From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793109974; b=ps6w0cUKeTybS2dg7Q6q6diVy3Hh/vOLfQU0R0zlM2B8n8ZivaUHE5ZV2XnR1h5uEghJ ZnBvZI4CuEnkJxOfKH4JKrV9tOHaIEtAUN5vy9iT6M6/AnfSX3BmV05+jf5Zu0D/BFZoi bECNkbncALmMLfPPLpbXyHxmqQQK95RkQa6KmzW09LDhRp0d1psVeFbK7XlC2FDRxNtNO 8oHtQvbp8lnh2PGfej1r6rOQ31oX02lr4jbYojMz+q/VH9kSSakD4nEHKzTWTONeLaad7 vR746LXh8Qahp4X4HfFwGsxBtYrpZj2bOpSw6B7MMhhTW41zmloFnIL10Xn+62uexlg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793109974; h=Received:DKIM-Signature:Message-ID:Date:MIME-Version:User-Agent: Subject:To:Cc:References:From:Content-Language:Autocrypt:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=82GVQF/r/unWzQfzjss77Hz55a2gB/UcDEpj21YiSxk=; b=A/05J3WsAYs87ZhwdTQ39JHEWwFllP1aSe4GI4okIbkp+bGuPR+GEg68qq0iSSVAdbaJ 1Oq9OyRRLsuoJCNzTLSJBpi5R9M3AT2dsftSJYwj/oDSfucq78JY/L9iqjLZGYgdi7s2Q JBMN5NXFfgqsY7T59Efg3oCpZA7YlG2cFEhefmiELOb+BWITrbHdr1iRYsY883g0mC6Y3 +Bb9kfTFQHZvKf07PbSbj9Vg3m2AC9ek4mcby5WWrtVKujhSuhJs8G99HlTxVK2rSs5XS OOjUx4V8c3p/poqgGlDEbs9ZmO8Mgnv/OPTkhIBs6KUDJqT+V4FHinUzMTShjxxir9g== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=nZUK+SXF; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BB3C7606A31A; Tue, 27 Oct 2026 14:06:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=nZUK+SXF Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1D0201F01825; Tue, 27 Oct 2026 14:06:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793109973; bh=82GVQF/r/unWzQfzjss77Hz55a2gB/UcDEpj21YiSxk=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=nZUK+SXFsAgy++54w5IClDKo7g3++cFiM8TnqT2+LuG2HpPq1/K3HIQXOOIqc8mVi mimy9pQ3LiHr7Uv0RMQYlxatSPdssmML/JLJvYuIdW+skcb7OAscL1zKzvE/7KFjSi C5SfM2niQETkzsKlEAsLJjyhwPpgFj3h1BLvGqJKVglngLpLProiWkhE3sxhOwjds8 Y9aYsuyyzfMODkxbCLDMI2MKNmGNxm1x3h2InAoU1pty5v5HJn/qrj2HC5Us/03zJT /pmxKM0bibEgfhWd8LG22BhwEnrdTBpRB7oS2UKU1CUeUtFxQc4UiWu8EfdKYfprbP 4ptN8qpbOZvCg== Message-ID: <99117abf-29eb-420d-bf8e-740c2068a0ba@kernel.org> Date: Tue, 27 Oct 2026 15:06:04 +0100 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 1/4] mm/rmap: duplicate a PMD mapping as one in folio_dup_file_rmap_pmd() To: "Lorenzo Stoakes (ARM)" , Konstantin Khorenko Cc: Andrew Morton , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Peter Xu , Alex Williamson , kvm@vger.kernel.org, =?UTF-8?Q?Lo=C3=AFc_Molinari?= , Shuah Khan , linux-kselftest@vger.kernel.org, dri-devel@lists.freedesktop.org, Madhavan Srinivasan , "Ritesh Harjani (IBM)" , linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Jason Gunthorpe References: <20261021-b4-prep-vstor-149847-copy_huge_pmd-recheck-special-pmd-v4-0-66f00b7a564c@virtuozzo.com> <20261021-b4-prep-vstor-149847-copy_huge_pmd-recheck-special-pmd-v4-1-66f00b7a564c@virtuozzo.com> <71101695-339d-4f8f-b9d8-dfadf7dbd0ed@virtuozzo.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+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: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 10/22/26 14:11, Lorenzo Stoakes (ARM) wrote: > On Thu, Oct 22, 2026 at 12:44:40PM +0200, Konstantin Khorenko wrote: >> On 10/22/26 10:07, Lorenzo Stoakes (ARM) wrote: >> >>> Was this a mistake in d8ef5e311d7b, or actually intentional for whatever reason? >>> If the latter this shouldn't be a fixes. >> >> commit d8ef5e311d7bfde54b60ab45026f206eff31b2d2 >> >> mm/rmap: convert page_dup_file_rmap() to folio_dup_file_rmap_[pte|ptes|pmd]() >> >> ... >> +static inline void folio_dup_file_rmap_ptes(struct folio *folio, >> + struct page *page, int nr_pages) >> +{ >> + __folio_dup_file_rmap(folio, page, nr_pages, RMAP_LEVEL_PTE); >> +} >> >> ... >> +static inline void folio_dup_file_rmap_pmd(struct folio *folio, >> + struct page *page) >> +{ >> +#ifdef CONFIG_TRANSPARENT_HUGEPAGE >> + __folio_dup_file_rmap(folio, page, HPAGE_PMD_NR, RMAP_LEVEL_PTE); >> +#else >> + WARN_ON_ONCE(true); >> +#endif >> +} > > OK so it was just wrong at the time :) > >> >> Both functions were introduced in a single commit, i think it's a simple copy-paste issue. >> >> The helper never had a caller, so nobody could hit it. If you prefer, I >> can drop the Fixes tag and only mention d8ef5e311d7b in the changelog, as >> there is nothing to backport. > > I mean, it seems like a bug to me? If there's no harm in backporting it I think you > should add Cc: stable@vger.kernel.org in that case actually. It was never used, so it's by definition not even a bug. :) Cc: stable makes sense if we want to backport it along the other things. -- Cheers, David