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 E9571D31A02 for ; Wed, 14 Jan 2026 01:47:25 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5DABE6B0092; Tue, 13 Jan 2026 20:47:25 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 584F26B0093; Tue, 13 Jan 2026 20:47:25 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4878D6B0095; Tue, 13 Jan 2026 20:47:25 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 35E536B0092 for ; Tue, 13 Jan 2026 20:47:25 -0500 (EST) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id F33C81AD85E for ; Wed, 14 Jan 2026 01:47:24 +0000 (UTC) X-FDA: 84328882008.02.09CC7CF Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf18.hostedemail.com (Postfix) with ESMTP id 4714B1C0008 for ; Wed, 14 Jan 2026 01:47:23 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=nMUZetUG; dmarc=none; spf=pass (imf18.hostedemail.com: domain of akpm@linux-foundation.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1768355243; a=rsa-sha256; cv=none; b=W6GEHwkk103ujuaB1a43S1qqciZ7FDYl4d9qmf8MStxspOW8UN2eZB9AvWweU9Rxpr0FFF WGSQ4RGmX/TZOo5Qo1Fcd0gJ0UkMoDL3tpIn1UOqZyrdn1Q8di90HM58GCtw4gfMVHhauB o+kCdAbpkPwS3Yn9aFn+A7FQ+CqldQI= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=nMUZetUG; dmarc=none; spf=pass (imf18.hostedemail.com: domain of akpm@linux-foundation.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1768355243; 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=CbQfZQIIOpzsrWPdxd8hqvH/53pZdu9JbkLMGzh3GNo=; b=ku3m2z6hmv2F0Ch9HWiT7Ba0RfALbqbc5q5tU6e0DPlPO7WYektNXnaFLK5BczxAP8A3Kd PqjZ12Ky+aQquJyxDrYCZhOQl+qyvyd0nK+TU7NJbfysISt2pK0djBayuWNHlESKFRgo9f rMaMlXlQkND8tEIRW5YVPtT6KMkxMas= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 91CF36001D; Wed, 14 Jan 2026 01:47:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E385FC116C6; Wed, 14 Jan 2026 01:47:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1768355242; bh=FRPsnoiRkODgwynUNMuiriUhpdUW/a1TX7VO4CmrSgY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=nMUZetUGq5t9FXORjBux3ic7ipCkK15b/0aIlPYXyzT3LjGiBNtw46yfVpPvq9gJW cCcsSL08rzEc/0uqeXKvfLPRlGr3DySymdxhtN5GVD9kXM3SOmDrlteUDE7J6MYvsP 5auIGPRnxjviXOJtvEb89I0FxT8fX0ibQE2hDtAA= Date: Tue, 13 Jan 2026 17:47:21 -0800 From: Andrew Morton To: Kefeng Wang Cc: Zi Yan , David Hildenbrand , Oscar Salvador , Muchun Song , , , , Vlastimil Babka , Brendan Jackman , Johannes Weiner , Matthew Wilcox Subject: Re: [PATCH 2/5] mm: page_alloc: optimize pfn_range_valid_contig() Message-Id: <20260113174721.1252583ed3b30c309dd91a4b@linux-foundation.org> In-Reply-To: <500811d3-67e9-44d3-bb67-095b23728aaa@huawei.com> References: <20260112150954.1802953-1-wangkefeng.wang@huawei.com> <20260112150954.1802953-3-wangkefeng.wang@huawei.com> <926A149E-FE2F-4F88-92D6-FA607398605F@nvidia.com> <9FC904C5-1C5A-45BE-BE0F-556AF573AD4A@nvidia.com> <500811d3-67e9-44d3-bb67-095b23728aaa@huawei.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspam-User: X-Stat-Signature: nctt1pk67kwreujnqp1objdawyca7a8y X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 4714B1C0008 X-HE-Tag: 1768355243-696592 X-HE-Meta: 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 aE8KCvTX 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 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 Tue, 13 Jan 2026 17:55:43 +0800 Kefeng Wang wrote: > > > > > With the changes to the commit message, feel free to add > > OK, I will update it. akpmbot already did that. > > > > Reviewed-by: Zi Yan Thanks both. From: Kefeng Wang Subject: mm: page_alloc: optimize pfn_range_valid_contig() Date: Mon, 12 Jan 2026 23:09:51 +0800 The alloc_contig_pages() spends a significant amount of time within pfn_range_valid_contig(). - set_max_huge_pages - 99.98% alloc_pool_huge_folio only_alloc_fresh_hugetlb_folio.isra.0 - alloc_contig_frozen_pages_noprof - 87.00% pfn_range_valid_contig pfn_to_online_page - 12.91% alloc_contig_frozen_range_noprof 4.51% replace_free_hugepage_folios - 4.02% prep_new_page prep_compound_page - 2.98% undo_isolate_page_range - 2.79% unset_migratetype_isolate - 2.75% __move_freepages_block_isolate 2.71% __move_freepages_block - 0.98% start_isolate_page_range 0.66% set_migratetype_isolate To optimize this process, use the new helper page_is_unmovable() to avoid more unnecessary iterations for compound pages, such as THP not on LRU, and high-order buddy pages, which significantly improving the efficiency of contiguous memory allocation. A simple test on machine with 114G free memory, allocate 120 * 1G HugeTLB folios(104 successfully returned), time echo 120 > /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages Before: 0m3.605s After: 0m0.602s Link: https://lkml.kernel.org/r/20260112150954.1802953-3-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang Reviewed-by: Oscar Salvador Reviewed-by: Zi Yan Cc: Brendan Jackman Cc: David Hildenbrand Cc: Jane Chu Cc: Johannes Weiner Cc: Matthew Wilcox (Oracle) Cc: Muchun Song Cc: Sidhartha Kumar Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- mm/page_alloc.c | 25 ++++++++----------------- 1 file changed, 8 insertions(+), 17 deletions(-) --- a/mm/page_alloc.c~mm-page_alloc-optimize-pfn_range_valid_contig +++ a/mm/page_alloc.c @@ -7157,18 +7157,20 @@ static bool pfn_range_valid_contig(struc unsigned long nr_pages, bool skip_hugetlb, bool *skipped_hugetlb) { - unsigned long i, end_pfn = start_pfn + nr_pages; + unsigned long end_pfn = start_pfn + nr_pages; struct page *page; - for (i = start_pfn; i < end_pfn; i++) { - page = pfn_to_online_page(i); + while (start_pfn < end_pfn) { + unsigned long step = 1; + + page = pfn_to_online_page(start_pfn); if (!page) return false; if (page_zone(page) != z) return false; - if (PageReserved(page)) + if (page_is_unmovable(z, page, PB_ISOLATE_MODE_OTHER, &step)) return false; /* @@ -7183,9 +7185,6 @@ static bool pfn_range_valid_contig(struc if (PageHuge(page)) { unsigned int order; - if (!IS_ENABLED(CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION)) - return false; - if (skip_hugetlb) { *skipped_hugetlb = true; return false; @@ -7196,17 +7195,9 @@ static bool pfn_range_valid_contig(struc if ((order >= MAX_FOLIO_ORDER) || (nr_pages <= (1 << order))) return false; - - /* - * Reaching this point means we've encounted a huge page - * smaller than nr_pages, skip all pfn's for that page. - * - * We can't get here from a tail-PageHuge, as it implies - * we started a scan in the middle of a hugepage larger - * than nr_pages - which the prior check filters for. - */ - i += (1 << order) - 1; } + + start_pfn += step; } return true; } _