From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 9185425E839 for ; Mon, 23 Jun 2025 15:38:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750693082; cv=none; b=ePCeEpvGbkMXJjvel4RCjpF+mZc9ygOq2zkLilQkoi03b7fsZCKl1AoX4TVQChzaznfsSfKKaocxNe32K9MtHxfU3U3zG2sTMBZzxEXCLFRU85jwbxqbV9RaGMKeljf0rnWLyyU0mRNPyg3HtWq0FDQ0RzQdS+/eld23BsEv1Gc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750693082; c=relaxed/simple; bh=bS2LEiehQHAQ8md5Caf5xXTI/g/ImM/+PBSHzX236OE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ORVEXXDLhaNvVt/9Z5rDSDq9o0/B3+Y1GdZvQZn1kg9YZwgmj9MSlQZoVfBp7d6PDyALDT0L0+EK7g/E5B8fXpfcAY/ZpEX2KpqA5wjeEE/pi4j1eX5ApHl4WQ9YIxYizHD8GK4nog+bQ7UsbfJLy12hwGeUY37laSL4mPP9GNo= 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=a803YZ1Z; arc=none smtp.client-ip=170.10.133.124 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="a803YZ1Z" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1750693079; 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=LicB6aTt8ax5xPgeYdYrlMm/Y9HO/56RSPqPiL4WYFk=; b=a803YZ1ZSPlRYNoWTdE0o0gp0/RacvhF6xiEIgvY31J3u2Ua2RzQCMc98h1V7xwLqwaot+ 5mRCEydxlgiKVwqov3YUSTv1DcO38jYU/4KIvi5L11XL1QhYsAAVImoADXC2tKlfGAF8lK 8v6Lq1zEVJTnUYm1j2zHLDG+iqRUR8A= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-344-B9zN-SEHP7ugzrPkaI1PQw-1; Mon, 23 Jun 2025 11:37:58 -0400 X-MC-Unique: B9zN-SEHP7ugzrPkaI1PQw-1 X-Mimecast-MFC-AGG-ID: B9zN-SEHP7ugzrPkaI1PQw_1750693077 Received: by mail-wr1-f69.google.com with SMTP id ffacd0b85a97d-3a50816cc58so1821824f8f.3 for ; Mon, 23 Jun 2025 08:37:57 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1750693077; x=1751297877; 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=LicB6aTt8ax5xPgeYdYrlMm/Y9HO/56RSPqPiL4WYFk=; b=Iba71XEUCtey35d9wY4X2hnbJrAlYwV0GZOKjNaEh8jAPy7xAK6ytBq6QznADMk1wg pJ63cuFOm4GP9rBlAb0kxvjWwljlE3CYz9dvg//WCc9+P64KjKJNp/5S1j/YQjwU9+rW LRzcFSgIeZGUaSf9tSxb06MXrqtLHK6NDCEjLqlO4D5Sn9DDctblxjKKfJXa5yfStL4V ivGMqMF4rTy/zmro0dkH7hgYtc2P4IqFJBGZyIBeZnkDh4sL+kfobXK1geefwFm91/Ev QQezWrchb7QEinT2ar8mquzCfJ4gn6DTe6xMr4vJAWiEwcFQqqQ5io+r8seWFYNKLMiI rCMQ== X-Forwarded-Encrypted: i=1; AJvYcCXuDN4OUsuefK/KeNHQzeDx72Qr69xLe0hVDlQYIZKn7TwaQC15ysEDbEYRvnKNWDehEdQoZj6oUK71JBkL@vger.kernel.org X-Gm-Message-State: AOJu0YzJcTpieh8BICxzLpq3zO3EzQezHq/z2TwhaQxW+AZtimWLsf3b Ap1PZ5Gxq1V8Yqh9EVnpfvFrfze/CQiyXCOSJB9f0g4FoIfAunYo29RGWQ5MhsgjzLxLWnGU3ti 5xRKziksXyi37L/P/j2H3ETIfDjqo9HEyN/72qGoZDWRKp1TdXo90PLcq6WExXlRIHzk= X-Gm-Gg: ASbGncs0S2K+jfqI2Pnx7XULy1WZKlEETQGCL+kXERnj94C3RbrAohNrDDYDTlE6K03 fVU3kvt28mEqn/lZtyvQMrgla3/EBjyDdWBFcdOn4U2VkfbB/SY0cwnqPUkEzvmtONi6gN//4H0 ieAQTvXBa/cC4/apwGO/slpzAISQ7IB2u293hoD8xxtU7N+aVIN9WoP4joy7eSArM4w6S1U20t5 uUjx70pkiuFkg+ErIhcuhMgu0ZX1JRpSbX5/lOJBKxZqk+YYr3iubcL10/lL93RwnlVixWfKciL QgbCY4TivwMOus020jVruwEplbjPNu29DKrLsBPCbqksN6+08K4j24t/0+GezelVYwYt7U0po19 Do2/vkOgT3jmWsHUD5oIhc/6YCUdDrDmoUjzO3oM0ULA6UCNjxQ== X-Received: by 2002:a05:6000:144e:b0:3a4:f520:8bfc with SMTP id ffacd0b85a97d-3a6d1322c05mr10926214f8f.36.1750693076849; Mon, 23 Jun 2025 08:37:56 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGnHfiFTC2ctHK0b/URPEZQLv2MoweNgFEhgPjLIeowyO7+RFR4pWrjKqMuwlyrsxqk2Ekvug== X-Received: by 2002:a05:6000:144e:b0:3a4:f520:8bfc with SMTP id ffacd0b85a97d-3a6d1322c05mr10926168f8f.36.1750693076380; Mon, 23 Jun 2025 08:37:56 -0700 (PDT) Received: from ?IPV6:2003:d8:2f4e:fd00:8e13:e3b5:90c8:1159? (p200300d82f4efd008e13e3b590c81159.dip0.t-ipconnect.de. [2003:d8:2f4e:fd00:8e13:e3b5:90c8:1159]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3a6d0f1d902sm9524926f8f.43.2025.06.23.08.37.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 23 Jun 2025 08:37:54 -0700 (PDT) Message-ID: <6406fd6e-907e-4c7a-96d1-def6a9a69a49@redhat.com> Date: Mon, 23 Jun 2025 17:37:51 +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 RFC 08/29] mm/migrate: rename putback_movable_folio() to putback_movable_ops_page() To: Matthew Wilcox , Zi Yan Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-doc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, virtualization@lists.linux.dev, linux-fsdevel@vger.kernel.org, Andrew Morton , Jonathan Corbet , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Jerrin Shaji George , Arnd Bergmann , Greg Kroah-Hartman , "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , =?UTF-8?Q?Eugenio_P=C3=A9rez?= , Alexander Viro , Christian Brauner , Jan Kara , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Minchan Kim , Sergey Senozhatsky , Brendan Jackman , Johannes Weiner , Jason Gunthorpe , John Hubbard , Peter Xu , Xu Xin , Chengming Zhou , Miaohe Lin , Naoya Horiguchi , Oscar Salvador , Rik van Riel , Harry Yoo , Qi Zheng , Shakeel Butt References: <20250618174014.1168640-1-david@redhat.com> <20250618174014.1168640-9-david@redhat.com> 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/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: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 18.06.25 22:04, Matthew Wilcox wrote: > On Wed, Jun 18, 2025 at 03:25:46PM -0400, Zi Yan wrote: >> On 18 Jun 2025, at 15:18, Matthew Wilcox wrote: >>>> Why not use page version of lock, unlock, and put? Especially you are >>>> thinking about not using folio for these pages. Just a question, >>>> I am OK with current patch. >>> >>> That would reintroduce unnecessary calls to compound_head(). Right. And I want to make it clear that everything that uses "folio" here must be reworked: not necessarily switching to the "page" variant, but actually by implementing it entirely differently. (e.g., store them in an array instead of a list, get rid of the lock bit, try getting rid of the refcount as well) >> >> Got it. But here page is not folio, so it cannot be a compound page. >> Then, we will need page versions without compound_head() for >> non compound pages. Could that happen in the future when only folio >> can be compound and page is only order-0? > > I think the assumption that we'll only see compound pages as part of > folios is untrue. For example, slabs will still allocate multiple > pages (though slabs aren't migratable at this point). The sketch at > https://kernelnewbies.org/MatthewWilcox/Memdescs supports "misc pages" > with an order stored in bits 12-17 of the memdesc. I don't know > how useful that will turn out to be; maybe we'll never implement that. Once we have to support that for movable_ops, it will be an interesting question how to handle that. Most certainly, these things will not be folios. :) -- Cheers, David / dhildenb