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
  ...

30 files changed, 952 insertions, 537 deletions

diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h
index 0217c1073735..c88fd4d37d1f 100644
--- a/include/linux/backing-dev-defs.h
+++ b/include/linux/backing-dev-defs.h
@@ -46,7 +46,6 @@ enum wb_reason {
 	WB_REASON_VMSCAN,
 	WB_REASON_SYNC,
 	WB_REASON_PERIODIC,
-	WB_REASON_LAPTOP_TIMER,
 	WB_REASON_FS_FREE_SPACE,
 	/*
 	 * There is no bdi forker thread any more and works are done
@@ -204,8 +203,6 @@ struct backing_dev_info {
 	char dev_name[64];
 	struct device *owner;
 
-	struct timer_list laptop_mode_wb_timer;
-
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *debug_dir;
 #endif
diff --git a/include/linux/balloon.h b/include/linux/balloon.h
new file mode 100644
index 000000000000..ca5b15150f42
--- /dev/null
+++ b/include/linux/balloon.h
@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Common interface for implementing a memory balloon, including support
+ * for migration of pages inflated in a memory balloon.
+ *
+ * Balloon page migration makes use of the general "movable_ops page migration"
+ * feature.
+ *
+ * page->private is used to reference the responsible balloon device.
+ * That these pages have movable_ops, and which movable_ops apply,
+ * is derived from the page type (PageOffline()) combined with the
+ * PG_movable_ops flag (PageMovableOps()).
+ *
+ * Once the page type and the PG_movable_ops are set, migration code
+ * can initiate page isolation by invoking the
+ * movable_operations()->isolate_page() callback
+ *
+ * As long as page->private is set, the page is either on the balloon list
+ * or isolated for migration. If page->private is not set, the page is
+ * either still getting inflated, or was deflated to be freed by the balloon
+ * driver soon. Isolation is impossible in both cases.
+ *
+ * As the page isolation scanning step a compaction thread does is a lockless
+ * procedure (from a page standpoint), it might bring some racy situations while
+ * performing balloon page migration. In order to sort out these racy scenarios
+ * and safely perform balloon's page migration we must, always, ensure following
+ * these simple rules:
+ *
+ *   i. Inflation/deflation must set/clear page->private under the
+ *      balloon_pages_lock
+ *
+ *  ii. isolation or dequeueing procedure must remove the page from balloon
+ *      device page list under balloon_pages_lock
+ *
+ * Copyright (C) 2012, Red Hat, Inc.  Rafael Aquini <aquini@redhat.com>
+ */
+#ifndef _LINUX_BALLOON_H
+#define _LINUX_BALLOON_H
+#include <linux/pagemap.h>
+#include <linux/page-flags.h>
+#include <linux/migrate.h>
+#include <linux/gfp.h>
+#include <linux/err.h>
+#include <linux/list.h>
+
+/*
+ * Balloon device information descriptor.
+ * This struct is used to allow the common balloon page migration interface
+ * procedures to find the proper balloon device holding memory pages they'll
+ * have to cope for page migration, as well as it serves the balloon driver as
+ * a page book-keeper for its registered balloon devices.
+ */
+struct balloon_dev_info {
+	unsigned long isolated_pages;	/* # of isolated pages for migration */
+	struct list_head pages;		/* Pages enqueued & handled to Host */
+	int (*migratepage)(struct balloon_dev_info *, struct page *newpage,
+			struct page *page, enum migrate_mode mode);
+	bool adjust_managed_page_count;
+};
+
+struct page *balloon_page_alloc(void);
+void balloon_page_enqueue(struct balloon_dev_info *b_dev_info,
+		struct page *page);
+struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info);
+size_t balloon_page_list_enqueue(struct balloon_dev_info *b_dev_info,
+		struct list_head *pages);
+size_t balloon_page_list_dequeue(struct balloon_dev_info *b_dev_info,
+		struct list_head *pages, size_t n_req_pages);
+
+static inline void balloon_devinfo_init(struct balloon_dev_info *balloon)
+{
+	balloon->isolated_pages = 0;
+	INIT_LIST_HEAD(&balloon->pages);
+	balloon->migratepage = NULL;
+	balloon->adjust_managed_page_count = false;
+}
+#endif /* _LINUX_BALLOON_H */
diff --git a/include/linux/balloon_compaction.h b/include/linux/balloon_compaction.h
deleted file mode 100644
index 7cfe48769239..000000000000
--- a/include/linux/balloon_compaction.h
+++ /dev/null
@@ -1,160 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * include/linux/balloon_compaction.h
- *
- * Common interface definitions for making balloon pages movable by compaction.
- *
- * Balloon page migration makes use of the general "movable_ops page migration"
- * feature.
- *
- * page->private is used to reference the responsible balloon device.
- * That these pages have movable_ops, and which movable_ops apply,
- * is derived from the page type (PageOffline()) combined with the
- * PG_movable_ops flag (PageMovableOps()).
- *
- * As the page isolation scanning step a compaction thread does is a lockless
- * procedure (from a page standpoint), it might bring some racy situations while
- * performing balloon page compaction. In order to sort out these racy scenarios
- * and safely perform balloon's page compaction and migration we must, always,
- * ensure following these simple rules:
- *
- *   i. Setting the PG_movable_ops flag and page->private with the following
- *	lock order
- *	    +-page_lock(page);
- *	      +--spin_lock_irq(&b_dev_info->pages_lock);
- *
- *  ii. isolation or dequeueing procedure must remove the page from balloon
- *      device page list under b_dev_info->pages_lock.
- *
- * The functions provided by this interface are placed to help on coping with
- * the aforementioned balloon page corner case, as well as to ensure the simple
- * set of exposed rules are satisfied while we are dealing with balloon pages
- * compaction / migration.
- *
- * Copyright (C) 2012, Red Hat, Inc.  Rafael Aquini <aquini@redhat.com>
- */
-#ifndef _LINUX_BALLOON_COMPACTION_H
-#define _LINUX_BALLOON_COMPACTION_H
-#include <linux/pagemap.h>
-#include <linux/page-flags.h>
-#include <linux/migrate.h>
-#include <linux/gfp.h>
-#include <linux/err.h>
-#include <linux/fs.h>
-#include <linux/list.h>
-
-/*
- * Balloon device information descriptor.
- * This struct is used to allow the common balloon compaction interface
- * procedures to find the proper balloon device holding memory pages they'll
- * have to cope for page compaction / migration, as well as it serves the
- * balloon driver as a page book-keeper for its registered balloon devices.
- */
-struct balloon_dev_info {
-	unsigned long isolated_pages;	/* # of isolated pages for migration */
-	spinlock_t pages_lock;		/* Protection to pages list */
-	struct list_head pages;		/* Pages enqueued & handled to Host */
-	int (*migratepage)(struct balloon_dev_info *, struct page *newpage,
-			struct page *page, enum migrate_mode mode);
-};
-
-extern struct page *balloon_page_alloc(void);
-extern void balloon_page_enqueue(struct balloon_dev_info *b_dev_info,
-				 struct page *page);
-extern struct page *balloon_page_dequeue(struct balloon_dev_info *b_dev_info);
-extern size_t balloon_page_list_enqueue(struct balloon_dev_info *b_dev_info,
-				      struct list_head *pages);
-extern size_t balloon_page_list_dequeue(struct balloon_dev_info *b_dev_info,
-				     struct list_head *pages, size_t n_req_pages);
-
-static inline void balloon_devinfo_init(struct balloon_dev_info *balloon)
-{
-	balloon->isolated_pages = 0;
-	spin_lock_init(&balloon->pages_lock);
-	INIT_LIST_HEAD(&balloon->pages);
-	balloon->migratepage = NULL;
-}
-
-#ifdef CONFIG_BALLOON_COMPACTION
-extern const struct movable_operations balloon_mops;
-/*
- * balloon_page_device - get the b_dev_info descriptor for the balloon device
- *			 that enqueues the given page.
- */
-static inline struct balloon_dev_info *balloon_page_device(struct page *page)
-{
-	return (struct balloon_dev_info *)page_private(page);
-}
-#endif /* CONFIG_BALLOON_COMPACTION */
-
-/*
- * balloon_page_insert - insert a page into the balloon's page list and make
- *			 the page->private assignment accordingly.
- * @balloon : pointer to balloon device
- * @page    : page to be assigned as a 'balloon page'
- *
- * Caller must ensure the page is locked and the spin_lock protecting balloon
- * pages list is held before inserting a page into the balloon device.
- */
-static inline void balloon_page_insert(struct balloon_dev_info *balloon,
-				       struct page *page)
-{
-	__SetPageOffline(page);
-	if (IS_ENABLED(CONFIG_BALLOON_COMPACTION)) {
-		SetPageMovableOps(page);
-		set_page_private(page, (unsigned long)balloon);
-	}
-	list_add(&page->lru, &balloon->pages);
-}
-
-static inline gfp_t balloon_mapping_gfp_mask(void)
-{
-	if (IS_ENABLED(CONFIG_BALLOON_COMPACTION))
-		return GFP_HIGHUSER_MOVABLE;
-	return GFP_HIGHUSER;
-}
-
-/*
- * balloon_page_finalize - prepare a balloon page that was removed from the
- *			   balloon list for release to the page allocator
- * @page: page to be released to the page allocator
- *
- * Caller must ensure that the page is locked.
- */
-static inline void balloon_page_finalize(struct page *page)
-{
-	if (IS_ENABLED(CONFIG_BALLOON_COMPACTION))
-		set_page_private(page, 0);
-	/* PageOffline is sticky until the page is freed to the buddy. */
-}
-
-/*
- * balloon_page_push - insert a page into a page list.
- * @head : pointer to list
- * @page : page to be added
- *
- * Caller must ensure the page is private and protect the list.
- */
-static inline void balloon_page_push(struct list_head *pages, struct page *page)
-{
-	list_add(&page->lru, pages);
-}
-
-/*
- * balloon_page_pop - remove a page from a page list.
- * @head : pointer to list
- * @page : page to be added
- *
- * Caller must ensure the page is private and protect the list.
- */
-static inline struct page *balloon_page_pop(struct list_head *pages)
-{
-	struct page *page = list_first_entry_or_null(pages, struct page, lru);
-
-	if (!page)
-		return NULL;
-
-	list_del(&page->lru);
-	return page;
-}
-#endif /* _LINUX_BALLOON_COMPACTION_H */
diff --git a/include/linux/cma.h b/include/linux/cma.h
index 2e6931735880..d0793eaaadaa 100644
--- a/include/linux/cma.h
+++ b/include/linux/cma.h
@@ -49,9 +49,14 @@ extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
 					struct cma **res_cma);
 extern struct page *cma_alloc(struct cma *cma, unsigned long count, unsigned int align,
 			      bool no_warn);
-extern bool cma_pages_valid(struct cma *cma, const struct page *pages, unsigned long count);
 extern bool cma_release(struct cma *cma, const struct page *pages, unsigned long count);
 
+struct page *cma_alloc_frozen(struct cma *cma, unsigned long count,
+		unsigned int align, bool no_warn);
+struct page *cma_alloc_frozen_compound(struct cma *cma, unsigned int order);
+bool cma_release_frozen(struct cma *cma, const struct page *pages,
+		unsigned long count);
+
 extern int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data);
 extern bool cma_intersects(struct cma *cma, unsigned long start, unsigned long end);
 
@@ -66,24 +71,4 @@ static inline bool cma_skip_dt_default_reserved_mem(void)
 }
 #endif
 
-#ifdef CONFIG_CMA
-struct folio *cma_alloc_folio(struct cma *cma, int order, gfp_t gfp);
-bool cma_free_folio(struct cma *cma, const struct folio *folio);
-bool cma_validate_zones(struct cma *cma);
-#else
-static inline struct folio *cma_alloc_folio(struct cma *cma, int order, gfp_t gfp)
-{
-	return NULL;
-}
-
-static inline bool cma_free_folio(struct cma *cma, const struct folio *folio)
-{
-	return false;
-}
-static inline bool cma_validate_zones(struct cma *cma)
-{
-	return false;
-}
-#endif
-
 #endif
diff --git a/include/linux/damon.h b/include/linux/damon.h
index 3813373a9200..a4fea23da857 100644
--- a/include/linux/damon.h
+++ b/include/linux/damon.h
@@ -15,7 +15,7 @@
 #include <linux/random.h>
 
 /* Minimal region size.  Every damon_region is aligned by this. */
-#define DAMON_MIN_REGION	PAGE_SIZE
+#define DAMON_MIN_REGION_SZ	PAGE_SIZE
 /* Max priority score for DAMON-based operation schemes */
 #define DAMOS_MAX_SCORE		(99)
 
@@ -155,6 +155,8 @@ enum damos_action {
  * @DAMOS_QUOTA_NODE_MEM_FREE_BP:	MemFree ratio of a node.
  * @DAMOS_QUOTA_NODE_MEMCG_USED_BP:	MemUsed ratio of a node for a cgroup.
  * @DAMOS_QUOTA_NODE_MEMCG_FREE_BP:	MemFree ratio of a node for a cgroup.
+ * @DAMOS_QUOTA_ACTIVE_MEM_BP:		Active to total LRU memory ratio.
+ * @DAMOS_QUOTA_INACTIVE_MEM_BP:	Inactive to total LRU memory ratio.
  * @NR_DAMOS_QUOTA_GOAL_METRICS:	Number of DAMOS quota goal metrics.
  *
  * Metrics equal to larger than @NR_DAMOS_QUOTA_GOAL_METRICS are unsupported.
@@ -166,6 +168,8 @@ enum damos_quota_goal_metric {
 	DAMOS_QUOTA_NODE_MEM_FREE_BP,
 	DAMOS_QUOTA_NODE_MEMCG_USED_BP,
 	DAMOS_QUOTA_NODE_MEMCG_FREE_BP,
+	DAMOS_QUOTA_ACTIVE_MEM_BP,
+	DAMOS_QUOTA_INACTIVE_MEM_BP,
 	NR_DAMOS_QUOTA_GOAL_METRICS,
 };
 
@@ -203,7 +207,7 @@ struct damos_quota_goal {
 		u64 last_psi_total;
 		struct {
 			int nid;
-			unsigned short memcg_id;
+			u64 memcg_id;
 		};
 	};
 	struct list_head list;
@@ -330,6 +334,8 @@ struct damos_watermarks {
  * @sz_ops_filter_passed:
  *		Total bytes that passed ops layer-handled DAMOS filters.
  * @qt_exceeds: Total number of times the quota of the scheme has exceeded.
+ * @nr_snapshots:
+ *		Total number of DAMON snapshots that the scheme has tried.
  *
  * "Tried an action to a region" in this context means the DAMOS core logic
  * determined the region as eligible to apply the action.  The access pattern
@@ -355,6 +361,7 @@ struct damos_stat {
 	unsigned long sz_applied;
 	unsigned long sz_ops_filter_passed;
 	unsigned long qt_exceeds;
+	unsigned long nr_snapshots;
 };
 
 /**
@@ -416,7 +423,7 @@ struct damos_filter {
 	bool matching;
 	bool allow;
 	union {
-		unsigned short memcg_id;
+		u64 memcg_id;
 		struct damon_addr_range addr_range;
 		int target_idx;
 		struct damon_size_range sz_range;
@@ -496,6 +503,7 @@ struct damos_migrate_dests {
  * @ops_filters:	ops layer handling &struct damos_filter objects list.
  * @last_applied:	Last @action applied ops-managing entity.
  * @stat:		Statistics of this scheme.
+ * @max_nr_snapshots:	Upper limit of nr_snapshots stat.
  * @list:		List head for siblings.
  *
  * For each @apply_interval_us, DAMON finds regions which fit in the
@@ -529,9 +537,10 @@ struct damos_migrate_dests {
  * unsets @last_applied when each regions walking for applying the scheme is
  * finished.
  *
- * After applying the &action to each region, &stat_count and &stat_sz is
- * updated to reflect the number of regions and total size of regions that the
- * &action is applied.
+ * After applying the &action to each region, &stat is updated.
+ *
+ * If &max_nr_snapshots is set as non-zero and &stat.nr_snapshots be same to or
+ * greater than it, the scheme is deactivated.
  */
 struct damos {
 	struct damos_access_pattern pattern;
@@ -566,6 +575,7 @@ struct damos {
 	struct list_head ops_filters;
 	void *last_applied;
 	struct damos_stat stat;
+	unsigned long max_nr_snapshots;
 	struct list_head list;
 };
 
@@ -597,7 +607,6 @@ enum damon_ops_id {
  * @apply_scheme:		Apply a DAMON-based operation scheme.
  * @target_valid:		Determine if the target is valid.
  * @cleanup_target:		Clean up each target before deallocation.
- * @cleanup:			Clean up the context.
  *
  * DAMON can be extended for various address spaces and usages.  For this,
  * users should register the low level operations for their target address
@@ -630,7 +639,6 @@ enum damon_ops_id {
  * @target_valid should check whether the target is still valid for the
  * monitoring.
  * @cleanup_target is called before the target will be deallocated.
- * @cleanup is called from @kdamond just before its termination.
  */
 struct damon_operations {
 	enum damon_ops_id id;
@@ -646,7 +654,6 @@ struct damon_operations {
 			struct damos *scheme, unsigned long *sz_filter_passed);
 	bool (*target_valid)(struct damon_target *t);
 	void (*cleanup_target)(struct damon_target *t);
-	void (*cleanup)(struct damon_ctx *context);
 };
 
 /*
@@ -656,7 +663,7 @@ struct damon_operations {
  * @data:		Data that will be passed to @fn.
  * @repeat:		Repeat invocations.
  * @return_code:	Return code from @fn invocation.
- * @dealloc_on_cancel:	De-allocate when canceled.
+ * @dealloc_on_cancel:	If @repeat is true, de-allocate when canceled.
  *
  * Control damon_call(), which requests specific kdamond to invoke a given
  * function.  Refer to damon_call() for more details.
@@ -749,27 +756,24 @@ struct damon_attrs {
  * of the monitoring.
  *
  * @attrs:		Monitoring attributes for accuracy/overhead control.
- * @kdamond:		Kernel thread who does the monitoring.
- * @kdamond_lock:	Mutex for the synchronizations with @kdamond.
  *
- * For each monitoring context, one kernel thread for the monitoring is
- * created.  The pointer to the thread is stored in @kdamond.
+ * For each monitoring context, one kernel thread for the monitoring, namely
+ * kdamond, is created.  The pid of kdamond can be retrieved using
+ * damon_kdamond_pid().
  *
- * Once started, the monitoring thread runs until explicitly required to be
- * terminated or every monitoring target is invalid.  The validity of the
- * targets is checked via the &damon_operations.target_valid of @ops.  The
- * termination can also be explicitly requested by calling damon_stop().
- * The thread sets @kdamond to NULL when it terminates. Therefore, users can
- * know whether the monitoring is ongoing or terminated by reading @kdamond.
- * Reads and writes to @kdamond from outside of the monitoring thread must
- * be protected by @kdamond_lock.
+ * Once started, kdamond runs until explicitly required to be terminated or
+ * every monitoring target is invalid.  The validity of the targets is checked
+ * via the &damon_operations.target_valid of @ops.  The termination can also be
+ * explicitly requested by calling damon_stop().  To know if a kdamond is
+ * running, damon_is_running() can be used.
  *
- * Note that the monitoring thread protects only @kdamond via @kdamond_lock.
- * Accesses to other fields must be protected by themselves.
+ * While the kdamond is running, all accesses to &struct damon_ctx from a
+ * thread other than the kdamond should be made using safe DAMON APIs,
+ * including damon_call() and damos_walk().
  *
  * @ops:	Set of monitoring operations for given use cases.
  * @addr_unit:	Scale factor for core to ops address conversion.
- * @min_sz_region:		Minimum region size.
+ * @min_region_sz:	Minimum region size.
  * @adaptive_targets:	Head of monitoring targets (&damon_target) list.
  * @schemes:		Head of schemes (&damos) list.
  */
@@ -806,13 +810,15 @@ struct damon_ctx {
 	struct damos_walk_control *walk_control;
 	struct mutex walk_control_lock;
 
-/* public: */
+	/* Working thread of the given DAMON context */
 	struct task_struct *kdamond;
+	/* Protects @kdamond field access */
 	struct mutex kdamond_lock;
 
+/* public: */
 	struct damon_operations ops;
 	unsigned long addr_unit;
-	unsigned long min_sz_region;
+	unsigned long min_region_sz;
 
 	struct list_head adaptive_targets;
 	struct list_head schemes;
@@ -901,7 +907,7 @@ static inline void damon_insert_region(struct damon_region *r,
 void damon_add_region(struct damon_region *r, struct damon_target *t);
 void damon_destroy_region(struct damon_region *r, struct damon_target *t);
 int damon_set_regions(struct damon_target *t, struct damon_addr_range *ranges,
-		unsigned int nr_ranges, unsigned long min_sz_region);
+		unsigned int nr_ranges, unsigned long min_region_sz);
 void damon_update_region_access_rate(struct damon_region *r, bool accessed,
 		struct damon_attrs *attrs);
 
@@ -962,13 +968,14 @@ bool damon_initialized(void);
 int damon_start(struct damon_ctx **ctxs, int nr_ctxs, bool exclusive);
 int damon_stop(struct damon_ctx **ctxs, int nr_ctxs);
 bool damon_is_running(struct damon_ctx *ctx);
+int damon_kdamond_pid(struct damon_ctx *ctx);
 
 int damon_call(struct damon_ctx *ctx, struct damon_call_control *control);
 int damos_walk(struct damon_ctx *ctx, struct damos_walk_control *control);
 
 int damon_set_region_biggest_system_ram_default(struct damon_target *t,
 				unsigned long *start, unsigned long *end,
-				unsigned long min_sz_region);
+				unsigned long min_region_sz);
 
 #endif	/* CONFIG_DAMON */
 
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index b155929af5b1..6ecf6dda93e0 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -407,9 +407,15 @@ extern gfp_t gfp_allowed_mask;
 /* Returns true if the gfp_mask allows use of ALLOC_NO_WATERMARK */
 bool gfp_pfmemalloc_allowed(gfp_t gfp_mask);
 
+/* A helper for checking if gfp includes all the specified flags */
+static inline bool gfp_has_flags(gfp_t gfp, gfp_t flags)
+{
+	return (gfp & flags) == flags;
+}
+
 static inline bool gfp_has_io_fs(gfp_t gfp)
 {
-	return (gfp & (__GFP_IO | __GFP_FS)) == (__GFP_IO | __GFP_FS);
+	return gfp_has_flags(gfp, __GFP_IO | __GFP_FS);
 }
 
 /*
@@ -430,39 +436,29 @@ typedef unsigned int __bitwise acr_flags_t;
 #define ACR_FLAGS_CMA ((__force acr_flags_t)BIT(0)) // allocate for CMA
 
 /* The below functions must be run on a range from a single zone. */
-extern int alloc_contig_range_noprof(unsigned long start, unsigned long end,
-				     acr_flags_t alloc_flags, gfp_t gfp_mask);
-#define alloc_contig_range(...)			alloc_hooks(alloc_contig_range_noprof(__VA_ARGS__))
-
-extern struct page *alloc_contig_pages_noprof(unsigned long nr_pages, gfp_t gfp_mask,
-					      int nid, nodemask_t *nodemask);
-#define alloc_contig_pages(...)			alloc_hooks(alloc_contig_pages_noprof(__VA_ARGS__))
-
-#endif
+int alloc_contig_frozen_range_noprof(unsigned long start, unsigned long end,
+		acr_flags_t alloc_flags, gfp_t gfp_mask);
+#define alloc_contig_frozen_range(...)	\
+	alloc_hooks(alloc_contig_frozen_range_noprof(__VA_ARGS__))
+
+int alloc_contig_range_noprof(unsigned long start, unsigned long end,
+		acr_flags_t alloc_flags, gfp_t gfp_mask);
+#define alloc_contig_range(...)	\
+	alloc_hooks(alloc_contig_range_noprof(__VA_ARGS__))
+
+struct page *alloc_contig_frozen_pages_noprof(unsigned long nr_pages,
+		gfp_t gfp_mask, int nid, nodemask_t *nodemask);
+#define alloc_contig_frozen_pages(...) \
+	alloc_hooks(alloc_contig_frozen_pages_noprof(__VA_ARGS__))
+
+struct page *alloc_contig_pages_noprof(unsigned long nr_pages, gfp_t gfp_mask,
+		int nid, nodemask_t *nodemask);
+#define alloc_contig_pages(...)	\
+	alloc_hooks(alloc_contig_pages_noprof(__VA_ARGS__))
+
+void free_contig_frozen_range(unsigned long pfn, unsigned long nr_pages);
 void free_contig_range(unsigned long pfn, unsigned long nr_pages);
-
-#ifdef CONFIG_CONTIG_ALLOC
-static inline struct folio *folio_alloc_gigantic_noprof(int order, gfp_t gfp,
-							int nid, nodemask_t *node)
-{
-	struct page *page;
-
-	if (WARN_ON(!order || !(gfp & __GFP_COMP)))
-		return NULL;
-
-	page = alloc_contig_pages_noprof(1 << order, gfp, nid, node);
-
-	return page ? page_folio(page) : NULL;
-}
-#else
-static inline struct folio *folio_alloc_gigantic_noprof(int order, gfp_t gfp,
-							int nid, nodemask_t *node)
-{
-	return NULL;
-}
 #endif
-/* This should be paired with folio_put() rather than free_contig_range(). */
-#define folio_alloc_gigantic(...) alloc_hooks(folio_alloc_gigantic_noprof(__VA_ARGS__))
 
 DEFINE_FREE(free_page, void *, free_page((unsigned long)_T))
 
diff --git a/include/linux/gfp_types.h b/include/linux/gfp_types.h
index 3de43b12209e..814bb2892f99 100644
--- a/include/linux/gfp_types.h
+++ b/include/linux/gfp_types.h
@@ -309,8 +309,10 @@ enum {
  *
  * %GFP_ATOMIC users can not sleep and need the allocation to succeed. A lower
  * watermark is applied to allow access to "atomic reserves".
- * The current implementation doesn't support NMI and few other strict
- * non-preemptive contexts (e.g. raw_spin_lock). The same applies to %GFP_NOWAIT.
+ * The current implementation doesn't support NMI, nor contexts that disable
+ * preemption under PREEMPT_RT. This includes raw_spin_lock() and plain
+ * preempt_disable() - see "Memory allocation" in
+ * Documentation/core-api/real-time/differences.rst for more info.
  *
  * %GFP_KERNEL is typical for kernel-internal allocations. The caller requires
  * %ZONE_NORMAL or a lower zone for direct access but can direct reclaim.
@@ -321,6 +323,7 @@ enum {
  * %GFP_NOWAIT is for kernel allocations that should not stall for direct
  * reclaim, start physical IO or use any