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 D6B78C79FB6 for ; Wed, 9 Sep 2026 13:39:42 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D4D2F6B0095; Wed, 9 Sep 2026 09:39:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CFE926B00AA; Wed, 9 Sep 2026 09:39:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BC6346B00AB; Wed, 9 Sep 2026 09:39:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 9E50F6B0095 for ; Wed, 9 Sep 2026 09:39:41 -0400 (EDT) Received: from smtpin15.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 0AA1B1C035D for ; Wed, 9 Sep 2026 13:39:41 +0000 (UTC) X-FDA: 85194331362.15.81E9C83 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf31.hostedemail.com (Postfix) with ESMTP id 5A98420005 for ; Wed, 9 Sep 2026 13:39:39 +0000 (UTC) Authentication-Results: imf31.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=aLPoNRcJ; spf=pass (imf31.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 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=1788961179; 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=2iP4r/Esf2pGXwRFwOfaFPtixVlzXtak19L1ZuCehHI=; b=7swE/lrAgEnWPZGHXQ4SY4j5gdcLIh2rA+RwPP37E+Ej7HwGBeaEYfYH4Kp1F3rS/UeR1o YMyxoZC8OI/9Lduay0PgmOF9OvRuF7IGxH0n/moTa6vDlZvy5Mx5lUIEBOCtYOSTzXunj9 f5U+acZxtMp1g436ja67xnIr0un7nJA= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1788961179; b=F25F7qKwGiEP3UuOx4GQYBQG/6m62Xmpe0PA1RqR4kEiFVPcGp+OgMQMFbXF4un5NC6eCg cDEA1J8kA7oPWAkCcgYgn1RjI+FChisJj7bev/QwZ5ydAnnx3eZ7ZgFxSMujBf81IqoGx4 lXm5liicuxcXHfYfmW6dbl/yKbr7VrM= ARC-Authentication-Results: i=1; imf31.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=aLPoNRcJ; spf=pass (imf31.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id B748860211; Wed, 9 Sep 2026 13:39:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DE4BA1F00A3A; Wed, 9 Sep 2026 13:39:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788961178; bh=2iP4r/Esf2pGXwRFwOfaFPtixVlzXtak19L1ZuCehHI=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=aLPoNRcJrIUL+1yqxoKS9+amtbp4r91seb6cACR5mTIDhpdc6wojfjfrTvCip5Glu tA7h5LfhL6E3cdvU+mtaMv36LFxeTn7cXy5YIvtuhuR1FyBs64qdeFCrBDIAu1eh/C IH0pR+3/vxzT3FMaHyneR1NIdYVAntqyeB1fpYiYh4QZq5ZGWsgi+avt6V6DFgbJzC QPOVxXnt+bRM9lkBejCdDiKLSUUL+oWMULfrXtNJ+Yhd6QxmbozNFQr9msKbjaC/Sy iM6lNn/cbUanuJCiCnm8KC0R3c923oFV9IZGvBgvEuaAxXL6jSzWrlNzAACXjnRwiw V/LNo3CKTkobQ== Message-ID: Date: Wed, 9 Sep 2026 15:39:33 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 10/17] mm/hugetlb: switch HugeTLB to section-based vmemmap optimization To: Muchun Song Cc: Muchun Song , Andrew Morton , Oscar Salvador , Mike Rapoport , Vlastimil Babka , Lorenzo Stoakes , Michal Hocko , David Laight , "Liam R . Howlett" , Suren Baghdasaryan , Qi Zheng , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20260825084608.47437-1-songmuchun@bytedance.com> <20260825084608.47437-11-songmuchun@bytedance.com> <67dc7ac8-b39d-4354-8cbf-f2a1c3a369ee@kernel.org> <82CAF33D-2482-4E8B-826D-8AF5E6FF8866@linux.dev> 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: <82CAF33D-2482-4E8B-826D-8AF5E6FF8866@linux.dev> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Stat-Signature: qp55dnkhinfrox5miky88afqipwcpmmt X-Rspam-User: X-Rspamd-Queue-Id: 5A98420005 X-Rspamd-Server: rspam03 X-HE-Tag: 1788961179-27120 X-HE-Meta: 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 EaqaTZcL EOA7tXGv5meotObQziOJygTVBHDX8C70sO5l8y27auZU7mgK0+PkrXN6K7NpnrAnE6+F47b4vcDFz9x49XgCURQX/ePhjQT04SVEks7+W1qSfcygiRamYAi0cYeq7PIvDbS2IDCvQh1fTCW1TgZF9CwdnvmNZeZZO0mK6yOtG+gFeUEDMc7yiQkBFW07cA7NBJDY0m46JwowDgP2lIuGOSoG3pTZ9Ky/qhYkIkXtR0v0hJSTGCsfXHebteE2XUBrYzbdzhkxlFCPZpIa+Yxd1N9nFQWqa00auAjVT/Ruaf6kpvdhhAaL2pev44qJSrxg+ackgw+hiMaFD49ep/6ISgr1tFX7XdIcyRxYQxNAQouTzeZaRcA50cuiKj1XA715gTsbn Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 9/9/26 15:08, Muchun Song wrote: > > >> On Sep 9, 2026, at 17:58, David Hildenbrand (Arm) wrote: >> >> On 8/25/26 10:46, Muchun Song wrote: >>> HugeTLB bootmem vmemmap optimization still carries its own early setup >>> path, including pre-populating optimized mappings before the generic >>> sparse-vmemmap code runs. >>> >>> Now that the section-based vmemmap optimization can derive HugeTLB >>> vmemmap deduplication from section metadata, HugeTLB only needs to mark >>> the bootmem huge page range with the appropriate order. The generic >>> sparse-vmemmap population path can then allocate and map the shared tail >>> vmemmap pages without any HugeTLB-specific early population code. >>> >>> Do that by setting the section order when a bootmem huge page is >>> allocated and dropping the dedicated pre-HVO helpers and related >>> special-casing. >>> >>> This removes duplicate early setup logic and switches HugeTLB to the >>> section-based vmemmap optimization path. >>> >>> Signed-off-by: Muchun Song >>> Acked-by: Mike Rapoport (Microsoft) >>> --- >>> v3: >>> - Use the order-based helper for the bootmem vmemmap-optimized check >>> >>> v2: >>> - Collect Acked-by from Mike Rapoport >>> --- >>> include/linux/hugetlb.h | 1 - >>> include/linux/mm.h | 3 -- >>> mm/hugetlb.c | 30 ++------------ >>> mm/hugetlb_vmemmap.c | 90 +++-------------------------------------- >>> mm/hugetlb_vmemmap.h | 14 +++---- >>> mm/sparse-vmemmap.c | 31 -------------- >>> mm/sparse.h | 27 +++++++++++++ >>> 7 files changed, 42 insertions(+), 154 deletions(-) >> >> Nice cleanup. >> >>> >>> diff --git a/mm/sparse.h b/mm/sparse.h >>> index e4617f9c8876..049272aba84e 100644 >>> --- a/mm/sparse.h >>> +++ b/mm/sparse.h >>> @@ -16,6 +16,24 @@ static inline unsigned int section_order(const struct mem_section *section) >>> return section->order; >>> } >>> >>> +static inline void section_set_order(struct mem_section *section, unsigned int order) >>> +{ >>> + VM_WARN_ON(section_order(section) && order && section_order(section) != order); >>> + section->order = order; >> >> As raised previously "section order" is entirely unclear. If this is a compound >> page order we should spell that out. > > But I also have another question. Should I also rename the helper name, > like section_set_compound_order? or it is enough to just renaming > the field name? Rename the helpers please. A memory section has a size (which is a power of two / order). The page order used inside the section should be clearly separated. BTW, I didn't mention it yet, but I really enjoy this cleanup. -- Cheers, David