[merged mm-stable] mm-sparse-drop-set_section_nid-from-sparse_add_section.patch removed from -mm tree

[merged mm-stable] mm-sparse-drop-set_section_nid-from-sparse_add_section.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/sparse: drop set_section_nid() from sparse_add_section()
has been removed from the -mm tree.  Its filename was
     mm-sparse-drop-set_section_nid-from-sparse_add_section.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)" <david@kernel.org>
Subject: mm/sparse: drop set_section_nid() from sparse_add_section()
Date: Fri, 20 Mar 2026 23:13:44 +0100

CONFIG_MEMORY_HOTPLUG is CONFIG_SPARSEMEM_VMEMMAP-only.  And
CONFIG_SPARSEMEM_VMEMMAP implies that NODE_NOT_IN_PAGE_FLAGS cannot be
set: see include/linux/page-flags-layout.h

	...
	#elif defined(CONFIG_SPARSEMEM_VMEMMAP)
	#error "Vmemmap: No space for nodes field in page flags"
	...

Which implies that the node is always stored in page flags and
NODE_NOT_IN_PAGE_FLAGS cannot be set.  Therefore, set_section_nid() is a
NOP on CONFIG_SPARSEMEM_VMEMMAP.

So let's remove the set_section_nid() call to prepare for moving
CONFIG_MEMORY_HOTPLUG to mm/sparse-vmemmap.c

Link: https://lkml.kernel.org/r/20260320-sparsemem_cleanups-v2-12-096addc8800d@kernel.org
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/sparse.c |    1 -
 1 file changed, 1 deletion(-)

--- a/mm/sparse.c~mm-sparse-drop-set_section_nid-from-sparse_add_section
+++ a/mm/sparse.c
@@ -765,7 +765,6 @@ int __meminit sparse_add_section(int nid
 	page_init_poison(memmap, sizeof(struct page) * nr_pages);
 
 	ms = __nr_to_section(section_nr);
-	set_section_nid(section_nr, nid);
 	__section_mark_present(ms, section_nr);
 
 	/* Align memmap to section boundary in the subsection case */
_

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