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 68883C61DD3 for ; Mon, 31 Aug 2026 09:45:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 647856B008C; Mon, 31 Aug 2026 05:45:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 61E5D6B0095; Mon, 31 Aug 2026 05:45:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 534B26B0096; Mon, 31 Aug 2026 05:45:00 -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 2EC8D6B008C for ; Mon, 31 Aug 2026 05:45:00 -0400 (EDT) Received: from smtpin07.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay07.hostedemail.com (Postfix) with ESMTP id A24411603E1 for ; Mon, 31 Aug 2026 09:44:59 +0000 (UTC) X-FDA: 85161080718.07.043B612 Received: from mta0.migadu.com (out-117.mta0.migadu.com [91.218.175.117]) by imf13.hostedemail.com (Postfix) with ESMTP id 7A47620003 for ; Mon, 31 Aug 2026 09:44:57 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=nozxP2y+; spf=pass (imf13.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.117 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1788169497; 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=lssN/+g4CsD3iBF3KDZ0/HynoTt5PqQamjTFAdGkwv8=; b=yMiun+eCM4vmi5NSVhQtt2DoIxLWWuL+TNTnflAUwN9Ev8xMDdk716zuTbKQtU5BVR6Bq5 uVJ3sjL1qt4cvyW+Fz+yHp5YGjMfLaeHG8A1OSeDJU4wzzs/Jp6H2b46KS55QtSI2LYCe1 ooLoMsiTq4n4znbqgDyRgRiFaCM56aI= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1788169497; b=4xuSMyazZGu8K3MvI31Nz4e0GxJxaNApzyNVeyJjE+jWagCiC0o3ryPZSGn4m/E0uQ4Bu6 I8XIQmFe9Jvl3dwf5JlTbYmWf2wzI2+r6lHbtW0WcY/1GV+Uzzq4myaTi85jOp/Wiw7BDJ KS4uF8faQolzMIjmNBub6FHWZkcA3hY= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=nozxP2y+; spf=pass (imf13.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.117 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev X-Envelope-To: linux-mm@kvack.org DKIM-Signature: a=rsa-sha256; bh=fQebo7Azp0AKIE2puaSGtaPeAdhrfMBt6pp9DjsjoIY=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1788169496; v=1; x=1788774296; b=nozxP2y+O+ZY0oaFDOzeJPJOb9gCKBWY/teoF3aGwrG4mrw/r+k2aeI5IqgECt4J6z5oI4Po L+vGlZ8Snw3uGHMYaCVOHM5FjLx+eeTK2IKVIriY931UZiMgnREdnXkJJwwfMStfde3qrkCWlSN D6dOnd9EyoIQxSQQBlzIz6sQ= X-Envelope-To: linux-mm@kvack.org Received: by smtp.migadu.com with ESMTPS id 9880a24a06b3ebf9; Mon, 31 Aug 2026 09:44:55 +0000 X-Mizu-Trace-ID: 9880a24a06b3ebf9 X-Migadu-Flow: FLOW_OUT Message-ID: <0e1c3bb8-49a4-479e-adb3-17c21261d409@linux.dev> Date: Mon, 31 Aug 2026 17:44:46 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 01/11] mm/sparse-vmemmap: introduce CONFIG_SPARSEMEM_VMEMMAP_OPTIMIZATION To: Muchun Song , Andrew Morton , David Hildenbrand , Oscar Salvador , Madhavan Srinivasan , Michael Ellerman , Jonathan Corbet Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-doc@vger.kernel.org, Muchun Song , Lorenzo Stoakes , Mike Rapoport , Nicholas Piggin , Christophe Leroy , Randy Dunlap References: <20260831075342.57563-1-songmuchun@bytedance.com> <20260831075342.57563-2-songmuchun@bytedance.com> From: Qi Zheng In-Reply-To: <20260831075342.57563-2-songmuchun@bytedance.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: ngy6tj37nma91tf1o6turktpxp3537re X-Rspamd-Queue-Id: 7A47620003 X-Rspamd-Server: rspam02 X-Rspam-User: X-HE-Tag: 1788169497-585850 X-HE-Meta: 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 9rv4ohsy sadIhAFA/yRXVHf6cushrKziCPxFjGegBnUynkOapUBSkIO3gPib1iG7EqGmDK7bEs+1vsQW/TPQMqRF6SsxaDTLkuumeRu39IshpqJmvJvhe7B+irMg1OXtGPDbDkzZ8RTsFM/JvgpCQ9bsvoxdZFU6y+OV+PxGni8eOtRH40h9QRG2uqVl2ihSm8DR8k4Q4lLCCMw0m2ZV6IBzNmWnckBXFlRpxOuGk+n0UgmqKvFyHCKdVylex8YwNJg3sx98nhJWpLa39r4ESNgKykuoKR7TV4Iui5cbPAkAYCqrqqMN8jvXhAHT/rSd7ro8pGVfaBScceyoz7K6NJpgMJwEGtUAVFFzebCYqdg/UWy6rXuBl8cnheJE+RlfkNe5tT22IOoGk+Yuz22dfx8c+1M8DLC4xnA== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 8/31/26 3:53 PM, Muchun Song wrote: > The section-based vmemmap optimization infrastructure is still guarded by > CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP, but it also can be used by device > DAX. Introduce CONFIG_SPARSEMEM_VMEMMAP_OPTIMIZATION as a common config > for the shared infrastructure. > > Select the new option from HUGETLB_PAGE_OPTIMIZE_VMEMMAP and from > DEV_DAX when the architecture opts in to DAX vmemmap optimization, and > use it to guard the generic sparse-vmemmap state and helpers. > > Signed-off-by: Muchun Song > --- > arch/x86/entry/vdso/vdso32/fake_32bit_build.h | 2 +- > drivers/dax/Kconfig | 1 + > fs/Kconfig | 1 + > include/linux/mm.h | 3 +++ > include/linux/mmzone.h | 13 +++++++------ > include/linux/page-flags.h | 5 ++--- > mm/Kconfig | 3 +++ > mm/sparse.h | 4 ++-- > 8 files changed, 20 insertions(+), 12 deletions(-) > > diff --git a/arch/x86/entry/vdso/vdso32/fake_32bit_build.h b/arch/x86/entry/vdso/vdso32/fake_32bit_build.h > index bc3e549795c3..5f8424eade2b 100644 > --- a/arch/x86/entry/vdso/vdso32/fake_32bit_build.h > +++ b/arch/x86/entry/vdso/vdso32/fake_32bit_build.h > @@ -11,7 +11,7 @@ > #undef CONFIG_PGTABLE_LEVELS > #undef CONFIG_ILLEGAL_POINTER_VALUE > #undef CONFIG_SPARSEMEM_VMEMMAP > -#undef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP > +#undef CONFIG_SPARSEMEM_VMEMMAP_OPTIMIZATION > #undef CONFIG_NR_CPUS > #undef CONFIG_PARAVIRT_XXL > > diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig > index 602f9a0839a9..85ad4c135cdd 100644 > --- a/drivers/dax/Kconfig > +++ b/drivers/dax/Kconfig > @@ -8,6 +8,7 @@ if DAX > config DEV_DAX > tristate "Device DAX: direct access mapping device" > depends on TRANSPARENT_HUGEPAGE > + select SPARSEMEM_VMEMMAP_OPTIMIZATION if ARCH_WANT_OPTIMIZE_DAX_VMEMMAP > help > Support raw access to differentiated (persistence, bandwidth, > latency...) memory via an mmap(2) capable character > diff --git a/fs/Kconfig b/fs/Kconfig > index d1c210c6508f..9b32ce79cc80 100644 > --- a/fs/Kconfig > +++ b/fs/Kconfig > @@ -278,6 +278,7 @@ config HUGETLB_PAGE_OPTIMIZE_VMEMMAP > def_bool HUGETLB_PAGE > depends on ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP > depends on SPARSEMEM_VMEMMAP > + select SPARSEMEM_VMEMMAP_OPTIMIZATION > > config HUGETLB_PMD_PAGE_TABLE_SHARING > def_bool HUGETLB_PAGE > diff --git a/include/linux/mm.h b/include/linux/mm.h > index a9fbe26536f4..edadd7549b72 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -5188,6 +5188,9 @@ static inline bool __vmemmap_can_optimize(struct vmem_altmap *altmap, > unsigned long nr_pages; > unsigned long nr_vmemmap_pages; > > + if (!IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP_OPTIMIZATION)) > + return false; > + > if (!pgmap || !is_power_of_2(sizeof(struct page))) > return false; > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index c9ae7991a8b2..e9b54ea0eff0 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h > @@ -102,9 +102,9 @@ > * > * HVO which is only active if the size of struct page is a power of 2. > */ > -#define MAX_FOLIO_VMEMMAP_ALIGN \ > - (IS_ENABLED(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP) && \ > - is_power_of_2(sizeof(struct page)) ? \ > +#define MAX_FOLIO_VMEMMAP_ALIGN \ > + (IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP_OPTIMIZATION) && \ > + is_power_of_2(sizeof(struct page)) ? \ > MAX_FOLIO_NR_PAGES * sizeof(struct page) : 0) > > /* The number of retained vmemmap pages with HVO enabled. */ > @@ -116,7 +116,8 @@ > #define __VMEMMAP_OPTIMIZATION_NR_ORDERS \ > (MAX_FOLIO_ORDER - VMEMMAP_OPTIMIZATION_MIN_ORDER + 1) > #define VMEMMAP_OPTIMIZATION_NR_ORDERS \ > - (__VMEMMAP_OPTIMIZATION_NR_ORDERS > 0 ? __VMEMMAP_OPTIMIZATION_NR_ORDERS : 0) > + ((__VMEMMAP_OPTIMIZATION_NR_ORDERS > 0 && \ > + IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP_OPTIMIZATION)) ? __VMEMMAP_OPTIMIZATION_NR_ORDERS : 0) > > enum migratetype { > MIGRATE_UNMOVABLE, > @@ -1155,7 +1156,7 @@ struct zone { > /* Zone statistics */ > atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; > atomic_long_t vm_numa_event[NR_VM_NUMA_EVENT_ITEMS]; > -#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP > +#ifdef CONFIG_SPARSEMEM_VMEMMAP_OPTIMIZATION > struct page *vmemmap_tails[VMEMMAP_OPTIMIZATION_NR_ORDERS]; > #endif > } ____cacheline_internodealigned_in_smp; > @@ -2019,7 +2020,7 @@ struct mem_section { > unsigned long section_mem_map; > > struct mem_section_usage *usage; > -#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP > +#ifdef CONFIG_SPARSEMEM_VMEMMAP_OPTIMIZATION > /* > * Normally, sections hold regular (order-0) pages. However, for > * sections with HVO enabled, this tracks the compound page order > diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h > index ae2ebaed6d4d..de3c06062bc6 100644 > --- a/include/linux/page-flags.h > +++ b/include/linux/page-flags.h > @@ -208,14 +208,13 @@ enum pageflags { > static __always_inline bool compound_info_has_mask(void) > { > /* > - * Limit mask usage to HugeTLB vmemmap optimization (HVO) where it > - * makes a difference. > + * Limit mask usage to HVO where it makes a difference. > * > * The approach with mask would work in the wider set of conditions, > * but it requires validating that struct pages are naturally aligned > * for all orders up to the MAX_FOLIO_ORDER, which can be tricky. > */ > - if (!IS_ENABLED(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP)) > + if (!IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP_OPTIMIZATION)) > return false; > > return is_power_of_2(sizeof(struct page)); > diff --git a/mm/Kconfig b/mm/Kconfig > index c1ddf59c0d71..b5f8372cd164 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -461,6 +461,9 @@ config SPARSEMEM_VMEMMAP > pfn_to_page and page_to_pfn operations. This is the most > efficient option when sufficient kernel resources are available. > > +config SPARSEMEM_VMEMMAP_OPTIMIZATION > + bool As sashiko was concerned about [1], it seems we need to add depends on SPARSEMEM_VMEMMAP here. Apart from that, LGTM. With this fix included: Acked-by: Qi Zheng Thanks, Qi [1]. https://sashiko.dev/#/patchset/20260831075342.57563-1-songmuchun%40bytedance.com > + > # > # Select this config option from the architecture Kconfig, if it is preferred > # to enable the feature of HugeTLB/dev_dax vmemmap optimization. > diff --git a/mm/sparse.h b/mm/sparse.h > index 049272aba84e..b408d15baf7b 100644 > --- a/mm/sparse.h > +++ b/mm/sparse.h > @@ -10,7 +10,7 @@ > > #include > > -#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP > +#ifdef CONFIG_SPARSEMEM_VMEMMAP_OPTIMIZATION > static inline unsigned int section_order(const struct mem_section *section) > { > return section->order; > @@ -72,7 +72,7 @@ static inline bool vmemmap_optimizable_pfn(unsigned long pfn) > > static inline bool vmemmap_optimizable_order(unsigned int order) > { > - if (!IS_ENABLED(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP)) > + if (!IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP_OPTIMIZATION)) > return false; > > if (!is_power_of_2(sizeof(struct page)))