+ mm-bootmem_info-stop-marking-mem_section_usage-as-mix_section_info.patch added to mm-new branch

+ mm-bootmem_info-stop-marking-mem_section_usage-as-mix_section_info.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm/bootmem_info: stop marking mem_section_usage as MIX_SECTION_INFO
has been added to the -mm mm-new branch.  Its filename is
     mm-bootmem_info-stop-marking-mem_section_usage-as-mix_section_info.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-bootmem_info-stop-marking-mem_section_usage-as-mix_section_info.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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------------------------------------------------------
From: "David Hildenbrand (Arm)" <david@kernel.org>
Subject: mm/bootmem_info: stop marking mem_section_usage as MIX_SECTION_INFO
Date: Mon, 11 May 2026 16:05:34 +0200

We never free the ms->usage data for boot memory sections (see
section_deactivate()). And to identify whether ms->usage was allocated
from memblock, we simply identify it by looking at PG_reserved.

Consequently, there is no need to mark ms->usage as MIX_SECTION_INFO.
Let's just stop doing that.

Link: https://lore.kernel.org/20260511-bootmem_info_prep-v1-6-3fb0be6fc688@kernel.org
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/bootmem_info.c |   12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

--- a/mm/bootmem_info.c~mm-bootmem_info-stop-marking-mem_section_usage-as-mix_section_info
+++ a/mm/bootmem_info.c
@@ -38,10 +38,8 @@ void put_page_bootmem(struct page *page)
 
 static void __init register_page_bootmem_info_section(unsigned long start_pfn)
 {
-	unsigned long mapsize, section_nr, i;
+	unsigned long section_nr;
 	struct mem_section *ms;
-	struct mem_section_usage *usage;
-	struct page *page;
 
 	start_pfn = SECTION_ALIGN_DOWN(start_pfn);
 	section_nr = pfn_to_section_nr(start_pfn);
@@ -50,14 +48,6 @@ static void __init register_page_bootmem
 	if (!preinited_vmemmap_section(ms))
 		register_page_bootmem_memmap(section_nr, pfn_to_page(start_pfn),
 					     PAGES_PER_SECTION);
-
-	usage = ms->usage;
-	page = virt_to_page(usage);
-
-	mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT;
-
-	for (i = 0; i < mapsize; i++, page++)
-		get_page_bootmem(section_nr, page, MIX_SECTION_INFO);
 }
 
 void __init register_page_bootmem_info_node(struct pglist_data *pgdat)
_

Patches currently in -mm which might be from david@kernel.org are

mm-page_alloc-fix-initialization-of-tags-of-the-huge-zero-folio-with-init_on_free.patch
mm-fix-__vm_normal_page-to-handle-missing-support-for-pmd_special-pud_special.patch
sh-use-folio_mapped-instead-of-page_mapped-in-sh4_flush_cache_page.patch
bpf-arena-use-page_ref_count-instead-of-page_mapped-in-arena_free_pages.patch
mm-remove-page_mapped.patch
sparc-mm-remove-register_page_bootmem_info.patch
mm-bootmem_info-drop-initialization-of-page-lru.patch
mm-bootmem_info-stop-using-pg_private.patch
mm-bootmem_info-remove-call-to-kmemleak_free_part_phys.patch
mm-bootmem_info-stop-marking-the-pgdat-as-node_info.patch
mm-bootmem_info-stop-marking-mem_section_usage-as-mix_section_info.patch
s390-mm-use-free_reserved_page-in-vmem_free_pages.patch
powerpc-mm-remove-config_have_bootmem_info_node.patch