From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 68DAA224247 for ; Thu, 17 Jul 2025 20:03:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752782633; cv=none; b=FDlQhj4fftoe50lQrKa3Ar1L9+5mhTUxKO0Gm7vgQD9oGzqpWJ6Lkzk48DakxH5powEx+hnP+tsP126TYbGO2eZkvv9XZG/Ps1esKrM0iyK0ExW/h+miKrGTkeJvIRz4m/tAukgLN0EuWtXUqqaggn1CMHI1o28K4fb94KTApJo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752782633; c=relaxed/simple; bh=Q/F1zAOvHokBZlzDec5Cjn3EbeBfpbAqOlMColJ54Aw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=uzKsRaKPNyPB1LkK0F3QibI7VvNGGbgM9ba+e91xuE5g/khwHXx+dwVRsksg52ipMf9QMMxA8EGW/MqJOFuvKPp5gPD/a4GBHE0Tbbwcs3Hu+O92I5V2U2TLThC5jq3cuu/gmxd0L3zrODbPhD+3QOZtiRXdWB6fruYoXlGCXkQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=g6J6wB7t; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="g6J6wB7t" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1752782630; 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=ClNVtTZhZp5gAwQFZwS1SAbGnOFesIfcYAsTrAvuVJw=; b=g6J6wB7tJUpEDS5+igQjHwbD2g3WVm8I3tKDeP9yweRvHhP5JNqBy3eE7rbLaj6u1cyy/B HpG5xmhqgFDwbrABLil8G9hCsGq2BhXgnXbpWECWiEhfiHSECfX34To8YLzzToUNntOkhl 92Wpzz+Cgup/BwnUf3q8aif/MTmX3Ew= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-645-6M77rKKVPGeyWzvpgGSD3Q-1; Thu, 17 Jul 2025 16:03:48 -0400 X-MC-Unique: 6M77rKKVPGeyWzvpgGSD3Q-1 X-Mimecast-MFC-AGG-ID: 6M77rKKVPGeyWzvpgGSD3Q_1752782627 Received: by mail-wm1-f71.google.com with SMTP id 5b1f17b1804b1-456267c79deso4354115e9.1 for ; Thu, 17 Jul 2025 13:03:48 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1752782627; x=1753387427; 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=ClNVtTZhZp5gAwQFZwS1SAbGnOFesIfcYAsTrAvuVJw=; b=JznaDFW15ac/sSkrtk2dsYY3kYSDfx2Ad5i9/hEwMbIDhcsAWKWlSSMxzn99LirgEw yqsIknc+IoqDw/DyjNZO+5CZnf7Qh5vz8zsS6iKNGpSBTCalSpzdJqjGxn7+7U9BA5uI vTUVnZPIeOXFMrGMoLSwBSN9mfGlth/F0u8JVjfqF8xUZpkniiEAKoBWv+l1Vt9565Rb B3wGwxmfZC+pRwfTFdEOGfSfWpfpxkCpyuLVES9QR1AvNSbnK3nF2IPwbr6t32N9idUq 2/QGAB3nvD32GSWY57dqlccFz3FDMZXhcZT9ZshK5u59wUO+vOdL/ww30VIu41rirk2Q Si3w== X-Forwarded-Encrypted: i=1; AJvYcCXWGkQa9UXpIU9x4UVst5JLFau4i0v3eaeeW4gO3/abff7Cqnhlpmu2bGJLxoCURkt+Y2/T8vxdKfoFxNUA@vger.kernel.org X-Gm-Message-State: AOJu0YykI1B1NcKN1wR5XiW8ufTp4A/OizPrCI2Z0Anfgv9QGOAeaVDY 3mSEwZrKEXylxbSj1u9nZuCW/79x7h9+h2nsKReD0i0NKHcFZRxQvnM6yRWTgUGaCJ4aLrVjnpS EHqnCetCtUlzSw6QBD5fyw1+OWK537XItPmmUHvD5Sv0KBiKdTuqq/1LrNFMP7n1Jr5E= X-Gm-Gg: ASbGncubS398V6pql11G1mf/wsK7oZg0W+bFTUa2dvt2KsSro4tsHa5dznDhEyRQUm2 P+Yp8tGsfDNBvLAEkZJiGHrHh7CaYxyUzcDCbnrZFU+HojINXA3uwgAMWH8QBbqDqeDEbVn02t0 EwuLDqoGqB+KyjkXrncCho3U4kelr9d0aKJQSz48FrlUnRnOPayJhWAbCaTul0cru4MbeQ+6b/6 9jXZpzZfW1/g5PAkcJ7B1cZhuiuGs8aktN/ck7LO/EcM1ckf7zPaiEWicgEO+pZDlemeriGcfg9 FEhGwPcRrflBx89/wSv8i6MnnlCpQUp3ixz4JZqtHrM+nKcLY2vZXfGFkGBTZaELcoLK8eBxDlj DXae8skFv5WYvGpih2UZGXOvEQSQcZ4BhK3Rl639Qxhm4HxOZ/TMa46WM41euDa0w X-Received: by 2002:a05:600c:3481:b0:456:f9f:657 with SMTP id 5b1f17b1804b1-4562e3c503amr79745955e9.27.1752782626932; Thu, 17 Jul 2025 13:03:46 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHITXVfZtwqa7P8f0u6oWcFw1NazxQtB99hClGfTnR+mgLoVDMe7M6pKVDkyJRWFMthviCSvw== X-Received: by 2002:a05:600c:3481:b0:456:f9f:657 with SMTP id 5b1f17b1804b1-4562e3c503amr79745695e9.27.1752782626423; Thu, 17 Jul 2025 13:03:46 -0700 (PDT) Received: from ?IPV6:2003:d8:2f35:2b00:b1a5:704a:6a0c:9ae? (p200300d82f352b00b1a5704a6a0c09ae.dip0.t-ipconnect.de. [2003:d8:2f35:2b00:b1a5:704a:6a0c:9ae]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-45630ec9129sm49616075e9.29.2025.07.17.13.03.44 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 17 Jul 2025 13:03:45 -0700 (PDT) Message-ID: Date: Thu, 17 Jul 2025 22:03:44 +0200 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 7/9] mm/memory: factor out common code from vm_normal_page_*() To: Lorenzo Stoakes Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, xen-devel@lists.xenproject.org, linux-fsdevel@vger.kernel.org, nvdimm@lists.linux.dev, Andrew Morton , Juergen Gross , Stefano Stabellini , Oleksandr Tyshchenko , Dan Williams , Matthew Wilcox , Jan Kara , Alexander Viro , Christian Brauner , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Jann Horn , Pedro Falcato , Hugh Dickins , Oscar Salvador , Lance Yang References: <20250717115212.1825089-1-david@redhat.com> <20250717115212.1825089-8-david@redhat.com> <1aef6483-18e6-463b-a197-34dd32dd6fbd@lucifer.local> <50190a14-78fb-4a4a-82fa-d7b887aa4754@lucifer.local> From: David Hildenbrand Content-Language: en-US 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/g1oFAmgsLPQFCRvGjuMACgkQTd4Q 9wD/g1o0bxAAqYC7gTyGj5rZwvy1VesF6YoQncH0yI79lvXUYOX+Nngko4v4dTlOQvrd/vhb 02e9FtpA1CxgwdgIPFKIuXvdSyXAp0xXuIuRPQYbgNriQFkaBlHe9mSf8O09J3SCVa/5ezKM OLW/OONSV/Fr2VI1wxAYj3/Rb+U6rpzqIQ3Uh/5Rjmla6pTl7Z9/o1zKlVOX1SxVGSrlXhqt kwdbjdj/csSzoAbUF/duDuhyEl11/xStm/lBMzVuf3ZhV5SSgLAflLBo4l6mR5RolpPv5wad GpYS/hm7HsmEA0PBAPNb5DvZQ7vNaX23FlgylSXyv72UVsObHsu6pT4sfoxvJ5nJxvzGi69U s1uryvlAfS6E+D5ULrV35taTwSpcBAh0/RqRbV0mTc57vvAoXofBDcs3Z30IReFS34QSpjvl Hxbe7itHGuuhEVM1qmq2U72ezOQ7MzADbwCtn+yGeISQqeFn9QMAZVAkXsc9Wp0SW/WQKb76 FkSRalBZcc2vXM0VqhFVzTb6iNqYXqVKyuPKwhBunhTt6XnIfhpRgqveCPNIasSX05VQR6/a OBHZX3seTikp7A1z9iZIsdtJxB88dGkpeMj6qJ5RLzUsPUVPodEcz1B5aTEbYK6428H8MeLq NFPwmknOlDzQNC6RND8Ez7YEhzqvw7263MojcmmPcLelYbfOwU0EVcufkQEQAOfX3n0g0fZz 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+DWgUCaCwtJQUJG8aPFAAKCRBN3hD3AP+DWlDnD/4k2TW+HyOOOePVm23F5HOhNNd7nNv3 Vq2cLcW1DteHUdxMO0X+zqrKDHI5hgnE/E2QH9jyV8mB8l/ndElobciaJcbl1cM43vVzPIWn 01vW62oxUNtEvzLLxGLPTrnMxWdZgxr7ACCWKUnMGE2E8eca0cT2pnIJoQRz242xqe/nYxBB /BAK+dsxHIfcQzl88G83oaO7vb7s/cWMYRKOg+WIgp0MJ8DO2IU5JmUtyJB+V3YzzM4cMic3 bNn8nHjTWw/9+QQ5vg3TXHZ5XMu9mtfw2La3bHJ6AybL0DvEkdGxk6YHqJVEukciLMWDWqQQ RtbBhqcprgUxipNvdn9KwNpGciM+hNtM9kf9gt0fjv79l/FiSw6KbCPX9b636GzgNy0Ev2UV m00EtcpRXXMlEpbP4V947ufWVK2Mz7RFUfU4+ETDd1scMQDHzrXItryHLZWhopPI4Z+ps0rB CQHfSpl+wG4XbJJu1D8/Ww3FsO42TMFrNr2/cmqwuUZ0a0uxrpkNYrsGjkEu7a+9MheyTzcm vyU2knz5/stkTN2LKz5REqOe24oRnypjpAfaoxRYXs+F8wml519InWlwCra49IUSxD1hXPxO WBe5lqcozu9LpNDH/brVSzHCSb7vjNGvvSVESDuoiHK8gNlf0v+epy5WYd7CGAgODPvDShGN g3eXuA== Organization: Red Hat In-Reply-To: <50190a14-78fb-4a4a-82fa-d7b887aa4754@lucifer.local> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 17.07.25 21:55, Lorenzo Stoakes wrote: > On Thu, Jul 17, 2025 at 08:51:51PM +0100, Lorenzo Stoakes wrote: >>> @@ -721,37 +772,21 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr, >>> print_bad_page_map(vma, addr, pmd_val(pmd), NULL); >>> return NULL; >>> } >>> - >>> - if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) { >>> - if (vma->vm_flags & VM_MIXEDMAP) { >>> - if (!pfn_valid(pfn)) >>> - return NULL; >>> - goto out; >>> - } else { >>> - unsigned long off; >>> - off = (addr - vma->vm_start) >> PAGE_SHIFT; >>> - if (pfn == vma->vm_pgoff + off) >>> - return NULL; >>> - if (!is_cow_mapping(vma->vm_flags)) >>> - return NULL; >>> - } >>> - } >>> - >>> - if (is_huge_zero_pfn(pfn)) >>> - return NULL; >>> - if (unlikely(pfn > highest_memmap_pfn)) { >>> - print_bad_page_map(vma, addr, pmd_val(pmd), NULL); >>> - return NULL; >>> - } >>> - >>> - /* >>> - * NOTE! We still have PageReserved() pages in the page tables. >>> - * eg. VDSO mappings can cause them to exist. >>> - */ >>> -out: >>> - return pfn_to_page(pfn); >>> + return vm_normal_page_pfn(vma, addr, pfn, pmd_val(pmd)); >> >> Hmm this seems broken, because you're now making these special on arches with >> pte_special() right? But then you're invoking the not-special function? >> >> Also for non-pte_special() arches you're kind of implying they _maybe_ could be >> special. > > OK sorry the diff caught me out here, you explicitly handle the pmd_special() > case here, duplicatively (yuck). > > Maybe you fix this up in a later patch :) I had that, but the conditions depend on the level, meaning: unnecessary checks for pte/pmd/pud level. I had a variant where I would pass "bool special" into vm_normal_page_pfn(), but I didn't like it. To optimize out, I would have to provide a "level" argument, and did not convince myself yet that that is a good idea at this point. -- Cheers, David / dhildenb