From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 12D464BE44C; Thu, 10 Sep 2026 15:15:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789053327; cv=none; b=Aj784+1oz4ZvErNpI3uEZmJswbjhEggvqr3G0XThTvf8FBpRB+vb37Uzgd3d9m92amipHtXhxN7ZttziIf7SQZENteu9FvtKpZOoI6/yC8noOyZflG83hQkDsAmMxiViWNY9oImyx7/8x2ruXh8HDG0UbCxQgXR+NWgUBEIQ0so= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789053327; c=relaxed/simple; bh=ffb815Sk7SvWr8R4++zCIiYhle6cC/UPA1DRcUOZMdY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rUcAsfyAIrKh1LxBXXFei5l4AyWCfj9qaaEGPzZIJP/Zjx6K2v3F4VLw/a7j2gMflUjLrPjAWNKtHF8eRK/Ky5U5sEogH+lCziO5X6bb2kqFcID9eJS1C+nsVxzxLfQLg+5XQgxBvW5ztTBdwQho4quuLrnXKz/nSENnd/NAwDQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ChFiY7I3; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ChFiY7I3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E86291F000FF; Thu, 10 Sep 2026 15:15:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789053318; bh=sEjaO8gOjD9f0+2IPCgP2BKjHuk9oDJMBENGv6o5iiw=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=ChFiY7I337QtzPmO3e7pcxLcEiMW3c1lGj7lAr0LVceobI2YDbaaxxmH1dC6zorIl 2CRvuMT7kg+rqXci4EFF4yJVGlkA9vNas9C0TInFKFDfqxKNb1rFMxCNo3/1UDihoW 0haaIsYy1dqa2/uNbuReA4WEbIKSJUekxWb70+W2gE8zsXlrbQXX9zzoKrfBQfs+Xn AhtS0iR5gFi2a/NG5ov/TJGW8Jqkth5BTSjOvDdr8srlm7rb/N3mlos5XxV9Sf5lLX LTajdiF1XC6BWLtjJtFqM4hjql8Y6Q2miG/DHnk/ybv8hIF0IVrw5RJ/A5GY1rJrk0 60aIeb92PeZwg== Message-ID: <73b9f7b5-1c4c-4b03-92a4-8b093a5c9a04@kernel.org> Date: Thu, 10 Sep 2026 17:15:06 +0200 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 12/12] mm/memory_hotplug: drop CONFIG_HAVE_ARCH_PFN_VALID handling from pfn_to_online_page() To: "Lorenzo Stoakes (ARM)" Cc: Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kairui Song , Qi Zheng , Shakeel Butt , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , Brendan Jackman , Johannes Weiner , Zi Yan , Oscar Salvador , Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , Jan Kiszka , Kieran Bingham , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-cxl@vger.kernel.org, driver-core@lists.linux.dev, linux-fsdevel@vger.kernel.org References: <20260909-b4-sparsemem_cleanups-v1-0-008fc8d579fe@kernel.org> <20260909-b4-sparsemem_cleanups-v1-12-008fc8d579fe@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: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/10/26 16:47, Lorenzo Stoakes (ARM) wrote: > On Wed, Sep 09, 2026 at 03:33:05PM +0200, David Hildenbrand (Arm) wrote: >> Drop CONFIG_HAVE_ARCH_PFN_VALID handling, as CONFIG_HAVE_ARCH_PFN_VALID >> is never used with CONFIG_MEMORY_HOTPLUG, as the latter depends on >> CONFIG_SPARSEMEM_VMEMMAP. Make sure it stays that way. > > So argument is: > > mm/Makefile: > > memory-hotplug-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o > > Is memory_hotplug.c even compiled at all? > > mm/Kconfig: > > menuconfig MEMORY_HOTPLUG > bool "Memory hotplug" > select MEMORY_ISOLATION > depends on SPARSEMEM_VMEMMAP > depends on ARCH_ENABLE_MEMORY_HOTPLUG > depends on 64BIT > select NUMA_KEEP_MEMINFO if NUMA > > $ cd arch > $ rg HAVE_ARCH_PFN_VALID > Kconfig > 1762:config HAVE_ARCH_PFN_VALID > > arm/Kconfig > 94: select HAVE_ARCH_PFN_VALID > > arm/mm/init.c > 121:#ifdef CONFIG_HAVE_ARCH_PFN_VALID > > arm/include/asm/page.h > 178:#ifdef CONFIG_HAVE_ARCH_PFN_VALID > > m68k/Kconfig.cpu > 23: select HAVE_ARCH_PFN_VALID > 40: select HAVE_ARCH_PFN_VALID > > arc/Kconfig > 463: select HAVE_ARCH_PFN_VALID > > All of arm, m68k and arc are 32-bit arches so by definition MEMORY_HOTPLUG > can't be selected. > >> >> Signed-off-by: David Hildenbrand (Arm) > > So LGTM and: > > Reviewed-by: Lorenzo Stoakes (ARM) > >> --- >> mm/memory_hotplug.c | 9 ++------- >> 1 file changed, 2 insertions(+), 7 deletions(-) >> >> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c >> index b428da66d279c..58ce35cb48f57 100644 >> --- a/mm/memory_hotplug.c >> +++ b/mm/memory_hotplug.c >> @@ -344,6 +344,8 @@ struct page *pfn_to_online_page(unsigned long pfn) >> struct dev_pagemap *pgmap; >> struct mem_section *ms; >> >> + BUILD_BUG_ON(IS_ENABLED(CONFIG_HAVE_ARCH_PFN_VALID)); > > Haha nicest way of removing some later code I've seen. Just make it not compile > if such a thing happens :) Better be safe than sorry :) Thanks! -- Cheers, David