+ mm-rename-zone-lock-to-zone-_lock.patch added to mm-new branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm: rename zone->lock to zone->_lock
has been added to the -mm mm-new branch.  Its filename is
     mm-rename-zone-lock-to-zone-_lock.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-rename-zone-lock-to-zone-_lock.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

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------------------------------------------------------
From: Dmitry Ilvokhin <d@ilvokhin.com>
Subject: mm: rename zone->lock to zone->_lock
Date: Fri, 27 Feb 2026 16:00:26 +0000

This intentionally breaks direct users of zone->lock at compile time so
all call sites are converted to the zone lock wrappers.  Without the
rename, present and future out-of-tree code could continue using
spin_lock(&zone->lock) and bypass the wrappers and tracing infrastructure.

No functional change intended.

Link: https://lkml.kernel.org/r/d61500c5784c64e971f4d328c57639303c475f81.1772206930.git.d@ilvokhin.com
Signed-off-by: Dmitry Ilvokhin <d@ilvokhin.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: SeongJae Park <sj@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/mmzone.h      |    7 +++++--
 include/linux/mmzone_lock.h |   12 ++++++------
 mm/compaction.c             |    4 ++--
 mm/internal.h               |    2 +-
 mm/page_alloc.c             |   16 ++++++++--------
 mm/page_isolation.c         |    4 ++--
 mm/page_owner.c             |    2 +-
 7 files changed, 25 insertions(+), 22 deletions(-)

--- a/include/linux/mmzone.h~mm-rename-zone-lock-to-zone-_lock
+++ a/include/linux/mmzone.h
@@ -1094,8 +1094,11 @@ struct zone {
 	/* zone flags, see below */
 	unsigned long		flags;
 
-	/* Primarily protects free_area */
-	spinlock_t		lock;
+	/*
+	 * Primarily protects free_area. Should be accessed via zone_lock_*
+	 * helpers.
+	 */
+	spinlock_t		_lock;
 
 	/* Pages to be freed when next trylock succeeds */
 	struct llist_head	trylock_free_pages;
--- a/include/linux/mmzone_lock.h~mm-rename-zone-lock-to-zone-_lock
+++ a/include/linux/mmzone_lock.h
@@ -7,32 +7,32 @@
 
 static inline void zone_lock_init(struct zone *zone)
 {
-	spin_lock_init(&zone->lock);
+	spin_lock_init(&zone->_lock);
 }
 
 #define zone_lock_irqsave(zone, flags)				\
 do {								\
-	spin_lock_irqsave(&(zone)->lock, flags);		\
+	spin_lock_irqsave(&(zone)->_lock, flags);		\
 } while (0)
 
 #define zone_trylock_irqsave(zone, flags)			\
 ({								\
-	spin_trylock_irqsave(&(zone)->lock, flags);		\
+	spin_trylock_irqsave(&(zone)->_lock, flags);		\
 })
 
 static inline void zone_unlock_irqrestore(struct zone *zone, unsigned long flags)
 {
-	spin_unlock_irqrestore(&zone->lock, flags);
+	spin_unlock_irqrestore(&zone->_lock, flags);
 }
 
 static inline void zone_lock_irq(struct zone *zone)
 {
-	spin_lock_irq(&zone->lock);
+	spin_lock_irq(&zone->_lock);
 }
 
 static inline void zone_unlock_irq(struct zone *zone)
 {
-	spin_unlock_irq(&zone->lock);
+	spin_unlock_irq(&zone->_lock);
 }
 
 #endif /* _LINUX_MMZONE_LOCK_H */
--- a/mm/compaction.c~mm-rename-zone-lock-to-zone-_lock
+++ a/mm/compaction.c
@@ -506,7 +506,7 @@ static bool test_and_set_skip(struct com
 static bool compact_zone_lock_irqsave(struct zone *zone,
 				      unsigned long *flags,
 				      struct compact_control *cc)
-	__acquires(&zone->lock)
+	__acquires(&zone->_lock)
 {
 	/* Track if the lock is contended in async mode */
 	if (cc->mode == MIGRATE_ASYNC && !cc->contended) {
@@ -1419,7 +1419,7 @@ static bool suitable_migration_target(st
 		int order = cc->order > 0 ? cc->order : pageblock_order;
 
 		/*
-		 * We are checking page_order without zone->lock taken. But
+		 * We are checking page_order without zone->_lock taken. But
 		 * the only small danger is that we skip a potentially suitable
 		 * pageblock, so it's not worth to check order for valid range.
 		 */
--- a/mm/internal.h~mm-rename-zone-lock-to-zone-_lock
+++ a/mm/internal.h
@@ -729,7 +729,7 @@ static inline unsigned int buddy_order(s
  * (d) a page and its buddy are in the same zone.
  *
  * For recording whether a page is in the buddy system, we set PageBuddy.
- * Setting, clearing, and testing PageBuddy is serialized by zone->lock.
+ * Setting, clearing, and testing PageBuddy is serialized by zone->_lock.
  *
  * For recording page's order, we use page_private(page).
  */
--- a/mm/page_alloc.c~mm-rename-zone-lock-to-zone-_lock
+++ a/mm/page_alloc.c
@@ -815,7 +815,7 @@ compaction_capture(struct capture_contro
 static inline void account_freepages(struct zone *zone, int nr_pages,
 				     int migratetype)
 {
-	lockdep_assert_held(&zone->lock);
+	lockdep_assert_held(&zone->_lock);
 
 	if (is_migrate_isolate(migratetype))
 		return;
@@ -2476,7 +2476,7 @@ enum rmqueue_mode {
 
 /*
  * Do the hard work of removing an element from the buddy allocator.
- * Call me with the zone->lock already held.
+ * Call me with the zone->_lock already held.
  */
 static __always_inline struct page *
 __rmqueue(struct zone *zone, unsigned int order, int migratetype,
@@ -2504,7 +2504,7 @@ __rmqueue(struct zone *zone, unsigned in
 	 * fallbacks modes with increasing levels of fragmentation risk.
 	 *
 	 * The fallback logic is expensive and rmqueue_bulk() calls in
-	 * a loop with the zone->lock held, meaning the freelists are
+	 * a loop with the zone->_lock held, meaning the freelists are
 	 * not subject to any outside changes. Remember in *mode where
 	 * we found pay dirt, to save us the search on the next call.
 	 */
@@ -3206,7 +3206,7 @@ void __putback_isolated_page(struct page
 	struct zone *zone = page_zone(page);
 
 	/* zone lock should be held when this function is called */
-	lockdep_assert_held(&zone->lock);
+	lockdep_assert_held(&zone->_lock);
 
 	/* Return isolated page to tail of freelist. */
 	__free_one_page(page, page_to_pfn(page), zone, order, mt,
@@ -7090,7 +7090,7 @@ int alloc_contig_frozen_range_noprof(uns
 	 * pages.  Because of this, we reserve the bigger range and
 	 * once this is done free the pages we are not interested in.
 	 *
-	 * We don't have to hold zone->lock here because the pages are
+	 * We don't have to hold zone->_lock here because the pages are
 	 * isolated thus they won't get removed from buddy.
 	 */
 	outer_start = find_large_buddy(start);
@@ -7659,7 +7659,7 @@ void accept_page(struct page *page)
 		return;
 	}
 
-	/* Unlocks zone->lock */
+	/* Unlocks zone->_lock */
 	__accept_page(zone, &flags, page);
 }
 
@@ -7676,7 +7676,7 @@ static bool try_to_accept_memory_one(str
 		return false;
 	}
 
-	/* Unlocks zone->lock */
+	/* Unlocks zone->_lock */
 	__accept_page(zone, &flags, page);
 
 	return true;
@@ -7817,7 +7817,7 @@ struct page *alloc_frozen_pages_nolock_n
 
 	/*
 	 * Best effort allocation from percpu free list.
-	 * If it's empty attempt to spin_trylock zone->lock.
+	 * If it's empty attempt to spin_trylock zone->_lock.
 	 */
 	page = get_page_from_freelist(alloc_gfp, order, alloc_flags, &ac);
 
--- a/mm/page_isolation.c~mm-rename-zone-lock-to-zone-_lock
+++ a/mm/page_isolation.c
@@ -212,7 +212,7 @@ static int set_migratetype_isolate(struc
 	zone_unlock_irqrestore(zone, flags);
 	if (mode == PB_ISOLATE_MODE_MEM_OFFLINE) {
 		/*
-		 * printk() with zone->lock held will likely trigger a
+		 * printk() with zone->_lock held will likely trigger a
 		 * lockdep splat, so defer it here.
 		 */
 		dump_page(unmovable, "unmovable page");
@@ -553,7 +553,7 @@ void undo_isolate_page_range(unsigned lo
 /*
  * Test all pages in the range is free(means isolated) or not.
  * all pages in [start_pfn...end_pfn) must be in the same zone.
- * zone->lock must be held before call this.
+ * zone->_lock must be held before call this.
  *
  * Returns the last tested pfn.
  */
--- a/mm/page_owner.c~mm-rename-zone-lock-to-zone-_lock
+++ a/mm/page_owner.c
@@ -799,7 +799,7 @@ static void init_pages_in_zone(struct zo
 				continue;
 
 			/*
-			 * To avoid having to grab zone->lock, be a little
+			 * To avoid having to grab zone->_lock, be a little
 			 * careful when reading buddy page order. The only
 			 * danger is that we skip too much and potentially miss
 			 * some early allocated pages, which is better than
_

Patches currently in -mm which might be from d@ilvokhin.com are

mm-introduce-zone-lock-wrappers.patch
mm-convert-zone-lock-users-to-wrappers.patch
mm-convert-compaction-to-zone-lock-wrappers.patch
mm-rename-zone-lock-to-zone-_lock.patch
mm-add-tracepoints-for-zone-lock.patch