Merge tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - The series "Enable strict percpu address space checks" from Uros
   Bizjak uses x86 named address space qualifiers to provide
   compile-time checking of percpu area accesses.

   This has caused a small amount of fallout - two or three issues were
   reported. In all cases the calling code was found to be incorrect.

 - The series "Some cleanup for memcg" from Chen Ridong implements some
   relatively monir cleanups for the memcontrol code.

 - The series "mm: fixes for device-exclusive entries (hmm)" from David
   Hildenbrand fixes a boatload of issues which David found then using
   device-exclusive PTE entries when THP is enabled. More work is
   needed, but this makes thins better - our own HMM selftests now
   succeed.

 - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed
   remove the z3fold and zbud implementations. They have been deprecated
   for half a year and nobody has complained.

 - The series "mm: further simplify VMA merge operation" from Lorenzo
   Stoakes implements numerous simplifications in this area. No runtime
   effects are anticipated.

 - The series "mm/madvise: remove redundant mmap_lock operations from
   process_madvise()" from SeongJae Park rationalizes the locking in the
   madvise() implementation. Performance gains of 20-25% were observed
   in one MADV_DONTNEED microbenchmark.

 - The series "Tiny cleanup and improvements about SWAP code" from
   Baoquan He contains a number of touchups to issues which Baoquan
   noticed when working on the swap code.

 - The series "mm: kmemleak: Usability improvements" from Catalin
   Marinas implements a couple of improvements to the kmemleak
   user-visible output.

 - The series "mm/damon/paddr: fix large folios access and schemes
   handling" from Usama Arif provides a couple of fixes for DAMON's
   handling of large folios.

 - The series "mm/damon/core: fix wrong and/or useless damos_walk()
   behaviors" from SeongJae Park fixes a few issues with the accuracy of
   kdamond's walking of DAMON regions.

 - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo
   Stoakes changes the interaction between framebuffer deferred-io and
   core MM. No functional changes are anticipated - this is preparatory
   work for the future removal of page structure fields.

 - The series "mm/damon: add support for hugepage_size DAMOS filter"
   from Usama Arif adds a DAMOS filter which permits the filtering by
   huge page sizes.

 - The series "mm: permit guard regions for file-backed/shmem mappings"
   from Lorenzo Stoakes extends the guard region feature from its
   present "anon mappings only" state. The feature now covers shmem and
   file-backed mappings.

 - The series "mm: batched unmap lazyfree large folios during
   reclamation" from Barry Song cleans up and speeds up the unmapping
   for pte-mapped large folios.

 - The series "reimplement per-vma lock as a refcount" from Suren
   Baghdasaryan puts the vm_lock back into the vma. Our reasons for
   pulling it out were largely bogus and that change made the code more
   messy. This patchset provides small (0-10%) improvements on one
   microbenchmark.

 - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and
   improves" from SeongJae Park does some maintenance work on the DAMON
   docs.

 - The series "hugetlb/CMA improvements for large systems" from Frank
   van der Linden addresses a pile of issues which have been observed
   when using CMA on large machines.

 - The series "mm/damon: introduce DAMOS filter type for unmapped pages"
   from SeongJae Park enables users of DMAON/DAMOS to filter my the
   page's mapped/unmapped status.

 - The series "zsmalloc/zram: there be preemption" from Sergey
   Senozhatsky teaches zram to run its compression and decompression
   operations preemptibly.

 - The series "selftests/mm: Some cleanups from trying to run them" from
   Brendan Jackman fixes a pile of unrelated issues which Brendan
   encountered while runnimg our selftests.

 - The series "fs/proc/task_mmu: add guard region bit to pagemap" from
   Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to
   determine whether a particular page is a guard page.

 - The series "mm, swap: remove swap slot cache" from Kairui Song
   removes the swap slot cache from the allocation path - it simply
   wasn't being effective.

 - The series "mm: cleanups for device-exclusive entries (hmm)" from
   David Hildenbrand implements a number of unrelated cleanups in this
   code.

 - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual
   implements a number of preparatoty cleanups to the GENERIC_PTDUMP
   Kconfig logic.

 - The series "mm/damon: auto-tune aggregation interval" from SeongJae
   Park implements a feedback-driven automatic tuning feature for
   DAMON's aggregation interval tuning.

 - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in
   powerpc, sparc and x86 lazy MMU implementations. Ryan did this in
   preparation for implementing lazy mmu mode for arm64 to optimize
   vmalloc.

 - The series "mm/page_alloc: Some clarifications for migratetype
   fallback" from Brendan Jackman reworks some commentary to make the
   code easier to follow.

 - The series "page_counter cleanup and size reduction" from Shakeel
   Butt cleans up the page_counter code and fixes a size increase which
   we accidentally added late last year.

 - The series "Add a command line option that enables control of how
   many threads should be used to allocate huge pages" from Thomas
   Prescher does that. It allows the careful operator to significantly
   reduce boot time by tuning the parallalization of huge page
   initialization.

 - The series "Fix calculations in trace_balance_dirty_pages() for cgwb"
   from Tang Yizhou fixes the tracing output from the dirty page
   balancing code.

 - The series "mm/damon: make allow filters after reject filters useful
   and intuitive" from SeongJae Park improves the handling of allow and
   reject filters. Behaviour is made more consistent and the documention
   is updated accordingly.

 - The series "Switch zswap to object read/write APIs" from Yosry Ahmed
   updates zswap to the new object read/write APIs and thus permits the
   removal of some legacy code from zpool and zsmalloc.

 - The series "Some trivial cleanups for shmem" from Baolin Wang does as
   it claims.

 - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from
   Alistair Popple regularizes the weird ZONE_DEVICE page refcount
   handling in DAX, permittig the removal of a number of special-case
   checks.

 - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a
   preparatoty refactoring and cleanup of the mremap() code.

 - The series "mm: MM owner tracking for large folios (!hugetlb) +
   CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in
   which we determine whether a large folio is known to be mapped
   exclusively into a single MM.

 - The series "mm/damon: add sysfs dirs for managing DAMOS filters based
   on handling layers" from SeongJae Park adds a couple of new sysfs
   directories to ease the management of DAMON/DAMOS filters.

 - The series "arch, mm: reduce code duplication in mem_init()" from
   Mike Rapoport consolidates many per-arch implementations of
   mem_init() into code generic code, where that is practical.

 - The series "mm/damon/sysfs: commit parameters online via
   damon_call()" from SeongJae Park continues the cleaning up of sysfs
   access to DAMON internal data.

 - The series "mm: page_ext: Introduce new iteration API" from Luiz
   Capitulino reworks the page_ext initialization to fix a boot-time
   crash which was observed with an unusual combination of compile and
   cmdline options.

 - The series "Buddy allocator like (or non-uniform) folio split" from
   Zi Yan reworks the code to split a folio into smaller folios. The
   main benefit is lessened memory consumption: fewer post-split folios
   are generated.

 - The series "Minimize xa_node allocation during xarry split" from Zi
   Yan reduces the number of xarray xa_nodes which are generated during
   an xarray split.

 - The series "drivers/base/memory: Two cleanups" from Gavin Shan
   performs some maintenance work on the drivers/base/memory code.

 - The series "Add tracepoints for lowmem reserves, watermarks and
   totalreserve_pages" from Martin Liu adds some more tracepoints to the
   page allocator code.

 - The series "mm/madvise: cleanup requests validations and
   classifications" from SeongJae Park cleans up some warts which
   SeongJae observed during his earlier madvise work.

 - The series "mm/hwpoison: Fix regressions in memory failure handling"
   from Shuai Xue addresses two quite serious regressions which Shuai
   has observed in the memory-failure implementation.

 - The series "mm: reliable huge page allocator" from Johannes Weiner
   makes huge page allocations cheaper and more reliable by reducing
   fragmentation.

 - The series "Minor memcg cleanups & prep for memdescs" from Matthew
   Wilcox is preparatory work for the future implementation of memdescs.

 - The series "track memory used by balloon drivers" from Nico Pache
   introduces a way to track memory used by our various balloon drivers.

 - The series "mm/damon: introduce DAMOS filter type for active pages"
   from Nhat Pham permits users to filter for active/inactive pages,
   separately for file and anon pages.

 - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia
   separates the proactive reclaim statistics from the direct reclaim
   statistics.

 - The series "mm/vmscan: don't try to reclaim hwpoison folio" from
   Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim
   code.

* tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits)
  mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex()
  x86/mm: restore early initialization of high_memory for 32-bits
  mm/vmscan: don't try to reclaim hwpoison folio
  mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper
  cgroup: docs: add pswpin and pswpout items in cgroup v2 doc
  mm: vmscan: split proactive reclaim statistics from direct reclaim statistics
  selftests/mm: speed up split_huge_page_test
  selftests/mm: uffd-unit-tests support for hugepages > 2M
  docs/mm/damon/design: document active DAMOS filter type
  mm/damon: implement a new DAMOS filter type for active pages
  fs/dax: don't disassociate zero page entries
  MM documentation: add "Unaccepted" meminfo entry
  selftests/mm: add commentary about 9pfs bugs
  fork: use __vmalloc_node() for stack allocation
  docs/mm: Physical Memory: Populate the "Zones" section
  xen: balloon: update the NR_BALLOON_PAGES state
  hv_balloon: update the NR_BALLOON_PAGES state
  balloon_compaction: update the NR_BALLOON_PAGES state
  meminfo: add a per node counter for balloon drivers
  mm: remove references to folio in __memcg_kmem_uncharge_page()
  ...

1 files changed, 148 insertions, 55 deletions

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 75e8850cec3a..56d07edd01f9 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -19,6 +19,7 @@
 #include <linux/workqueue.h>
 #include <linux/seqlock.h>
 #include <linux/percpu_counter.h>
+#include <linux/types.h>
 
 #include <asm/mmu.h>
 
@@ -133,8 +134,11 @@ struct page {
 			unsigned long compound_head;	/* Bit zero is set */
 		};
 		struct {	/* ZONE_DEVICE pages */
-			/** @pgmap: Points to the hosting device page map. */
-			struct dev_pagemap *pgmap;
+			/*
+			 * The first word is used for compound_head or folio
+			 * pgmap
+			 */
+			void *_unused_pgmap_compound_head;
 			void *zone_device_data;
 			/*
 			 * ZONE_DEVICE private pages are counted as being
@@ -287,6 +291,49 @@ typedef struct {
 	unsigned long val;
 } swp_entry_t;
 
+#if defined(CONFIG_MEMCG) || defined(CONFIG_SLAB_OBJ_EXT)
+/* We have some extra room after the refcount in tail pages. */
+#define NR_PAGES_IN_LARGE_FOLIO
+#endif
+
+/*
+ * On 32bit, we can cut the required metadata in half, because:
+ * (a) PID_MAX_LIMIT implicitly limits the number of MMs we could ever have,
+ *     so we can limit MM IDs to 15 bit (32767).
+ * (b) We don't expect folios where even a single complete PTE mapping by
+ *     one MM would exceed 15 bits (order-15).
+ */
+#ifdef CONFIG_64BIT
+typedef int mm_id_mapcount_t;
+#define MM_ID_MAPCOUNT_MAX		INT_MAX
+typedef unsigned int mm_id_t;
+#else /* !CONFIG_64BIT */
+typedef short mm_id_mapcount_t;
+#define MM_ID_MAPCOUNT_MAX		SHRT_MAX
+typedef unsigned short mm_id_t;
+#endif /* CONFIG_64BIT */
+
+/* We implicitly use the dummy ID for init-mm etc. where we never rmap pages. */
+#define MM_ID_DUMMY			0
+#define MM_ID_MIN			(MM_ID_DUMMY + 1)
+
+/*
+ * We leave the highest bit of each MM id unused, so we can store a flag
+ * in the highest bit of each folio->_mm_id[].
+ */
+#define MM_ID_BITS			((sizeof(mm_id_t) * BITS_PER_BYTE) - 1)
+#define MM_ID_MASK			((1U << MM_ID_BITS) - 1)
+#define MM_ID_MAX			MM_ID_MASK
+
+/*
+ * In order to use bit_spin_lock(), which requires an unsigned long, we
+ * operate on folio->_mm_ids when working on flags.
+ */
+#define FOLIO_MM_IDS_LOCK_BITNUM	MM_ID_BITS
+#define FOLIO_MM_IDS_LOCK_BIT		BIT(FOLIO_MM_IDS_LOCK_BITNUM)
+#define FOLIO_MM_IDS_SHARED_BITNUM	(2 * MM_ID_BITS + 1)
+#define FOLIO_MM_IDS_SHARED_BIT		BIT(FOLIO_MM_IDS_SHARED_BITNUM)
+
 /**
  * struct folio - Represents a contiguous set of bytes.
  * @flags: Identical to the page flags.
@@ -296,6 +343,8 @@ typedef struct {
  *    anonymous memory.
  * @index: Offset within the file, in units of pages.  For anonymous memory,
  *    this is the index from the beginning of the mmap.
+ * @share: number of DAX mappings that reference this folio. See
+ *    dax_associate_entry.
  * @private: Filesystem per-folio data (see folio_attach_private()).
  * @swap: Used for swp_entry_t if folio_test_swapcache().
  * @_mapcount: Do not access this member directly.  Use folio_mapcount() to
@@ -303,13 +352,17 @@ typedef struct {
  * @_refcount: Do not access this member directly.  Use folio_ref_count()
  *    to find how many references there are to this folio.
  * @memcg_data: Memory Control Group data.
+ * @pgmap: Metadata for ZONE_DEVICE mappings
  * @virtual: Virtual address in the kernel direct map.
  * @_last_cpupid: IDs of last CPU and last process that accessed the folio.
  * @_entire_mapcount: Do not use directly, call folio_entire_mapcount().
  * @_large_mapcount: Do not use directly, call folio_mapcount().
  * @_nr_pages_mapped: Do not use outside of rmap and debug code.
  * @_pincount: Do not use directly, call folio_maybe_dma_pinned().
- * @_folio_nr_pages: Do not use directly, call folio_nr_pages().
+ * @_nr_pages: Do not use directly, call folio_nr_pages().
+ * @_mm_id: Do not use outside of rmap code.
+ * @_mm_ids: Do not use outside of rmap code.
+ * @_mm_id_mapcount: Do not use outside of rmap code.
  * @_hugetlb_subpool: Do not use directly, use accessor in hugetlb.h.
  * @_hugetlb_cgroup: Do not use directly, use accessor in hugetlb_cgroup.h.
  * @_hugetlb_cgroup_rsvd: Do not use directly, use accessor in hugetlb_cgroup.h.
@@ -341,9 +394,13 @@ struct folio {
 	/* private: */
 				};
 	/* public: */
+				struct dev_pagemap *pgmap;
 			};
 			struct address_space *mapping;
-			pgoff_t index;
+			union {
+				pgoff_t index;
+				unsigned long share;
+			};
 			union {
 				void *private;
 				swp_entry_t swap;
@@ -369,14 +426,30 @@ struct folio {
 		struct {
 			unsigned long _flags_1;
 			unsigned long _head_1;
+			union {
+				struct {
 	/* public: */
-			atomic_t _large_mapcount;
-			atomic_t _entire_mapcount;
-			atomic_t _nr_pages_mapped;
-			atomic_t _pincount;
+					atomic_t _large_mapcount;
+					atomic_t _nr_pages_mapped;
 #ifdef CONFIG_64BIT
-			unsigned int _folio_nr_pages;
-#endif
+					atomic_t _entire_mapcount;
+					atomic_t _pincount;
+#endif /* CONFIG_64BIT */
+					mm_id_mapcount_t _mm_id_mapcount[2];
+					union {
+						mm_id_t _mm_id[2];
+						unsigned long _mm_ids;
+					};
+	/* private: the union with struct page is transitional */
+				};
+				unsigned long _usable_1[4];
+			};
+			atomic_t _mapcount_1;
+			atomic_t _refcount_1;
+	/* public: */
+#ifdef NR_PAGES_IN_LARGE_FOLIO
+			unsigned int _nr_pages;
+#endif /* NR_PAGES_IN_LARGE_FOLIO */
 	/* private: the union with struct page is transitional */
 		};
 		struct page __page_1;
@@ -386,20 +459,27 @@ struct folio {
 			unsigned long _flags_2;
 			unsigned long _head_2;
 	/* public: */
-			void *_hugetlb_subpool;
-			void *_hugetlb_cgroup;
-			void *_hugetlb_cgroup_rsvd;
-			void *_hugetlb_hwpoison;
+			struct list_head _deferred_list;
+#ifndef CONFIG_64BIT
+			atomic_t _entire_mapcount;
+			atomic_t _pincount;
+#endif /* !CONFIG_64BIT */
 	/* private: the union with struct page is transitional */
 		};
+		struct page __page_2;
+	};
+	union {
 		struct {
-			unsigned long _flags_2a;
-			unsigned long _head_2a;
+			unsigned long _flags_3;
+			unsigned long _head_3;
 	/* public: */
-			struct list_head _deferred_list;
+			void *_hugetlb_subpool;
+			void *_hugetlb_cgroup;
+			void *_hugetlb_cgroup_rsvd;
+			void *_hugetlb_hwpoison;
 	/* private: the union with struct page is transitional */
 		};
-		struct page __page_2;
+		struct page __page_3;
 	};
 };
 
@@ -428,14 +508,20 @@ FOLIO_MATCH(_last_cpupid, _last_cpupid);
 			offsetof(struct page, pg) + sizeof(struct page))
 FOLIO_MATCH(flags, _flags_1);
 FOLIO_MATCH(compound_head, _head_1);
+FOLIO_MATCH(_mapcount, _mapcount_1);
+FOLIO_MATCH(_refcount, _refcount_1);
 #undef FOLIO_MATCH
 #define FOLIO_MATCH(pg, fl)						\
 	static_assert(offsetof(struct folio, fl) ==			\
 			offsetof(struct page, pg) + 2 * sizeof(struct page))
 FOLIO_MATCH(flags, _flags_2);
 FOLIO_MATCH(compound_head, _head_2);
-FOLIO_MATCH(flags, _flags_2a);
-FOLIO_MATCH(compound_head, _head_2a);
+#undef FOLIO_MATCH
+#define FOLIO_MATCH(pg, fl)						\
+	static_assert(offsetof(struct folio, fl) ==			\
+			offsetof(struct page, pg) + 3 * sizeof(struct page))
+FOLIO_MATCH(flags, _flags_3);
+FOLIO_MATCH(compound_head, _head_3);
 #undef FOLIO_MATCH
 
 /**
@@ -578,6 +664,12 @@ static inline void *folio_get_private(struct folio *folio)
 typedef unsigned long vm_flags_t;
 
 /*
+ * freeptr_t represents a SLUB freelist pointer, which might be encoded
+ * and not dereferenceable if CONFIG_SLAB_FREELIST_HARDENED is enabled.
+ */
+typedef struct { unsigned long v; } freeptr_t;
+
+/*
  * A region containing a mapping of a non-memory backed file under NOMMU
  * conditions.  These are held in a global tree and are pinned by the VMAs that
  * map parts of them.
@@ -633,9 +725,8 @@ static inline struct anon_vma_name *anon_vma_name_alloc(const char *name)
 }
 #endif
 
-struct vma_lock {
-	struct rw_semaphore lock;
-};
+#define VMA_LOCK_OFFSET	0x40000000
+#define VMA_REF_LIMIT	(VMA_LOCK_OFFSET - 1)
 
 struct vma_numab_state {
 	/*
@@ -681,6 +772,9 @@ struct vma_numab_state {
  *
  * Only explicitly marked struct members may be accessed by RCU readers before
  * getting a stable reference.
+ *
+ * WARNING: when adding new members, please update vm_area_init_from() to copy
+ * them during vm_area_struct content duplication.
  */
 struct vm_area_struct {
 	/* The first cache line has the info for VMA tree walking. */
@@ -691,9 +785,7 @@ struct vm_area_struct {
 			unsigned long vm_start;
 			unsigned long vm_end;
 		};
-#ifdef CONFIG_PER_VMA_LOCK
-		struct rcu_head vm_rcu;	/* Used for deferred freeing. */
-#endif
+		freeptr_t vm_freeptr; /* Pointer used by SLAB_TYPESAFE_BY_RCU */
 	};
 
 	/*
@@ -714,18 +806,12 @@ struct vm_area_struct {
 
 #ifdef CONFIG_PER_VMA_LOCK
 	/*
-	 * Flag to indicate areas detached from the mm->mm_mt tree.
-	 * Unstable RCU readers are allowed to read this.
-	 */
-	bool detached;
-
-	/*
 	 * Can only be written (using WRITE_ONCE()) while holding both:
 	 *  - mmap_lock (in write mode)
-	 *  - vm_lock->lock (in write mode)
+	 *  - vm_refcnt bit at VMA_LOCK_OFFSET is set
 	 * Can be read reliably while holding one of:
 	 *  - mmap_lock (in read or write mode)
-	 *  - vm_lock->lock (in read or write mode)
+	 *  - vm_refcnt bit at VMA_LOCK_OFFSET is set or vm_refcnt > 1
 	 * Can be read unreliably (using READ_ONCE()) for pessimistic bailout
 	 * while holding nothing (except RCU to keep the VMA struct allocated).
 	 *
@@ -734,20 +820,7 @@ struct vm_area_struct {
 	 * slowpath.
 	 */
 	unsigned int vm_lock_seq;
-	/* Unstable RCU readers are allowed to read this. */
-	struct vma_lock *vm_lock;
 #endif
-
-	/*
-	 * For areas with an address space and backing store,
-	 * linkage into the address_space->i_mmap interval tree.
-	 *
-	 */
-	struct {
-		struct rb_node rb;
-		unsigned long rb_subtree_last;
-	} shared;
-
 	/*
 	 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
 	 * list, after a COW of one of the file pages.	A MAP_SHARED vma
@@ -767,14 +840,6 @@ struct vm_area_struct {
 	struct file * vm_file;		/* File we map to (can be NULL). */
 	void * vm_private_data;		/* was vm_pte (shared mem) */
 
-#ifdef CONFIG_ANON_VMA_NAME
-	/*
-	 * For private and shared anonymous mappings, a pointer to a null
-	 * terminated string containing the name given to the vma, or NULL if
-	 * unnamed. Serialized by mmap_lock. Use anon_vma_name to access.
-	 */
-	struct anon_vma_name *anon_name;
-#endif
 #ifdef CONFIG_SWAP
 	atomic_long_t swap_readahead_info;
 #endif
@@ -787,6 +852,30 @@ struct vm_area_struct {
 #ifdef CONFIG_NUMA_BALANCING
 	struct vma_numab_state *numab_state;	/* NUMA Balancing state */
 #endif
+#ifdef CONFIG_PER_VMA_LOCK
+	/* Unstable RCU readers are allowed to read this. */
+	refcount_t vm_refcnt ____cacheline_aligned_in_smp;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+	struct lockdep_map vmlock_dep_map;
+#endif
+#endif
+	/*
+	 * For areas with an address space and backing store,
+	 * linkage into the address_space->i_mmap interval tree.
+	 *
+	 */
+	struct {
+		struct rb_node rb;
+		unsigned long rb_subtree_last;
+	} shared;
+#ifdef CONFIG_ANON_VMA_NAME
+	/*
+	 * For private and shared anonymous mappings, a pointer to a null
+	 * terminated string containing the name given to the vma, or NULL if
+	 * unnamed. Serialized by mmap_lock. Use anon_vma_name to access.
+	 */
+	struct anon_vma_name *anon_name;
+#endif
 	struct vm_userfaultfd_ctx vm_userfaultfd_ctx;
 } __randomize_layout;
 
@@ -922,6 +1011,7 @@ struct mm_struct {
 					  * by mmlist_lock
 					  */
 #ifdef CONFIG_PER_VMA_LOCK
+		struct rcuwait vma_writer_wait;
 		/*
 		 * This field has lock-like semantics, meaning it is sometimes
 		 * accessed with ACQUIRE/RELEASE semantics.
@@ -1074,6 +1164,9 @@ struct mm_struct {
 #endif
 		} lru_gen;
 #endif /* CONFIG_LRU_GEN_WALKS_MMU */
+#ifdef CONFIG_MM_ID
+		mm_id_t mm_id;
+#endif /* CONFIG_MM_ID */
 	} __randomize_layout;
 
 	/*