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 D700E79CD for ; Thu, 17 Sep 2026 01:36:35 +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=1789608997; cv=none; b=j248mb1xPAS4ej2HCTgUvQOjTsRRGFmoaMt27uVEpnGaQA4VaqQUOg0W/Qpw0pXQc4695Qxatw0b6py92i5nfmugBl2Kaz640qnfosNHIDKsNbkH8M5Ft79ejxZqnZyFkkAYNZ7H62UxA182CsBHe6Yy2H4kWeXOQL9GAVMDjBg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789608997; c=relaxed/simple; bh=5dFsvF34oevoPlwFZiHvrdB0MYTJg56bNrMba92TRrU=; h=Date:To:From:Subject:Message-Id; b=huDkEp1Q4MFndElM/76qcQlUaGQFfseEA3m7o7vbexaqyfjFVo7RCj0XN+RapdDlmbP1t0P9UD98CykusVL0OSUWCKD22MYej5SAOQikWsxlOruH/+E+LFkkwopYBzSovAjvCsA92QHdRVpxxI6rBNxXXIXq9qhEKG88CEFXXXY= 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=2BW7HV1L; 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="2BW7HV1L" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6AFC41F000FF; Thu, 17 Sep 2026 01:36:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1789608995; bh=7IgzOxm3Jdcj5jKng2cNBwmMEnmDx9iOc0J6KhwN7co=; h=Date:To:From:Subject; b=2BW7HV1L/Pe5kuNWekGXTN5n17ecIeFrDid+Cv5qssYKhg1DwtP2K7i+nJQzftldf KJ7MyYfK9XLDl6duwK2QYtzjmhI+2Gd9dpwNCKdbl4H2GokJM+JABTzY73DvVZDOQ8 +QiHa4UJsQRNtePBujO9237Y4zfu4wqxhR5HCjFs= Date: Wed, 16 Sep 2026 18:36:35 -0700 To: mm-commits@vger.kernel.org,songmuchun@bytedance.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-sparse-vmemmap-move-vmemmap-optimization-helpers-to-a-public-header.patch added to mm-unstable branch Message-Id: <20260917013635.6AFC41F000FF@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: move vmemmap optimization helpers to a public header has been added to the -mm mm-unstable branch. Its filename is mm-sparse-vmemmap-move-vmemmap-optimization-helpers-to-a-public-header.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-move-vmemmap-optimization-helpers-to-a-public-header.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: move vmemmap optimization helpers to a public header Date: Wed, 16 Sep 2026 14:43:37 +0800 The vmemmap optimization helpers currently live in mm/sparse.h, which is an internal MM header. That works for MM code, but prevents powerpc from using the same interfaces without including a private header. Move the declarations and inline helpers to include/linux/vmemmap-optimization.h. This is a preparatory change for powerpc, which has its own vmemmap optimization implementation and needs to use the common vmemmap optimization interfaces from architecture code. Link: https://lore.kernel.org/20260916064341.1825793-8-songmuchun@bytedance.com Signed-off-by: Muchun Song Signed-off-by: Andrew Morton Acked-by: Qi Zheng Acked-by: Mike Rapoport (Microsoft) Cc: David Hildenbrand (Arm) Cc: Jonathan Corbet Cc: Lorenzo Stoakes Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Oscar Salvador Cc: Randy Dunlap --- MAINTAINERS | 1 include/linux/vmemmap-optimization.h | 94 +++++++++++++++++++++++++ mm/hugetlb.c | 2 mm/hugetlb_vmemmap.c | 2 mm/sparse.h | 76 -------------------- 5 files changed, 98 insertions(+), 77 deletions(-) diff --git a/include/linux/vmemmap-optimization.h a/include/linux/vmemmap-optimization.h new file mode 100644 --- /dev/null +++ a/include/linux/vmemmap-optimization.h @@ -0,0 +1,94 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * vmemmap-optimization.h + * + * Generic vmemmap optimization declarations. + * + * Author: Muchun Song + */ +#ifndef _LINUX_VMEMMAP_OPTIMIZATION_H +#define _LINUX_VMEMMAP_OPTIMIZATION_H + +#include +#include +#include +#include + +#ifdef CONFIG_VMEMMAP_OPTIMIZATION +static inline unsigned int section_compound_order(const struct mem_section *section) +{ + return section->compound_page_order; +} + +static inline void section_set_compound_order(struct mem_section *section, + unsigned int order) +{ + VM_WARN_ON(section_compound_order(section) && order && + section_compound_order(section) != order); + section->compound_page_order = order; +} + +static inline void section_set_compound_order_range(unsigned long pfn, + unsigned long nr_pages, unsigned int order) +{ + unsigned long section_nr = pfn_to_section_nr(pfn); + + if (!IS_ALIGNED(pfn | nr_pages, PAGES_PER_SECTION)) + return; + + for (unsigned long i = 0; i < nr_pages / PAGES_PER_SECTION; i++) + section_set_compound_order(__nr_to_section(section_nr + i), order); +} + +static inline unsigned int pfn_to_section_compound_order(unsigned long pfn) +{ + return section_compound_order(__pfn_to_section(pfn)); +} +#else +static inline unsigned int section_compound_order(const struct mem_section *section) +{ + return 0; +} + +static inline void section_set_compound_order(struct mem_section *section, + unsigned int order) +{ +} + +static inline void section_set_compound_order_range(unsigned long pfn, + unsigned long nr_pages, unsigned int order) +{ +} + +static inline unsigned int pfn_to_section_compound_order(unsigned long pfn) +{ + return 0; +} +#endif /* CONFIG_VMEMMAP_OPTIMIZATION */ + +static inline bool vmemmap_optimizable_pfn(unsigned long pfn) +{ + const unsigned int order = pfn_to_section_compound_order(pfn); + const unsigned long nr_pages = 1UL << order; + + if (!is_power_of_2(sizeof(struct page))) + return false; + + return (pfn & (nr_pages - 1)) >= VMEMMAP_OPTIMIZATION_NR_STRUCT_PAGES; +} + +static inline bool vmemmap_optimizable_order(unsigned int order) +{ + if (!IS_ENABLED(CONFIG_VMEMMAP_OPTIMIZATION)) + return false; + + if (!is_power_of_2(sizeof(struct page))) + return false; + + return order >= VMEMMAP_OPTIMIZATION_MIN_ORDER; +} + +#ifdef CONFIG_SPARSEMEM_VMEMMAP +struct page *vmemmap_shared_tail_page(unsigned int order, struct zone *zone); +#endif /* CONFIG_SPARSEMEM_VMEMMAP */ +#endif /* _LINUX_VMEMMAP_OPTIMIZATION_H */ --- a/MAINTAINERS~mm-sparse-vmemmap-move-vmemmap-optimization-helpers-to-a-public-header +++ a/MAINTAINERS @@ -12096,6 +12096,7 @@ F: Documentation/mm/hugetlbfs_reserv.rst F: Documentation/mm/vmemmap_dedup.rst F: fs/hugetlbfs/ F: include/linux/hugetlb.h +F: include/linux/vmemmap-optimization.h F: include/trace/events/hugetlbfs.h F: mm/hugetlb.c F: mm/hugetlb_cgroup.c --- a/mm/hugetlb.c~mm-sparse-vmemmap-move-vmemmap-optimization-helpers-to-a-public-header +++ a/mm/hugetlb.c @@ -38,6 +38,7 @@ #include #include #include +#include #include #include @@ -52,7 +53,6 @@ #include "hugetlb_cma.h" #include "hugetlb_internal.h" #include "mm_init.h" -#include "sparse.h" #include #define HUGE_BOOTMEM_ZONES_VALID BIT(0) --- a/mm/hugetlb_vmemmap.c~mm-sparse-vmemmap-move-vmemmap-optimization-helpers-to-a-public-header +++ a/mm/hugetlb_vmemmap.c @@ -15,10 +15,10 @@ #include #include #include +#include #include #include "hugetlb_vmemmap.h" -#include "sparse.h" #include "internal.h" /** --- a/mm/sparse.h~mm-sparse-vmemmap-move-vmemmap-optimization-helpers-to-a-public-header +++ a/mm/sparse.h @@ -9,80 +9,7 @@ #define __MM_SPARSE_H #include - -#ifdef CONFIG_VMEMMAP_OPTIMIZATION -static inline unsigned int section_compound_order(const struct mem_section *section) -{ - return section->compound_page_order; -} - -static inline void section_set_compound_order(struct mem_section *section, - unsigned int order) -{ - VM_WARN_ON(section_compound_order(section) && order && - section_compound_order(section) != order); - section->compound_page_order = order; -} - -static inline void section_set_compound_order_range(unsigned long pfn, - unsigned long nr_pages, unsigned int order) -{ - unsigned long section_nr = pfn_to_section_nr(pfn); - - if (!IS_ALIGNED(pfn | nr_pages, PAGES_PER_SECTION)) - return; - - for (unsigned long i = 0; i < nr_pages / PAGES_PER_SECTION; i++) - section_set_compound_order(__nr_to_section(section_nr + i), order); -} - -static inline unsigned int pfn_to_section_compound_order(unsigned long pfn) -{ - return section_compound_order(__pfn_to_section(pfn)); -} -#else -static inline unsigned int section_compound_order(const struct mem_section *section) -{ - return 0; -} - -static inline void section_set_compound_order(struct mem_section *section, - unsigned int order) -{ -} - -static inline void section_set_compound_order_range(unsigned long pfn, - unsigned long nr_pages, unsigned int order) -{ -} - -static inline unsigned int pfn_to_section_compound_order(unsigned long pfn) -{ - return 0; -} -#endif - -static inline bool vmemmap_optimizable_pfn(unsigned long pfn) -{ - const unsigned int order = pfn_to_section_compound_order(pfn); - const unsigned long nr_pages = 1UL << order; - - if (!is_power_of_2(sizeof(struct page))) - return false; - - return (pfn & (nr_pages - 1)) >= VMEMMAP_OPTIMIZATION_NR_STRUCT_PAGES; -} - -static inline bool vmemmap_optimizable_order(unsigned int order) -{ - if (!IS_ENABLED(CONFIG_VMEMMAP_OPTIMIZATION)) - return false; - - if (!is_power_of_2(sizeof(struct page))) - return false; - - return order >= VMEMMAP_OPTIMIZATION_MIN_ORDER; -} +#include /* * mm/sparse.c @@ -142,7 +69,6 @@ static inline void sparse_sections_init( * mm/sparse-vmemmap.c */ #ifdef CONFIG_SPARSEMEM_VMEMMAP -struct page *vmemmap_shared_tail_page(unsigned int order, struct zone *zone); void sparse_init_subsection_map(void); int section_nr_vmemmap_pages(unsigned long pfn, unsigned long nr_pages, struct vmem_altmap *altmap, struct dev_pagemap *pgmap); _ Patches currently in -mm which might be from songmuchun@bytedance.com are mm-sparse-relax-struct-mem_section-size-constraints.patch mm-sparse-vmemmap-rename-hvo-order-macros.patch mm-mm_init-skip-initializing-shared-vmemmap-tail-pages.patch mm-sparse-vmemmap-initialize-shared-tail-vmemmap-pages-on-allocation.patch mm-sparse-vmemmap-support-section-based-vmemmap-accounting.patch mm-mm_init-factor-out-pfn_to_zone.patch mm-sparse-vmemmap-move-helpers-ahead-of-future-callers.patch mm-sparse-vmemmap-support-section-based-vmemmap-optimization.patch mm-sparse-initialize-memory-sections-earlier.patch mm-hugetlb-switch-hugetlb-to-section-based-vmemmap-optimization.patch mm-sparse-vmemmap-remove-sparsemem_vmemmap_preinit-support.patch mm-sparse-inline-usemap-allocation-into-sparse_init_nid.patch mm-sparse-remove-section_map_size.patch mm-hugetlb-remove-huge_bootmem_hvo.patch mm-hugetlb-remove-huge_bootmem_cma.patch mm-hugetlb-localize-struct-huge_bootmem_page.patch mm-hugetlb-localize-huge_bootmem_zones_valid.patch mm-sparse-vmemmap-introduce-config_vmemmap_optimization.patch mm-sparse-vmemmap-introduce-config_vmemmap_optimization-fix.patch mm-sparse-vmemmap-factor-out-shared-vmemmap-tail-page-allocation.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-move-vmemmap-optimization-helpers-to-a-public-header.patch powerpc-mm-switch-device-dax-to-shared-tail-vmemmap-pages.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