diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 0e537e580dc1..5d36015071d2 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -777,7 +777,8 @@ 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/mm.h b/include/linux/mm.h
index cf3d0d673f6b..ed5393e5930d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1060,6 +1060,8 @@ 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
diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index fb8aadb81cd6..2ff703900fd0 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -40,6 +40,9 @@ static __always_inline void __update_lru_size(struct lruvec *lruvec,
 {
 	struct pglist_data *pgdat = lruvec_pgdat(lruvec);
 
+	lockdep_assert_held(&lruvec->lru_lock);
+	WARN_ON_ONCE(nr_pages != (int)nr_pages);
+
 	__mod_lruvec_state(lruvec, NR_LRU_BASE + lru, nr_pages);
 	__mod_zone_page_state(&pgdat->node_zones[zid],
 				NR_ZONE_LRU_BASE + lru, nr_pages);
@@ -101,11 +104,177 @@ static __always_inline enum lru_list folio_lru_list(struct folio *folio)
 	return lru;
 }
 
+#ifdef CONFIG_LRU_GEN
+
+static inline bool lru_gen_enabled(void)
+{
+	return true;
+}
+
+static inline bool lru_gen_in_fault(void)
+{
+	return current->in_lru_fault;
+}
+
+static inline int lru_gen_from_seq(unsigned long seq)
+{
+	return seq % MAX_NR_GENS;
+}
+
+static inline int folio_lru_gen(struct folio *folio)
+{
+	unsigned long flags = READ_ONCE(folio->flags);
+
+	return ((flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;
+}
+
+static inline bool lru_gen_is_active(struct lruvec *lruvec, int gen)
+{
+	unsigned long max_seq = lruvec->lrugen.max_seq;
+
+	VM_WARN_ON_ONCE(gen >= MAX_NR_GENS);
+
+	/* see the comment on MIN_NR_GENS */
+	return gen == lru_gen_from_seq(max_seq) || gen == lru_gen_from_seq(max_seq - 1);
+}
+
+static inline void lru_gen_update_size(struct lruvec *lruvec, 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);
+	enum lru_list lru = type * LRU_INACTIVE_FILE;
+	struct lru_gen_struct *lrugen = &lruvec->lrugen;
+
+	VM_WARN_ON_ONCE(old_gen != -1 && old_gen >= MAX_NR_GENS);
+	VM_WARN_ON_ONCE(new_gen != -1 && new_gen >= MAX_NR_GENS);
+	VM_WARN_ON_ONCE(old_gen == -1 && new_gen == -1);
+
+	if (old_gen >= 0)
+		WRITE_ONCE(lrugen->nr_pages[old_gen][type][zone],
+			   lrugen->nr_pages[old_gen][type][zone] - delta);
+	if (new_gen >= 0)
+		WRITE_ONCE(lrugen->nr_pages[new_gen][type][zone],
+			   lrugen->nr_pages[new_gen][type][zone] + delta);
+
+	/* addition */
+	if (old_gen < 0) {
+		if (lru_gen_is_active(lruvec, new_gen))
+			lru += LRU_ACTIVE;
+		__update_lru_size(lruvec, lru, zone, delta);
+		return;
+	}
+
+	/* deletion */
+	if (new_gen < 0) {
+		if (lru_gen_is_active(lruvec, old_gen))
+			lru += LRU_ACTIVE;
+		__update_lru_size(lruvec, lru, zone, -delta);
+		return;
+	}
+}
+
+static inline bool lru_gen_add_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
+{
+	unsigned long seq;
+	unsigned long flags;
+	int gen = folio_lru_gen(folio);
+	int type = folio_is_file_lru(folio);
+	int zone = folio_zonenum(folio);
+	struct lru_gen_struct *lrugen = &lruvec->lrugen;
+
+	VM_WARN_ON_ONCE_FOLIO(gen != -1, folio);
+
+	if (folio_test_unevictable(folio))
+		return false;
+	/*
+	 * There are three common cases for this page:
+	 * 1. If it's hot, e.g., freshly faulted in or previously hot and
+	 *    migrated, add it to the youngest generation.
+	 * 2. If it's cold but can't be evicted immediately, i.e., an anon page
+	 *    not in swapcache or a dirty page pending writeback, add it to the
+	 *    second oldest generation.
+	 * 3. Everything else (clean, cold) is added to the oldest generation.
+	 */
+	if (folio_test_active(folio))
+		seq = lrugen->max_seq;
+	else if ((type == LRU_GEN_ANON && !folio_test_swapcache(folio)) ||
+		 (folio_test_reclaim(folio) &&
+		  (folio_test_dirty(folio) || folio_test_writeback(folio))))
+		seq = lrugen->min_seq[type] + 1;
+	else
+		seq = lrugen->min_seq[type];
+
+	gen = lru_gen_from_seq(seq);
+	flags = (gen + 1UL) << LRU_GEN_PGOFF;
+	/* see the comment on MIN_NR_GENS about PG_active */
+	set_mask_bits(&folio->flags, LRU_GEN_MASK | BIT(PG_active), flags);
+
+	lru_gen_update_size(lruvec, folio, -1, gen);
+	/* for folio_rotate_reclaimable() */
+	if (reclaiming)
+		list_add_tail(&folio->lru, &lrugen->lists[gen][type][zone]);
+	else
+		list_add(&folio->lru, &lrugen->lists[gen][type][zone]);
+
+	return true;
+}
+
+static inline bool lru_gen_del_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
+{
+	unsigned long flags;
+	int gen = folio_lru_gen(folio);
+
+	if (gen < 0)
+		return false;
+
+	VM_WARN_ON_ONCE_FOLIO(folio_test_active(folio), folio);
+	VM_WARN_ON_ONCE_FOLIO(folio_test_unevictable(folio), folio);
+
+	/* for folio_migrate_flags() */
+	flags = !reclaiming && lru_gen_is_active(lruvec, gen) ? BIT(PG_active) : 0;
+	flags = set_mask_bits(&folio->flags, LRU_GEN_MASK, flags);
+	gen = ((flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;
+
+	lru_gen_update_size(lruvec, folio, gen, -1);
+	list_del(&folio->lru);
+
+	return true;
+}
+
+#else /* !CONFIG_LRU_GEN */
+
+static inline bool lru_gen_enabled(void)
+{
+	return false;
+}
+
+static inline bool lru_gen_in_fault(void)
+{
+	return false;
+}
+
+static inline bool lru_gen_add_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
+{
+	return false;
+}
+
+static inline bool lru_gen_del_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
+{
+	return false;
+}
+
+#endif /* CONFIG_LRU_GEN */
+
 static __always_inline
 void lruvec_add_folio(struct lruvec *lruvec, struct folio *folio)
 {
 	enum lru_list lru = folio_lru_list(folio);
 
+	if (lru_gen_add_folio(lruvec, folio, false))
+		return;
+
 	update_lru_size(lruvec, lru, folio_zonenum(folio),
 			folio_nr_pages(folio));
 	if (lru != LRU_UNEVICTABLE)
@@ -123,6 +292,9 @@ void lruvec_add_folio_tail(struct lruvec *lruvec, struct folio *folio)
 {
 	enum lru_list lru = folio_lru_list(folio);
 
+	if (lru_gen_add_folio(lruvec, folio, true))
+		return;
+
 	update_lru_size(lruvec, lru, folio_zonenum(folio),
 			folio_nr_pages(folio));
 	/* This is not expected to be used on LRU_UNEVICTABLE */
@@ -140,6 +312,9 @@ void lruvec_del_folio(struct lruvec *lruvec, struct folio *folio)
 {
 	enum lru_list lru = folio_lru_list(folio);
 
+	if (lru_gen_del_folio(lruvec, folio, false))
+		return;
+
 	if (lru != LRU_UNEVICTABLE)
 		list_del(&folio->lru);
 	update_lru_size(lruvec, lru, folio_zonenum(folio),
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index aab70355d64f..c90c2282044e 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -314,6 +314,102 @@ enum lruvec_flags {
 					 */
 };
 
+#endif /* !__GENERATING_BOUNDS_H */
+
+/*
+ * Evictable pages are divided into multiple generations. The youngest and the
+ * oldest generation numbers, max_seq and min_seq, are monotonically increasing.
+ * They form a sliding window of a variable size [MIN_NR_GENS, MAX_NR_GENS]. An
+ * offset within MAX_NR_GENS, i.e., gen, indexes the LRU list of the
+ * corresponding generation. The gen counter in folio->flags stores gen+1 while
+ * a page is on one of lrugen->lists[]. Otherwise it stores 0.
+ *
+ * A page is added to the youngest generation on faulting. The aging needs to
+ * check the accessed bit at least twice before handing this page over to the
+ * eviction. The first check takes care of the accessed bit set on the initial
+ * fault; the second check makes sure this page hasn't been used since then.
+ * This process, AKA second chance, requires a minimum of two generations,
+ * hence MIN_NR_GENS. And to maintain ABI compatibility with the active/inactive
+ * LRU, e.g., /proc/vmstat, these two generations are considered active; the
+ * rest of generations, if they exist, are considered inactive. See
+ * lru_gen_is_active().
+ *
+ * PG_active is always cleared while a page is on one of lrugen->lists[] so that
+ * the aging needs not to worry about it. And it's set again when a page
+ * considered active is isolated for non-reclaiming purposes, e.g., migration.
+ * See lru_gen_add_folio() and lru_gen_del_folio().
+ *
+ * MAX_NR_GENS is set to 4 so that the multi-gen LRU can support twice the
+ * number of categories of the active/inactive LRU when keeping track of
+ * accesses through page tables. This requires order_base_2(MAX_NR_GENS+1) bits
+ * in folio->flags.
+ */
+#define MIN_NR_GENS		2U
+#define MAX_NR_GENS		4U
+
+#ifndef __GENERATING_BOUNDS_H
+
+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
+
+enum {
+	LRU_GEN_ANON,
+	LRU_GEN_FILE,
+};
+
+/*
+ * The youngest generation number is stored in max_seq for both anon and file
+ * types as they are aged on an equal footing. The oldest generation numbers are
+ * stored in min_seq[] separately for anon and file types as clean file pages
+ * can be evicted regardless of swap constraints.
+ *
+ * Normally anon and file min_seq are in sync. But if swapping is constrained,
+ * e.g., out of swap space, file min_seq is allowed to advance and leave anon
+ * min_seq behind.
+ *
+ * The number of pages in each generation is eventually consistent and therefore
+ * can be transiently negative.
+ */
+struct lru_gen_struct {
+	/* the aging increments the youngest generation number */
+	unsigned long max_seq;
+	/* the eviction increments the oldest generation numbers */
+	unsigned long min_seq[ANON_AND_FILE];
+	/* the multi-gen LRU lists, lazily sorted on eviction */
+	struct list_head lists[MAX_NR_GENS][ANON_AND_FILE][MAX_NR_ZONES];
+	/* the multi-gen LRU sizes, eventually consistent */
+	long nr_pages[MAX_NR_GENS][ANON_AND_FILE][MAX_NR_ZONES];
+};
+
+void lru_gen_init_lruvec(struct lruvec *lruvec);
+
+#ifdef CONFIG_MEMCG
+void lru_gen_init_memcg(struct mem_cgroup *memcg);
+void lru_gen_exit_memcg(struct mem_cgroup *memcg);
+#endif
+
+#else /* !CONFIG_LRU_GEN */
+
+static inline void lru_gen_init_lruvec(struct lruvec *lruvec)
+{
+}
+
+#ifdef CONFIG_MEMCG
+static inline void lru_gen_init_memcg(struct mem_cgroup *memcg)
+{
+}
+
+static inline void lru_gen_exit_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 */
@@ -331,6 +427,10 @@ struct lruvec {
 	unsigned long			refaults[ANON_AND_FILE];
 	/* Various lruvec state flags (enum lruvec_flags) */
 	unsigned long			flags;
+#ifdef CONFIG_LRU_GEN
+	/* evictable pages divided into generations */
+	struct lru_gen_struct		lrugen;
+#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..240905407a18 100644
--- a/include/linux/page-flags-layout.h
+++ b/include/linux/page-flags-layout.h
@@ -55,7 +55,8 @@
 #define SECTIONS_WIDTH		0
 #endif
 
-#if ZONES_WIDTH + SECTIONS_WIDTH + NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
+#if ZONES_WIDTH + LRU_GEN_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 +90,8 @@
 #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 + 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
@@ -100,10 +101,12 @@
 #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 + SECTIONS_WIDTH + NODES_WIDTH + \
+	KASAN_TAG_WIDTH + LAST_CPUPID_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
 #error "Not enough bits in page flags"
 #endif
 
+#define LRU_REFS_WIDTH	0
+
 #endif
 #endif /* _LINUX_PAGE_FLAGS_LAYOUT */
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index e66f7aa3191d..8d466d724852 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -1059,7 +1059,7 @@ static __always_inline void __ClearPageAnonExclusive(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.
@@ -1070,7 +1070,7 @@ static __always_inline void __ClearPageAnonExclusive(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 c46f3a63b758..744340a96ace 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -912,6 +912,10 @@ struct task_struct {
 #ifdef CONFIG_MEMCG
 	unsigned			in_user_fault:1;
 #endif
+#ifdef CONFIG_LRU_GEN
+	/* whether the LRU algorithm may apply to this access */
+	unsigned			in_lru_fault:1;
+#endif
 #ifdef CONFIG_COMPAT_BRK
 	unsigned			brk_randomized:1;
 #endif
diff --git a/kernel/bounds.c b/kernel/bounds.c
index 9795d75b09b2..5ee60777d8e4 100644
--- a/kernel/bounds.c
+++ b/kernel/bounds.c
@@ -22,6 +22,11 @@ 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(MAX_NR_GENS + 1));
+#else
+	DEFINE(LRU_GEN_WIDTH, 0);
+#endif
 	/* End of constants */
 
 	return 0;
diff --git a/mm/Kconfig b/mm/Kconfig
index 169e64192e48..cee109f3128a 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -1130,6 +1130,14 @@ config PTE_MARKER_UFFD_WP
 	  purposes.  It is required to enable userfaultfd write protection on
 	  file-backed memory types like shmem and hugetlbfs.
 
+config LRU_GEN
+	bool "Multi-Gen LRU"
+	depends on MMU
+	# make sure folio->flags has enough spare bits
+	depends on 64BIT || !SPARSEMEM || SPARSEMEM_VMEMMAP
+	help
+	  A high performance LRU implementation to overcommit memory.
+
 source "mm/damon/Kconfig"
 
 endmenu
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 834f288b3769..5500583e35b8 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2370,7 +2370,8 @@ 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 618c366a2f07..7d58e8a73ece 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5105,6 +5105,7 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg)
 
 static void mem_cgroup_free(struct mem_cgroup *memcg)
 {
+	lru_gen_exit_memcg(memcg);
 	memcg_wb_domain_exit(memcg);
 	__mem_cgroup_free(memcg);
 }
@@ -5163,6 +5164,7 @@ 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 49500390b91b..85d3961c2bd5 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5091,6 +5091,27 @@ static inline void mm_account_fault(struct pt_regs *regs,
 		perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs, address);
 }
 
+#ifdef CONFIG_LRU_GEN
+static void lru_gen_enter_fault(struct vm_area_struct *vma)
+{
+	/* the LRU algorithm doesn't apply to sequential or random reads */
+	current->in_lru_fault = !(vma->vm_flags & (VM_SEQ_READ | VM_RAND_READ));
+}
+
+static void lru_gen_exit_fault(void)
+{
+	current->in_lru_fault = false;
+}
+#else
+static void lru_gen_enter_fault(struct vm_area_struct *vma)
+{
+}
+
+static void lru_gen_exit_fault(void)
+{
+}
+#endif /* CONFIG_LRU_GEN */
+
 /*
  * By the time we get here, we already hold the mm semaphore
  *
@@ -5122,11 +5143,15 @@ vm_fault_t handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
 	if (flags & FAULT_FLAG_USER)
 		mem_cgroup_enter_user_fault();
 
+	lru_gen_enter_fault(vma);
+
 	if (unlikely(is_vm_hugetlb_page(vma)))
 		ret = hugetlb_fault(vma->vm_mm, vma, address, flags);
 	else
 		ret = __handle_mm_fault(vma, address, flags);
 
+	lru_gen_exit_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/mmzone.c b/mm/mmzone.c
index 0ae7571e35ab..68e1511be12d 100644
--- a/mm/mmzone.c
+++ b/mm/mmzone.c
@@ -88,6 +88,8 @@ void lruvec_init(struct lruvec *lruvec)
 	 * Poison its list head, so that any operations on it would crash.
 	 */
 	list_del(&lruvec->lists[LRU_UNEVICTABLE]);
+
+	lru_gen_init_lruvec(lruvec);
 }
 
 #if defined(CONFIG_NUMA_BALANCING) && !defined(LAST_CPUPID_NOT_IN_PAGE_FLAGS)
diff --git a/mm/swap.c b/mm/swap.c
index 034bb24879a3..b062729b340f 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -460,6 +460,11 @@ void folio_add_lru(struct folio *folio)
 	VM_BUG_ON_FOLIO(folio_test_active(folio) && folio_test_unevictable(folio), folio);
 	VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);
 
+	/* see the comment in lru_gen_add_folio() */
+	if (lru_gen_enabled() && !folio_test_unevictable(folio) &&
+	    lru_gen_in_fault() && !(current->flags & PF_MEMALLOC))
+		folio_set_active(folio);
+
 	folio_get(folio);
 	local_lock(&lru_pvecs.lock);
 	pvec = this_cpu_ptr(&lru_pvecs.lru_add);
@@ -551,7 +556,7 @@ 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);
@@ -666,7 +671,7 @@ void deactivate_file_folio(struct folio *folio)
  */
 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/vmscan.c b/mm/vmscan.c
index fddb9bd3c6c2..1fcc0feed985 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2992,6 +2992,81 @@ 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 struct lruvec __maybe_unused *get_lruvec(struct mem_cgroup *memcg, int nid)
+{
+	struct pglist_data *pgdat = NODE_DATA(nid);
+
+#ifdef CONFIG_MEMCG
+	if (memcg) {
+		struct lruvec *lruvec = &memcg->nodeinfo[nid]->lruvec;
+
+		/* for hotadd_new_pgdat() */
+		if (!lruvec->pgdat)
+			lruvec->pgdat = pgdat;
+
+		return lruvec;
+	}
+#endif
+	VM_WARN_ON_ONCE(!mem_cgroup_disabled());
+
+	return pgdat ? &pgdat->__lruvec : NULL;
+}
+
+/******************************************************************************
+ *                          initialization
+ ******************************************************************************/
+
+void lru_gen_init_lruvec(struct lruvec *lruvec)
+{
+	int gen, type, zone;
+	struct lru_gen_struct *lrugen = &lruvec->lrugen;
+
+	lrugen->max_seq = MIN_NR_GENS + 1;
+
+	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)
+{
+}
+
+void lru_gen_exit_memcg(struct mem_cgroup *memcg)
+{
+	int nid;
+
+	for_each_node(nid) {
+		struct lruvec *lruvec = get_lruvec(memcg, nid);
+
+		VM_WARN_ON_ONCE(memchr_inv(lruvec->lrugen.nr_pages, 0,
+					   sizeof(lruvec->lrugen.nr_pages)));
+	}
+}
+#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];
