[merged mm-stable] mm-sparse-move-initialization-of-section-metadata-to-sparse_metadata_init.patch removed from -mm tree

[merged mm-stable] mm-sparse-move-initialization-of-section-metadata-to-sparse_metadata_init.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/sparse: move initialization of section metadata to sparse_metadata_init()
has been removed from the -mm tree.  Its filename was
     mm-sparse-move-initialization-of-section-metadata-to-sparse_metadata_init.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: move initialization of section metadata to sparse_metadata_init()
Date: Mon, 21 Sep 2026 21:58:55 +0200

Let's move the code responsible for initializing sparse metadata (usemap,
memmap) into a helper.  Cleanup the variable while at it (e.g.,
"map_count").

Drop the rather obvious code comments.

No functional change intended.

Link: https://lore.kernel.org/20260921-b4-sparsemem_cleanups-v2-3-54d81d65e125@kernel.org
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Qi Zheng <qi.zheng@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Danilo Krummrich <dakr@kernel.org>
---

 mm/sparse.c |   43 ++++++++++++++++++++++---------------------
 1 file changed, 22 insertions(+), 21 deletions(-)

--- a/mm/sparse.c~mm-sparse-move-initialization-of-section-metadata-to-sparse_metadata_init
+++ a/mm/sparse.c
@@ -255,38 +255,39 @@ static void __init sparse_init_nid(int n
 	}
 }
 
+static void __init sparse_metadata_init(void)
+{
+	unsigned long start_section_nr = first_present_section_nr();
+	int nid_begin = sparse_early_nid(__nr_to_section(start_section_nr));
+	unsigned long section_nr, nr_sections = 1;
+
+	for_each_present_section_nr(start_section_nr + 1, section_nr) {
+		const int nid = sparse_early_nid(__nr_to_section(section_nr));
+
+		if (nid == nid_begin) {
+			nr_sections++;
+			continue;
+		}
+		sparse_init_nid(nid_begin, start_section_nr, section_nr, nr_sections);
+		nid_begin = nid;
+		start_section_nr = section_nr;
+		nr_sections = 1;
+	}
+	sparse_init_nid(nid_begin, start_section_nr, section_nr, nr_sections);
+}
+
 /*
  * Allocate the accumulated non-linear sections, allocate a mem_map
  * for each and record the physical to section mapping.
  */
 void __init sparse_init(void)
 {
-	unsigned long pnum_end, pnum_begin, map_count = 1;
-	int nid_begin;
-
 	if (compound_info_has_mask()) {
 		VM_WARN_ON_ONCE(!IS_ALIGNED((unsigned long) pfn_to_page(0),
 				    MAX_FOLIO_VMEMMAP_ALIGN));
 	}
 
-	pnum_begin = first_present_section_nr();
-	nid_begin = sparse_early_nid(__nr_to_section(pnum_begin));
-
-	for_each_present_section_nr(pnum_begin + 1, pnum_end) {
-		int nid = sparse_early_nid(__nr_to_section(pnum_end));
-
-		if (nid == nid_begin) {
-			map_count++;
-			continue;
-		}
-		/* Init node with sections in range [pnum_begin, pnum_end) */
-		sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count);
-		nid_begin = nid;
-		pnum_begin = pnum_end;
-		map_count = 1;
-	}
-	/* cover the last node */
-	sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count);
+	sparse_metadata_init();
 	sparse_init_subsection_map();
 	vmemmap_populate_print_last();
 }
_

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

mm-fix-address-wraparound-when-scanning-large-folio-ptes.patch
mm-hugetlb-disable-pmd-sharing-for-uffd-missing-mode.patch
mm-vma-write-lock-source-vma-before-duplicating-it-in-__split_vma.patch
mm-madvise-preserve-vma_softdirty_bit-when-changing-anonymous-names.patch