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 492F4EC1106 for ; Mon, 23 Feb 2026 16:20:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 845396B008A; Mon, 23 Feb 2026 11:20:29 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 81CF06B0095; Mon, 23 Feb 2026 11:20:29 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 72FBD6B0096; Mon, 23 Feb 2026 11:20:29 -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 5BC646B008A for ; Mon, 23 Feb 2026 11:20:29 -0500 (EST) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 0A01F1B5522 for ; Mon, 23 Feb 2026 16:20:29 +0000 (UTC) X-FDA: 84476234178.24.62BE4DF Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf07.hostedemail.com (Postfix) with ESMTP id 34A6E4000F for ; Mon, 23 Feb 2026 16:20:27 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=PvSQrdeo; spf=pass (imf07.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=1771863627; 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=NVI0Y7WWrko3nhGx2NU9ZJ8Sd9AAcRODnva0eiUT/8w=; b=GWuIPbUU4HuBK/55FWhhtkDjDRlzaoQw7YwBZEhmGd+DzFH2IRWeD80KSqUPLsh17du/y3 Z2MjbY0xYFMk/aelSsGzcM39oR7y9oZmmok1qa+pnGID9ZPsyuaos7sJU5Fv751KvIhNFj OOnVXTcSCVRti1c9YkIyoWA+u4/DMW0= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=PvSQrdeo; spf=pass (imf07.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=1771863627; a=rsa-sha256; cv=none; b=xrDyYlHe22yEG0qJOYgYRmvYuV9HK6/LRjF3IjeYxHh08+4K1rqWpoZeB54YFwq/wXNtYi kc4LHWup4CZ5j9d8xwVcH2WP6DohGSeVhp+aZE1NEAiSWsl+99UqEBc3n5ybZ3t/K26gV7 6CLOPH27jXMhPBbIpui9w6z2uOX0FWo= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 8C6BF6013A; Mon, 23 Feb 2026 16:20:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 491D5C19421; Mon, 23 Feb 2026 16:20:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771863626; bh=r8mDeUpeW8tBUm82rtc4kcjK4ONsKrxt6c1CNArIpvE=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=PvSQrdeocpoNN0p9MaK3sggyEhP6bDqgKlYc4yggH5rAQfcrJSEuKTtELQhVIOkjx 27RQ0W9Om2jLvItanmN74NXkqDRCxLkjXjaCXz5bEKdFVStFxL1rlOWFSZbj8akEiQ RTIy9lvApB5TO1WlSYuX4YYlQUEqNRrOHfiiFgYlCTl+BgTe7OSrlqkia9urvm4gfH wEnzHCtCVlI5CNU0NW15/hd1zgUBBwRbdtJjTdH3whUnlSskR3W3fdLulPBddBqTd9 p/zoAG/hQZwKDfywAO//6WYOrm1PgrTL/1tu0We8q3IF+9vQhWyrE7DidGdwP4gezC Z3Nfs3HSc7qbw== Message-ID: <4bbe1b83-da01-4226-9a86-1bf6194c22e4@kernel.org> Date: Mon, 23 Feb 2026 17:20:13 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 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: <20260209144058.2092871-1-rppt@kernel.org> <20260209144058.2092871-5-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: <20260209144058.2092871-5-rppt@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Queue-Id: 34A6E4000F X-Rspamd-Server: rspam02 X-Stat-Signature: dhea7cgap439dyfmpqmzabfgqwkmsqsy X-HE-Tag: 1771863627-442329 X-HE-Meta: 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 ZRcLshCd 8oNQ/KHF8haUhjpnh3+oRA1qIJsAVq3OlL3TEGtNKo8dv1sri7acdvtjX+ILzDLS8qYdN+FCM/cxNrsqfyrlmvtTvCo7FyIKq+OAttl4b0XwqUP9u08lKtYqnyjiEZdsvcC7fPP9kN3LpBmSAL0OD5AmFM+FCi2VrJkARCIvNJdLeeDFl+SciOeymt/dgZNGMnA8rSHJ6wQpgEcEj1RVI0YCdoWg79GrY2H3xdcGM3sZYKcLmsINJZzcOdIE/VxVW3Hrst6ibBZ1O4Hc4es3VoCXQhqIqVZPMk+SFfx5wvY4mNTVekszXcVb8O8bNuw3VvqsceagAtsXqZpg= 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 2/9/26 15:40, 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(). > > Signed-off-by: Mike Rapoport (Microsoft) Acked-by: David Hildenbrand (Arm) -- Cheers, David