Merge tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - "powerpc/64s: do not re-activate batched TLB flush" makes
   arch_{enter|leave}_lazy_mmu_mode() nest properly (Alexander Gordeev)

   It adds a generic enter/leave layer and switches architectures to use
   it. Various hacks were removed in the process.

 - "zram: introduce compressed data writeback" implements data
   compression for zram writeback (Richard Chang and Sergey Senozhatsky)

 - "mm: folio_zero_user: clear page ranges" adds clearing of contiguous
   page ranges for hugepages. Large improvements during demand faulting
   are demonstrated (David Hildenbrand)

 - "memcg cleanups" tidies up some memcg code (Chen Ridong)

 - "mm/damon: introduce {,max_}nr_snapshots and tracepoint for damos
   stats" improves DAMOS stat's provided information, deterministic
   control, and readability (SeongJae Park)

 - "selftests/mm: hugetlb cgroup charging: robustness fixes" fixes a few
   issues in the hugetlb cgroup charging selftests (Li Wang)

 - "Fix va_high_addr_switch.sh test failure - again" addresses several
   issues in the va_high_addr_switch test (Chunyu Hu)

 - "mm/damon/tests/core-kunit: extend existing test scenarios" improves
   the KUnit test coverage for DAMON (Shu Anzai)

 - "mm/khugepaged: fix dirty page handling for MADV_COLLAPSE" fixes a
   glitch in khugepaged which was causing madvise(MADV_COLLAPSE) to
   transiently return -EAGAIN (Shivank Garg)

 - "arch, mm: consolidate hugetlb early reservation" reworks and
   consolidates a pile of straggly code related to reservation of
   hugetlb memory from bootmem and creation of CMA areas for hugetlb
   (Mike Rapoport)

 - "mm: clean up anon_vma implementation" cleans up the anon_vma
   implementation in various ways (Lorenzo Stoakes)

 - "tweaks for __alloc_pages_slowpath()" does a little streamlining of
   the page allocator's slowpath code (Vlastimil Babka)

 - "memcg: separate private and public ID namespaces" cleans up the
   memcg ID code and prevents the internal-only private IDs from being
   exposed to userspace (Shakeel Butt)

 - "mm: hugetlb: allocate frozen gigantic folio" cleans up the
   allocation of frozen folios and avoids some atomic refcount
   operations (Kefeng Wang)

 - "mm/damon: advance DAMOS-based LRU sorting" improves DAMOS's movement
   of memory betewwn the active and inactive LRUs and adds auto-tuning
   of the ratio-based quotas and of monitoring intervals (SeongJae Park)

 - "Support page table check on PowerPC" makes
   CONFIG_PAGE_TABLE_CHECK_ENFORCED work on powerpc (Andrew Donnellan)

 - "nodemask: align nodes_and{,not} with underlying bitmap ops" makes
   nodes_and() and nodes_andnot() propagate the return values from the
   underlying bit operations, enabling some cleanup in calling code
   (Yury Norov)

 - "mm/damon: hide kdamond and kdamond_lock from API callers" cleans up
   some DAMON internal interfaces (SeongJae Park)

 - "mm/khugepaged: cleanups and scan limit fix" does some cleanup work
   in khupaged and fixes a scan limit accounting issue (Shivank Garg)

 - "mm: balloon infrastructure cleanups" goes to town on the balloon
   infrastructure and its page migration function. Mainly cleanups, also
   some locking simplification (David Hildenbrand)

 - "mm/vmscan: add tracepoint and reason for kswapd_failures reset" adds
   additional tracepoints to the page reclaim code (Jiayuan Chen)

 - "Replace wq users and add WQ_PERCPU to alloc_workqueue() users" is
   part of Marco's kernel-wide migration from the legacy workqueue APIs
   over to the preferred unbound workqueues (Marco Crivellari)

 - "Various mm kselftests improvements/fixes" provides various unrelated
   improvements/fixes for the mm kselftests (Kevin Brodsky)

 - "mm: accelerate gigantic folio allocation" greatly speeds up gigantic
   folio allocation, mainly by avoiding unnecessary work in
   pfn_range_valid_contig() (Kefeng Wang)

 - "selftests/damon: improve leak detection and wss estimation
   reliability" improves the reliability of two of the DAMON selftests
   (SeongJae Park)

 - "mm/damon: cleanup kdamond, damon_call(), damos filter and
   DAMON_MIN_REGION" does some cleanup work in the core DAMON code
   (SeongJae Park)

 - "Docs/mm/damon: update intro, modules, maintainer profile, and misc"
   performs maintenance work on the DAMON documentation (SeongJae Park)

 - "mm: add and use vma_assert_stabilised() helper" refactors and cleans
   up the core VMA code. The main aim here is to be able to use the mmap
   write lock's lockdep state to perform various assertions regarding
   the locking which the VMA code requires (Lorenzo Stoakes)

 - "mm, swap: swap table phase II: unify swapin use" removes some old
   swap code (swap cache bypassing and swap synchronization) which
   wasn't working very well. Various other cleanups and simplifications
   were made. The end result is a 20% speedup in one benchmark (Kairui
   Song)

 - "enable PT_RECLAIM on more 64-bit architectures" makes PT_RECLAIM
   available on 64-bit alpha, loongarch, mips, parisc, and um. Various
   cleanups were performed along the way (Qi Zheng)

* tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (325 commits)
  mm/memory: handle non-split locks correctly in zap_empty_pte_table()
  mm: move pte table reclaim code to memory.c
  mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE
  mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config
  um: mm: enable MMU_GATHER_RCU_TABLE_FREE
  parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE
  mips: mm: enable MMU_GATHER_RCU_TABLE_FREE
  LoongArch: mm: enable MMU_GATHER_RCU_TABLE_FREE
  alpha: mm: enable MMU_GATHER_RCU_TABLE_FREE
  mm: change mm/pt_reclaim.c to use asm/tlb.h instead of asm-generic/tlb.h
  mm/damon/stat: remove __read_mostly from memory_idle_ms_percentiles
  zsmalloc: make common caches global
  mm: add SPDX id lines to some mm source files
  mm/zswap: use %pe to print error pointers
  mm/vmscan: use %pe to print error pointers
  mm/readahead: fix typo in comment
  mm: khugepaged: fix NR_FILE_PAGES and NR_SHMEM in collapse_file()
  mm: refactor vma_map_pages to use vm_insert_pages
  mm/damon: unify address range representation with damon_addr_range
  mm/cma: replace snprintf with strscpy in cma_new_area
  ...

2 files changed, 30 insertions, 77 deletions

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index d7d41b054b98..5cc79d1517af 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -410,7 +410,7 @@ config DS1682
 config VMWARE_BALLOON
 	tristate "VMware Balloon Driver"
 	depends on VMWARE_VMCI && X86 && HYPERVISOR_GUEST
-	select MEMORY_BALLOON
+	select BALLOON
 	help
 	  This is VMware physical memory management driver which acts
 	  like a "balloon" that can be inflated to reclaim physical pages
diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c
index cc1d18b3df5c..216a16395968 100644
--- a/drivers/misc/vmw_balloon.c
+++ b/drivers/misc/vmw_balloon.c
@@ -29,7 +29,7 @@
 #include <linux/rwsem.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
-#include <linux/balloon_compaction.h>
+#include <linux/balloon.h>
 #include <linux/vmw_vmci_defs.h>
 #include <linux/vmw_vmci_api.h>
 #include <asm/hypervisor.h>
@@ -354,11 +354,16 @@ struct vmballoon {
 	/**
 	 * @huge_pages - list of the inflated 2MB pages.
 	 *
-	 * Protected by @b_dev_info.pages_lock .
+	 * Protected by @huge_pages_lock.
 	 */
 	struct list_head huge_pages;
 
 	/**
+	 * @huge_pages_lock: lock for the list of inflated 2MB pages.
+	 */
+	spinlock_t huge_pages_lock;
+
+	/**
 	 * @vmci_doorbell.
 	 *
 	 * Protected by @conf_sem.
@@ -987,7 +992,6 @@ static void vmballoon_enqueue_page_list(struct vmballoon *b,
 					unsigned int *n_pages,
 					enum vmballoon_page_size_type page_size)
 {
-	unsigned long flags;
 	struct page *page;
 
 	if (page_size == VMW_BALLOON_4K_PAGE) {
@@ -995,9 +999,9 @@ static void vmballoon_enqueue_page_list(struct vmballoon *b,
 	} else {
 		/*
 		 * Keep the huge pages in a local list which is not available
-		 * for the balloon compaction mechanism.
+		 * for the balloon page migration.
 		 */
-		spin_lock_irqsave(&b->b_dev_info.pages_lock, flags);
+		spin_lock(&b->huge_pages_lock);
 
 		list_for_each_entry(page, pages, lru) {
 			vmballoon_mark_page_offline(page, VMW_BALLOON_2M_PAGE);
@@ -1006,7 +1010,7 @@ static void vmballoon_enqueue_page_list(struct vmballoon *b,
 		list_splice_init(pages, &b->huge_pages);
 		__count_vm_events(BALLOON_INFLATE, *n_pages *
 				  vmballoon_page_in_frames(VMW_BALLOON_2M_PAGE));
-		spin_unlock_irqrestore(&b->b_dev_info.pages_lock, flags);
+		spin_unlock(&b->huge_pages_lock);
 	}
 
 	*n_pages = 0;
@@ -1033,7 +1037,6 @@ static void vmballoon_dequeue_page_list(struct vmballoon *b,
 {
 	struct page *page, *tmp;
 	unsigned int i = 0;
-	unsigned long flags;
 
 	/* In the case of 4k pages, use the compaction infrastructure */
 	if (page_size == VMW_BALLOON_4K_PAGE) {
@@ -1043,7 +1046,7 @@ static void vmballoon_dequeue_page_list(struct vmballoon *b,
 	}
 
 	/* 2MB pages */
-	spin_lock_irqsave(&b->b_dev_info.pages_lock, flags);
+	spin_lock(&b->huge_pages_lock);
 	list_for_each_entry_safe(page, tmp, &b->huge_pages, lru) {
 		vmballoon_mark_page_online(page, VMW_BALLOON_2M_PAGE);
 
@@ -1054,7 +1057,7 @@ static void vmballoon_dequeue_page_list(struct vmballoon *b,
 
 	__count_vm_events(BALLOON_DEFLATE,
 			  i * vmballoon_page_in_frames(VMW_BALLOON_2M_PAGE));
-	spin_unlock_irqrestore(&b->b_dev_info.pages_lock, flags);
+	spin_unlock(&b->huge_pages_lock);
 	*n_pages = i;
 }
 
@@ -1716,7 +1719,7 @@ static inline void vmballoon_debugfs_exit(struct vmballoon *b)
 #endif	/* CONFIG_DEBUG_FS */
 
 
-#ifdef CONFIG_BALLOON_COMPACTION
+#ifdef CONFIG_BALLOON_MIGRATION
 /**
  * vmballoon_migratepage() - migrates a balloon page.
  * @b_dev_info: balloon device information descriptor.
@@ -1724,18 +1727,17 @@ static inline void vmballoon_debugfs_exit(struct vmballoon *b)
  * @page: a ballooned page that should be migrated.
  * @mode: migration mode, ignored.
  *
- * This function is really open-coded, but that is according to the interface
- * that balloon_compaction provides.
- *
  * Return: zero on success, -EAGAIN when migration cannot be performed
- *	   momentarily, and -EBUSY if migration failed and should be retried
- *	   with that specific page.
+ *	   momentarily, -EBUSY if migration failed and should be retried
+ *	   with that specific page, and -ENOENT when deflating @page
+ *	   succeeded but inflating @newpage failed, effectively deflating
+ *	   the balloon.
  */
 static int vmballoon_migratepage(struct balloon_dev_info *b_dev_info,
 				 struct page *newpage, struct page *page,
 				 enum migrate_mode mode)
 {
-	unsigned long status, flags;
+	unsigned long status;
 	struct vmballoon *b;
 	int ret = 0;
 
@@ -1773,14 +1775,6 @@ static int vmballoon_migratepage(struct balloon_dev_info *b_dev_info,
 		goto out_unlock;
 	}
 
-	/*
-	 * The page is isolated, so it is safe to delete it without holding
-	 * @pages_lock . We keep holding @comm_lock since we will need it in a
-	 * second.
-	 */
-	balloon_page_finalize(page);
-	put_page(page);
-
 	/* Inflate */
 	vmballoon_add_page(b, 0, newpage);
 	status = vmballoon_lock_op(b, 1, VMW_BALLOON_4K_PAGE,
@@ -1799,60 +1793,21 @@ static int vmballoon_migratepage(struct balloon_dev_info *b_dev_info,
 		 * change.
 		 */
 		atomic64_dec(&b->size);
-	} else {
 		/*
-		 * Success. Take a reference for the page, and we will add it to
-		 * the list after acquiring the lock.
+		 * Tell the core that we're deflating the old page and don't
+		 * need the new page.
 		 */
-		get_page(newpage);
-	}
-
-	/* Update the balloon list under the @pages_lock */
-	spin_lock_irqsave(&b->b_dev_info.pages_lock, flags);
-
-	/*
-	 * On inflation success, we already took a reference for the @newpage.
-	 * If we succeed just insert it to the list and update the statistics
-	 * under the lock.
-	 */
-	if (status == VMW_BALLOON_SUCCESS) {
-		balloon_page_insert(&b->b_dev_info, newpage);
-		__count_vm_event(BALLOON_MIGRATE);
+		ret = -ENOENT;
 	}
-
-	/*
-	 * We deflated successfully, so regardless to the inflation success, we
-	 * need to reduce the number of isolated_pages.
-	 */
-	b->b_dev_info.isolated_pages--;
-	spin_unlock_irqrestore(&b->b_dev_info.pages_lock, flags);
-
 out_unlock:
 	up_read(&b->conf_sem);
 	return ret;
 }
-
-/**
- * vmballoon_compaction_init() - initialized compaction for the balloon.
- *
- * @b: pointer to the balloon.
- *
- * If during the initialization a failure occurred, this function does not
- * perform cleanup. The caller must call vmballoon_compaction_deinit() in this
- * case.
- *
- * Return: zero on success or error code on failure.
- */
-static __init void vmballoon_compaction_init(struct vmballoon *b)
-{
-	b->b_dev_info.migratepage = vmballoon_migratepage;
-}
-
-#else /* CONFIG_BALLOON_COMPACTION */
-static inline void vmballoon_compaction_init(struct vmballoon *b)
-{
-}
-#endif /* CONFIG_BALLOON_COMPACTION */
+#else /* CONFIG_BALLOON_MIGRATION */
+int vmballoon_migratepage(struct balloon_dev_info *b_dev_info,
+			  struct page *newpage, struct page *page,
+			  enum migrate_mode mode);
+#endif /* CONFIG_BALLOON_MIGRATION */
 
 static int __init vmballoon_init(void)
 {
@@ -1871,14 +1826,12 @@ static int __init vmballoon_init(void)
 	if (error)
 		return error;
 
-	/*
-	 * Initialization of compaction must be done after the call to
-	 * balloon_devinfo_init() .
-	 */
 	balloon_devinfo_init(&balloon.b_dev_info);
-	vmballoon_compaction_init(&balloon);
+	if (IS_ENABLED(CONFIG_BALLOON_MIGRATION))
+		balloon.b_dev_info.migratepage = vmballoon_migratepage;
 
 	INIT_LIST_HEAD(&balloon.huge_pages);
+	spin_lock_init(&balloon.huge_pages_lock);
 	spin_lock_init(&balloon.comm_lock);
 	init_rwsem(&balloon.conf_sem);
 	balloon.vmci_doorbell = VMCI_INVALID_HANDLE;