diff --git a/fs/exec.c b/fs/exec.c
index 9a5ca7b82bfc..507a317d54db 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1014,6 +1014,7 @@ static int exec_mmap(struct mm_struct *mm)
 	active_mm = tsk->active_mm;
 	tsk->active_mm = mm;
 	tsk->mm = mm;
+	lru_gen_add_mm(mm);
 	/*
 	 * This prevents preemption while active_mm is being loaded and
 	 * it and mm are being updated, which could cause problems for
@@ -1029,6 +1030,7 @@ static int exec_mmap(struct mm_struct *mm)
 	tsk->mm->vmacache_seqnum = 0;
 	vmacache_flush(tsk);
 	task_unlock(tsk);
+	lru_gen_use_mm(mm);
 
 	if (vfork)
 		timens_on_fork(tsk->nsproxy, tsk);
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 9b8ab121d948..344022f102c2 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -350,6 +350,11 @@ struct mem_cgroup {
 	struct deferred_split deferred_split_queue;
 #endif
 
+#ifdef CONFIG_LRU_GEN
+	/* per-memcg mm_struct list */
+	struct lru_gen_mm_list mm_list;
+#endif
+
 	struct mem_cgroup_per_node *nodeinfo[];
 };
 
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index cf97f3884fda..e1797813cc2c 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -672,6 +672,22 @@ struct mm_struct {
 		 */
 		unsigned long ksm_merging_pages;
 #endif
+#ifdef CONFIG_LRU_GEN
+		struct {
+			/* this mm_struct is on lru_gen_mm_list */
+			struct list_head list;
+			/*
+			 * Set when switching to this mm_struct, as a hint of
+			 * whether it has been used since the last time per-node
+			 * page table walkers cleared the corresponding bits.
+			 */
+			unsigned long bitmap;
+#ifdef CONFIG_MEMCG
+			/* points to the memcg of "owner" above */
+			struct mem_cgroup *memcg;
+#endif
+		} lru_gen;
+#endif /* CONFIG_LRU_GEN */
 	} __randomize_layout;
 
 	/*
@@ -698,6 +714,66 @@ static inline cpumask_t *mm_cpumask(struct mm_struct *mm)
 	return (struct cpumask *)&mm->cpu_bitmap;
 }
 
+#ifdef CONFIG_LRU_GEN
+
+struct lru_gen_mm_list {
+	/* mm_struct list for page table walkers */
+	struct list_head fifo;
+	/* protects the list above */
+	spinlock_t lock;
+};
+
+void lru_gen_add_mm(struct mm_struct *mm);
+void lru_gen_del_mm(struct mm_struct *mm);
+#ifdef CONFIG_MEMCG
+void lru_gen_migrate_mm(struct mm_struct *mm);
+#endif
+
+static inline void lru_gen_init_mm(struct mm_struct *mm)
+{
+	INIT_LIST_HEAD(&mm->lru_gen.list);
+	mm->lru_gen.bitmap = 0;
+#ifdef CONFIG_MEMCG
+	mm->lru_gen.memcg = NULL;
+#endif
+}
+
+static inline void lru_gen_use_mm(struct mm_struct *mm)
+{
+	/*
+	 * When the bitmap is set, page reclaim knows this mm_struct has been
+	 * used since the last time it cleared the bitmap. So it might be worth
+	 * walking the page tables of this mm_struct to clear the accessed bit.
+	 */
+	WRITE_ONCE(mm->lru_gen.bitmap, -1);
+}
+
+#else /* !CONFIG_LRU_GEN */
+
+static inline void lru_gen_add_mm(struct mm_struct *mm)
+{
+}
+
+static inline void lru_gen_del_mm(struct mm_struct *mm)
+{
+}
+
+#ifdef CONFIG_MEMCG
+static inline void lru_gen_migrate_mm(struct mm_struct *mm)
+{
+}
+#endif
+
+static inline void lru_gen_init_mm(struct mm_struct *mm)
+{
+}
+
+static inline void lru_gen_use_mm(struct mm_struct *mm)
+{
+}
+
+#endif /* CONFIG_LRU_GEN */
+
 struct mmu_gather;
 extern void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm);
 extern void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm);
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 9ef5aa37c60c..b1635c4020dc 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -408,7 +408,7 @@ enum {
  * min_seq behind.
  *
  * The number of pages in each generation is eventually consistent and therefore
- * can be transiently negative.
+ * can be transiently negative when reset_batch_size() is pending.
  */
 struct lru_gen_struct {
 	/* the aging increments the youngest generation number */
@@ -430,6 +430,53 @@ struct lru_gen_struct {
 	atomic_long_t refaulted[NR_HIST_GENS][ANON_AND_FILE][MAX_NR_TIERS];
 };
 
+enum {
+	MM_LEAF_TOTAL,		/* total leaf entries */
+	MM_LEAF_OLD,		/* old leaf entries */
+	MM_LEAF_YOUNG,		/* young leaf entries */
+	MM_NONLEAF_TOTAL,	/* total non-leaf entries */
+	MM_NONLEAF_FOUND,	/* non-leaf entries found in Bloom filters */
+	MM_NONLEAF_ADDED,	/* non-leaf entries added to Bloom filters */
+	NR_MM_STATS
+};
+
+/* double-buffering Bloom filters */
+#define NR_BLOOM_FILTERS	2
+
+struct lru_gen_mm_state {
+	/* set to max_seq after each iteration */
+	unsigned long seq;
+	/* where the current iteration continues (inclusive) */
+	struct list_head *head;
+	/* where the last iteration ended (exclusive) */
+	struct list_head *tail;
+	/* to wait for the last page table walker to finish */
+	struct wait_queue_head wait;
+	/* Bloom filters flip after each iteration */
+	unsigned long *filters[NR_BLOOM_FILTERS];
+	/* the mm stats for debugging */
+	unsigned long stats[NR_HIST_GENS][NR_MM_STATS];
+	/* the number of concurrent page table walkers */
+	int nr_walkers;
+};
+
+struct lru_gen_mm_walk {
+	/* the lruvec under reclaim */
+	struct lruvec *lruvec;
+	/* unstable max_seq from lru_gen_struct */
+	unsigned long max_seq;
+	/* the next address within an mm to scan */
+	unsigned long next_addr;
+	/* to batch promoted pages */
+	int nr_pages[MAX_NR_GENS][ANON_AND_FILE][MAX_NR_ZONES];
+	/* to batch the mm stats */
+	int mm_stats[NR_MM_STATS];
+	/* total batched items */
+	int batched;
+	bool can_swap;
+	bool force_scan;
+};
+
 void lru_gen_init_lruvec(struct lruvec *lruvec);
 void lru_gen_look_around(struct page_vma_mapped_walk *pvmw);
 
@@ -480,6 +527,8 @@ struct lruvec {
 #ifdef CONFIG_LRU_GEN
 	/* evictable pages divided into generations */
 	struct lru_gen_struct		lrugen;
+	/* to concurrently iterate lru_gen_mm_list */
+	struct lru_gen_mm_state		mm_state;
 #endif
 #ifdef CONFIG_MEMCG
 	struct pglist_data *pgdat;
@@ -1176,6 +1225,11 @@ typedef struct pglist_data {
 
 	unsigned long		flags;
 
+#ifdef CONFIG_LRU_GEN
+	/* kswap mm walk data */
+	struct lru_gen_mm_walk	mm_walk;
+#endif
+
 	ZONE_PADDING(_pad2_)
 
 	/* Per-node vmstats */
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 43150b9bbc5c..6308150b234a 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -162,6 +162,10 @@ union swap_header {
  */
 struct reclaim_state {
 	unsigned long reclaimed_slab;
+#ifdef CONFIG_LRU_GEN
+	/* per-thread mm walk data */
+	struct lru_gen_mm_walk *mm_walk;
+#endif
 };
 
 #ifdef __KERNEL__
diff --git a/kernel/exit.c b/kernel/exit.c
index 84021b24f79e..98a33bd7c25c 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -466,6 +466,7 @@ void mm_update_next_owner(struct mm_struct *mm)
 		goto retry;
 	}
 	WRITE_ONCE(mm->owner, c);
+	lru_gen_migrate_mm(mm);
 	task_unlock(c);
 	put_task_struct(c);
 }
diff --git a/kernel/fork.c b/kernel/fork.c
index 90c85b17bf69..d2da065442af 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1152,6 +1152,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
 		goto fail_nocontext;
 
 	mm->user_ns = get_user_ns(user_ns);
+	lru_gen_init_mm(mm);
 	return mm;
 
 fail_nocontext:
@@ -1194,6 +1195,7 @@ static inline void __mmput(struct mm_struct *mm)
 	}
 	if (mm->binfmt)
 		module_put(mm->binfmt->module);
+	lru_gen_del_mm(mm);
 	mmdrop(mm);
 }
 
@@ -2694,6 +2696,13 @@ pid_t kernel_clone(struct kernel_clone_args *args)
 		get_task_struct(p);
 	}
 
+	if (IS_ENABLED(CONFIG_LRU_GEN) && !(clone_flags & CLONE_VM)) {
+		/* lock the task to synchronize with memcg migration */
+		task_lock(p);
+		lru_gen_add_mm(p->mm);
+		task_unlock(p);
+	}
+
 	wake_up_new_task(p);
 
 	/* forking complete and child started to run, tell ptracer */
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 8fccd8721bb8..2c605bdede47 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5180,6 +5180,7 @@ context_switch(struct rq *rq, struct task_struct *prev,
 		 * finish_task_switch()'s mmdrop().
 		 */
 		switch_mm_irqs_off(prev->active_mm, next->mm, next);
+		lru_gen_use_mm(next->mm);
 
 		if (!prev->mm) {                        // from kernel
 			/* will mmdrop() in finish_task_switch(). */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 4ea49113b0dd..392b1fd1e8c4 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -6204,6 +6204,30 @@ static void mem_cgroup_move_task(void)
 }
 #endif
 
+#ifdef CONFIG_LRU_GEN
+static void mem_cgroup_attach(struct cgroup_taskset *tset)
+{
+	struct task_struct *task;
+	struct cgroup_subsys_state *css;
+
+	/* find the first leader if there is any */
+	cgroup_taskset_for_each_leader(task, css, tset)
+		break;
+
+	if (!task)
+		return;
+
+	task_lock(task);
+	if (task->mm && READ_ONCE(task->mm->owner) == task)
+		lru_gen_migrate_mm(task->mm);
+	task_unlock(task);
+}
+#else
+static void mem_cgroup_attach(struct cgroup_taskset *tset)
+{
+}
+#endif /* CONFIG_LRU_GEN */
+
 static int seq_puts_memcg_tunable(struct seq_file *m, unsigned long value)
 {
 	if (value == PAGE_COUNTER_MAX)
@@ -6609,6 +6633,7 @@ struct cgroup_subsys memory_cgrp_subsys = {
 	.css_reset = mem_cgroup_css_reset,
 	.css_rstat_flush = mem_cgroup_css_rstat_flush,
 	.can_attach = mem_cgroup_can_attach,
+	.attach = mem_cgroup_attach,
 	.cancel_attach = mem_cgroup_cancel_attach,
 	.post_attach = mem_cgroup_move_task,
 	.dfl_cftypes = memory_files,
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 33a1bdfc04bd..c579b254fec7 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -49,6 +49,8 @@
 #include <linux/printk.h>
 #include <linux/dax.h>
 #include <linux/psi.h>
+#include <linux/pagewalk.h>
+#include <linux/shmem_fs.h>
 
 #include <asm/tlbflush.h>
 #include <asm/div64.h>
@@ -3082,7 +3084,7 @@ static bool can_age_anon_pages(struct pglist_data *pgdat,
 		for ((type) = 0; (type) < ANON_AND_FILE; (type)++)	\
 			for ((zone) = 0; (zone) < MAX_NR_ZONES; (zone)++)
 
-static struct lruvec __maybe_unused *get_lruvec(struct mem_cgroup *memcg, int nid)
+static struct lruvec *get_lruvec(struct mem_cgroup *memcg, int nid)
 {
 	struct pglist_data *pgdat = NODE_DATA(nid);
 
@@ -3127,6 +3129,371 @@ static bool __maybe_unused seq_is_valid(struct lruvec *lruvec)
 	       get_nr_gens(lruvec, LRU_GEN_ANON) <= MAX_NR_GENS;
 }
 
+/******************************************************************************
+ *                          mm_struct list
+ ******************************************************************************/
+
+static struct lru_gen_mm_list *get_mm_list(struct mem_cgroup *memcg)
+{
+	static struct lru_gen_mm_list mm_list = {
+		.fifo = LIST_HEAD_INIT(mm_list.fifo),
+		.lock = __SPIN_LOCK_UNLOCKED(mm_list.lock),
+	};
+
+#ifdef CONFIG_MEMCG
+	if (memcg)
+		return &memcg->mm_list;
+#endif
+	VM_WARN_ON_ONCE(!mem_cgroup_disabled());
+
+	return &mm_list;
+}
+
+void lru_gen_add_mm(struct mm_struct *mm)
+{
+	int nid;
+	struct mem_cgroup *memcg = get_mem_cgroup_from_mm(mm);
+	struct lru_gen_mm_list *mm_list = get_mm_list(memcg);
+
+	VM_WARN_ON_ONCE(!list_empty(&mm->lru_gen.list));
+#ifdef CONFIG_MEMCG
+	VM_WARN_ON_ONCE(mm->lru_gen.memcg);
+	mm->lru_gen.memcg = memcg;
+#endif
+	spin_lock(&mm_list->lock);
+
+	for_each_node_state(nid, N_MEMORY) {
+		struct lruvec *lruvec = get_lruvec(memcg, nid);
+
+		if (!lruvec)
+			continue;
+
+		/* the first addition since the last iteration */
+		if (lruvec->mm_state.tail == &mm_list->fifo)
+			lruvec->mm_state.tail = &mm->lru_gen.list;
+	}
+
+	list_add_tail(&mm->lru_gen.list, &mm_list->fifo);
+
+	spin_unlock(&mm_list->lock);
+}
+
+void lru_gen_del_mm(struct mm_struct *mm)
+{
+	int nid;
+	struct lru_gen_mm_list *mm_list;
+	struct mem_cgroup *memcg = NULL;
+
+	if (list_empty(&mm->lru_gen.list))
+		return;
+
+#ifdef CONFIG_MEMCG
+	memcg = mm->lru_gen.memcg;
+#endif
+	mm_list = get_mm_list(memcg);
+
+	spin_lock(&mm_list->lock);
+
+	for_each_node(nid) {
+		struct lruvec *lruvec = get_lruvec(memcg, nid);
+
+		if (!lruvec)
+			continue;
+
+		/* where the last iteration ended (exclusive) */
+		if (lruvec->mm_state.tail == &mm->lru_gen.list)
+			lruvec->mm_state.tail = lruvec->mm_state.tail->next;
+
+		/* where the current iteration continues (inclusive) */
+		if (lruvec->mm_state.head != &mm->lru_gen.list)
+			continue;
+
+		lruvec->mm_state.head = lruvec->mm_state.head->next;
+		/* the deletion ends the current iteration */
+		if (lruvec->mm_state.head == &mm_list->fifo)
+			WRITE_ONCE(lruvec->mm_state.seq, lruvec->mm_state.seq + 1);
+	}
+
+	list_del_init(&mm->lru_gen.list);
+
+	spin_unlock(&mm_list->lock);
+
+#ifdef CONFIG_MEMCG
+	mem_cgroup_put(mm->lru_gen.memcg);
+	mm->lru_gen.memcg = NULL;
+#endif
+}
+
+#ifdef CONFIG_MEMCG
+void lru_gen_migrate_mm(struct mm_struct *mm)
+{
+	struct mem_cgroup *memcg;
+	struct task_struct *task = rcu_dereference_protected(mm->owner, true);
+
+	VM_WARN_ON_ONCE(task->mm != mm);
+	lockdep_assert_held(&task->alloc_lock);
+
+	/* for mm_update_next_owner() */
+	if (mem_cgroup_disabled())
+		return;
+
+	rcu_read_lock();
+	memcg = mem_cgroup_from_task(task);
+	rcu_read_unlock();
+	if (memcg == mm->lru_gen.memcg)
+		return;
+
+	VM_WARN_ON_ONCE(!mm->lru_gen.memcg);
+	VM_WARN_ON_ONCE(list_empty(&mm->lru_gen.list));
+
+	lru_gen_del_mm(mm);
+	lru_gen_add_mm(mm);
+}
+#endif
+
+/*
+ * Bloom filters with m=1<<15, k=2 and the false positive rates of ~1/5 when
+ * n=10,000 and ~1/2 when n=20,000, where, conventionally, m is the number of
+ * bits in a bitmap, k is the number of hash functions and n is the number of
+ * inserted items.
+ *
+ * Page table walkers use one of the two filters to reduce their search space.
+ * To get rid of non-leaf entries that no longer have enough leaf entries, the
+ * aging uses the double-buffering technique to flip to the other filter each
+ * time it produces a new generation. For non-leaf entries that have enough
+ * leaf entries, the aging carries them over to the next generation in
+ * walk_pmd_range(); the eviction also report them when walking the rmap
+ * in lru_gen_look_around().
+ *
+ * For future optimizations:
+ * 1. It's not necessary to keep both filters all the time. The spare one can be
+ *    freed after the RCU grace period and reallocated if needed again.
+ * 2. And when reallocating, it's worth scaling its size according to the number
+ *    of inserted entries in the other filter, to reduce the memory overhead on
+ *    small systems and false positives on large systems.
+ * 3. Jenkins' hash function is an alternative to Knuth's.
+ */
+#define BLOOM_FILTER_SHIFT	15
+
+static inline int filter_gen_from_seq(unsigned long seq)
+{
+	return seq % NR_BLOOM_FILTERS;
+}
+
+static void get_item_key(void *item, int *key)
+{
+	u32 hash = hash_ptr(item, BLOOM_FILTER_SHIFT * 2);
+
+	BUILD_BUG_ON(BLOOM_FILTER_SHIFT * 2 > BITS_PER_TYPE(u32));
+
+	key[0] = hash & (BIT(BLOOM_FILTER_SHIFT) - 1);
+	key[1] = hash >> BLOOM_FILTER_SHIFT;
+}
+
+static void reset_bloom_filter(struct lruvec *lruvec, unsigned long seq)
+{
+	unsigned long *filter;
+	int gen = filter_gen_from_seq(seq);
+
+	filter = lruvec->mm_state.filters[gen];
+	if (filter) {
+		bitmap_clear(filter, 0, BIT(BLOOM_FILTER_SHIFT));
+		return;
+	}
+
+	filter = bitmap_zalloc(BIT(BLOOM_FILTER_SHIFT),
+			       __GFP_HIGH | __GFP_NOMEMALLOC | __GFP_NOWARN);
+	WRITE_ONCE(lruvec->mm_state.filters[gen], filter);
+}
+
+static void update_bloom_filter(struct lruvec *lruvec, unsigned long seq, void *item)
+{
+	int key[2];
+	unsigned long *filter;
+	int gen = filter_gen_from_seq(seq);
+
+	filter = READ_ONCE(lruvec->mm_state.filters[gen]);
+	if (!filter)
+		return;
+
+	get_item_key(item, key);
+
+	if (!test_bit(key[0], filter))
+		set_bit(key[0], filter);
+	if (!test_bit(key[1], filter))
+		set_bit(key[1], filter);
+}
+
+static bool test_bloom_filter(struct lruvec *lruvec, unsigned long seq, void *item)
+{
+	int key[2];
+	unsigned long *filter;
+	int gen = filter_gen_from_seq(seq);
+
+	filter = READ_ONCE(lruvec->mm_state.filters[gen]);
+	if (!filter)
+		return true;
+
+	get_item_key(item, key);
+
+	return test_bit(key[0], filter) && test_bit(key[1], filter);
+}
+
+static void reset_mm_stats(struct lruvec *lruvec, struct lru_gen_mm_walk *walk, bool last)
+{
+	int i;
+	int hist;
+
+	lockdep_assert_held(&get_mm_list(lruvec_memcg(lruvec))->lock);
+
+	if (walk) {
+		hist = lru_hist_from_seq(walk->max_seq);
+
+		for (i = 0; i < NR_MM_STATS; i++) {
+			WRITE_ONCE(lruvec->mm_state.stats[hist][i],
+				   lruvec->mm_state.stats[hist][i] + walk->mm_stats[i]);
+			walk->mm_stats[i] = 0;
+		}
+	}
+
+	if (NR_HIST_GENS > 1 && last) {
+		hist = lru_hist_from_seq(lruvec->mm_state.seq + 1);
+
+		for (i = 0; i < NR_MM_STATS; i++)
+			WRITE_ONCE(lruvec->mm_state.stats[hist][i], 0);
+	}
+}
+
+static bool should_skip_mm(struct mm_struct *mm, struct lru_gen_mm_walk *walk)
+{
+	int type;
+	unsigned long size = 0;
+	struct pglist_data *pgdat = lruvec_pgdat(walk->lruvec);
+	int key = pgdat->node_id % BITS_PER_TYPE(mm->lru_gen.bitmap);
+
+	if (!walk->force_scan && !test_bit(key, &mm->lru_gen.bitmap))
+		return true;
+
+	clear_bit(key, &mm->lru_gen.bitmap);
+
+	for (type = !walk->can_swap; type < ANON_AND_FILE; type++) {
+		size += type ? get_mm_counter(mm, MM_FILEPAGES) :
+			       get_mm_counter(mm, MM_ANONPAGES) +
+			       get_mm_counter(mm, MM_SHMEMPAGES);
+	}
+
+	if (size < MIN_LRU_BATCH)
+		return true;
+
+	return !mmget_not_zero(mm);
+}
+
+static bool iterate_mm_list(struct lruvec *lruvec, struct lru_gen_mm_walk *walk,
+			    struct mm_struct **iter)
+{
+	bool first = false;
+	bool last = true;
+	struct mm_struct *mm = NULL;
+	struct mem_cgroup *memcg = lruvec_memcg(lruvec);
+	struct lru_gen_mm_list *mm_list = get_mm_list(memcg);
+	struct lru_gen_mm_state *mm_state = &lruvec->mm_state;
+
+	/*
+	 * There are four interesting cases for this page table walker:
+	 * 1. It tries to start a new iteration of mm_list with a stale max_seq;
+	 *    there is nothing left to do.
+	 * 2. It's the first of the current generation, and it needs to reset
+	 *    the Bloom filter for the next generation.
+	 * 3. It reaches the end of mm_list, and it needs to increment
+	 *    mm_state->seq; the iteration is done.
+	 * 4. It's the last of the current generation, and it needs to reset the
+	 *    mm stats counters for the next generation.
+	 */
+	spin_lock(&mm_list->lock);
+
+	VM_WARN_ON_ONCE(mm_state->seq + 1 < walk->max_seq);
+	VM_WARN_ON_ONCE(*iter && mm_state->seq > walk->max_seq);
+	VM_WARN_ON_ONCE(*iter && !mm_state->nr_walkers);
+
+	if (walk->max_seq <= mm_state->seq) {
+		if (!*iter)
+			last = false;
+		goto done;
+	}
+
+	if (!mm_state->nr_walkers) {
+		VM_WARN_ON_ONCE(mm_state->head && mm_state->head != &mm_list->fifo);
+
+		mm_state->head = mm_list->fifo.next;
+		first = true;
+	}
+
+	while (!mm && mm_state->head != &mm_list->fifo) {
+		mm = list_entry(mm_state->head, struct mm_struct, lru_gen.list);
+
+		mm_state->head = mm_state->head->next;
+
+		/* force scan for those added after the last iteration */
+		if (!mm_state->tail || mm_state->tail == &mm->lru_gen.list) {
+			mm_state->tail = mm_state->head;
+			walk->force_scan = true;
+		}
+
+		if (should_skip_mm(mm, walk))
+			mm = NULL;
+	}
+
+	if (mm_state->head == &mm_list->fifo)
+		WRITE_ONCE(mm_state->seq, mm_state->seq + 1);
+done:
+	if (*iter && !mm)
+		mm_state->nr_walkers--;
+	if (!*iter && mm)
+		mm_state->nr_walkers++;
+
+	if (mm_state->nr_walkers)
+		last = false;
+
+	if (*iter || last)
+		reset_mm_stats(lruvec, walk, last);
+
+	spin_unlock(&mm_list->lock);
+
+	if (mm && first)
+		reset_bloom_filter(lruvec, walk->max_seq + 1);
+
+	if (*iter)
+		mmput_async(*iter);
+
+	*iter = mm;
+
+	return last;
+}
+
+static bool iterate_mm_list_nowalk(struct lruvec *lruvec, unsigned long max_seq)
+{
+	bool success = false;
+	struct mem_cgroup *memcg = lruvec_memcg(lruvec);
+	struct lru_gen_mm_list *mm_list = get_mm_list(memcg);
+	struct lru_gen_mm_state *mm_state = &lruvec->mm_state;
+
+	spin_lock(&mm_list->lock);
+
+	VM_WARN_ON_ONCE(mm_state->seq + 1 < max_seq);
+
+	if (max_seq > mm_state->seq && !mm_state->nr_walkers) {
+		VM_WARN_ON_ONCE(mm_state->head && mm_state->head != &mm_list->fifo);
+
+		WRITE_ONCE(mm_state->seq, mm_state->seq + 1);
+		reset_mm_stats(lruvec, NULL, true);
+		success = true;
+	}
+
+	spin_unlock(&mm_list->lock);
+
+	return success;
+}
+
 /******************************************************************************
  *                          refault feedback loop
  ******************************************************************************/
@@ -3277,6 +3644,118 @@ static int folio_inc_gen(struct lruvec *lruvec, struct folio *folio, bool reclai
 	return new_gen;
 }
 
+static void update_batch_size(struct lru_gen_mm_walk *walk, struct folio *folio,
+			      int old_gen, int new_gen)
+{
+	int type = folio_is_file_lru(folio);
+	int zone = folio_zonenum(folio);
+	int delta = folio_nr_pages(folio);
+
+	VM_WARN_ON_ONCE(old_gen >= MAX_NR_GENS);
+	VM_WARN_ON_ONCE(new_gen >= MAX_NR_GENS);
+
+	walk->batched++;
+
+	walk->nr_pages[old_gen][type][zone] -= delta;
+	walk->nr_pages[new_gen][type][zone] += delta;
+}
+
+static void reset_batch_size(struct lruvec *lruvec, struct lru_gen_mm_walk *walk)
+{
+	int gen, type, zone;
+	struct lru_gen_struct *lrugen = &lruvec->lrugen;
+
+	walk->batched = 0;
+
+	for_each_gen_type_zone(gen, type, zone) {
+		enum lru_list lru = type * LRU_INACTIVE_FILE;
+		int delta = walk->nr_pages[gen][type][zone];
+
+		if (!delta)
+			continue;
+
+		walk->nr_pages[gen][type][zone] = 0;
+		WRITE_ONCE(lrugen->nr_pages[gen][type][zone],
+			   lrugen->nr_pages[gen][type][zone] + delta);
+
+		if (lru_gen_is_active(lruvec, gen))
+			lru += LRU_ACTIVE;
+		__update_lru_size(lruvec, lru, zone, delta);
+	}
+}
+
+static int should_skip_vma(unsigned long start, unsigned long end, struct mm_walk *args)
+{
+	struct address_space *mapping;
+	struct vm_area_struct *vma = args->vma;
+	struct lru_gen_mm_walk *walk = args->private;
+
+	if (!vma_is_accessible(vma))
+		return true;
+
+	if (is_vm_hugetlb_page(vma))
+		return true;
+
+	if (vma->vm_flags & (VM_LOCKED | VM_SPECIAL | VM_SEQ_READ | VM_RAND_READ))
+		return true;
+
+	if (vma == get_gate_vma(vma->vm_mm))
+		return true;
+
+	if (vma_is_anonymous(vma))
+		return !walk->can_swap;
+
+	if (WARN_ON_ONCE(!vma->vm_file || !vma->vm_file->f_mapping))
+		return true;
+
+	mapping = vma->vm_file->f_mapping;
+	if (mapping_unevictable(mapping))
+		return true;
+
+	if (shmem_mapping(mapping))
+		return !walk->can_swap;
+
+	/* to exclude special mappings like dax, etc. */
+	return !mapping->a_ops->read_folio;
+}
+
+/*
+ * Some userspace memory allocators map many single-page VMAs. Instead of
+ * returning back to the PGD table for each of such VMAs, finish an entire PMD
+ * table to reduce zigzags and improve cache performance.
+ */
+static bool get_next_vma(unsigned long mask, unsigned long size, struct mm_walk *args,
+			 unsigned long *vm_start, unsigned long *vm_end)
+{
+	unsigned long start = round_up(*vm_end, size);
+	unsigned long end = (start | ~mask) + 1;
+
+	VM_WARN_ON_ONCE(mask & size);
+	VM_WARN_ON_ONCE((start & mask) != (*vm_start & mask));
+
+	while (args->vma) {
+		if (start >= args->vma->vm_end) {
+			args->vma = args->vma->vm_next;
+			continue;
+		}
+
+		if (end && end <= args->vma->vm_start)
+			return false;
+
+		if (should_skip_vma(args->vma->vm_start, args->vma->vm_end, args)) {
+			args->vma = args->vma->vm_next;
+			continue;
+		}
+
+		*vm_start = max(start, args->vma->vm_start);
+		*vm_end = min(end - 1, args->vma->vm_end - 1) + 1;
+
+		return true;
+	}
+
+	return false;
+}
+
 static unsigned long get_pte_pfn(pte_t pte, struct vm_area_struct *vma, unsigned long addr)
 {
 	unsigned long pfn = pte_pfn(pte);
@@ -3295,8 +3774,28 @@ static unsigned long get_pte_pfn(pte_t pte, struct vm_area_struct *vma, unsigned
 	return pfn;
 }
 
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG)
+static unsigned long get_pmd_pfn(pmd_t pmd, struct vm_area_struct *vma, unsigned long addr)
+{
+	unsigned long pfn = pmd_pfn(pmd);
+
+	VM_WARN_ON_ONCE(addr < vma->vm_start || addr >= vma->vm_end);
+
+	if (!pmd_present(pmd) || is_huge_zero_pmd(pmd))
+		return -1;
+
+	if (WARN_ON_ONCE(pmd_devmap(pmd)))
+		return -1;
+
+	if (WARN_ON_ONCE(!pfn_valid(pfn)))
+		return -1;
+
+	return pfn;
+}
+#endif
+
 static struct folio *get_pfn_folio(unsigned long pfn, struct mem_cgroup *memcg,
-				   struct pglist_data *pgdat)
+				   struct pglist_data *pgdat, bool can_swap)
 {
 	struct folio *folio;
 
@@ -3311,9 +3810,375 @@ static struct folio *get_pfn_folio(unsigned long pfn, struct mem_cgroup *memcg,
 	if (folio_memcg_rcu(folio) != memcg)
 		return NULL;
 
+	/* file VMAs can contain anon pages from COW */
+	if (!folio_is_file_lru(folio) && !can_swap)
+		return NULL;
+
 	return folio;
 }
 
+static bool suitable_to_scan(int total, int young)
+{
+	int n = clamp_t(int, cache_line_size() / sizeof(pte_t), 2, 8);
+
+	/* suitable if the average number of young PTEs per cacheline is >=1 */
+	return young * n >= total;
+}
+
+static bool walk_pte_range(pmd_t *pmd, unsigned long start, unsigned long end,
+			   struct mm_walk *args)
+{
+	int i;
+	pte_t *pte;
+	spinlock_t *ptl;
+	unsigned long addr;
+	int total = 0;
+	int young = 0;
+	struct lru_gen_mm_walk *walk = args->private;
+	struct mem_cgroup *memcg = lruvec_memcg(walk->lruvec);
+	struct pglist_data *pgdat = lruvec_pgdat(walk->lruvec);
+	int old_gen, new_gen = lru_gen_from_seq(walk->max_seq);
+
+	VM_WARN_ON_ONCE(pmd_leaf(*pmd));
+
+	ptl = pte_lockptr(args->mm, pmd);
+	if (!spin_trylock(ptl))
+		return false;
+
+	arch_enter_lazy_mmu_mode();
+
+	pte = pte_offset_map(pmd, start & PMD_MASK);
+restart:
+	for (i = pte_index(start), addr = start; addr != end; i++, addr += PAGE_SIZE) {
+		unsigned long pfn;
+		struct folio *folio;
+
+		total++;
+		walk->mm_stats[MM_LEAF_TOTAL]++;
+
+		pfn = get_pte_pfn(pte[i], args->vma, addr);
+		if (pfn == -1)
+			continue;
+
+		if (!pte_young(pte[i])) {
+			walk->mm_stats[MM_LEAF_OLD]++;
+			continue;
+		}
+
+		folio = get_pfn_folio(pfn, memcg, pgdat, walk->can_swap);
+		if (!folio)
+			continue;
+
+		if (!ptep_test_and_clear_young(args->vma, addr, pte + i))
+			VM_WARN_ON_ONCE(true);
+
+		young++;
+		walk->mm_stats[MM_LEAF_YOUNG]++;
+
+		if (pte_dirty(pte[i]) && !folio_test_dirty(folio) &&
+		    !(folio_test_anon(folio) && folio_test_swapbacked(folio) &&
+		      !folio_test_swapcache(folio)))
+			folio_mark_dirty(folio);
+
+		old_gen = folio_update_gen(folio, new_gen);
+		if (old_gen >= 0 && old_gen != new_gen)
+			update_batch_size(walk, folio, old_gen, new_gen);
+	}
+
+	if (i < PTRS_PER_PTE && get_next_vma(PMD_MASK, PAGE_SIZE, args, &start, &end))
+		goto restart;
+
+	pte_unmap(pte);
+
+	arch_leave_lazy_mmu_mode();
+	spin_unlock(ptl);
+
+	return suitable_to_scan(total, young);
+}
+
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG)
+static void walk_pmd_range_locked(pud_t *pud, unsigned long next, struct vm_area_struct *vma,
+				  struct mm_walk *args, unsigned long *bitmap, unsigned long *start)
+{
+	int i;
+	pmd_t *pmd;
+	spinlock_t *ptl;
+	struct lru_gen_mm_walk *walk = args->private;
+	struct mem_cgroup *memcg = lruvec_memcg(walk->lruvec);
+	struct pglist_data *pgdat = lruvec_pgdat(walk->lruvec);
+	int old_gen, new_gen = lru_gen_from_seq(walk->max_seq);
+
+	VM_WARN_ON_ONCE(pud_leaf(*pud));
+
+	/* try to batch at most 1+MIN_LRU_BATCH+1 entries */
+	if (*start == -1) {
+		*start = next;
+		return;
+	}
+
+	i = next == -1 ? 0 : pmd_index(next) - pmd_index(*start);
+	if (i && i <= MIN_LRU_BATCH) {
+		__set_bit(i - 1, bitmap);
+		return;
+	}
+
+	pmd = pmd_offset(pud, *start);
+
+	ptl = pmd_lockptr(args->mm, pmd);
+	if (!spin_trylock(ptl))
+		goto done;
+
+	arch_enter_lazy_mmu_mode();
+
+	do {
+		unsigned long pfn;
+		struct folio *folio;
+		unsigned long addr = i ? (*start & PMD_MASK) + i * PMD_SIZE : *start;
+
+		pfn = get_pmd_pfn(pmd[i], vma, addr);
+		if (pfn == -1)
+			goto next;
+
+		if (!pmd_trans_huge(pmd[i])) {
+			if (IS_ENABLED(CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG))
+				pmdp_test_and_clear_young(vma, addr, pmd + i);
+			goto next;
+		}
+
+		folio = get_pfn_folio(pfn, memcg, pgdat, walk->can_swap);
+		if (!folio)
+			goto next;
+
+		if (!pmdp_test_and_clear_young(vma, addr, pmd + i))
+			goto next;
+
+		walk->mm_stats[MM_LEAF_YOUNG]++;
+
+		if (pmd_dirty(pmd[i]) && !folio_test_dirty(folio) &&
+		    !(folio_test_anon(folio) && folio_test_swapbacked(folio) &&
+		      !folio_test_swapcache(folio)))
+			folio_mark_dirty(folio);
+
+		old_gen = folio_update_gen(folio, new_gen);
+		if (old_gen >= 0 && old_gen != new_gen)
+			update_batch_size(walk, folio, old_gen, new_gen);
+next:
+		i = i > MIN_LRU_BATCH ? 0 : find_next_bit(bitmap, MIN_LRU_BATCH, i) + 1;
+	} while (i <= MIN_LRU_BATCH);
+
+	arch_leave_lazy_mmu_mode();
+	spin_unlock(ptl);
+done:
+	*start = -1;
+	bitmap_zero(bitmap, MIN_LRU_BATCH);
+}
+#else
+static void walk_pmd_range_locked(pud_t *pud, unsigned long next, struct vm_area_struct *vma,
+				  struct mm_walk *args, unsigned long *bitmap, unsigned long *start)
+{
+}
+#endif
+
+static void walk_pmd_range(pud_t *pud, unsigned long start, unsigned long end,
+			   struct mm_walk *args)
+{
+	int i;
+	pmd_t *pmd;
+	unsigned long next;
+	unsigned long addr;
+	struct vm_area_struct *vma;
+	unsigned long pos = -1;
+	struct lru_gen_mm_walk *walk = args->private;
+	unsigned long bitmap[BITS_TO_LONGS(MIN_LRU_BATCH)] = {};
+
+	VM_WARN_ON_ONCE(pud_leaf(*pud));
+
+	/*
+	 * Finish an entire PMD in two passes: the first only reaches to PTE
+	 * tables to avoid taking the PMD lock; the second, if necessary, takes
+	 * the PMD lock to clear the accessed bit in PMD entries.
+	 */
+	pmd = pmd_offset(pud, start & PUD_MASK);
+restart:
+	/* walk_pte_range() may call get_next_vma() */
+	vma = args->vma;
+	for (i = pmd_index(start), addr = start; addr != end; i++, addr = next) {
+		pmd_t val = pmd_read_atomic(pmd + i);
+
+		/* for pmd_read_atomic() */
+		barrier();
+
+		next = pmd_addr_end(addr, end);
+
+		if (!pmd_present(val) || is_huge_zero_pmd(val)) {
+			walk->mm_stats[MM_LEAF_TOTAL]++;
+			continue;
+		}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+		if (pmd_trans_huge(val)) {
+			unsigned long pfn = pmd_pfn(val);
+			struct pglist_data *pgdat = lruvec_pgdat(walk->lruvec);
+
+			walk->mm_stats[MM_LEAF_TOTAL]++;
+
+			if (!pmd_young(val)) {
+				walk->mm_stats[MM_LEAF_OLD]++;
+				continue;
+			}
+
+			/* try to avoid unnecessary memory loads */
+			if (pfn < pgdat->node_start_pfn || pfn >= pgdat_end_pfn(pgdat))
+				continue;
+
+			walk_pmd_range_locked(pud, addr, vma, args, bitmap, &pos);
+			continue;
+		}
+#endif
+		walk->mm_stats[MM_NONLEAF_TOTAL]++;
+
+#ifdef CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG
+		if (!pmd_young(val))
+			continue;
+
+		walk_pmd_range_locked(pud, addr, vma, args, bitmap, &pos);
+#endif
+		if (!walk->force_scan && !test_bloom_filter(walk->lruvec, walk->max_seq, pmd + i))
+			continue;
+
+		walk->mm_stats[MM_NONLEAF_FOUND]++;
+
+		if (!walk_pte_range(&val, addr, next, args))
+			continue;
+
+		walk->mm_stats[MM_NONLEAF_ADDED]++;
+
+		/* carry over to the next generation */
+		update_bloom_filter(walk->lruvec, walk->max_seq + 1, pmd + i);
+	}
+
+	walk_pmd_range_locked(pud, -1, vma, args, bitmap, &pos);
+
+	if (i < PTRS_PER_PMD && get_next_vma(PUD_MASK, PMD_SIZE, args, &start, &end))
+		goto restart;
+}
+
+static int walk_pud_range(p4d_t *p4d, unsigned long start, unsigned long end,
+			  struct mm_walk *args)
+{
+	int i;
+	pud_t *pud;
+	unsigned long addr;
+	unsigned long next;
+	struct lru_gen_mm_walk *walk = args->private;
+
+	VM_WARN_ON_ONCE(p4d_leaf(*p4d));
+
+	pud = pud_offset(p4d, start & P4D_MASK);
+restart:
+	for (i = pud_index(start), addr = start; addr != end; i++, addr = next) {
+		pud_t val = READ_ONCE(pud[i]);
+
+		next = pud_addr_end(addr, end);
+
+		if (!pud_present(val) || WARN_ON_ONCE(pud_leaf(val)))
+			continue;
+
+		walk_pmd_range(&val, addr, next, args);
+
+		/* a racy check to curtail the waiting time */
+		if (wq_has_sleeper(&walk->lruvec->mm_state.wait))
+			return 1;
+
+		if (need_resched() || walk->batched >= MAX_LRU_BATCH) {
+			end = (addr | ~PUD_MASK) + 1;
+			goto done;
+		}
+	}
+
+	if (i < PTRS_PER_PUD && get_next_vma(P4D_MASK, PUD_SIZE, args, &start, &end))
+		goto restart;
+
+	end = round_up(end, P4D_SIZE);
+done:
+	if (!end || !args->vma)
+		return 1;
+
+	walk->next_addr = max(end, args->vma->vm_start);
+
+	return -EAGAIN;
+}
+
+static void walk_mm(struct lruvec *lruvec, struct mm_struct *mm, struct lru_gen_mm_walk *walk)
+{
+	static const struct mm_walk_ops mm_walk_ops = {
+		.test_walk = should_skip_vma,
+		.p4d_entry = walk_pud_range,
+	};
+
+	int err;
+	struct mem_cgroup *memcg = lruvec_memcg(lruvec);
+
+	walk->next_addr = FIRST_USER_ADDRESS;
+
+	do {
+		err = -EBUSY;
+
+		/* folio_update_gen() requires stable folio_memcg() */
+		if (!mem_cgroup_trylock_pages(memcg))
+			break;
+
+		/* the caller might be holding the lock for write */
+		if (mmap_read_trylock(mm)) {
+			err = walk_page_range(mm, walk->next_addr, ULONG_MAX, &mm_walk_ops, walk);
+
+			mmap_read_unlock(mm);
+		}
+
+		mem_cgroup_unlock_pages();
+
+		if (walk->batched) {
+			spin_lock_irq(&lruvec->lru_lock);
+			reset_batch_size(lruvec, walk);
+			spin_unlock_irq(&lruvec->lru_lock);
+		}
+
+		cond_resched();
+	} while (err == -EAGAIN);
+}
+
+static struct lru_gen_mm_walk *set_mm_walk(struct pglist_data *pgdat)
+{
+	struct lru_gen_mm_walk *walk = current->reclaim_state->mm_walk;
+
+	if (pgdat && current_is_kswapd()) {
+		VM_WARN_ON_ONCE(walk);
+
+		walk = &pgdat->mm_walk;
+	} else if (!pgdat && !walk) {
+		VM_WARN_ON_ONCE(current_is_kswapd());
+
+		walk = kzalloc(sizeof(*walk), __GFP_HIGH | __GFP_NOMEMALLOC | __GFP_NOWARN);
+	}
+
+	current->reclaim_state->mm_walk = walk;
+
+	return walk;
+}
+
+static void clear_mm_walk(void)
+{
+	struct lru_gen_mm_walk *walk = current->reclaim_state->mm_walk;
+
+	VM_WARN_ON_ONCE(walk && memchr_inv(walk->nr_pages, 0, sizeof(walk->nr_pages)));
+	VM_WARN_ON_ONCE(walk && memchr_inv(walk->mm_stats, 0, sizeof(walk->mm_stats)));
+
+	current->reclaim_state->mm_walk = NULL;
+
+	if (!current_is_kswapd())
+		kfree(walk);
+}
+
 static void inc_min_seq(struct lruvec *lruvec, int type)
 {
 	struct lru_gen_struct *lrugen = &lruvec->lrugen;
@@ -3365,7 +4230,7 @@ static bool try_to_inc_min_seq(struct lruvec *lruvec, bool can_swap)
 	return success;
 }
 
-static void inc_max_seq(struct lruvec *lruvec, unsigned long max_seq, bool can_swap)
+static void inc_max_seq(struct lruvec *lruvec, bool can_swap)
 {
 	int prev, next;
 	int type, zone;
@@ -3375,9 +4240,6 @@ static void inc_max_seq(struct lruvec *lruvec, unsigned long max_seq, bool can_s
 
 	VM_WARN_ON_ONCE(!seq_is_valid(lruvec));
 
-	if (max_seq != lrugen->max_seq)
-		goto unlock;
-
 	for (type = ANON_AND_FILE - 1; type >= 0; type--) {
 		if (get_nr_gens(lruvec, type) != MAX_NR_GENS)
 			continue;
@@ -3415,10 +4277,76 @@ static void inc_max_seq(struct lruvec *lruvec, unsigned long max_seq, bool can_s
 
 	/* make sure preceding modifications appear */
 	smp_store_release(&lrugen->max_seq, lrugen->max_seq + 1);
-unlock:
+
 	spin_unlock_irq(&lruvec->lru_lock);
 }
 
+static bool try_to_inc_max_seq(struct lruvec *lruvec, unsigned long max_seq,
+			       struct scan_control *sc, bool can_swap)
+{
+	bool success;
+	struct lru_gen_mm_walk *walk;
+	struct mm_struct *mm = NULL;
+	struct lru_gen_struct *lrugen = &lruvec->lrugen;
+
+	VM_WARN_ON_ONCE(max_seq > READ_ONCE(lrugen->max_seq));
+
+	/* see the comment in iterate_mm_list() */
+	if (max_seq <= READ_ONCE(lruvec->mm_state.seq)) {
+		success = false;
+		goto done;
+	}
+
+	/*
+	 * If the hardware doesn't automatically set the accessed bit, fallback
+	 * to lru_gen_look_around(), which only clears the accessed bit in a
+	 * handful of PTEs. Spreading the work out over a period of time usually
+	 * is less efficient, but it avoids bursty page faults.
+	 */
+	if (!arch_has_hw_pte_young()) {
+		success = iterate_mm_list_nowalk(lruvec, max_seq);
+		goto done;
+	}
+
+	walk = set_mm_walk(NULL);
+	if (!walk) {
+		success = iterate_mm_list_nowalk(lruvec, max_seq);
+		goto done;
+	}
+
+	walk->lruvec = lruvec;
+	walk->max_seq = max_seq;
+	walk->can_swap = can_swap;
+	walk->force_scan = false;
+
+	do {
+		success = iterate_mm_list(lruvec, walk, &mm);
+		if (mm)
+			walk_mm(lruvec, mm, walk);
+
+		cond_resched();
+	} while (mm);
+done:
+	if (!success) {
+		if (sc->priority <= DEF_PRIORITY - 2)
+			wait_event_killable(lruvec->mm_state.wait,
+					    max_seq < READ_ONCE(lrugen->max_seq));
+
+		return max_seq < READ_ONCE(lrugen->max_seq);
+	}
+
+	VM_WARN_ON_ONCE(max_seq != READ_ONCE(lrugen->max_seq));
+
+	inc_max_seq(lruvec, can_swap);
+	/* either this sees any waiters or they will see updated max_seq */
+	if (wq_has_sleeper(&lruvec->mm_state.wait))
+		wake_up_all(&lruvec->mm_state.wait);
+
+	wakeup_flusher_threads(WB_REASON_VMSCAN);
+
+	return true;
+}
+
 static bool should_run_aging(struct lruvec *lruvec, unsigned long max_seq, unsigned long *min_seq,
 			     struct scan_control *sc, bool can_swap, unsigned long *nr_to_scan)
 {
@@ -3494,7 +4422,7 @@ static void age_lruvec(struct lruvec *lruvec, struct scan_control *sc)
 
 	need_aging = should_run_aging(lruvec, max_seq, min_seq, sc, swappiness, &nr_to_scan);
 	if (need_aging)
-		inc_max_seq(lruvec, max_seq, swappiness);
+		try_to_inc_max_seq(lruvec, max_seq, sc, swappiness);
 }
 
 static void lru_gen_age_node(struct pglist_data *pgdat, struct scan_control *sc)
@@ -3503,6 +4431,8 @@ static void lru_gen_age_node(struct pglist_data *pgdat, struct scan_control *sc)
 
 	VM_WARN_ON_ONCE(!current_is_kswapd());
 
+	set_mm_walk(pgdat);
+
 	memcg = mem_cgroup_iter(NULL, NULL, NULL);
 	do {
 		struct lruvec *lruvec = mem_cgroup_lruvec(memcg, pgdat);
@@ -3511,11 +4441,16 @@ static void lru_gen_age_node(struct pglist_data *pgdat, struct scan_control *sc)
 
 		cond_resched();
 	} while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)));
+
+	clear_mm_walk();
 }
 
 /*
  * This function exploits spatial locality when shrink_page_list() walks the
- * rmap. It scans the adjacent PTEs of a young PTE and promotes hot pages.
+ * rmap. It scans the adjacent PTEs of a young PTE and promotes hot pages. If
+ * the scan was done cacheline efficiently, it adds the PMD entry pointing to
+ * the PTE table to the Bloom filter. This forms a feedback loop between the
+ * eviction and the aging.
  */
 void lru_gen_look_around(struct page_vma_mapped_walk *pvmw)
 {
@@ -3524,6 +4459,8 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw)
 	unsigned long start;
 	unsigned long end;
 	unsigned long addr;
+	struct lru_gen_mm_walk *walk;
+	int young = 0;
 	unsigned long bitmap[BITS_TO_LONGS(MIN_LRU_BATCH)] = {};
 	struct folio *folio = pfn_folio(pvmw->pfn);
 	struct mem_cgroup *memcg = folio_memcg(folio);
@@ -3538,6 +4475,9 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw)
 	if (spin_is_contended(pvmw->ptl))
 		return;
 
+	/* avoid taking the LRU lock under the PTL when possible */
+	walk = current->reclaim_state ? current->reclaim_state->mm_walk : NULL;
+
 	start = max(pvmw->address & PMD_MASK, pvmw->vma->vm_start);
 	end = min(pvmw->address | ~PMD_MASK, pvmw->vma->vm_end - 1) + 1;
 
@@ -3567,13 +4507,15 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw)
 		if (!pte_young(pte[i]))
 			continue;
 
-		folio = get_pfn_folio(pfn, memcg, pgdat);
+		folio = get_pfn_folio(pfn, memcg, pgdat, !walk || walk->can_swap);
 		if (!folio)
 			continue;
 
 		if (!ptep_test_and_clear_young(pvmw->vma, addr, pte + i))
 			VM_WARN_ON_ONCE(true);
 
+		young++;
+
 		if (pte_dirty(pte[i]) && !folio_test_dirty(folio) &&
 		    !(folio_test_anon(folio) && folio_test_swapbacked(folio) &&
 		      !folio_test_swapcache(folio)))
@@ -3589,7 +4531,11 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw)
 	arch_leave_lazy_mmu_mode();
 	rcu_read_unlock();
 
-	if (bitmap_weight(bitmap, MIN_LRU_BATCH) < PAGEVEC_SIZE) {
+	/* feedback from rmap walkers to page table walkers */
+	if (suitable_to_scan(i, young))
+		update_bloom_filter(lruvec, max_seq, pvmw->pmd);
+
+	if (!walk && bitmap_weight(bitmap, MIN_LRU_BATCH) < PAGEVEC_SIZE) {
 		for_each_set_bit(i, bitmap, MIN_LRU_BATCH) {
 			folio = pfn_folio(pte_pfn(pte[i]));
 			folio_activate(folio);
@@ -3601,8 +4547,10 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw)
 	if (!mem_cgroup_trylock_pages(memcg))
 		return;
 
-	spin_lock_irq(&lruvec->lru_lock);
-	new_gen = lru_gen_from_seq(lruvec->lrugen.max_seq);
+	if (!walk) {
+		spin_lock_irq(&lruvec->lru_lock);
+		new_gen = lru_gen_from_seq(lruvec->lrugen.max_seq);
+	}
 
 	for_each_set_bit(i, bitmap, MIN_LRU_BATCH) {
 		folio = pfn_folio(pte_pfn(pte[i]));
@@ -3613,10 +4561,14 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw)
 		if (old_gen < 0 || old_gen == new_gen)
 			continue;
 
-		lru_gen_update_size(lruvec, folio, old_gen, new_gen);
+		if (walk)
+			update_batch_size(walk, folio, old_gen, new_gen);
+		else
+			lru_gen_update_size(lruvec, folio, old_gen, new_gen);
 	}
 
-	spin_unlock_irq(&lruvec->lru_lock);
+	if (!walk)
+		spin_unlock_irq(&lruvec->lru_lock);
 
 	mem_cgroup_unlock_pages();
 }
@@ -3899,6 +4851,7 @@ static int evict_folios(struct lruvec *lruvec, struct scan_control *sc, int swap
 	struct folio *folio;
 	enum vm_event_item item;
 	struct reclaim_stat stat;
+	struct lru_gen_mm_walk *walk;
 	struct mem_cgroup *memcg = lruvec_memcg(lruvec);
 	struct pglist_data *pgdat = lruvec_pgdat(lruvec);
 
@@ -3935,6 +4888,10 @@ static int evict_folios(struct lruvec *lruvec, struct scan_control *sc, int swap
 
 	move_pages_to_lru(lruvec, &list);
 
+	walk = current->reclaim_state->mm_walk;
+	if (walk && walk->batched)
+		reset_batch_size(lruvec, walk);
+
 	item = current_is_kswapd() ? PGSTEAL_KSWAPD : PGSTEAL_DIRECT;
 	if (!cgroup_reclaim(sc))
 		__count_vm_events(item, reclaimed);
@@ -3951,6 +4908,11 @@ static int evict_folios(struct lruvec *lruvec, struct scan_control *sc, int swap
 	return scanned;
 }
 
+/*
+ * For future optimizations:
+ * 1. Defer try_to_inc_max_seq() to workqueues to reduce latency for memcg
+ *    reclaim.
+ */
 static unsigned long get_nr_to_scan(struct lruvec *lruvec, struct scan_control *sc,
 				    bool can_swap)
 {
@@ -3976,7 +4938,8 @@ static unsigned long get_nr_to_scan(struct lruvec *lruvec, struct scan_control *
 	if (current_is_kswapd())
 		return 0;
 
-	inc_max_seq(lruvec, max_seq, can_swap);
+	if (try_to_inc_max_seq(lruvec, max_seq, sc, can_swap))
+		return nr_to_scan;
 done:
 	return min_seq[!can_swap] + MIN_NR_GENS <= max_seq ? nr_to_scan : 0;
 }
@@ -3990,6 +4953,8 @@ static void lru_gen_shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc
 
 	blk_start_plug(&plug);
 
+	set_mm_walk(lruvec_pgdat(lruvec));
+
 	while (true) {
 		int delta;
 		int swappiness;
@@ -4017,6 +4982,8 @@ static void lru_gen_shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc
 		cond_resched();
 	}
 
+	clear_mm_walk();
+
 	blk_finish_plug(&plug);
 }
 
@@ -4033,15 +5000,21 @@ void lru_gen_init_lruvec(struct lruvec *lruvec)
 
 	for_each_gen_type_zone(gen, type, zone)
 		INIT_LIST_HEAD(&lrugen->lists[gen][type][zone]);
+
+	lruvec->mm_state.seq = MIN_NR_GENS;
+	init_waitqueue_head(&lruvec->mm_state.wait);
 }
 
 #ifdef CONFIG_MEMCG
 void lru_gen_init_memcg(struct mem_cgroup *memcg)
 {
+	INIT_LIST_HEAD(&memcg->mm_list.fifo);
+	spin_lock_init(&memcg->mm_list.lock);
 }
 
 void lru_gen_exit_memcg(struct mem_cgroup *memcg)
 {
+	int i;
 	int nid;
 
 	for_each_node(nid) {
@@ -4049,6 +5022,11 @@ void lru_gen_exit_memcg(struct mem_cgroup *memcg)
 
 		VM_WARN_ON_ONCE(memchr_inv(lruvec->lrugen.nr_pages, 0,
 					   sizeof(lruvec->lrugen.nr_pages)));
+
+		for (i = 0; i < NR_BLOOM_FILTERS; i++) {
+			bitmap_free(lruvec->mm_state.filters[i]);
+			lruvec->mm_state.filters[i] = NULL;
+		}
 	}
 }
 #endif
