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 9DC17EB48EC for ; Thu, 12 Feb 2026 09:09:10 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 163D86B0089; Thu, 12 Feb 2026 04:09:10 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 11A7B6B008A; Thu, 12 Feb 2026 04:09:10 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 046EF6B008C; Thu, 12 Feb 2026 04:09:09 -0500 (EST) 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 E64BB6B0089 for ; Thu, 12 Feb 2026 04:09:09 -0500 (EST) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id B8B25160783 for ; Thu, 12 Feb 2026 09:09:09 +0000 (UTC) X-FDA: 84435230418.18.6FD98EF Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf16.hostedemail.com (Postfix) with ESMTP id 117EF180008 for ; Thu, 12 Feb 2026 09:09:07 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=JL7zXOIf; spf=pass (imf16.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 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=1770887348; 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=E+3mySfOCyr9xxEniwc0oVzeTFE2afaJqeWbH9jB1BI=; b=NsRxFhl163yuSVUgvAY4DHvaWAZhvH8BtGAIRpaMxXdzd+GdAnNt9cOJ9+d0Nhnpe7vKyi jUHOXf83FrHxfPHloc4VGyDf9Ia5iEjRublOWxOWq0X5iR9wJgpij2HPWRQ0RI9IYMHG8y dwkKhT77XeEg0ikV92F4wxVHo9K/u/o= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=JL7zXOIf; spf=pass (imf16.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1770887348; a=rsa-sha256; cv=none; b=U649XyTqRkDTlxyy1QpBkEPpBZuVMy27dc7HXHIP9V7UDAaZRJ5AOtHeHXnTTbBRQuxatS i+89hew0bvNQgR6s2ucEbplRCIZlAluC4AQLRjTZoRdiWgFeEkguVe85Y0lrJHuxx5Rktx X5zXj1risBstETr/PUU3UyWKukmHinI= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 640F260010; Thu, 12 Feb 2026 09:09:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 40AB9C4CEF7; Thu, 12 Feb 2026 09:08:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770887347; bh=l0CiImdGPEMjvntKjVO4vTyF7c5lEReGL3YH8ki5SX4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=JL7zXOIfmbtfplPYGRKggj+zQaJ/W4E7I3zHrBBeaXS5iyDfe15uR6ojcLyHoADhz ASVbwGBjjNrJqydFjg/nqkI8DF6MlCTjypxaCqPE7UE7nu4k27rSeN/ckWyOmHYMyW QIz9WT0uvqOIPHZYIXj1uDLn9QueOOng49umF+qfRWJw4gT8oj2WMC5dEJOCAMMUzU OKBluCHgAyknx+26IfmrH/jDAGseIPsZxPQ92lk7POP0Oyd43tN4La6jxIIHfHOk7i VbduYtT6sgmjpfTTRP+yI43QIuisDCWtzpophYjXrV3ZFcfBgWkthdmqpUCbklpfIn cSnnsPmseSZ+g== Message-ID: <612ea310-699a-4fa4-b007-5b4ab5019eda@kernel.org> Date: Thu, 12 Feb 2026 10:08:49 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 4/4] mm: cache struct page for empty_zero_page and return it from ZERO_PAGE() To: Mike Rapoport , Andrew Morton Cc: Andreas Larsson , Borislav Petkov , Brian Cain , Catalin Marinas , "Christophe Leroy (CS GROUP)" , "David S. Miller" , Dave Hansen , Dinh Nguyen , Geert Uytterhoeven , Guo Ren , Helge Deller , Huacai Chen , Ingo Molnar , Johannes Berg , John Paul Adrian Glaubitz , "Liam R. Howlett" , Lorenzo Stoakes , Madhavan Srinivasan , Magnus Lindholm , Matt Turner , Max Filippov , Michael Ellerman , Michal Hocko , Michal Simek , Palmer Dabbelt , Richard Weinberger , Russell King , Stafford Horne , Suren Baghdasaryan , Thomas Gleixner , Vineet Gupta , Vlastimil Babka , Will Deacon , linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, loongarch@lists.linux.dev, linux-m68k@lists.linux-m68k.org, linux-openrisc@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-mm@kvack.org, x86@kernel.org References: <20260211103141.3215197-1-rppt@kernel.org> <20260211103141.3215197-5-rppt@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: <20260211103141.3215197-5-rppt@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam12 X-Stat-Signature: 96i59qnggdot4g9qjidhm781cmxsjh59 X-Rspamd-Queue-Id: 117EF180008 X-Rspam-User: X-HE-Tag: 1770887347-876074 X-HE-Meta: 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 mqyM50Cc NgjuQq0d28+R9Cyey/u486MbeHbWqVpozavhzuZh5ef7LYfDd2X6cyG/hseJKHexZHCmf38DJiB8AEKKZU4dalyEUp6r71h7reIZAmedNeMsrgjcaHD09/MFT5k67NaEGcfog5oLELycj1WXX3VZlc4eEvRjTA1JAuldt4zrSQrQ48s2oyKRKL+PCZ2WD+Fj4ySwQoxShrEY5tFbfQNq1VA711hxqQjsQsIrVjzlEHo48+5MCpAIF8hOWOZzso/fOPuEgab97AaxROPp9uR0ECT7dzA0gTqWKqiDpw/ZIJ9kQvTTRex1SgTCYyAti9aNZJXuKQV2KKWw5+pGJxPRcXuz/MIPRDsNs7xBK+tLrzs8lNvm6ci5vhB+uzfuwR1+FPB0j8KLGM+/ne2Q= 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: On 2/11/26 11:31, Mike Rapoport wrote: > From: "Mike Rapoport (Microsoft)" > > For most architectures every invocation of ZERO_PAGE() does > virt_to_page(empty_zero_page). But empty_zero_page is in BSS and it is > enough to get its struct page once at initialization time and then use > it whenever a zero page should be accessed. > > Add yet another __zero_page variable that will be initialized as > virt_to_page(empty_zero_page) for most architectures in a weak > arch_setup_zero_pages() function. > > For architectures that use colored zero pages (MIPS and s390) rename their > setup_zero_pages() to arch_setup_zero_pages() and make it global rather > than static. > > For architectures that cannot use virt_to_page() for BSS (arm64 and > sparc64) add override of arch_setup_zero_pages(). > > Acked-by: Catalin Marinas > Signed-off-by: Mike Rapoport (Microsoft) > --- Acked-by: David Hildenbrand (Arm) -- Cheers, David