diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index dde341a6388a..33a2fda7462e 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -785,7 +785,8 @@ static int fuse_check_page(struct page *page)
 	       1 << PG_active |
 	       1 << PG_workingset |
 	       1 << PG_reclaim |
-	       1 << PG_waiters))) {
+	       1 << PG_waiters |
+	       LRU_GEN_MASK | LRU_REFS_MASK))) {
 		dump_page(page, "fuse: trying to steal weird page");
 		return 1;
 	}
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 75c151413fda..b145025f3eac 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -432,6 +432,18 @@ static inline void cgroup_put(struct cgroup *cgrp)
 	css_put(&cgrp->self);
 }
 
+extern struct mutex cgroup_mutex;
+
+static inline void cgroup_lock(void)
+{
+	mutex_lock(&cgroup_mutex);
+}
+
+static inline void cgroup_unlock(void)
+{
+	mutex_unlock(&cgroup_mutex);
+}
+
 /**
  * task_css_set_check - obtain a task's css_set with extra access conditions
  * @task: the task to obtain css_set for
@@ -446,7 +458,6 @@ static inline void cgroup_put(struct cgroup *cgrp)
  * as locks used during the cgroup_subsys::attach() methods.
  */
 #ifdef CONFIG_PROVE_RCU
-extern struct mutex cgroup_mutex;
 extern spinlock_t css_set_lock;
 #define task_css_set_check(task, __c)					\
 	rcu_dereference_check((task)->cgroups,				\
@@ -707,6 +718,8 @@ struct cgroup;
 static inline u64 cgroup_id(const struct cgroup *cgrp) { return 1; }
 static inline void css_get(struct cgroup_subsys_state *css) {}
 static inline void css_put(struct cgroup_subsys_state *css) {}
+static inline void cgroup_lock(void) {}
+static inline void cgroup_unlock(void) {}
 static inline int cgroup_attach_task_all(struct task_struct *from,
 					 struct task_struct *t) { return 0; }
 static inline int cgroupstats_build(struct cgroupstats *stats,
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 73a52aba448f..9d3bcc30dfda 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1093,6 +1093,8 @@ vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf);
 #define ZONES_PGOFF		(NODES_PGOFF - ZONES_WIDTH)
 #define LAST_CPUPID_PGOFF	(ZONES_PGOFF - LAST_CPUPID_WIDTH)
 #define KASAN_TAG_PGOFF		(LAST_CPUPID_PGOFF - KASAN_TAG_WIDTH)
+#define LRU_GEN_PGOFF		(KASAN_TAG_PGOFF - LRU_GEN_WIDTH)
+#define LRU_REFS_PGOFF		(LRU_GEN_PGOFF - LRU_REFS_WIDTH)
 
 /*
  * Define the bit shifts to access each section.  For non-existent
@@ -1800,6 +1802,40 @@ static inline void unmap_mapping_range(struct address_space *mapping,
 		loff_t const holebegin, loff_t const holelen, int even_cows) { }
 #endif
 
+#ifdef CONFIG_LRU_GEN
+static inline void task_enter_nonseq_fault(void)
+{
+	WARN_ON(current->in_nonseq_fault);
+
+	current->in_nonseq_fault = 1;
+}
+
+static inline void task_exit_nonseq_fault(void)
+{
+	WARN_ON(!current->in_nonseq_fault);
+
+	current->in_nonseq_fault = 0;
+}
+
+static inline bool task_in_nonseq_fault(void)
+{
+	return current->in_nonseq_fault;
+}
+#else
+static inline void task_enter_nonseq_fault(void)
+{
+}
+
+static inline void task_exit_nonseq_fault(void)
+{
+}
+
+static inline bool task_in_nonseq_fault(void)
+{
+	return false;
+}
+#endif /* CONFIG_LRU_GEN */
+
 static inline void unmap_shared_mapping_range(struct address_space *mapping,
 		loff_t const holebegin, loff_t const holelen)
 {
diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index 355ea1ee32bd..b2583f0f8813 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -79,11 +79,187 @@ static __always_inline enum lru_list page_lru(struct page *page)
 	return lru;
 }
 
+#ifdef CONFIG_LRU_GEN
+
+static inline bool lru_gen_enabled(void)
+{
+#ifdef CONFIG_LRU_GEN_ENABLED
+	DECLARE_STATIC_KEY_TRUE(lru_gen_static_key);
+
+	return static_branch_likely(&lru_gen_static_key);
+#else
+	DECLARE_STATIC_KEY_FALSE(lru_gen_static_key);
+
+	return static_branch_unlikely(&lru_gen_static_key);
+#endif
+}
+
+/* Return an index within the sliding window that tracks MAX_NR_GENS generations. */
+static inline int lru_gen_from_seq(unsigned long seq)
+{
+	return seq % MAX_NR_GENS;
+}
+
+/* The youngest and the second youngest generations are counted as active. */
+static inline bool lru_gen_is_active(struct lruvec *lruvec, int gen)
+{
+	unsigned long max_seq = lruvec->evictable.max_seq;
+
+	VM_BUG_ON(gen >= MAX_NR_GENS);
+
+	return gen == lru_gen_from_seq(max_seq) || gen == lru_gen_from_seq(max_seq - 1);
+}
+
+/* Update the sizes of the multigenerational lru lists. */
+static inline void lru_gen_update_size(struct page *page, struct lruvec *lruvec,
+				       int old_gen, int new_gen)
+{
+	int type = page_is_file_lru(page);
+	int zone = page_zonenum(page);
+	int delta = thp_nr_pages(page);
+	enum lru_list lru = type * LRU_FILE;
+	struct lrugen *lrugen = &lruvec->evictable;
+
+	lockdep_assert_held(&lruvec->lru_lock);
+	VM_BUG_ON(old_gen != -1 && old_gen >= MAX_NR_GENS);
+	VM_BUG_ON(new_gen != -1 && new_gen >= MAX_NR_GENS);
+	VM_BUG_ON(old_gen == -1 && new_gen == -1);
+
+	if (old_gen >= 0)
+		WRITE_ONCE(lrugen->sizes[old_gen][type][zone],
+			   lrugen->sizes[old_gen][type][zone] - delta);
+	if (new_gen >= 0)
+		WRITE_ONCE(lrugen->sizes[new_gen][type][zone],
+			   lrugen->sizes[new_gen][type][zone] + delta);
+
+	if (old_gen < 0) {
+		if (lru_gen_is_active(lruvec, new_gen))
+			lru += LRU_ACTIVE;
+		update_lru_size(lruvec, lru, zone, delta);
+		return;
+	}
+
+	if (new_gen < 0) {
+		if (lru_gen_is_active(lruvec, old_gen))
+			lru += LRU_ACTIVE;
+		update_lru_size(lruvec, lru, zone, -delta);
+		return;
+	}
+
+	if (!lru_gen_is_active(lruvec, old_gen) && lru_gen_is_active(lruvec, new_gen)) {
+		update_lru_size(lruvec, lru, zone, -delta);
+		update_lru_size(lruvec, lru + LRU_ACTIVE, zone, delta);
+	}
+
+	VM_BUG_ON(lru_gen_is_active(lruvec, old_gen) && !lru_gen_is_active(lruvec, new_gen));
+}
+
+/* Add a page to one of the multigenerational lru lists. Return true on success. */
+static inline bool lru_gen_add_page(struct page *page, struct lruvec *lruvec, bool reclaiming)
+{
+	int gen;
+	unsigned long old_flags, new_flags;
+	int type = page_is_file_lru(page);
+	int zone = page_zonenum(page);
+	struct lrugen *lrugen = &lruvec->evictable;
+
+	if (PageUnevictable(page) || !lrugen->enabled[type])
+		return false;
+	/*
+	 * If a page shouldn't be considered for eviction, i.e., a page mapped
+	 * upon fault during which the accessed bit is set, add it to the
+	 * youngest generation.
+	 *
+	 * If a page can't be evicted immediately, i.e., an anon page not in
+	 * swap cache or a dirty page pending writeback, add it to the second
+	 * oldest generation.
+	 *
+	 * If a page could be evicted immediately, e.g., a clean page, add it to
+	 * the oldest generation.
+	 */
+	if (PageActive(page))
+		gen = lru_gen_from_seq(lrugen->max_seq);
+	else if ((!type && !PageSwapCache(page)) ||
+		 (PageReclaim(page) && (PageDirty(page) || PageWriteback(page))))
+		gen = lru_gen_from_seq(lrugen->min_seq[type] + 1);
+	else
+		gen = lru_gen_from_seq(lrugen->min_seq[type]);
+
+	do {
+		new_flags = old_flags = READ_ONCE(page->flags);
+		VM_BUG_ON_PAGE(new_flags & LRU_GEN_MASK, page);
+
+		new_flags &= ~(LRU_GEN_MASK | BIT(PG_active));
+		new_flags |= (gen + 1UL) << LRU_GEN_PGOFF;
+	} while (cmpxchg(&page->flags, old_flags, new_flags) != old_flags);
+
+	lru_gen_update_size(page, lruvec, -1, gen);
+	/* for rotate_reclaimable_page() */
+	if (reclaiming)
+		list_add_tail(&page->lru, &lrugen->lists[gen][type][zone]);
+	else
+		list_add(&page->lru, &lrugen->lists[gen][type][zone]);
+
+	return true;
+}
+
+/* Delete a page from one of the multigenerational lru lists. Return true on success. */
+static inline bool lru_gen_del_page(struct page *page, struct lruvec *lruvec, bool reclaiming)
+{
+	int gen;
+	unsigned long old_flags, new_flags;
+
+	do {
+		new_flags = old_flags = READ_ONCE(page->flags);
+		if (!(new_flags & LRU_GEN_MASK))
+			return false;
+
+		VM_BUG_ON_PAGE(PageActive(page), page);
+		VM_BUG_ON_PAGE(PageUnevictable(page), page);
+
+		gen = ((new_flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;
+
+		new_flags &= ~LRU_GEN_MASK;
+		/* for shrink_page_list() */
+		if (reclaiming)
+			new_flags &= ~(BIT(PG_referenced) | BIT(PG_reclaim));
+		else if (lru_gen_is_active(lruvec, gen))
+			new_flags |= BIT(PG_active);
+	} while (cmpxchg(&page->flags, old_flags, new_flags) != old_flags);
+
+	lru_gen_update_size(page, lruvec, gen, -1);
+	list_del(&page->lru);
+
+	return true;
+}
+
+#else
+
+static inline bool lru_gen_enabled(void)
+{
+	return false;
+}
+
+static inline bool lru_gen_add_page(struct page *page, struct lruvec *lruvec, bool reclaiming)
+{
+	return false;
+}
+
+static inline bool lru_gen_del_page(struct page *page, struct lruvec *lruvec, bool reclaiming)
+{
+	return false;
+}
+
+#endif /* CONFIG_LRU_GEN */
+
 static __always_inline void add_page_to_lru_list(struct page *page,
 				struct lruvec *lruvec)
 {
 	enum lru_list lru = page_lru(page);
 
+	if (lru_gen_add_page(page, lruvec, false))
+		return;
+
 	update_lru_size(lruvec, lru, page_zonenum(page), thp_nr_pages(page));
 	list_add(&page->lru, &lruvec->lists[lru]);
 }
@@ -93,6 +269,9 @@ static __always_inline void add_page_to_lru_list_tail(struct page *page,
 {
 	enum lru_list lru = page_lru(page);
 
+	if (lru_gen_add_page(page, lruvec, true))
+		return;
+
 	update_lru_size(lruvec, lru, page_zonenum(page), thp_nr_pages(page));
 	list_add_tail(&page->lru, &lruvec->lists[lru]);
 }
@@ -100,6 +279,9 @@ static __always_inline void add_page_to_lru_list_tail(struct page *page,
 static __always_inline void del_page_from_lru_list(struct page *page,
 				struct lruvec *lruvec)
 {
+	if (lru_gen_del_page(page, lruvec, false))
+		return;
+
 	list_del(&page->lru);
 	update_lru_size(lruvec, page_lru(page), page_zonenum(page),
 			-thp_nr_pages(page));
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 6a1d79d84675..66d706472c9e 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -294,6 +294,72 @@ enum lruvec_flags {
 					 */
 };
 
+struct lruvec;
+
+#define LRU_GEN_MASK		((BIT(LRU_GEN_WIDTH) - 1) << LRU_GEN_PGOFF)
+#define LRU_REFS_MASK		((BIT(LRU_REFS_WIDTH) - 1) << LRU_REFS_PGOFF)
+
+#ifdef CONFIG_LRU_GEN
+
+/*
+ * For each lruvec, evictable pages are divided into multiple generations. The
+ * youngest and the oldest generation numbers, AKA max_seq and min_seq, are
+ * monotonically increasing. The sliding window technique is used to track at
+ * least MIN_NR_GENS and at most MAX_NR_GENS generations. An offset within the
+ * window, AKA gen, indexes an array of per-type and per-zone lists for the
+ * corresponding generation. The counter in page->flags stores gen+1 while a
+ * page is on one of the multigenerational lru lists. Otherwise, it stores 0.
+ *
+ * After a page is faulted in, the aging must check the accessed bit at least
+ * twice before the eviction would consider it. The first check clears the
+ * accessed bit set during the initial fault. The second check makes sure this
+ * page hasn't been used since then.
+ */
+#define MIN_NR_GENS		2
+#define MAX_NR_GENS		((unsigned int)CONFIG_NR_LRU_GENS)
+
+struct lrugen {
+	/* the aging increments the max generation number */
+	unsigned long max_seq;
+	/* the eviction increments the min generation numbers */
+	unsigned long min_seq[ANON_AND_FILE];
+	/* the birth time of each generation in jiffies */
+	unsigned long timestamps[MAX_NR_GENS];
+	/* the multigenerational lru lists */
+	struct list_head lists[MAX_NR_GENS][ANON_AND_FILE][MAX_NR_ZONES];
+	/* the sizes of the multigenerational lru lists in pages */
+	unsigned long sizes[MAX_NR_GENS][ANON_AND_FILE][MAX_NR_ZONES];
+	/* whether the multigenerational lru is enabled */
+	bool enabled[ANON_AND_FILE];
+};
+
+#define MAX_BATCH_SIZE		8192
+
+void lru_gen_init_state(struct mem_cgroup *memcg, struct lruvec *lruvec);
+void lru_gen_change_state(bool enable, bool main, bool swap);
+
+#ifdef CONFIG_MEMCG
+void lru_gen_init_memcg(struct mem_cgroup *memcg);
+#endif
+
+#else /* !CONFIG_LRU_GEN */
+
+static inline void lru_gen_init_state(struct mem_cgroup *memcg, struct lruvec *lruvec)
+{
+}
+
+static inline void lru_gen_change_state(bool enable, bool main, bool swap)
+{
+}
+
+#ifdef CONFIG_MEMCG
+static inline void lru_gen_init_memcg(struct mem_cgroup *memcg)
+{
+}
+#endif
+
+#endif /* CONFIG_LRU_GEN */
+
 struct lruvec {
 	struct list_head		lists[NR_LRU_LISTS];
 	/* per lruvec lru_lock for memcg */
@@ -311,6 +377,10 @@ struct lruvec {
 	unsigned long			refaults[ANON_AND_FILE];
 	/* Various lruvec state flags (enum lruvec_flags) */
 	unsigned long			flags;
+#ifdef CONFIG_LRU_GEN
+	/* unevictable pages are on LRU_UNEVICTABLE */
+	struct lrugen			evictable;
+#endif
 #ifdef CONFIG_MEMCG
 	struct pglist_data *pgdat;
 #endif
diff --git a/include/linux/page-flags-layout.h b/include/linux/page-flags-layout.h
index ef1e3e736e14..8cdbbdccb5ad 100644
--- a/include/linux/page-flags-layout.h
+++ b/include/linux/page-flags-layout.h
@@ -26,6 +26,14 @@
 
 #define ZONES_WIDTH		ZONES_SHIFT
 
+#ifdef CONFIG_LRU_GEN
+/* LRU_GEN_WIDTH is generated from order_base_2(CONFIG_NR_LRU_GENS + 1). */
+#define LRU_REFS_WIDTH		(CONFIG_TIERS_PER_GEN - 2)
+#else
+#define LRU_GEN_WIDTH		0
+#define LRU_REFS_WIDTH		0
+#endif /* CONFIG_LRU_GEN */
+
 #ifdef CONFIG_SPARSEMEM
 #include <asm/sparsemem.h>
 #define SECTIONS_SHIFT	(MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
@@ -55,7 +63,8 @@
 #define SECTIONS_WIDTH		0
 #endif
 
-#if ZONES_WIDTH + SECTIONS_WIDTH + NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
+#if ZONES_WIDTH + LRU_GEN_WIDTH + LRU_REFS_WIDTH + SECTIONS_WIDTH + NODES_SHIFT \
+	<= BITS_PER_LONG - NR_PAGEFLAGS
 #define NODES_WIDTH		NODES_SHIFT
 #elif defined(CONFIG_SPARSEMEM_VMEMMAP)
 #error "Vmemmap: No space for nodes field in page flags"
@@ -89,8 +98,8 @@
 #define LAST_CPUPID_SHIFT 0
 #endif
 
-#if ZONES_WIDTH + SECTIONS_WIDTH + NODES_WIDTH + KASAN_TAG_WIDTH + LAST_CPUPID_SHIFT \
-	<= BITS_PER_LONG - NR_PAGEFLAGS
+#if ZONES_WIDTH + LRU_GEN_WIDTH + LRU_REFS_WIDTH + SECTIONS_WIDTH + NODES_WIDTH + \
+	KASAN_TAG_WIDTH + LAST_CPUPID_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
 #define LAST_CPUPID_WIDTH LAST_CPUPID_SHIFT
 #else
 #define LAST_CPUPID_WIDTH 0
@@ -100,8 +109,8 @@
 #define LAST_CPUPID_NOT_IN_PAGE_FLAGS
 #endif
 
-#if ZONES_WIDTH + SECTIONS_WIDTH + NODES_WIDTH + KASAN_TAG_WIDTH + LAST_CPUPID_WIDTH \
-	> BITS_PER_LONG - NR_PAGEFLAGS
+#if ZONES_WIDTH + LRU_GEN_WIDTH + LRU_REFS_WIDTH + SECTIONS_WIDTH + NODES_WIDTH + \
+	KASAN_TAG_WIDTH + LAST_CPUPID_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
 #error "Not enough bits in page flags"
 #endif
 
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index fbfd3fad48f2..a7d7ff4c621d 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -845,7 +845,7 @@ static inline void ClearPageSlabPfmemalloc(struct page *page)
 	 1UL << PG_private	| 1UL << PG_private_2	|	\
 	 1UL << PG_writeback	| 1UL << PG_reserved	|	\
 	 1UL << PG_slab		| 1UL << PG_active 	|	\
-	 1UL << PG_unevictable	| __PG_MLOCKED)
+	 1UL << PG_unevictable	| __PG_MLOCKED | LRU_GEN_MASK)
 
 /*
  * Flags checked when a page is prepped for return by the page allocator.
@@ -856,7 +856,7 @@ static inline void ClearPageSlabPfmemalloc(struct page *page)
  * alloc-free cycle to prevent from reusing the page.
  */
 #define PAGE_FLAGS_CHECK_AT_PREP	\
-	(PAGEFLAGS_MASK & ~__PG_HWPOISON)
+	((PAGEFLAGS_MASK & ~__PG_HWPOISON) | LRU_GEN_MASK | LRU_REFS_MASK)
 
 #define PAGE_FLAGS_PRIVATE				\
 	(1UL << PG_private | 1UL << PG_private_2)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index c1a927ddec64..556b3d66c70d 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -911,6 +911,9 @@ struct task_struct {
 #ifdef CONFIG_MEMCG
 	unsigned			in_user_fault:1;
 #endif
+#ifdef CONFIG_LRU_GEN
+	unsigned			in_nonseq_fault:1;
+#endif
 #ifdef CONFIG_COMPAT_BRK
 	unsigned			brk_randomized:1;
 #endif
diff --git a/kernel/bounds.c b/kernel/bounds.c
index 9795d75b09b2..aba13aa7336c 100644
--- a/kernel/bounds.c
+++ b/kernel/bounds.c
@@ -22,6 +22,9 @@ int main(void)
 	DEFINE(NR_CPUS_BITS, ilog2(CONFIG_NR_CPUS));
 #endif
 	DEFINE(SPINLOCK_SIZE, sizeof(spinlock_t));
+#ifdef CONFIG_LRU_GEN
+	DEFINE(LRU_GEN_WIDTH, order_base_2(CONFIG_NR_LRU_GENS + 1));
+#endif
 	/* End of constants */
 
 	return 0;
diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h
index bfbeabc17a9d..bec59189e206 100644
--- a/kernel/cgroup/cgroup-internal.h
+++ b/kernel/cgroup/cgroup-internal.h
@@ -146,7 +146,6 @@ struct cgroup_mgctx {
 #define DEFINE_CGROUP_MGCTX(name)						\
 	struct cgroup_mgctx name = CGROUP_MGCTX_INIT(name)
 
-extern struct mutex cgroup_mutex;
 extern spinlock_t css_set_lock;
 extern struct cgroup_subsys *cgroup_subsys[];
 extern struct list_head cgroup_roots;
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index c5142d237e48..875ed5559d95 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2364,7 +2364,8 @@ static void __split_huge_page_tail(struct page *head, int tail,
 #ifdef CONFIG_64BIT
 			 (1L << PG_arch_2) |
 #endif
-			 (1L << PG_dirty)));
+			 (1L << PG_dirty) |
+			 LRU_GEN_MASK | LRU_REFS_MASK));
 
 	/* ->mapping in first tail page is compound_mapcount */
 	VM_BUG_ON_PAGE(tail > 2 && page_tail->mapping != TAIL_MAPPING,
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6da5020a8656..d72bfc960fc3 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5173,6 +5173,7 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
 	memcg->deferred_split_queue.split_queue_len = 0;
 #endif
 	idr_replace(&mem_cgroup_idr, memcg, memcg->id.id);
+	lru_gen_init_memcg(memcg);
 	return memcg;
 fail:
 	mem_cgroup_id_remove(memcg);
diff --git a/mm/memory.c b/mm/memory.c
index 012fad94bc77..6b2b665c0866 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4762,6 +4762,7 @@ vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
 			   unsigned int flags, struct pt_regs *regs)
 {
 	vm_fault_t ret;
+	bool nonseq_fault = !(vma->vm_flags & VM_SEQ_READ);
 
 	__set_current_state(TASK_RUNNING);
 
@@ -4783,11 +4784,17 @@ vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
 	if (flags & FAULT_FLAG_USER)
 		mem_cgroup_enter_user_fault();
 
+	if (nonseq_fault)
+		task_enter_nonseq_fault();
+
 	if (unlikely(is_vm_hugetlb_page(vma)))
 		ret = hugetlb_fault(vma->vm_mm, vma, address, flags);
 	else
 		ret = __handle_mm_fault(vma, address, flags);
 
+	if (nonseq_fault)
+		task_exit_nonseq_fault();
+
 	if (flags & FAULT_FLAG_USER) {
 		mem_cgroup_exit_user_fault();
 		/*
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 9ddaf0e1b0ab..0d7b2bd2454a 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -65,14 +65,16 @@ void __init mminit_verify_pageflags_layout(void)
 
 	shift = 8 * sizeof(unsigned long);
 	width = shift - SECTIONS_WIDTH - NODES_WIDTH - ZONES_WIDTH
-		- LAST_CPUPID_SHIFT - KASAN_TAG_WIDTH;
+		- LAST_CPUPID_SHIFT - KASAN_TAG_WIDTH - LRU_GEN_WIDTH - LRU_REFS_WIDTH;
 	mminit_dprintk(MMINIT_TRACE, "pageflags_layout_widths",
-		"Section %d Node %d Zone %d Lastcpupid %d Kasantag %d Flags %d\n",
+		"Section %d Node %d Zone %d Lastcpupid %d Kasantag %d Gen %d Tier %d Flags %d\n",
 		SECTIONS_WIDTH,
 		NODES_WIDTH,
 		ZONES_WIDTH,
 		LAST_CPUPID_WIDTH,
 		KASAN_TAG_WIDTH,
+		LRU_GEN_WIDTH,
+		LRU_REFS_WIDTH,
 		NR_PAGEFLAGS);
 	mminit_dprintk(MMINIT_TRACE, "pageflags_layout_shifts",
 		"Section %d Node %d Zone %d Lastcpupid %d Kasantag %d\n",
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 23d3339ac4e8..5bee46999f60 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7405,6 +7405,7 @@ static void __meminit pgdat_init_internals(struct pglist_data *pgdat)
 
 	pgdat_page_ext_init(pgdat);
 	lruvec_init(&pgdat->__lruvec);
+	lru_gen_init_state(NULL, &pgdat->__lruvec);
 }
 
 static void __meminit zone_init_internals(struct zone *zone, enum zone_type idx, int nid,
diff --git a/mm/swap.c b/mm/swap.c
index af3cad4e5378..4bd55b429693 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -446,6 +446,11 @@ void lru_cache_add(struct page *page)
 	VM_BUG_ON_PAGE(PageActive(page) && PageUnevictable(page), page);
 	VM_BUG_ON_PAGE(PageLRU(page), page);
 
+	/* see the comment in lru_gen_add_page() */
+	if (lru_gen_enabled() && !PageUnevictable(page) &&
+	    task_in_nonseq_fault() && !(current->flags & PF_MEMALLOC))
+		SetPageActive(page);
+
 	get_page(page);
 	local_lock(&lru_pvecs.lock);
 	pvec = this_cpu_ptr(&lru_pvecs.lru_add);
@@ -547,7 +552,7 @@ static void lru_deactivate_file_fn(struct page *page, struct lruvec *lruvec)
 
 static void lru_deactivate_fn(struct page *page, struct lruvec *lruvec)
 {
-	if (PageActive(page) && !PageUnevictable(page)) {
+	if (!PageUnevictable(page) && (PageActive(page) || lru_gen_enabled())) {
 		int nr_pages = thp_nr_pages(page);
 
 		del_page_from_lru_list(page, lruvec);
@@ -661,7 +666,7 @@ void deactivate_file_page(struct page *page)
  */
 void deactivate_page(struct page *page)
 {
-	if (PageLRU(page) && PageActive(page) && !PageUnevictable(page)) {
+	if (PageLRU(page) && !PageUnevictable(page) && (PageActive(page) || lru_gen_enabled())) {
 		struct pagevec *pvec;
 
 		local_lock(&lru_pvecs.lock);
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 22d10f713848..2ac9ac0b5ec3 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2688,6 +2688,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 	err = 0;
 	atomic_inc(&proc_poll_event);
 	wake_up_interruptible(&proc_poll_wait);
+	lru_gen_change_state(false, false, true);
 
 out_dput:
 	filp_close(victim, NULL);
@@ -3349,6 +3350,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 	mutex_unlock(&swapon_mutex);
 	atomic_inc(&proc_poll_event);
 	wake_up_interruptible(&proc_poll_wait);
+	lru_gen_change_state(true, false, true);
 
 	error = 0;
 	goto out;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 802b6c7ce5b5..cfda593af4f4 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -50,6 +50,7 @@
 #include <linux/printk.h>
 #include <linux/dax.h>
 #include <linux/psi.h>
+#include <linux/memory.h>
 
 #include <asm/tlbflush.h>
 #include <asm/div64.h>
@@ -2880,6 +2881,267 @@ static bool can_age_anon_pages(struct pglist_data *pgdat,
 	return can_demote(pgdat->node_id, sc);
 }
 
+#ifdef CONFIG_LRU_GEN
+
+/******************************************************************************
+ *                          shorthand helpers
+ ******************************************************************************/
+
+#define for_each_gen_type_zone(gen, type, zone)				\
+	for ((gen) = 0; (gen) < MAX_NR_GENS; (gen)++)			\
+		for ((type) = 0; (type) < ANON_AND_FILE; (type)++)	\
+			for ((zone) = 0; (zone) < MAX_NR_ZONES; (zone)++)
+
+static int page_lru_gen(struct page *page)
+{
+	unsigned long flags = READ_ONCE(page->flags);
+
+	return ((flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;
+}
+
+static struct lruvec *get_lruvec(int nid, struct mem_cgroup *memcg)
+{
+	struct pglist_data *pgdat = NODE_DATA(nid);
+
+#ifdef CONFIG_MEMCG
+	if (memcg)
+		return &memcg->nodeinfo[nid]->lruvec;
+#endif
+	return pgdat ? &pgdat->__lruvec : NULL;
+}
+
+static int get_nr_gens(struct lruvec *lruvec, int type)
+{
+	return lruvec->evictable.max_seq - lruvec->evictable.min_seq[type] + 1;
+}
+
+static bool __maybe_unused seq_is_valid(struct lruvec *lruvec)
+{
+	return get_nr_gens(lruvec, 1) >= MIN_NR_GENS &&
+	       get_nr_gens(lruvec, 1) <= get_nr_gens(lruvec, 0) &&
+	       get_nr_gens(lruvec, 0) <= MAX_NR_GENS;
+}
+
+/******************************************************************************
+ *                          state change
+ ******************************************************************************/
+
+#ifdef CONFIG_LRU_GEN_ENABLED
+DEFINE_STATIC_KEY_TRUE(lru_gen_static_key);
+#else
+DEFINE_STATIC_KEY_FALSE(lru_gen_static_key);
+#endif
+
+static int lru_gen_nr_swapfiles;
+
+static bool __maybe_unused state_is_valid(struct lruvec *lruvec)
+{
+	int gen, type, zone;
+	enum lru_list lru;
+	struct lrugen *lrugen = &lruvec->evictable;
+
+	for_each_evictable_lru(lru) {
+		type = is_file_lru(lru);
+
+		if (lrugen->enabled[type] && !list_empty(&lruvec->lists[lru]))
+			return false;
+	}
+
+	for_each_gen_type_zone(gen, type, zone) {
+		if (!lrugen->enabled[type] && !list_empty(&lrugen->lists[gen][type][zone]))
+			return false;
+
+		/* unlikely but not a bug when reset_batch_size() is pending */
+		VM_WARN_ON(!lrugen->enabled[type] && lrugen->sizes[gen][type][zone]);
+	}
+
+	return true;
+}
+
+static bool fill_lists(struct lruvec *lruvec)
+{
+	enum lru_list lru;
+	int remaining = MAX_BATCH_SIZE;
+
+	for_each_evictable_lru(lru) {
+		int type = is_file_lru(lru);
+		bool active = is_active_lru(lru);
+		struct list_head *head = &lruvec->lists[lru];
+
+		if (!lruvec->evictable.enabled[type])
+			continue;
+
+		while (!list_empty(head)) {
+			bool success;
+			struct page *page = lru_to_page(head);
+
+			VM_BUG_ON_PAGE(PageTail(page), page);
+			VM_BUG_ON_PAGE(PageUnevictable(page), page);
+			VM_BUG_ON_PAGE(PageActive(page) != active, page);
+			VM_BUG_ON_PAGE(page_is_file_lru(page) != type, page);
+			VM_BUG_ON_PAGE(page_lru_gen(page) < MAX_NR_GENS, page);
+
+			prefetchw_prev_lru_page(page, head, flags);
+
+			del_page_from_lru_list(page, lruvec);
+			success = lru_gen_add_page(page, lruvec, false);
+			VM_BUG_ON(!success);
+
+			if (!--remaining)
+				return false;
+		}
+	}
+
+	return true;
+}
+
+static bool drain_lists(struct lruvec *lruvec)
+{
+	int gen, type, zone;
+	int remaining = MAX_BATCH_SIZE;
+
+	for_each_gen_type_zone(gen, type, zone) {
+		struct list_head *head = &lruvec->evictable.lists[gen][type][zone];
+
+		if (lruvec->evictable.enabled[type])
+			continue;
+
+		while (!list_empty(head)) {
+			bool success;
+			struct page *page = lru_to_page(head);
+
+			VM_BUG_ON_PAGE(PageTail(page), page);
+			VM_BUG_ON_PAGE(PageUnevictable(page), page);
+			VM_BUG_ON_PAGE(PageActive(page), page);
+			VM_BUG_ON_PAGE(page_is_file_lru(page) != type, page);
+			VM_BUG_ON_PAGE(page_zonenum(page) != zone, page);
+
+			prefetchw_prev_lru_page(page, head, flags);
+
+			success = lru_gen_del_page(page, lruvec, false);
+			VM_BUG_ON(!success);
+			add_page_to_lru_list(page, lruvec);
+
+			if (!--remaining)
+				return false;
+		}
+	}
+
+	return true;
+}
+
+/*
+ * For file page tracking, we enable/disable it according to the main switch.
+ * For anon page tracking, we only enabled it when the main switch is on and
+ * there is at least one swapfile; we disable it when there are no swapfiles
+ * regardless of the value of the main switch. Otherwise, we will eventually
+ * reach the max size of the sliding window and have to call inc_min_seq().
+ */
+void lru_gen_change_state(bool enable, bool main, bool swap)
+{
+	static DEFINE_MUTEX(state_mutex);
+
+	struct mem_cgroup *memcg;
+
+	mem_hotplug_begin();
+	cgroup_lock();
+	mutex_lock(&state_mutex);
+
+	if (swap) {
+		if (enable)
+			swap = !lru_gen_nr_swapfiles++;
+		else
+			swap = !--lru_gen_nr_swapfiles;
+	}
+
+	if (main && enable != lru_gen_enabled()) {
+		if (enable)
+			static_branch_enable(&lru_gen_static_key);
+		else
+			static_branch_disable(&lru_gen_static_key);
+	} else if (!swap || !lru_gen_enabled())
+		goto unlock;
+
+	memcg = mem_cgroup_iter(NULL, NULL, NULL);
+	do {
+		int nid;
+
+		for_each_node(nid) {
+			struct lruvec *lruvec = get_lruvec(nid, memcg);
+
+			if (!lruvec)
+				continue;
+
+			spin_lock_irq(&lruvec->lru_lock);
+
+			VM_BUG_ON(!seq_is_valid(lruvec));
+			VM_BUG_ON(!state_is_valid(lruvec));
+
+			lruvec->evictable.enabled[0] = lru_gen_enabled() && lru_gen_nr_swapfiles;
+			lruvec->evictable.enabled[1] = lru_gen_enabled();
+
+			while (!(enable ? fill_lists(lruvec) : drain_lists(lruvec))) {
+				spin_unlock_irq(&lruvec->lru_lock);
+				cond_resched();
+				spin_lock_irq(&lruvec->lru_lock);
+			}
+
+			spin_unlock_irq(&lruvec->lru_lock);
+		}
+
+		cond_resched();
+	} while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)));
+unlock:
+	mutex_unlock(&state_mutex);
+	cgroup_unlock();
+	mem_hotplug_done();
+}
+
+/******************************************************************************
+ *                          initialization
+ ******************************************************************************/
+
+void lru_gen_init_state(struct mem_cgroup *memcg, struct lruvec *lruvec)
+{
+	int i;
+	int gen, type, zone;
+	struct lrugen *lrugen = &lruvec->evictable;
+
+	lrugen->max_seq = MIN_NR_GENS + 1;
+	lrugen->enabled[0] = lru_gen_enabled() && lru_gen_nr_swapfiles;
+	lrugen->enabled[1] = lru_gen_enabled();
+
+	for (i = 0; i <= MIN_NR_GENS + 1; i++)
+		lrugen->timestamps[i] = jiffies;
+
+	for_each_gen_type_zone(gen, type, zone)
+		INIT_LIST_HEAD(&lrugen->lists[gen][type][zone]);
+}
+
+#ifdef CONFIG_MEMCG
+void lru_gen_init_memcg(struct mem_cgroup *memcg)
+{
+	int nid;
+
+	for_each_node(nid) {
+		struct lruvec *lruvec = get_lruvec(nid, memcg);
+
+		lru_gen_init_state(memcg, lruvec);
+	}
+}
+#endif
+
+static int __init init_lru_gen(void)
+{
+	BUILD_BUG_ON(MIN_NR_GENS + 1 >= MAX_NR_GENS);
+	BUILD_BUG_ON(BIT(LRU_GEN_WIDTH) <= MAX_NR_GENS);
+
+	return 0;
+};
+late_initcall(init_lru_gen);
+
+#endif /* CONFIG_LRU_GEN */
+
 static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
 {
 	unsigned long nr[NR_LRU_LISTS];
