From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 93B09770FE; Thu, 12 Feb 2026 05:33:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770874394; cv=none; b=GJTIWK3oDzvaitiEk0lkhQGTq72K6cM9r9m2hRcFsVj+dySdcRDVRy9FGMHdjIAKdwKupyLQQ0yifeWzYBrike/bvgpmuE661dFmlYum6qRW9ECi+BRHMocS6dIVDHpcIqgB7gjaH2YWnqI2dq+ptZ9DFD8M1IK8Q/ZNy5/VTEc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770874394; c=relaxed/simple; bh=xWdXZIArybbo9Rgxccq3nL2HLMDxrTRxGRMmTyJ92Ek=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=djLoT/Kk+9pEThaGVdBaSXB+pnlsoiQYT0rKVdT8qURacVBExasiHj3cExYDf2uBH3AM8sniqmB55G3YGDOad51dHtI84pXJxrvYa2yMFwHTFif8dHUu/T9JskUqQ7rmlyQHNg5oH6W9X8bIE2kKW4rHsgveD1zDPyK/zeqUoWA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fnRt4bNT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="fnRt4bNT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D227FC4CEF7; Thu, 12 Feb 2026 05:33:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770874394; bh=xWdXZIArybbo9Rgxccq3nL2HLMDxrTRxGRMmTyJ92Ek=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=fnRt4bNTruqGWDCex4UgCYs5xfFXruN8Lon65hP9g22+WBdZKtSwF7Vlpe0Cerco4 bvwxt2r8yj+pM8xOwU8CRkM4OmUaUA/+Tzc72yQC0G+UVZeUmzyMyMPGyxL/xNIa4X +/VC+HyZKbjW0nnljKGakLZZFB897pqnLw9d71EIpoTCJ5wnD5VHVMEklBRL/Jcabq Mwmjfv/JZu6GfI7SyoqZ+mxEsaOK/PQXeGkhDnmh+ztI8JZFzkYG9tnpHFUHqIR6N4 w+N5IHX73Du91X+qNAEJ7TQrDCCl9z1LnQGwJBdYZfNUoF2uBKOsddFYGgsxivKLws KFvp/8rynpEOQ== Message-ID: <0b420450-a85f-4f7c-93c2-4d2de37d257b@kernel.org> Date: Wed, 11 Feb 2026 23:33:09 -0600 Precedence: bulk X-Mailing-List: loongarch@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 3/4] arch, mm: consolidate empty_zero_page Content-Language: en-US To: Mike Rapoport , Andrew Morton Cc: Andreas Larsson , Borislav Petkov , Brian Cain , Catalin Marinas , "Christophe Leroy (CS GROUP)" , "David S. Miller" , Dave Hansen , David Hildenbrand , 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: Dinh Nguyen In-Reply-To: <20260211103141.3215197-4-rppt@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2/11/26 04:31, 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) > --- > arch/nios2/include/asm/pgtable.h | 7 ------- > arch/nios2/kernel/head.S | 10 ---------- > arch/nios2/kernel/nios2_ksyms.c | 1 - For nios2, Acked-by: Dinh Nguyen