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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 519D3CAC581 for ; Mon, 8 Sep 2025 15:24:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B05DC8E0014; Mon, 8 Sep 2025 11:24:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id ADD898E0001; Mon, 8 Sep 2025 11:24:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9CB9D8E0014; Mon, 8 Sep 2025 11:24:33 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 8B3D88E0001 for ; Mon, 8 Sep 2025 11:24:33 -0400 (EDT) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 474AE1401CF for ; Mon, 8 Sep 2025 15:24:33 +0000 (UTC) X-FDA: 83866454826.27.7D0D5AC Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf10.hostedemail.com (Postfix) with ESMTP id E24B8C0009 for ; Mon, 8 Sep 2025 15:24:30 +0000 (UTC) Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="htBqgRd/"; spf=pass (imf10.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1757345071; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=OFR4fsYCPzy26gT9T9kYZtLy/SzbzsJmYYmla+zsN4U=; b=5V7sLKg4O1eXADeNqLpX3k6+noeGaM3cs0aIVkd8jFAAw2r7Nw5mW3l4UEKjsSTaF2zbX+ GCSGtLhIVx2IR6HUwidO5e9lzyTheS0y45z3hEjlPxO+LzPZgibB1QPpzaHa3TWLAsJkIs BMP43vpb9GW5qRHr8dNryTTxubFmODk= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="htBqgRd/"; spf=pass (imf10.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1757345071; a=rsa-sha256; cv=none; b=kvDBPkLj+apDN4D2NWWPyHcp8YQrs1nJh9xPH+VmeehyB+OkHwYmO7ICS/w6yTzH2JoudH w5J7HL1YcqLqESlmWiNh+E2eLLI9IYw7QL0eYLVMwIRAe3JsuEh3ScQ4munnFB1JIjJpcP kmAHWeHQLKk8Z207FwFcus7a5eanBSg= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1757345070; 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=OFR4fsYCPzy26gT9T9kYZtLy/SzbzsJmYYmla+zsN4U=; b=htBqgRd/qyFNyyTi4BFWHd6hVcEbYVVz6ntBKZt3GbW6k1td4G6tjkcFR4qz6CzYujKRix XoctZf6Yk4TZcG69SM9UE0Jow0nqjHNoEXj8RPfDS0ehPu3zf5vIzEQi1zeJBtduz9VrzP VTxNheMK1F6TDnek563RUKtJpR+Arlk= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-659-4Obb_63wOzikj_CtzuaNCw-1; Mon, 08 Sep 2025 11:24:29 -0400 X-MC-Unique: 4Obb_63wOzikj_CtzuaNCw-1 X-Mimecast-MFC-AGG-ID: 4Obb_63wOzikj_CtzuaNCw_1757345068 Received: by mail-wr1-f72.google.com with SMTP id ffacd0b85a97d-3df19a545c2so3477285f8f.3 for ; Mon, 08 Sep 2025 08:24:29 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757345068; x=1757949868; h=content-transfer-encoding:in-reply-to: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=OFR4fsYCPzy26gT9T9kYZtLy/SzbzsJmYYmla+zsN4U=; b=Hr87jfI7M+bxKt/kevsksfQJpQ9uA3JeaJySKo0E6CLU9DRZCv7VTP5NDhupjDYVQ3 mzgaFpZyyFm8aW5C29UzSUnDmc3VM4xvsWIiXHEq0NfcPZ5Qvz2xR6RBaGxSllA8pmXS HctyVt9W+RgpA33A5GlCjMrWEPxxic6XVP5KLSiS0055IqK93FZEtwk8wiCR83172G29 9jnnpU9jQosDCTQnPcG/EM7VQw2lmEeR/70qs40tIdoqc8RWNnz2ftsWNn8af6QTkbfG hNX1PH0yZQB7rBtAakc2QbLJUVbyeLx+FKDlRE1uEDEhKSBSqHItR/V7KYhERRMnxX0z gSJw== X-Forwarded-Encrypted: i=1; AJvYcCVvxmhf0wjl7Nh5prD9nQYijaYEih1z+d36z7QhXY3A2mYwYv/32vDj9yq71ztuYGi6IwlBp6Qdhg==@kvack.org X-Gm-Message-State: AOJu0YwYoZD/Xjknjhmr5KFenyXdRXXxrCTbC16PcMNI4NoAl4IauNll S4NPEIKLWmQOvqxu6ln/W4dIkHGwIoUz118m+sdzkApq+kKDIcSpi8xIPCxa8i+3tqVdjopuqe0 h7V6Si0j87Sixv4vx0OOyvC2ixd2KbqLJAOVt/APrzLT7PCfRWapr X-Gm-Gg: ASbGncspZwO4TetP0DoSStdq/B8fyiJwpZr6faEqrXA6nXCadRoZAF05IgbmjPB0YqI bnHbiGFlI3qJo6gKKysSHRrpvNS9P9MCVzM+1WnRrzd8adSjk2wkBL7dCKxH2/wGvtu2w9mSvEO IYtzNrEB0tqJWmULRPDwlHOgbmKp6kwoQOVUuiKLX6fhRWOvDhM7Z3yaS+NAvIxLFjERIPJWtSg xze2lIvazh6dps5qCmHhfpKEv3j6jlYSVcUpfg24biXoAmYIORW6XHCd/+hSaBiKllDeQYiVCz0 EnK2JOt3d10cSFl7CgyLTbZpGDQIiNoDermNDBPRSDX4/JxLkURDPc+yy+JMQYVSAb1U/4UecZO jlmX+OLZnjTcggDTbZlOh1PZFhMr9UC2JopMyEdP/v5wVTBYyvK4nSWJlj1QKVvwt X-Received: by 2002:a05:6000:2087:b0:3de:c5b3:dda3 with SMTP id ffacd0b85a97d-3e645c9d0fbmr7224248f8f.44.1757345067799; Mon, 08 Sep 2025 08:24:27 -0700 (PDT) X-Google-Smtp-Source: AGHT+IF1+PXcaDlfYMG7l/tiEGAk9GKqnsTr1vgulen25L6LSRNlWKiBe/sZ6bAf6RuwddMzqclqxA== X-Received: by 2002:a05:6000:2087:b0:3de:c5b3:dda3 with SMTP id ffacd0b85a97d-3e645c9d0fbmr7224167f8f.44.1757345067184; Mon, 08 Sep 2025 08:24:27 -0700 (PDT) Received: from ?IPV6:2003:d8:2f25:700:d846:15f3:6ca0:8029? (p200300d82f250700d84615f36ca08029.dip0.t-ipconnect.de. [2003:d8:2f25:700:d846:15f3:6ca0:8029]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3cf33add504sm41539994f8f.30.2025.09.08.08.24.24 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 08 Sep 2025 08:24:26 -0700 (PDT) Message-ID: <8edb13fc-e58d-4480-8c94-c321da0f4d8e@redhat.com> Date: Mon, 8 Sep 2025 17:24:23 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 03/16] mm: add vma_desc_size(), vma_desc_pages() helpers To: Jason Gunthorpe , Lorenzo Stoakes Cc: Andrew Morton , Jonathan Corbet , Matthew Wilcox , Guo Ren , Thomas Bogendoerfer , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , "David S . Miller" , Andreas Larsson , Arnd Bergmann , Greg Kroah-Hartman , Dan Williams , Vishal Verma , Dave Jiang , Nicolas Pitre , Muchun Song , Oscar Salvador , Konstantin Komarov , Baoquan He , Vivek Goyal , Dave Young , Tony Luck , Reinette Chatre , Dave Martin , James Morse , Alexander Viro , Christian Brauner , Jan Kara , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Hugh Dickins , Baolin Wang , Uladzislau Rezki , Dmitry Vyukov , Andrey Konovalov , Jann Horn , Pedro Falcato , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-csky@vger.kernel.org, linux-mips@vger.kernel.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, linux-mm@kvack.org, ntfs3@lists.linux.dev, kexec@lists.infradead.org, kasan-dev@googlegroups.com References: <20250908125101.GX616306@nvidia.com> <20250908133224.GE616306@nvidia.com> <090675bd-cb18-4148-967b-52cca452e07b@lucifer.local> <20250908142011.GK616306@nvidia.com> <764d413a-43a3-4be2-99c4-616cd8cd3998@lucifer.local> <20250908151637.GM616306@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 ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZoEEwEIAEQCGwMCF4ACGQEFCwkIBwICIgIG FQoJCAsCBBYCAwECHgcWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaJzangUJJlgIpAAKCRBN 3hD3AP+DWhAxD/9wcL0A+2rtaAmutaKTfxhTP0b4AAp1r/eLxjrbfbCCmh4pqzBhmSX/4z11 opn2KqcOsueRF1t2ENLOWzQu3Roiny2HOU7DajqB4dm1BVMaXQya5ae2ghzlJN9SIoopTWlR 0Af3hPj5E2PYvQhlcqeoehKlBo9rROJv/rjmr2x0yOM8qeTroH/ZzNlCtJ56AsE6Tvl+r7cW 3x7/Jq5WvWeudKrhFh7/yQ7eRvHCjd9bBrZTlgAfiHmX9AnCCPRPpNGNedV9Yty2Jnxhfmbv Pw37LA/jef8zlCDyUh2KCU1xVEOWqg15o1RtTyGV1nXV2O/mfuQJud5vIgzBvHhypc3p6VZJ lEf8YmT+Ol5P7SfCs5/uGdWUYQEMqOlg6w9R4Pe8d+mk8KGvfE9/zTwGg0nRgKqlQXrWRERv cuEwQbridlPAoQHrFWtwpgYMXx2TaZ3sihcIPo9uU5eBs0rf4mOERY75SK+Ekayv2ucTfjxr Kf014py2aoRJHuvy85ee/zIyLmve5hngZTTe3Wg3TInT9UTFzTPhItam6dZ1xqdTGHZYGU0O otRHcwLGt470grdiob6PfVTXoHlBvkWRadMhSuG4RORCDpq89vu5QralFNIf3EysNohoFy2A LYg2/D53xbU/aa4DDzBb5b1Rkg/udO1gZocVQWrDh6I2K3+cCs7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <20250908151637.GM616306@nvidia.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: eb1Ja6956CBvpzNz3CGu_N5U6PukEvLXOhg46XzLtRc_1757345068 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: E24B8C0009 X-Rspam-User: X-Rspamd-Server: rspam07 X-Stat-Signature: t7bny7etsrskk4zdczoxa8rmund6om7r X-HE-Tag: 1757345070-296194 X-HE-Meta: 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 qWllKhUi 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 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: > >> I think we need to be cautious of scope here :) I don't want to >> accidentally break things this way. > > IMHO it is worth doing when you get into more driver places it is far > more obvious why the VM_SHARED is being checked. > >> OK I think a sensible way forward - How about I add desc_is_cowable() or >> vma_desc_cowable() and only set this if I'm confident it's correct? > > I'm thinking to call it vma_desc_never_cowable() as that is much much > clear what the purpose is. Secretmem wants no private mappings. So we should check exactly that, not whether we might have a cow mapping. -- Cheers David / dhildenb