Merge tag 'mm-stable-2025-10-01-19-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - "mm, swap: improve cluster scan strategy" from Kairui Song improves
   performance and reduces the failure rate of swap cluster allocation

 - "support large align and nid in Rust allocators" from Vitaly Wool
   permits Rust allocators to set NUMA node and large alignment when
   perforning slub and vmalloc reallocs

 - "mm/damon/vaddr: support stat-purpose DAMOS" from Yueyang Pan extend
   DAMOS_STAT's handling of the DAMON operations sets for virtual
   address spaces for ops-level DAMOS filters

 - "execute PROCMAP_QUERY ioctl under per-vma lock" from Suren
   Baghdasaryan reduces mmap_lock contention during reads of
   /proc/pid/maps

 - "mm/mincore: minor clean up for swap cache checking" from Kairui Song
   performs some cleanup in the swap code

 - "mm: vm_normal_page*() improvements" from David Hildenbrand provides
   code cleanup in the pagemap code

 - "add persistent huge zero folio support" from Pankaj Raghav provides
   a block layer speedup by optionalls making the
   huge_zero_pagepersistent, instead of releasing it when its refcount
   falls to zero

 - "kho: fixes and cleanups" from Mike Rapoport adds a few touchups to
   the recently added Kexec Handover feature

 - "mm: make mm->flags a bitmap and 64-bit on all arches" from Lorenzo
   Stoakes turns mm_struct.flags into a bitmap. To end the constant
   struggle with space shortage on 32-bit conflicting with 64-bit's
   needs

 - "mm/swapfile.c and swap.h cleanup" from Chris Li cleans up some swap
   code

 - "selftests/mm: Fix false positives and skip unsupported tests" from
   Donet Tom fixes a few things in our selftests code

 - "prctl: extend PR_SET_THP_DISABLE to only provide THPs when advised"
   from David Hildenbrand "allows individual processes to opt-out of
   THP=always into THP=madvise, without affecting other workloads on the
   system".

   It's a long story - the [1/N] changelog spells out the considerations

 - "Add and use memdesc_flags_t" from Matthew Wilcox gets us started on
   the memdesc project. Please see

      https://kernelnewbies.org/MatthewWilcox/Memdescs and
      https://blogs.oracle.com/linux/post/introducing-memdesc

 - "Tiny optimization for large read operations" from Chi Zhiling
   improves the efficiency of the pagecache read path

 - "Better split_huge_page_test result check" from Zi Yan improves our
   folio splitting selftest code

 - "test that rmap behaves as expected" from Wei Yang adds some rmap
   selftests

 - "remove write_cache_pages()" from Christoph Hellwig removes that
   function and converts its two remaining callers

 - "selftests/mm: uffd-stress fixes" from Dev Jain fixes some UFFD
   selftests issues

 - "introduce kernel file mapped folios" from Boris Burkov introduces
   the concept of "kernel file pages". Using these permits btrfs to
   account its metadata pages to the root cgroup, rather than to the
   cgroups of random inappropriate tasks

 - "mm/pageblock: improve readability of some pageblock handling" from
   Wei Yang provides some readability improvements to the page allocator
   code

 - "mm/damon: support ARM32 with LPAE" from SeongJae Park teaches DAMON
   to understand arm32 highmem

 - "tools: testing: Use existing atomic.h for vma/maple tests" from
   Brendan Jackman performs some code cleanups and deduplication under
   tools/testing/

 - "maple_tree: Fix testing for 32bit compiles" from Liam Howlett fixes
   a couple of 32-bit issues in tools/testing/radix-tree.c

 - "kasan: unify kasan_enabled() and remove arch-specific
   implementations" from Sabyrzhan Tasbolatov moves KASAN arch-specific
   initialization code into a common arch-neutral implementation

 - "mm: remove zpool" from Johannes Weiner removes zspool - an
   indirection layer which now only redirects to a single thing
   (zsmalloc)

 - "mm: task_stack: Stack handling cleanups" from Pasha Tatashin makes a
   couple of cleanups in the fork code

 - "mm: remove nth_page()" from David Hildenbrand makes rather a lot of
   adjustments at various nth_page() callsites, eventually permitting
   the removal of that undesirable helper function

 - "introduce kasan.write_only option in hw-tags" from Yeoreum Yun
   creates a KASAN read-only mode for ARM, using that architecture's
   memory tagging feature. It is felt that a read-only mode KASAN is
   suitable for use in production systems rather than debug-only

 - "mm: hugetlb: cleanup hugetlb folio allocation" from Kefeng Wang does
   some tidying in the hugetlb folio allocation code

 - "mm: establish const-correctness for pointer parameters" from Max
   Kellermann makes quite a number of the MM API functions more accurate
   about the constness of their arguments. This was getting in the way
   of subsystems (in this case CEPH) when they attempt to improving
   their own const/non-const accuracy

 - "Cleanup free_pages() misuse" from Vishal Moola fixes a number of
   code sites which were confused over when to use free_pages() vs
   __free_pages()

 - "Add Rust abstraction for Maple Trees" from Alice Ryhl makes the
   mapletree code accessible to Rust. Required by nouveau and by its
   forthcoming successor: the new Rust Nova driver

 - "selftests/mm: split_huge_page_test: split_pte_mapped_thp
   improvements" from David Hildenbrand adds a fix and some cleanups to
   the thp selftesting code

 - "mm, swap: introduce swap table as swap cache (phase I)" from Chris
   Li and Kairui Song is the first step along the path to implementing
   "swap tables" - a new approach to swap allocation and state tracking
   which is expected to yield speed and space improvements. This
   patchset itself yields a 5-20% performance benefit in some situations

 - "Some ptdesc cleanups" from Matthew Wilcox utilizes the new memdesc
   layer to clean up the ptdesc code a little

 - "Fix va_high_addr_switch.sh test failure" from Chunyu Hu fixes some
   issues in our 5-level pagetable selftesting code

 - "Minor fixes for memory allocation profiling" from Suren Baghdasaryan
   addresses a couple of minor issues in relatively new memory
   allocation profiling feature

 - "Small cleanups" from Matthew Wilcox has a few cleanups in
   preparation for more memdesc work

 - "mm/damon: add addr_unit for DAMON_LRU_SORT and DAMON_RECLAIM" from
   Quanmin Yan makes some changes to DAMON in furtherance of supporting
   arm highmem

 - "selftests/mm: Add -Wunreachable-code and fix warnings" from Muhammad
   Anjum adds that compiler check to selftests code and fixes the
   fallout, by removing dead code

 - "Improvements to Victim Process Thawing and OOM Reaper Traversal
   Order" from zhongjinji makes a number of improvements in the OOM
   killer: mainly thawing a more appropriate group of victim threads so
   they can release resources

 - "mm/damon: misc fixups and improvements for 6.18" from SeongJae Park
   is a bunch of small and unrelated fixups for DAMON

 - "mm/damon: define and use DAMON initialization check function" from
   SeongJae Park implement reliability and maintainability improvements
   to a recently-added bug fix

 - "mm/damon/stat: expose auto-tuned intervals and non-idle ages" from
   SeongJae Park provides additional transparency to userspace clients
   of the DAMON_STAT information

 - "Expand scope of khugepaged anonymous collapse" from Dev Jain removes
   some constraints on khubepaged's collapsing of anon VMAs. It also
   increases the success rate of MADV_COLLAPSE against an anon vma

 - "mm: do not assume file == vma->vm_file in compat_vma_mmap_prepare()"
   from Lorenzo Stoakes moves us further towards removal of
   file_operations.mmap(). This patchset concentrates upon clearing up
   the treatment of stacked filesystems

 - "mm: Improve mlock tracking for large folios" from Kiryl Shutsemau
   provides some fixes and improvements to mlock's tracking of large
   folios. /proc/meminfo's "Mlocked" field became more accurate

 - "mm/ksm: Fix incorrect accounting of KSM counters during fork" from
   Donet Tom fixes several user-visible KSM stats inaccuracies across
   forks and adds selftest code to verify these counters

 - "mm_slot: fix the usage of mm_slot_entry" from Wei Yang addresses
   some potential but presently benign issues in KSM's mm_slot handling

* tag 'mm-stable-2025-10-01-19-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (372 commits)
  mm: swap: check for stable address space before operating on the VMA
  mm: convert folio_page() back to a macro
  mm/khugepaged: use start_addr/addr for improved readability
  hugetlbfs: skip VMAs without shareable locks in hugetlb_vmdelete_list
  alloc_tag: fix boot failure due to NULL pointer dereference
  mm: silence data-race in update_hiwater_rss
  mm/memory-failure: don't select MEMORY_ISOLATION
  mm/khugepaged: remove definition of struct khugepaged_mm_slot
  mm/ksm: get mm_slot by mm_slot_entry() when slot is !NULL
  hugetlb: increase number of reserving hugepages via cmdline
  selftests/mm: add fork inheritance test for ksm_merging_pages counter
  mm/ksm: fix incorrect KSM counter handling in mm_struct during fork
  drivers/base/node: fix double free in register_one_node()
  mm: remove PMD alignment constraint in execmem_vmalloc()
  mm/memory_hotplug: fix typo 'esecially' -> 'especially'
  mm/rmap: improve mlock tracking for large folios
  mm/filemap: map entire large folio faultaround
  mm/fault: try to map the entire file folio in finish_fault()
  mm/rmap: mlock large folios in try_to_unmap_one()
  mm/rmap: fix a mlock race condition in folio_referenced_one()
  ...

1 files changed, 58 insertions, 33 deletions

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 0c5da9141983..7fb7331c5725 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -234,7 +234,21 @@ enum node_stat_item {
 #endif
 #ifdef CONFIG_NUMA_BALANCING
 	PGPROMOTE_SUCCESS,	/* promote successfully */
-	PGPROMOTE_CANDIDATE,	/* candidate pages to promote */
+	/**
+	 * Candidate pages for promotion based on hint fault latency.  This
+	 * counter is used to control the promotion rate and adjust the hot
+	 * threshold.
+	 */
+	PGPROMOTE_CANDIDATE,
+	/**
+	 * Not rate-limited (NRL) candidate pages for those can be promoted
+	 * without considering hot threshold because of enough free pages in
+	 * fast-tier node.  These promotions bypass the regular hotness checks
+	 * and do NOT influence the promotion rate-limiter or
+	 * threshold-adjustment logic.
+	 * This is for statistics/monitoring purposes.
+	 */
+	PGPROMOTE_CANDIDATE_NRL,
 #endif
 	/* PGDEMOTE_*: pages demoted */
 	PGDEMOTE_KSWAPD,
@@ -245,6 +259,7 @@ enum node_stat_item {
 	NR_HUGETLB,
 #endif
 	NR_BALLOON_PAGES,
+	NR_KERNEL_FILE_PAGES,
 	NR_VM_NODE_STAT_ITEMS
 };
 
@@ -1089,7 +1104,7 @@ static inline unsigned long promo_wmark_pages(const struct zone *z)
 	return wmark_pages(z, WMARK_PROMO);
 }
 
-static inline unsigned long zone_managed_pages(struct zone *zone)
+static inline unsigned long zone_managed_pages(const struct zone *zone)
 {
 	return (unsigned long)atomic_long_read(&zone->managed_pages);
 }
@@ -1113,12 +1128,12 @@ static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn)
 	return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone);
 }
 
-static inline bool zone_is_initialized(struct zone *zone)
+static inline bool zone_is_initialized(const struct zone *zone)
 {
 	return zone->initialized;
 }
 
-static inline bool zone_is_empty(struct zone *zone)
+static inline bool zone_is_empty(const struct zone *zone)
 {
 	return zone->spanned_pages == 0;
 }
@@ -1169,26 +1184,31 @@ static inline bool zone_is_empty(struct zone *zone)
 #define KASAN_TAG_MASK		((1UL << KASAN_TAG_WIDTH) - 1)
 #define ZONEID_MASK		((1UL << ZONEID_SHIFT) - 1)
 
+static inline enum zone_type memdesc_zonenum(memdesc_flags_t flags)
+{
+	ASSERT_EXCLUSIVE_BITS(flags.f, ZONES_MASK << ZONES_PGSHIFT);
+	return (flags.f >> ZONES_PGSHIFT) & ZONES_MASK;
+}
+
 static inline enum zone_type page_zonenum(const struct page *page)
 {
-	ASSERT_EXCLUSIVE_BITS(page->flags, ZONES_MASK << ZONES_PGSHIFT);
-	return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
+	return memdesc_zonenum(page->flags);
 }
 
 static inline enum zone_type folio_zonenum(const struct folio *folio)
 {
-	return page_zonenum(&folio->page);
+	return memdesc_zonenum(folio->flags);
 }
 
 #ifdef CONFIG_ZONE_DEVICE
-static inline bool is_zone_device_page(const struct page *page)
+static inline bool memdesc_is_zone_device(memdesc_flags_t mdf)
 {
-	return page_zonenum(page) == ZONE_DEVICE;
+	return memdesc_zonenum(mdf) == ZONE_DEVICE;
 }
 
 static inline struct dev_pagemap *page_pgmap(const struct page *page)
 {
-	VM_WARN_ON_ONCE_PAGE(!is_zone_device_page(page), page);
+	VM_WARN_ON_ONCE_PAGE(!memdesc_is_zone_device(page->flags), page);
 	return page_folio(page)->pgmap;
 }
 
@@ -1203,9 +1223,9 @@ static inline struct dev_pagemap *page_pgmap(const struct page *page)
 static inline bool zone_device_pages_have_same_pgmap(const struct page *a,
 						     const struct page *b)
 {
-	if (is_zone_device_page(a) != is_zone_device_page(b))
+	if (memdesc_is_zone_device(a->flags) != memdesc_is_zone_device(b->flags))
 		return false;
-	if (!is_zone_device_page(a))
+	if (!memdesc_is_zone_device(a->flags))
 		return true;
 	return page_pgmap(a) == page_pgmap(b);
 }
@@ -1213,7 +1233,7 @@ static inline bool zone_device_pages_have_same_pgmap(const struct page *a,
 extern void memmap_init_zone_device(struct zone *, unsigned long,
 				    unsigned long, struct dev_pagemap *);
 #else
-static inline bool is_zone_device_page(const struct page *page)
+static inline bool memdesc_is_zone_device(memdesc_flags_t mdf)
 {
 	return false;
 }
@@ -1228,9 +1248,14 @@ static inline struct dev_pagemap *page_pgmap(const struct page *page)
 }
 #endif
 
+static inline bool is_zone_device_page(const struct page *page)
+{
+	return memdesc_is_zone_device(page->flags);
+}
+
 static inline bool folio_is_zone_device(const struct folio *folio)
 {
-	return is_zone_device_page(&folio->page);
+	return memdesc_is_zone_device(folio->flags);
 }
 
 static inline bool is_zone_movable_page(const struct page *page)
@@ -1248,7 +1273,7 @@ static inline bool folio_is_zone_movable(const struct folio *folio)
  * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty
  * intersection with the given zone
  */
-static inline bool zone_intersects(struct zone *zone,
+static inline bool zone_intersects(const struct zone *zone,
 		unsigned long start_pfn, unsigned long nr_pages)
 {
 	if (zone_is_empty(zone))
@@ -1415,7 +1440,7 @@ typedef struct pglist_data {
 	int kswapd_order;
 	enum zone_type kswapd_highest_zoneidx;
 
-	int kswapd_failures;		/* Number of 'reclaimed == 0' runs */
+	atomic_t kswapd_failures;	/* Number of 'reclaimed == 0' runs */
 
 #ifdef CONFIG_COMPACTION
 	int kcompactd_max_order;
@@ -1556,12 +1581,12 @@ static inline int local_memory_node(int node_id) { return node_id; };
 #define zone_idx(zone)		((zone) - (zone)->zone_pgdat->node_zones)
 
 #ifdef CONFIG_ZONE_DEVICE
-static inline bool zone_is_zone_device(struct zone *zone)
+static inline bool zone_is_zone_device(const struct zone *zone)
 {
 	return zone_idx(zone) == ZONE_DEVICE;
 }
 #else
-static inline bool zone_is_zone_device(struct zone *zone)
+static inline bool zone_is_zone_device(const struct zone *zone)
 {
 	return false;
 }
@@ -1573,19 +1598,19 @@ static inline bool zone_is_zone_device(struct zone *zone)
  * populated_zone(). If the whole zone is reserved then we can easily
  * end up with populated_zone() && !managed_zone().
  */
-static inline bool managed_zone(struct zone *zone)
+static inline bool managed_zone(const struct zone *zone)
 {
 	return zone_managed_pages(zone);
 }
 
 /* Returns true if a zone has memory */
-static inline bool populated_zone(struct zone *zone)
+static inline bool populated_zone(const struct zone *zone)
 {
 	return zone->present_pages;
 }
 
 #ifdef CONFIG_NUMA
-static inline int zone_to_nid(struct zone *zone)
+static inline int zone_to_nid(const struct zone *zone)
 {
 	return zone->node;
 }
@@ -1595,7 +1620,7 @@ static inline void zone_set_nid(struct zone *zone, int nid)
 	zone->node = nid;
 }
 #else
-static inline int zone_to_nid(struct zone *zone)
+static inline int zone_to_nid(const struct zone *zone)
 {
 	return 0;
 }
@@ -1622,7 +1647,7 @@ static inline int is_highmem_idx(enum zone_type idx)
  * @zone: pointer to struct zone variable
  * Return: 1 for a highmem zone, 0 otherwise
  */
-static inline int is_highmem(struct zone *zone)
+static inline int is_highmem(const struct zone *zone)
 {
 	return is_highmem_idx(zone_idx(zone));
 }
@@ -1688,12 +1713,12 @@ static inline struct zone *zonelist_zone(struct zoneref *zoneref)
 	return zoneref->zone;
 }
 
-static inline int zonelist_zone_idx(struct zoneref *zoneref)
+static inline int zonelist_zone_idx(const struct zoneref *zoneref)
 {
 	return zoneref->zone_idx;
 }
 
-static inline int zonelist_node_idx(struct zoneref *zoneref)
+static inline int zonelist_node_idx(const struct zoneref *zoneref)
 {
 	return zone_to_nid(zoneref->zone);
 }
@@ -1996,7 +2021,7 @@ static inline struct page *__section_mem_map_addr(struct mem_section *section)
 	return (struct page *)map;
 }
 
-static inline int present_section(struct mem_section *section)
+static inline int present_section(const struct mem_section *section)
 {
 	return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
 }
@@ -2006,12 +2031,12 @@ static inline int present_section_nr(unsigned long nr)
 	return present_section(__nr_to_section(nr));
 }
 
-static inline int valid_section(struct mem_section *section)
+static inline int valid_section(const struct mem_section *section)
 {
 	return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
 }
 
-static inline int early_section(struct mem_section *section)
+static inline int early_section(const struct mem_section *section)
 {
 	return (section && (section->section_mem_map & SECTION_IS_EARLY));
 }
@@ -2021,27 +2046,27 @@ static inline int valid_section_nr(unsigned long nr)
 	return valid_section(__nr_to_section(nr));
 }
 
-static inline int online_section(struct mem_section *section)
+static inline int online_section(const struct mem_section *section)
 {
 	return (section && (section->section_mem_map & SECTION_IS_ONLINE));
 }
 
 #ifdef CONFIG_ZONE_DEVICE
-static inline int online_device_section(struct mem_section *section)
+static inline int online_device_section(const struct mem_section *section)
 {
 	unsigned long flags = SECTION_IS_ONLINE | SECTION_TAINT_ZONE_DEVICE;
 
 	return section && ((section->section_mem_map & flags) == flags);
 }
 #else
-static inline int online_device_section(struct mem_section *section)
+static inline int online_device_section(const struct mem_section *section)
 {
 	return 0;
 }
 #endif
 
 #ifdef CONFIG_SPARSEMEM_VMEMMAP_PREINIT
-static inline int preinited_vmemmap_section(struct mem_section *section)
+static inline int preinited_vmemmap_section(const struct mem_section *section)
 {
 	return (section &&
 		(section->section_mem_map & SECTION_IS_VMEMMAP_PREINIT));
@@ -2051,7 +2076,7 @@ void sparse_vmemmap_init_nid_early(int nid);
 void sparse_vmemmap_init_nid_late(int nid);
 
 #else
-static inline int preinited_vmemmap_section(struct mem_section *section)
+static inline int preinited_vmemmap_section(const struct mem_section *section)
 {
 	return 0;
 }