34XgF 89cct7wJMjOF7bBefo0fPPZQuIma0Zym71cP61OP/i11ahNye6HGKfxGCOcs5wW9kRQEk8P9 M/k2wt3mt/fCQnuP/mWutNPt95w9wSsUyATLmtNrwccz63XOwU0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCXw7HsgUJEqkpoQAKCRBN3hD3AP+DWrrpD/4qS3dyVRxDcDHIlmguXjC1Q5tZTwNB boaBTPHSy/Nksu0eY7x6HfQJ3xajVH32Ms6t1trDQmPx2iP5+7iDsb7OKAb5eOS8h+BEBDeq 3ecsQDv0fFJOA9ag5O3LLNk+3x3q7e0uo06XMaY7UHS341ozXUUI7wC7iKfoUTv03iO9El5f XpNMx/YrIMduZ2+nd9Di7o5+KIwlb2mAB9sTNHdMrXesX8eBL6T9b+MZJk+mZuPxKNVfEQMQ a5SxUEADIPQTPNvBewdeI80yeOCrN+Zzwy/Mrx9EPeu59Y5vSJOx/z6OUImD/GhX7Xvkt3kq Er5KTrJz3++B6SH9pum9PuoE/k+nntJkNMmQpR4MCBaV/J9gIOPGodDKnjdng+mXliF3Ptu6 3oxc2RCyGzTlxyMwuc2U5Q7KtUNTdDe8T0uE+9b8BLMVQDDfJjqY0VVqSUwImzTDLX9S4g/8 kC4HRcclk8hpyhY2jKGluZO0awwTIMgVEzmTyBphDg/Gx7dZU1Xf8HFuE+UZ5UDHDTnwgv7E th6RC9+WrhDNspZ9fJjKWRbveQgUFCpe1sa77LAw+XFrKmBHXp9ZVIe90RMe2tRL06BGiRZr jPrnvUsUUsjRoRNJjKKA/REq+sAnhkNPPZ/NNMjaZ5b8Tovi8C0tmxiCHaQYqj7G2rgnT0kt WNyWQQ== Organization: Red Hat In-Reply-To: <50013c1ee52b5bb1213571bff66780568455f54c.1719386613.git-series.apopple@nvidia.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240702_001838_108565_78174C79 X-CRM114-Status: GOOD ( 12.31 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 27.06.24 02:54, Alistair Popple wrote: > Currently to map a DAX page the DAX driver calls vmf_insert_pfn. This > creates a special devmap PTE entry for the pfn but does not take a > reference on the underlying struct page for the mapping. This is > because DAX page refcounts are treated specially, as indicated by the > presence of a devmap entry. > > To allow DAX page refcounts to be managed the same as normal page > refcounts introduce dax_insert_pfn. This will take a reference on the > underlying page much the same as vmf_insert_page, except it also > permits upgrading an existing mapping to be writable if > requested/possible. We have this comparably nasty vmf_insert_mixed() that FS dax abused to insert into !VM_MIXED VMAs. Is that abuse now stopping and are there maybe ways to get rid of vmf_insert_mixed()? -- Cheers, David / dhildenb