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 AFBDEC5B572 for ; Wed, 19 Aug 2026 15:53:56 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A18626B0092; Wed, 19 Aug 2026 11:53:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9C9886B0093; Wed, 19 Aug 2026 11:53:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8B7AC6B009D; Wed, 19 Aug 2026 11:53:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 65F106B0092 for ; Wed, 19 Aug 2026 11:53:55 -0400 (EDT) Received: from smtpin16.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay10.hostedemail.com (Postfix) with ESMTP id C562EC0439 for ; Wed, 19 Aug 2026 15:53:54 +0000 (UTC) X-FDA: 85118464788.16.D1BD527 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf31.hostedemail.com (Postfix) with ESMTP id F19D120008 for ; Wed, 19 Aug 2026 15:53:52 +0000 (UTC) Authentication-Results: imf31.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=oGEaAZsL; spf=pass (imf31.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=1787154833; 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=QLHvEXhl7bh0vVvB52S7db8GJd87oXRQT+N5wVcQ1Ws=; b=D6Jifsq3GyhZvQ50xutvev/910VJx1nufURfWfEp1G68SSKSGmT00XTBK8DNuRI/iDypyz FzAR5+QHK7k587+9u5a7KTzuRgKp8IyJfwhLFFo6H0y4l2P+V+fsnMJcD9mKyKRharQd+f qQ11UFdq2RBy+Zkhp8qOExttM2/t588= ARC-Authentication-Results: i=1; imf31.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=oGEaAZsL; spf=pass (imf31.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-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1787154833; b=rhN54ZcwlzeeGXlR/J5lqGmvKGkhoqTWmw54I+4jYJG0rct3esD7rlYH4MiZ8zqXG+fWdM WNM/nfv2GqSv9yK6E6ZFOYnaRbSf4A+OPoNia2Wd+fWZdiMjVHDa2Nff6j0deHGhQHbhyK xX66JgDn3cyhshaaoP6ji56YKhH8fyY= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 13D20416BB; Wed, 19 Aug 2026 15:53:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7E5631F000E9; Wed, 19 Aug 2026 15:53:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787154832; bh=QLHvEXhl7bh0vVvB52S7db8GJd87oXRQT+N5wVcQ1Ws=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=oGEaAZsLUiOpJaCVmkYmiTswK1xknZbj0vjIV5zZsc7E6d0UpT2EhwqajNnX9CTDx clsyRk+c5aszdB0sdGkj2MwkAj47YUPGM2xS98Vc2RAPPam+Z0GAwg/DrstZ0Kz7yX yrh41chB/jZcKZpz84nhP+H7xMDPQRAhLbToA8Ga2Gr4PRpEyfHK5W44tYLki3Ey1x AnUEUKUknX2PrTQY+fLdA1c2mnIoqTj7XuT+pRCIUNfEm2wNLJmHyO7zkxg5mF6EsG Ylkuolzme/9nR60/L4lDSzBc5S0FhBY514UPxGCxCBWMShNXgd1MTeuK6r4dWyI3MH nKuXqk3wSrTDA== Message-ID: Date: Wed, 19 Aug 2026 17:53:45 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v7 2/2] mm/memory_hotplug: optimize zone contiguous check when changing pfn range To: Yuan Liu , Oscar Salvador , Mike Rapoport , Wei Yang Cc: linux-mm@kvack.org, Nanhai Zou , Chen Zhang , Jason Zeng , Chen Yu , Pan Deng , Tianyou Li , linux-kernel@vger.kernel.org References: <20260818085702.3395529-1-yuan1.liu@intel.com> <20260818085702.3395529-3-yuan1.liu@intel.com> 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: <20260818085702.3395529-3-yuan1.liu@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: F19D120008 X-Stat-Signature: mdgfjikiikwd44yfe4czkecnhgo5h7he X-Rspam-User: X-HE-Tag: 1787154832-532542 X-HE-Meta: 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 gyZkvViK JM0sZK2advy//absj332XV3yV/uAzYJJov1TShGQrrAYYoqC+1Ow950j9Dcm079xQWOO+6ZhTQV3K40YrFR805DCdoGuX/jBS3wCPqb+xlxiGObMwniyZhuiLDfT76s8DP+HAVLgN88qeZB3Ecdo0U66hHk9vQC2tm1LsRjnmOS758YEEpST51P9YqFArxCBSJznT5RoQSqbL4Efao1QGqZblSzBNWxCwJEl7KPeOBX5rib9+ydtnAeMG9E2YcnNBpsYCgvEsfBEcwnSO3A1/WTauh+drcHV/DzlW8gZUlwFTtoPZeNq1YlpTFucL/bv1H9yuODhMrEOKiIDCsWHhLYroxr9lJ1EniHvWA43OF14OwGYFXtnt4KO2qLApTe17LWsL Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > /* > * Only struct pages that correspond to ranges defined by memblock.memory > * are zeroed and initialized by going through __init_single_page() during > @@ -822,22 +844,27 @@ void __meminit init_deferred_page(unsigned long pfn, int nid) > * zone/node above the hole except for the trailing pages in the last > * section that will be appended to the zone/node below. > */ > -static void __init init_unavailable_range(unsigned long spfn, > - unsigned long epfn, > - int zone, int node) > +static unsigned long __init init_unavailable_range(unsigned long spfn, > + unsigned long epfn, > + int zone, int node) > { > unsigned long pfn; > - u64 pgcnt = 0; > + u64 pgcnt = 0, online_pgcnt = 0; > + unsigned long last_subsection = -1; > + bool is_online = false; > > for_each_valid_pfn(pfn, spfn, epfn) { > __init_single_page(pfn_to_page(pfn), pfn, zone, node); > __SetPageReserved(pfn_to_page(pfn)); > + if (unavailable_pfn_is_online(pfn, &last_subsection, &is_online)) > + online_pgcnt++; Can we avoid these helpers? const unsigned long subsection = pfn & PAGE_SUBSECTION_MASK; /* We can have section-sized online holes with VMEMMAP. */ if (IS_ENMABLED(CONFIG_SPARSEMEM_VMEMMAP) && subsection != last_subsection) { is_online = pfn_to_online_page(pfn); last_subsection = subsection; } if (is_online) online_pgcnt++; An alternative is an inner loop that just walks in SUBSECTION chunks until epfn. That would probably be even cleaner and faster. I remember !vmemmap always only has early sections when they are actually online. We could extent the comment to clarify that. (I have patches to clean that init code up) -- Cheers, David