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 DE87B49E134 for ; Thu, 10 Sep 2026 23:00:48 +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=1789081250; cv=none; b=HaRI+3EDNHnlUqxaUNMbXeLJdjIpzEYKXWI3ByGwGg4ndgQo3CqPLx3EN1nwurLuNwUgWr5ZD9djWgwm5q8ltzCtiCdKDcacvfZ3dBHMhFmMPrRWhfja+blihzYeS4h5nd+u6lzL2+4M6Ca2S8JRi9jmzkB7rX4kbKTTn99HOUg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789081250; c=relaxed/simple; bh=gtg5XyAKz/TBVroeDgx77ieHTRPPTP4RY003jFBbGE0=; h=Date:To:From:Subject:Message-Id; b=gHxh42mTvtxG4r7m2qewR2gHAwY8PVj9R+76OyaoBNzs/L9w5/av9Pd6ojY1xPlxkYcgC8rjKqCIT6VQ9APD899G693NhKGDL4VVqeAQ+Ncc8ONGlQcjRlxwrzHya6RbOAzL2V/OZbZa+qfk1ZpEMBPS9L2rIJUhfWc9wDIMkFg= 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=GXXoufhp; 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="GXXoufhp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B2B1E1F000FF; Thu, 10 Sep 2026 23:00:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1789081248; bh=5YKOXJTRB7Ibau2iiKCDgRM7a3OtSIlDeJXl624DAlY=; h=Date:To:From:Subject; b=GXXoufhp6uIQRF8u73IglPN6ii6szn6Uon1rpLWFsS3KSeGbXwR+NgB1tv/krOc+n 48iVnbkm5ct/V/LN+S1bIf4GU3lRted6jDEiY3i1Jk0nwtPJ/qkwOSv6y7UIKMYHNR Ezb7JBckFJCiB3oLj8ayu09NBihDUjkHXIBf0p7E= Date: Thu, 10 Sep 2026 16:00:48 -0700 To: mm-commits@vger.kernel.org,songmuchun@bytedance.com,akpm@linux-foundation.org From: Andrew Morton Subject: [to-be-updated] mm-sparse-vmemmap-support-section-based-vmemmap-optimization.patch removed from -mm tree Message-Id: <20260910230048.B2B1E1F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/sparse-vmemmap: support section-based vmemmap optimization has been removed from the -mm tree. Its filename was mm-sparse-vmemmap-support-section-based-vmemmap-optimization.patch This patch was dropped because an updated version will be issued ------------------------------------------------------ From: Muchun Song Subject: mm/sparse-vmemmap: support section-based vmemmap optimization Date: Tue, 25 Aug 2026 16:45:59 +0800 Teach sparse-vmemmap population code to use the compound page order when deciding whether a vmemmap page can be optimized. With this information, the common sparse-vmemmap population path can allocate or reuse shared tail vmemmap pages directly instead of relying on HugeTLB-specific handling. This centralizes vmemmap optimization logic in the sparse-vmemmap code, based on section metadata, and prepares for sharing the same mechanism across different users of vmemmap optimization, including HugeTLB and DAX. Link: https://lore.kernel.org/20260825084608.47437-9-songmuchun@bytedance.com Signed-off-by: Muchun Song Acked-by: Mike Rapoport (Microsoft) Acked-by: Qi Zheng Cc: David Hildenbrand Cc: David Laight Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Oscar Salvador Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- mm/sparse-vmemmap.c | 46 ++++++++++++++++++++++++++++++++++-------- mm/sparse.c | 4 +-- mm/sparse.h | 7 ++++++ 3 files changed, 47 insertions(+), 10 deletions(-) --- a/mm/sparse.c~mm-sparse-vmemmap-support-section-based-vmemmap-optimization +++ a/mm/sparse.c @@ -305,8 +305,8 @@ static void __init sparse_init_nid(int n nid, NULL, NULL); if (!map) panic("Failed to allocate memmap for section %lu\n", pnum); - memmap_boot_pages_add(DIV_ROUND_UP(PAGES_PER_SECTION * sizeof(struct page), - PAGE_SIZE)); + memmap_boot_pages_add(section_nr_vmemmap_pages(pfn, PAGES_PER_SECTION, + NULL, NULL)); sparse_init_early_section(nid, map, pnum, 0); } } --- a/mm/sparse.h~mm-sparse-vmemmap-support-section-based-vmemmap-optimization +++ a/mm/sparse.h @@ -111,8 +111,15 @@ static inline void sparse_init(void) {} */ #ifdef CONFIG_SPARSEMEM_VMEMMAP 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); #else static inline void sparse_init_subsection_map(void) {} +static inline int section_nr_vmemmap_pages(unsigned long pfn, unsigned long nr_pages, + struct vmem_altmap *altmap, struct dev_pagemap *pgmap) +{ + return DIV_ROUND_UP(nr_pages * sizeof(struct page), PAGE_SIZE); +} #endif /* CONFIG_SPARSEMEM_VMEMMAP */ #endif /* __MM_SPARSE_H */ --- a/mm/sparse-vmemmap.c~mm-sparse-vmemmap-support-section-based-vmemmap-optimization +++ a/mm/sparse-vmemmap.c @@ -148,8 +148,7 @@ void __meminit vmemmap_verify(pte_t *pte start, end - 1); } -#ifdef CONFIG_MEMORY_HOTPLUG -static int __meminit section_nr_vmemmap_pages(unsigned long pfn, unsigned long nr_pages, +int __meminit section_nr_vmemmap_pages(unsigned long pfn, unsigned long nr_pages, struct vmem_altmap *altmap, struct dev_pagemap *pgmap) { const struct mem_section *ms = __pfn_to_section(pfn); @@ -175,7 +174,6 @@ static int __meminit section_nr_vmemmap_ return 0; } -#endif static void * __meminit vmemmap_alloc_block_zero(unsigned long size, int node) { @@ -215,19 +213,44 @@ static __meminit struct page *vmemmap_ge return tail; } +#else +static inline struct page *vmemmap_get_tail(unsigned int order, struct zone *zone) +{ + return NULL; +} #endif +static __meminit void *vmemmap_alloc_pte(unsigned long pfn, int node, + struct vmem_altmap *altmap) +{ + struct zone *zone; + struct page *page; + const unsigned int order = pfn_to_section_order(pfn); + + if (!vmemmap_optimizable_pfn(pfn)) + return vmemmap_alloc_block_buf(PAGE_SIZE, node, altmap); + + zone = pfn_to_zone(pfn, node); + page = vmemmap_get_tail(order, zone); + if (!page) + return NULL; + + return page_address(page); +} + static pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node, struct vmem_altmap *altmap, unsigned long ptpfn, unsigned long flags) { pte_t *pte = pte_offset_kernel(pmd, addr); + unsigned long pfn = page_to_pfn((struct page *)addr); + if (pte_none(ptep_get(pte))) { pte_t entry; - void *p; if (ptpfn == (unsigned long)-1) { - p = vmemmap_alloc_block_buf(PAGE_SIZE, node, altmap); + void *p = vmemmap_alloc_pte(pfn, node, altmap); + if (!p) return NULL; ptpfn = PHYS_PFN(__pa(p)); @@ -246,7 +269,8 @@ static pte_t * __meminit vmemmap_pte_pop } entry = pfn_pte(ptpfn, PAGE_KERNEL); set_pte_at(&init_mm, addr, pte, entry); - } + } else if (WARN_ON_ONCE(vmemmap_optimizable_pfn(pfn))) + return NULL; return pte; } @@ -435,6 +459,9 @@ int __meminit vmemmap_populate_hugepages pmd_t *pmd; for (addr = start; addr < end; addr = next) { + unsigned long pfn = page_to_pfn((struct page *)addr); + const struct mem_section *ms = __pfn_to_section(pfn); + next = pmd_addr_end(addr, end); pgd = vmemmap_pgd_populate(addr, node); @@ -450,7 +477,7 @@ int __meminit vmemmap_populate_hugepages return -ENOMEM; pmd = pmd_offset(pud, addr); - if (pmd_none(pmdp_get(pmd))) { + if (pmd_none(pmdp_get(pmd)) && !section_vmemmap_optimizable(ms)) { void *p; p = vmemmap_alloc_block_buf(PMD_SIZE, node, altmap); @@ -468,8 +495,11 @@ int __meminit vmemmap_populate_hugepages */ return -ENOMEM; } - } else if (vmemmap_check_pmd(pmd, node, addr, next)) + } else if (vmemmap_check_pmd(pmd, node, addr, next)) { + if (WARN_ON_ONCE(section_vmemmap_optimizable(ms))) + return -EOPNOTSUPP; continue; + } if (vmemmap_populate_basepages(addr, next, node, altmap)) return -ENOMEM; } _ Patches currently in -mm which might be from songmuchun@bytedance.com are 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_sparsemem_vmemmap_optimization.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-section-orders.patch mm-sparse-vmemmap-set-section-order-for-device-dax.patch mm-sparse-vmemmap-switch-device-dax-to-shared-tail-vmemmap-pages.patch mm-sparse-vmemmap-move-hvo-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