From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792832519; b=F/xLPiv2CRDJyYQ69N/2CKxX5skDpINoO0ysbi1WJ7lzumK45BaOjeTKT0l505zdaoRs ZyIfS4rJ8xYHC4Pl/0gb46kIc7mbIb7RuR9c9iwBcbSpak/p6n9/iJvkubW0dUtqkWlhR TchpWjYtPNJbDNkfHp77aDlxqx6XKNx8DuM2AKoVo1hWuftxAYOlHg4+rr9pa+58+n4m3 WUWMOMzFS0V/qM+6R5kF5ZjQcn6mRnVImU0c3k1XLkurDiyzeHblANdJqhVw3cIADcsq1 PTHrUkAqN8XyZgXhdUkm7i1yi9lv2nqZykDerrJX5lhP0b0bVdY3BHkebm8ixsHkehA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792832519; h=Received:DKIM-Signature:Date:To:From:Subject:Message-Id; bh=O1QZkei0Ityifl+LUX9ibbcFwxVb9g/VIXpmyz/Zzt0=; b=S8Rfxjx4I+sX4YUHeC4zaWfOa99FT8o6fjEhogwodjSE2GoeIi+/zvvDfYj/B+9MoJ8T zKD3tazFD4Q2CnsozDP9ORe4RztHEkU+xNz3WJHVscN2wDxlLckAzeHUmBi4m2kiANLV6 RZrlhOmedBBkmVu4UVkrkqnZI6EhzJn8zGuCBmqKhRfelCDoEzW4vR7zKe8RbbdQHs+1Y rInGLWDWJDIXOHJHqupoYL48JEsYgDQJnpX+xhsAtQwDOhnQ3H20xpPad8S+c9NBbAA2Y zyuFFfsVMWsyyydXHVfRyZSjYvxRUa9yeJzCqTs3S6rQ+He5zsSaSVitNAjOQI2rWfQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=jJBY47Am; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 93672606A31B for ; Sat, 24 Oct 2026 09:01:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=jJBY47Am Received: by smtp.kernel.org (Postfix) with ESMTPSA id 618E01F01825; Sat, 24 Oct 2026 09:01:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1792832519; bh=O1QZkei0Ityifl+LUX9ibbcFwxVb9g/VIXpmyz/Zzt0=; h=Date:To:From:Subject; b=jJBY47AmwwaVpwod7OBgYCeouJB0yZSRSdn773jKS26T/yb5GZMwlYfYpmtlRxKOT Q21KlNLQ4sL7Rgk8s7J8cW2cA4SsmPuu2c2LWDSfVAKKY1yp1flrZGr6NeoKUAMDfi K1O1pyMP2EAE1tHiA+XCn96kX4Ce01ZfJdFBgLD0= Date: Sat, 24 Oct 2026 02:01:58 -0700 To: mm-commits@vger.kernel.org,vbabka@kernel.org,surenb@google.com,sshegde@linux.ibm.com,rppt@kernel.org,ritesh.list@gmail.com,qi.zheng@linux.dev,npiggin@gmail.com,mpe@ellerman.id.au,mhocko@suse.com,maddy@linux.ibm.com,ljs@kernel.org,liam@infradead.org,lance.yang@linux.dev,david@kernel.org,chleroy@kernel.org,muchun.song@linux.dev,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-sparse-vmemmap-drop-device-dax-specific-population-path.patch removed from -mm tree Message-Id: <20261024090159.618E01F01825@smtp.kernel.org> X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list The quilt patch titled Subject: mm/sparse-vmemmap: drop Device DAX-specific population path has been removed from the -mm tree. Its filename was mm-sparse-vmemmap-drop-device-dax-specific-population-path.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Muchun Song Subject: mm/sparse-vmemmap: drop Device DAX-specific population path Date: Sat, 10 Oct 2026 15:57:52 +0800 The common vmemmap path selects the shared page for optimized mappings itself, so Device DAX no longer needs vmemmap_populate_compound_pages() to find a shared tail page and pass its backing PFN through the generic population helpers. Remove the Device DAX-specific population path and let section memmap population always use vmemmap_populate(). The powerpc retains an architecture-specific compound-page implementation, so select it directly from radix__vmemmap_populate() for optimizable sections. Link: https://lore.kernel.org/20261010075755.83339-4-songmuchun@bytedance.com Signed-off-by: Muchun Song Signed-off-by: Andrew Morton Reviewed-by: Lance Yang Acked-by: Qi Zheng Cc: Madhavan Srinivasan Cc: Mike Rapoport Cc: David Hildenbrand Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Christophe Leroy Cc: Ritesh Harjani (IBM) Cc: Shrikanth Hegde Cc: Lorenzo Stoakes Cc: Liam R. Howlett Cc: Vlastimil Babka Cc: Suren Baghdasaryan Cc: Michal Hocko --- arch/powerpc/mm/book3s64/radix_pgtable.c | 3 mm/mm_init.c | 2 mm/sparse-vmemmap.c | 71 --------------------- 3 files changed, 5 insertions(+), 71 deletions(-) --- a/arch/powerpc/mm/book3s64/radix_pgtable.c~mm-sparse-vmemmap-drop-device-dax-specific-population-path +++ a/arch/powerpc/mm/book3s64/radix_pgtable.c @@ -1126,7 +1126,10 @@ int __meminit radix__vmemmap_populate(un pud_t *pud; pmd_t *pmd; pte_t *pte; + unsigned long pfn = page_to_pfn((struct page *)start); + if (vmemmap_optimizable_order(pfn_to_section_compound_order(pfn))) + return vmemmap_populate_compound_pages(pfn, start, end, node, NULL); /* * If altmap is present, Make sure we align the start vmemmap addr * to PAGE_SIZE so that we calculate the correct start_pfn in --- a/mm/mm_init.c~mm-sparse-vmemmap-drop-device-dax-specific-population-path +++ a/mm/mm_init.c @@ -1046,7 +1046,7 @@ static void zone_device_page_init_from_t * initialize is a lot smaller that the total amount of struct pages being * mapped. This is a paired / mild layering violation with explicit knowledge * of how the sparse_vmemmap internals handle compound pages in the lack - * of an altmap. See vmemmap_populate_compound_pages(). + * of an altmap. */ static inline unsigned long compound_nr_pages(unsigned long pfn, struct dev_pagemap *pgmap) --- a/mm/sparse-vmemmap.c~mm-sparse-vmemmap-drop-device-dax-specific-population-path +++ a/mm/sparse-vmemmap.c @@ -503,71 +503,6 @@ int __meminit vmemmap_populate_hugepages return 0; } -#ifndef vmemmap_populate_compound_pages -/* - * For compound pages bigger than section size (e.g. x86 1G compound - * pages with 2M subsection size) fill the rest of sections as tail - * pages. - * - * Note that memremap_pages() resets @nr_range value and will increment - * it after each range successful onlining. Thus the value or @nr_range - * at section memmap populate corresponds to the in-progress range - * being onlined here. - */ -static bool __meminit reuse_compound_section(unsigned long start_pfn, - struct dev_pagemap *pgmap) -{ - unsigned long nr_pages = pgmap_vmemmap_nr(pgmap); - unsigned long offset = start_pfn - - PHYS_PFN(pgmap->ranges[pgmap->nr_range].start); - - return !IS_ALIGNED(offset, nr_pages) && nr_pages > PAGES_PER_SUBSECTION; -} - -static int __meminit vmemmap_populate_compound_pages(unsigned long start_pfn, - unsigned long start, - unsigned long end, int node, - struct dev_pagemap *pgmap) -{ - const unsigned int order = pfn_to_section_compound_order(start_pfn); - unsigned long size, addr; - pte_t *pte; - struct page *page; - int rc; - - page = vmemmap_shared_tail_page(order, device_zone(node)); - if (!page) - return -ENOMEM; - - if (reuse_compound_section(start_pfn, pgmap)) - return vmemmap_populate_range(start, end, node, NULL, - page_to_pfn(page)); - - size = min(end - start, (1UL << order) * sizeof(struct page)); - for (addr = start; addr < end; addr += size) { - unsigned long next, last = addr + size; - - /* Populate the head page vmemmap page */ - pte = vmemmap_populate_address(addr, node, NULL, -1); - if (!pte) - return -ENOMEM; - - /* - * Reuse the shared page for the rest of tail pages - * See layout diagram in Documentation/mm/vmemmap_dedup.rst - */ - next = addr + PAGE_SIZE; - rc = vmemmap_populate_range(next, last, node, NULL, - page_to_pfn(page)); - if (rc) - return -ENOMEM; - } - - return 0; -} - -#endif - struct page * __meminit __populate_section_memmap(unsigned long pfn, unsigned long nr_pages, int nid, struct vmem_altmap *altmap, struct dev_pagemap *pgmap) @@ -580,11 +515,7 @@ struct page * __meminit __populate_secti !IS_ALIGNED(nr_pages, PAGES_PER_SUBSECTION))) return NULL; - if (pgmap && section_vmemmap_optimizable(__pfn_to_section(pfn))) - r = vmemmap_populate_compound_pages(pfn, start, end, nid, pgmap); - else - r = vmemmap_populate(start, end, nid, altmap); - + r = vmemmap_populate(start, end, nid, altmap); if (r < 0) return NULL; _ Patches currently in -mm which might be from muchun.song@linux.dev are mm-fix-missing-page-table-destructor-in-pagetable_free.patch arm64-mm-fix-destructor-for-unconstructed-hotplug-page-tables.patch