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 5A8623C7DF5 for ; Wed, 30 Sep 2026 19:01:40 +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=1790794901; cv=none; b=dVqwPWAOjIw4soNQl9O0vYum64B7Dzgtk67JDpSontlnqLyxgRxjkxaNqRVQ4+Tg4/lNoUaeK96ditC4s1i4fk+bJltx7Q5IoWjofUgmTuKEJIOF32yd9oaPCE40xZplfQtg/O5IOhMxjC+PZO0FGcl0c4phCQRb/b4/QlXMkQQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790794901; c=relaxed/simple; bh=+WdhEb977XJnYUT3+zCxiMVJfmLXQzUiBAg+Z1rrBuw=; h=Date:To:From:Subject:Message-Id; b=AgaSp52q9KnvcpLnWb89QNrwyk2TouL1VRSRY/DzmALUC3+C5GBSdw1G+BJ0qwG6eVYjH4g3kapwaHRRgNIkUNXmW2EyXHZkQ4ISa2Q9jvq/mEhkxzcUyZcXYF16oFfYh/4jVTVpta6v7I1XXPp+pfGc6dNplQkSZg8hlwU4d3I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=VGAYVquW; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="VGAYVquW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BFA7E1F000FF; Wed, 30 Sep 2026 19:01:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1790794899; bh=xc+6RvwHoQep9wMG7YL6ot71dffVEKvjCeppZKmLmfM=; h=Date:To:From:Subject; b=VGAYVquWEiThLjR8xVJMM7+48UJ6cdndn8jygsUhI1El3fkmjY6OhNNbo1GukoxKn mEjr4KwSXJDurosMJYCcvLZ5fadMxTDEE0ALVP620J173HcElBp1h0dks3kUv7nE4M adKaXT+UdN0Fms+8q7P2UsAvlPhHab9jS7inEDB0= Date: Wed, 30 Sep 2026 12:01:39 -0700 To: mm-commits@vger.kernel.org,muchun.song@linux.dev,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-sparse-vmemmap-introduce-config_vmemmap_optimization.patch added to mm-unstable branch Message-Id: <20260930190139.BFA7E1F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/sparse-vmemmap: introduce CONFIG_VMEMMAP_OPTIMIZATION has been added to the -mm mm-unstable branch. Its filename is mm-sparse-vmemmap-introduce-config_vmemmap_optimization.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-sparse-vmemmap-introduce-config_vmemmap_optimization.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Muchun Song Subject: mm/sparse-vmemmap: introduce CONFIG_VMEMMAP_OPTIMIZATION Date: Wed, 30 Sep 2026 22:06:18 +0800 The section-based vmemmap optimization infrastructure is guarded by CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP, but it can also be used by ZONE_DEVICE users that set dev_pagemap::vmemmap_shift. Introduce CONFIG_VMEMMAP_OPTIMIZATION as a common config for the shared infrastructure. Select the new option from HUGETLB_PAGE_OPTIMIZE_VMEMMAP and from ZONE_DEVICE when the architecture opts in to DAX vmemmap optimization, and use it to guard the generic sparse-vmemmap state and helpers. Link: https://lore.kernel.org/20260930140627.57431-4-songmuchun@bytedance.com Signed-off-by: Muchun Song Signed-off-by: Andrew Morton Acked-by: Qi Zheng Acked-by: Mike Rapoport (Microsoft) Acked-by: David Hildenbrand (Arm) Cc: Oscar Salvador Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Jonathan Corbet Cc: Lorenzo Stoakes Cc: Nicholas Piggin Cc: Christophe Leroy Cc: Ritesh Harjani (IBM) Cc: Shrikanth Hegde Cc: Randy Dunlap Cc: Lance Yang --- arch/x86/entry/vdso/vdso32/fake_32bit_build.h | 2 +- fs/Kconfig | 1 + include/linux/mm.h | 3 +++ include/linux/mmzone.h | 10 +++++----- include/linux/page-flags.h | 5 ++--- mm/Kconfig | 5 +++++ mm/sparse-vmemmap.c | 2 +- mm/sparse.h | 6 +++--- 8 files changed, 21 insertions(+), 13 deletions(-) --- a/arch/x86/entry/vdso/vdso32/fake_32bit_build.h~mm-sparse-vmemmap-introduce-config_vmemmap_optimization +++ a/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_VMEMMAP_OPTIMIZATION #undef CONFIG_NR_CPUS #undef CONFIG_PARAVIRT_XXL --- a/fs/Kconfig~mm-sparse-vmemmap-introduce-config_vmemmap_optimization +++ a/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 VMEMMAP_OPTIMIZATION config HUGETLB_PMD_PAGE_TABLE_SHARING def_bool HUGETLB_PAGE --- a/include/linux/mm.h~mm-sparse-vmemmap-introduce-config_vmemmap_optimization +++ a/include/linux/mm.h @@ -5175,6 +5175,9 @@ static inline bool __vmemmap_can_optimiz unsigned long nr_pages; unsigned long nr_vmemmap_pages; + if (!IS_ENABLED(CONFIG_VMEMMAP_OPTIMIZATION)) + return false; + if (!pgmap || !is_power_of_2(sizeof(struct page))) return false; --- a/include/linux/mmzone.h~mm-sparse-vmemmap-introduce-config_vmemmap_optimization +++ a/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_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. */ @@ -1150,7 +1150,7 @@ 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_VMEMMAP_OPTIMIZATION struct page **vmemmap_tails; #endif } ____cacheline_internodealigned_in_smp; @@ -2014,7 +2014,7 @@ struct mem_section { unsigned long section_mem_map; struct mem_section_usage *usage; -#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP +#ifdef CONFIG_VMEMMAP_OPTIMIZATION /* * Normally, sections hold regular (order-0) pages. However, for * sections with HVO enabled, this tracks the compound page order --- a/include/linux/page-flags.h~mm-sparse-vmemmap-introduce-config_vmemmap_optimization +++ a/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_VMEMMAP_OPTIMIZATION)) return false; return is_power_of_2(sizeof(struct page)); --- a/mm/Kconfig~mm-sparse-vmemmap-introduce-config_vmemmap_optimization +++ a/mm/Kconfig @@ -461,6 +461,10 @@ config SPARSEMEM_VMEMMAP pfn_to_page and page_to_pfn operations. This is the most efficient option when sufficient kernel resources are available. +config VMEMMAP_OPTIMIZATION + bool + depends on SPARSEMEM_VMEMMAP + # # Select this config option from the architecture Kconfig, if it is preferred # to enable the feature of HugeTLB/dev_dax vmemmap optimization. @@ -1220,6 +1224,7 @@ config ZONE_DMA32 config ZONE_DEVICE bool "Device memory (pmem, HMM, etc...) hotplug support" depends on MEMORY_HOTREMOVE + select VMEMMAP_OPTIMIZATION if ARCH_WANT_OPTIMIZE_DAX_VMEMMAP select XARRAY_MULTI help --- a/mm/sparse.h~mm-sparse-vmemmap-introduce-config_vmemmap_optimization +++ a/mm/sparse.h @@ -10,7 +10,7 @@ #include -#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP +#ifdef CONFIG_VMEMMAP_OPTIMIZATION static inline unsigned int section_compound_order(const struct mem_section *section) { return section->compound_page_order; @@ -75,7 +75,7 @@ static inline bool vmemmap_optimizable_p static inline bool vmemmap_optimizable_order(unsigned int order) { - if (!IS_ENABLED(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP)) + if (!IS_ENABLED(CONFIG_VMEMMAP_OPTIMIZATION)) return false; if (!is_power_of_2(sizeof(struct page))) @@ -142,7 +142,7 @@ static inline void sparse_sections_init( * mm/sparse-vmemmap.c */ #ifdef CONFIG_SPARSEMEM_VMEMMAP -#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP +#ifdef CONFIG_VMEMMAP_OPTIMIZATION struct page *vmemmap_shared_tail_page(unsigned int order, struct zone *zone); #endif void sparse_init_subsection_map(void); --- a/mm/sparse-vmemmap.c~mm-sparse-vmemmap-introduce-config_vmemmap_optimization +++ a/mm/sparse-vmemmap.c @@ -169,7 +169,7 @@ static void * __meminit vmemmap_alloc_bl return p; } -#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP +#ifdef CONFIG_VMEMMAP_OPTIMIZATION #define VMEMMAP_OPTIMIZATION_NR_ORDERS (MAX_FOLIO_ORDER - VMEMMAP_OPTIMIZATION_MIN_ORDER + 1) static __ref struct page **vmemmap_tails(struct zone *zone) _ Patches currently in -mm which might be from muchun.song@linux.dev are mm-sparse-vmemmap-factor-out-shared-vmemmap-tail-page-allocation.patch mm-sparse-vmemmap-allocate-shared-tail-page-array-dynamically.patch mm-sparse-vmemmap-introduce-config_vmemmap_optimization.patch mm-sparse-vmemmap-open-code-init_compound_tail.patch mm-sparse-vmemmap-prepare-dax-vmemmap-population-for-compound-page-orders.patch mm-sparse-vmemmap-set-compound-page-order-for-device-dax.patch mm-sparse-vmemmap-switch-device-dax-to-shared-tail-vmemmap-pages.patch mm-sparse-vmemmap-switch-device-dax-to-shared-tail-vmemmap-pages-fix.patch mm-sparse-vmemmap-move-vmemmap-optimization-helpers-to-a-public-header.patch powerpc-mm-switch-device-dax-to-shared-tail-vmemmap-pages.patch powerpc-mm-switch-device-dax-to-shared-tail-vmemmap-pages-fix.patch mm-sparse-vmemmap-drop-the-extra-tail-page-from-device-dax-reservation.patch mm-sparse-vmemmap-drop-unused-section_nr_vmemmap_pages-arguments.patch documentation-mm-update-dax-vmemmap-deduplication-docs.patch mm-sparse-vmemmap-drop-vmemmap_populate_dax.patch mm-sparse-vmemmap-support-device-dax-in-common-vmemmap-path.patch mm-sparse-vmemmap-drop-device-dax-specific-population-path.patch mm-sparse-vmemmap-remove-the-unused-ptpfn-argument.patch mm-sparse-vmemmap-open-code-vmemmap_populate_address.patch mm-mm_init-add-zone-mismatch-warning-during-page-init.patch