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 B8365EB48EE for ; Thu, 12 Feb 2026 09:04:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D577B6B0005; Thu, 12 Feb 2026 04:04:25 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D18456B008A; Thu, 12 Feb 2026 04:04:25 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C31A56B008C; Thu, 12 Feb 2026 04:04:25 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id AFFF06B0005 for ; Thu, 12 Feb 2026 04:04:25 -0500 (EST) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 5C802BB22F for ; Thu, 12 Feb 2026 09:04:25 +0000 (UTC) X-FDA: 84435218490.27.6CCB9CB Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf02.hostedemail.com (Postfix) with ESMTP id 83A5680006 for ; Thu, 12 Feb 2026 09:04:23 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=bNnfeoAt; spf=pass (imf02.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=1770887063; 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=PDxX4Bl5Xr/BgdWguC8kIXgQbO6qTM/fd2AbuaAVfA4=; b=COex/q2kjqx935eDaO8EAzwGwUeKTw0NVRKVGLSQUppArEQFq/8/pA8KH+WRAojeJevD7N YuHpIzUnCwKtKCVSMT1AZ7n5ECv5vLCMpQlr9l7+gkWwjoc8RikIKuJad9Rl0e7jbPvYhk wSsqTy3if9ltI/QXr0elCLKatbqKNuc= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1770887063; a=rsa-sha256; cv=none; b=1613okTZK2wjIoMRdhyGk+iCKjnKlomlYHIC6lYW7x9XQPyCi0axJZAO83CT86P8My4PoX r5frldn/PZXBJQimhJ+Z62t+m36h5Rp634GVewg/35NFW32nKJIMP3UbVzN5Zp53Aw3H5p KGPxKK7C0n71TGBCbu7rV40F4Ll4xDU= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=bNnfeoAt; spf=pass (imf02.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 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 8D21A43674; Thu, 12 Feb 2026 09:04:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 71D11C4CEF7; Thu, 12 Feb 2026 09:04:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770887062; bh=YEYpkZLUlFlbKqsflfJtNOc0Ggxqs/f6W1To9Vfn59U=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=bNnfeoAtLa0hXzqKvIHyMr+ZKSt/lTaoozr8i/6qDMdX4Qr32k5vitKFWpZlh6DUL oczE+Hxh/xEnDXFfN75yR2w3uM7CES3YXY+JPyKSIeq2VOME6/iAhIfRixWe2Rdadh m/AZVkOqqAKmd94qCKEq7WAenzya93vkXzxgMvl0UN23v/bMwExSikhLVZ8nbVOzxZ hs0J0u9sH20XFuQm0shKmxoYkayELZlvDkHTH3V8ZK9dVNOT7TDHe+AD+hVj4+Ir0K Jiil+G/E0XS9gXCgcx7aaQbCEAvbEQCHcOb8Su7LVvRbbF7CmIgrxOnRops3vHvHY+ CXFHXEkFDaAcw== Message-ID: <79b41762-fb76-4443-9f38-98be1045322f@kernel.org> Date: Thu, 12 Feb 2026 10:04:03 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 3/4] arch, mm: consolidate empty_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> <20260211103141.3215197-4-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: <20260211103141.3215197-4-rppt@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 83A5680006 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: pdpibaeujj5d8bstxnkgnujb368kb71x X-HE-Tag: 1770887063-603880 X-HE-Meta: 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 CEAWskxX JMfGkBw3guauhFz1R2ITivNS3SPEKIt5kR55lPQhdoNAn83EMrT4+v/qXdRgrYcB3R+6T4F03L5jxu92+ZG4zw5NXSSM+/z1j59ARGaHVnLmrplW08k7Vfj9rusb4psnu975U1kdf0IuXvfb2npNU+T6Rsb6h/YN5LLd3gpdJX09EudMN7WVQrUEbxZCT8GWYPd+wbxaXkz/yvoDpYceaAtMWJ7s14pXS07tLCAB2fC7Kb16XzJVeGpX31qubl03mL2wD+BcrUY/97pcJlCabIZWYIJKAeLchuAnn7Fw3eD6qaJNSfliS7+7wc4kp+PUR9XbWZQABwu+0w3eBZeOIgiehMZ9nqaVn9ZxurhyZUdPqivGwiIQuVXEkhfkrOfW0Pnrm/6Yf8muW7+a8bL/zKMLoXWVc59GEoIIP 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)" > > Reduce 22 declarations of empty_zero_page to 3 and 23 declarations of > ZERO_PAGE() to 4. > > Every architecture defines empty_zero_page that way or another, but for the > most of them it is always a page aligned page in BSS and most definitions > of ZERO_PAGE do virt_to_page(empty_zero_page). > > Move Linus vetted x86 definition of empty_zero_page and ZERO_PAGE() to the > core MM and drop these definitions in architectures that do not implement > colored zero page (MIPS and s390). > > ZERO_PAGE() remains a macro because turning it to a wrapper for a static > inline causes severe pain in header dependencies. > > For the most part the change is mechanical, with these being noteworthy: > > * alpha: aliased empty_zero_page with ZERO_PGE that was also used for boot > parameters. Switching to a generic empty_zero_page removes the aliasing > and keeps ZERO_PGE for boot parameters only > * arm64: uses __pa_symbol() in ZERO_PAGE() so that definition of > ZERO_PAGE() is kept intact. > * m68k/parisc/um: allocated empty_zero_page from memblock, > although they do not support zero page coloring and having it in BSS > will work fine. > * sparc64 can have empty_zero_page in BSS rather allocate it, but it > can't use virt_to_page() for BSS. Keep it's definition of ZERO_PAGE() > but instead of allocating it, make mem_map_zero point to > empty_zero_page. > * sh: used empty_zero_page for boot parameters at the very early boot. > Rename the parameters page to boot_params_page and let sh use the generic > empty_zero_page. > * hexagon: had an amusing comment about empty_zero_page > > /* A handy thing to have if one has the RAM. Declared in head.S */ > > that unfortunately had to go :) > > Acked-by: Helge Deller # parisc > Tested-by: Helge Deller # parisc > Reviewed-by: Christophe Leroy (CS GROUP) > Acked-by: Dave Hansen > Acked-by: Catalin Marinas > Signed-off-by: Mike Rapoport (Microsoft) > --- Acked-by: David Hildenbrand (Arm) -- Cheers, David