[merged mm-stable] mm-sparse-rename-__highest_present_section_nr-to-__highest_used_section_nr.patch removed from -mm tree

[merged mm-stable] mm-sparse-rename-__highest_present_section_nr-to-__highest_used_section_nr.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/sparse: rename __highest_present_section_nr to __highest_used_section_nr
has been removed from the -mm tree.  Its filename was
     mm-sparse-rename-__highest_present_section_nr-to-__highest_used_section_nr.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: rename __highest_present_section_nr to __highest_used_section_nr
Date: Mon, 21 Sep 2026 21:58:58 +0200

In preparation for getting rid of SECTION_MARKED_PRESENT, rename
__highest_present_section_nr and clarify the comment.

Link: https://lore.kernel.org/20260921-b4-sparsemem_cleanups-v2-6-54d81d65e125@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>
---

 include/linux/mmzone.h |    6 +++---
 mm/compaction.c        |    2 +-
 mm/sparse.c            |   12 ++++--------
 mm/sparse.h            |    4 ++--
 4 files changed, 10 insertions(+), 14 deletions(-)

--- a/include/linux/mmzone.h~mm-sparse-rename-__highest_present_section_nr-to-__highest_used_section_nr
+++ a/include/linux/mmzone.h
@@ -2155,7 +2155,7 @@ static inline struct mem_section *__pfn_
 	return __nr_to_section(pfn_to_section_nr(pfn));
 }
 
-extern unsigned long __highest_present_section_nr;
+extern unsigned long __highest_used_section_nr;
 
 static inline int subsection_map_index(unsigned long pfn)
 {
@@ -2254,7 +2254,7 @@ static inline unsigned long first_valid_
 
 	rcu_read_lock_sched();
 
-	while (nr <= __highest_present_section_nr && pfn < end_pfn) {
+	while (nr <= __highest_used_section_nr && pfn < end_pfn) {
 		struct mem_section *ms = __pfn_to_section(pfn);
 
 		if (valid_section(ms) &&
@@ -2309,7 +2309,7 @@ static inline int pfn_in_present_section
 
 static inline unsigned long next_present_section_nr(unsigned long section_nr)
 {
-	while (++section_nr <= __highest_present_section_nr) {
+	while (++section_nr <= __highest_used_section_nr) {
 		if (present_section_nr(section_nr))
 			return section_nr;
 	}
--- a/mm/compaction.c~mm-sparse-rename-__highest_present_section_nr-to-__highest_used_section_nr
+++ a/mm/compaction.c
@@ -216,7 +216,7 @@ static unsigned long skip_offline_sectio
 	if (online_section_nr(start_nr))
 		return 0;
 
-	while (++start_nr <= __highest_present_section_nr) {
+	while (++start_nr <= __highest_used_section_nr) {
 		if (online_section_nr(start_nr))
 			return section_nr_to_pfn(start_nr);
 	}
--- a/mm/sparse.c~mm-sparse-rename-__highest_present_section_nr-to-__highest_used_section_nr
+++ a/mm/sparse.c
@@ -164,15 +164,11 @@ static void __init mminit_validate_memmo
 }
 
 /*
- * There are a number of times that we loop over NR_MEM_SECTIONS,
- * looking for section_present() on each.  But, when we have very
- * large physical address spaces, NR_MEM_SECTIONS can also be
- * very large which makes the loops quite long.
- *
- * Keeping track of this gives us an easy way to break out of
- * those loops early.
+ * Looping over all possible memory sections is expensive, especially if
+ * NR_MEM_SECTIONS is large but only a fraction is actually used. Keep track of
+ * the highest section number we ever used.
  */
-unsigned long __highest_present_section_nr;
+unsigned long __highest_used_section_nr;
 
 static inline unsigned long first_present_section_nr(void)
 {
--- a/mm/sparse.h~mm-sparse-rename-__highest_present_section_nr-to-__highest_used_section_nr
+++ a/mm/sparse.h
@@ -44,8 +44,8 @@ static inline void sparse_init_one_secti
 static inline void __section_mark_present(struct mem_section *ms,
 		unsigned long section_nr)
 {
-	if (section_nr > __highest_present_section_nr)
-		__highest_present_section_nr = section_nr;
+	if (section_nr > __highest_used_section_nr)
+		__highest_used_section_nr = section_nr;
 
 	ms->section_mem_map |= SECTION_MARKED_PRESENT;
 }
_

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