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 48ED7C9833F for ; Mon, 28 Sep 2026 12:06:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 659936B0088; Mon, 28 Sep 2026 08:06:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 60AA06B00A7; Mon, 28 Sep 2026 08:06:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4D3136B00A9; Mon, 28 Sep 2026 08:06:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 2182B6B0088 for ; Mon, 28 Sep 2026 08:06:57 -0400 (EDT) Received: from smtpin05.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 8A11E1C1C2E for ; Mon, 28 Sep 2026 12:06:56 +0000 (UTC) X-FDA: 85263044832.05.ADD247C Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf25.hostedemail.com (Postfix) with ESMTP id C0C09A0004 for ; Mon, 28 Sep 2026 12:06:54 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=ZM4pATIs; spf=pass (imf25.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1790597214; 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=X+J2tmzVsgooMXBbKivE7bEvNfx2Ag9Y7fspt+jroYc=; b=UF32U5v1D4BC2hMc8g+MxojzWIrj/IdFi9p5AhlUmCQUm/Fl8ynEoa2R1e+0b73/szlMne wR4QeLiCT6cBkLzBI5ShMJVTeRNfg8+qec9X65Gjw3o9UgLdP0nzDCqMTXH77NipJZhsw9 zNcL1ppnXKY43IkGLnJtboz9lE6xVn0= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=ZM4pATIs; spf=pass (imf25.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1790597214; b=An8eVBxykXXnnaVXSgJbpJE+zbGJzHHO2jRoxDnS83jNeCDHVZFERvxr6VG+/orkP+5O13 eObr3wllxD9r7KjT05ufrX5OxGMVc2JklSQuMQSZuhd6Fr8dgvRJ4bQ01j+zhyztsgCI6n bMiWfQ2BGXk8wusYmgne9aepN/O6C64= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id A678843D4A; Mon, 28 Sep 2026 12:06:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5F2D11F000FF; Mon, 28 Sep 2026 12:06:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790597213; bh=X+J2tmzVsgooMXBbKivE7bEvNfx2Ag9Y7fspt+jroYc=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=ZM4pATIsX2hT8zVjh+/O7BaWcif1c4FeEots55BNVQ1Mx9iZ1bILJzL1cp3i+SxFL vDQ1FQFTOctpx4oEcNE41IjsJxt9Iu5JECieYmlGJDMh6fAwKZ38/yuPA+TLmmNwJQ 5vyj8YgTP3Gjh9k1zZWvvSc6b1EEwjnRO8tk7IYj5gqdkMRHc0o3fvlQ36u2GJWF2E 2cV8TbA4Ffe7iKukUkkOEq6+eRTjIaIyJKsBC8rqm3MQQ4xvzxT7Wh4R0cWK6i2ivc LHow86aIUs5raGniD+ujL659sTH1zZI7ncmRSs78xGgDeutYj0VsS2yWSjZemekhPS 7o/JAv+f61zXQ== Message-ID: <232ea2c2-a594-4a31-8ec8-7884707f1bc9@kernel.org> Date: Mon, 28 Sep 2026 14:06:22 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 12/12] mm: change the contract for free_pgtables(), update docs To: "Lorenzo Stoakes (ARM)" , Andrew Morton , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Guo Ren , Brian Cain , Geert Uytterhoeven , Dinh Nguyen , Simon Schuster , Jonas Bonn , Stefan Kristiansson , Stafford Horne , Rich Felker , John Paul Adrian Glaubitz , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Russell King , Vineet Gupta , Michal Simek , Chris Zankel , Max Filippov , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Peter Zijlstra , "David S. Miller" , Andreas Larsson , Richard Henderson , Matt Turner , Magnus Lindholm , Catalin Marinas , Mark Rutland , Huacai Chen , WANG Xuerui , Thomas Bogendoerfer , "James E.J. Bottomley" , Helge Deller , Madhavan Srinivasan , Michael Ellerman , "Christophe Leroy (CS GROUP)" , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Richard Weinberger , Anton Ivanov , Johannes Berg , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Arnd Bergmann , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jason Gunthorpe , John Hubbard , Peter Xu , Yoshinori Sato , Shakeel Butt , Jonathan Corbet , Randy Dunlap Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-openrisc@vger.kernel.org, linux-sh@vger.kernel.org, linux-riscv@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-snps-arc@lists.infradead.org, linux-arch@vger.kernel.org, sparclinux@vger.kernel.org, linux-alpha@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-um@lists.infradead.org, Hugh Dickins , Qi Zheng , linux-doc@vger.kernel.org References: <20260925-rcu-pagetable-freeing-v5-0-31e91065fea4@kernel.org> <20260925-rcu-pagetable-freeing-v5-12-31e91065fea4@kernel.org> 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: <20260925-rcu-pagetable-freeing-v5-12-31e91065fea4@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: C0C09A0004 X-Stat-Signature: 5ndwu386sxtp4wmrg8tt3ynyi9soa5oc X-HE-Tag: 1790597214-29593 X-HE-Meta: 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 I5BI37Ea TBJBitwc6f6BpUEIpUPTfrDvBUR7QUGKIEMWQtmTt6gUY+/wzHua6E75VaNdI+7B7Bp6vYibY/itHKw4/x6n6H2jE629Fbo/r66xhEvyEV6AAp85hs+nNErCPqoDbEIJyPH0qMByh9TAhazOZ6iakRBTBIStW27MLEbky9rKVcQ2wRzJhn2M3LkSOGADffl6re2+SUGeq5UJWjaeOyNXd15GVYUMsiSG/dbv6w/BxFPHwobNfMvDBv1H96QRG0G5c4etuWGgCZqFWGPgg4p72RJMGqq3rXiyh3mKp5talSqPXxvzJ5PeSU3UfsByXmjXgo6htw1OfuCX+wOz6uqncpFB6QHkD6t4Qx1Qzt7XbTZIjtmMs/QEDcSbzh6nTbd7LCGuIpOY89I+7T6O/DINB327hPg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 9/25/26 22:09, Lorenzo Stoakes (ARM) wrote: > Now that page tables are freed after an RCU grace period, it is safe for > read-only page table walkers to walk page table ranges that are being > concurrently torn down, provided the mm is kept alive via mmgrab(). > > It is however unsafe for writers to do so, as they must obtain an > appropriate lock to do so safely. > > Update the pte_offset_map_lock()'s comment block to reflect this. > > Similarly update the process addresses documentation. > > Acked-by: Kiryl Shutsemau (Meta) > Signed-off-by: Lorenzo Stoakes (ARM) > --- Acked-by: David Hildenbrand (Arm) -- Cheers, David