[merged mm-stable] x86-mm-stop-marking-page-tables-as-mix_section_info.patch removed from -mm tree

Andrew Morton <[email protected]> Tue, 04 Aug 2026 19:24:15 -0700
Newsgroups org.kernel.vger.mm-commits
Message-ID <[email protected]>
The quilt patch titled
     Subject: x86/mm: stop marking page tables as MIX_SECTION_INFO
has been removed from the -mm tree.  Its filename was
     x86-mm-stop-marking-page-tables-as-mix_section_info.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: "David Hildenbrand (Arm)" <[email protected]>
Subject: x86/mm: stop marking page tables as MIX_SECTION_INFO
Date: Thu, 16 Jul 2026 16:51:05 +0200

There is no good reason to mark boot page tables as MIX_SECTION_INFO: we
only free boot page tables when they are completely empty, and memory
offlining/hotunplug doesn't benefit from it in any way.

So just stop marking page tables as MIX_SECTION_INFO.  In
free_pagetable(), we can now simply free reserved pages directly.

Link: https://lore.kernel.org/[email protected]
Signed-off-by: David Hildenbrand (Arm) <[email protected]>
Reviewed-by: Mike Rapoport (Microsoft) <[email protected]>
Reviewed-by: Dave Hansen <[email protected]>
Cc: Alexander Gordeev <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: "Borislav Petkov (AMD)" <[email protected]>
Cc: Brendan Jackman <[email protected]>
Cc: Brendan Jackman <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Gerald Schaefer <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---

 arch/x86/mm/init_64.c |   59 +---------------------------------------
 1 file changed, 2 insertions(+), 57 deletions(-)

--- a/arch/x86/mm/init_64.c~x86-mm-stop-marking-page-tables-as-mix_section_info
+++ a/arch/x86/mm/init_64.c
@@ -1002,21 +1002,10 @@ int arch_add_memory(int nid, u64 start,
 
 static void __meminit free_pagetable(struct page *page)
 {
-	/* bootmem page has reserved flag */
-	if (PageReserved(page)) {
-#ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE
-		enum bootmem_type type = bootmem_type(page);
-
-		if (type == MIX_SECTION_INFO)
-			put_page_bootmem(page);
-		else
-			free_reserved_page(page);
-#else
+	if (PageReserved(page))
 		free_reserved_page(page);
-#endif
-	} else {
+	else
 		pagetable_free(page_ptdesc(page));
-	}
 }
 
 static void __meminit free_vmemmap_pages(struct page *page, unsigned int order,
@@ -1579,50 +1568,6 @@ int __meminit vmemmap_populate(unsigned
 void register_page_bootmem_memmap(unsigned long section_nr,
 				  struct page *start_page, unsigned long nr_pages)
 {
-	unsigned long addr = (unsigned long)start_page;
-	unsigned long end = (unsigned long)(start_page + nr_pages);
-	unsigned long next;
-	pgd_t *pgd;
-	p4d_t *p4d;
-	pud_t *pud;
-	pmd_t *pmd;
-
-	for (; addr < end; addr = next) {
-		pgd = pgd_offset_k(addr);
-		if (pgd_none(*pgd)) {
-			next = (addr + PAGE_SIZE) & PAGE_MASK;
-			continue;
-		}
-		get_page_bootmem(section_nr, pgd_page(*pgd), MIX_SECTION_INFO);
-
-		p4d = p4d_offset(pgd, addr);
-		if (p4d_none(*p4d)) {
-			next = (addr + PAGE_SIZE) & PAGE_MASK;
-			continue;
-		}
-		get_page_bootmem(section_nr, p4d_page(*p4d), MIX_SECTION_INFO);
-
-		pud = pud_offset(p4d, addr);
-		if (pud_none(*pud)) {
-			next = (addr + PAGE_SIZE) & PAGE_MASK;
-			continue;
-		}
-		get_page_bootmem(section_nr, pud_page(*pud), MIX_SECTION_INFO);
-
-		pmd = pmd_offset(pud, addr);
-		if (pmd_none(*pmd)) {
-			next = (addr + PAGE_SIZE) & PAGE_MASK;
-			continue;
-		}
-
-		if (!boot_cpu_has(X86_FEATURE_PSE) || !pmd_leaf(*pmd)) {
-			next = (addr + PAGE_SIZE) & PAGE_MASK;
-			get_page_bootmem(section_nr, pmd_page(*pmd),
-					 MIX_SECTION_INFO);
-		} else {
-			next = pmd_addr_end(addr, end);
-		}
-	}
 }
 #endif
 
_

Patches currently in -mm which might be from [email protected] are

mm-standardize-printing-for-pgtable-entries.patch
mm-gup-fix-always-draining-lru-caches-in-collect_longterm_unpinnable_folios.patch