Merge tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - The series "Enable strict percpu address space checks" from Uros
   Bizjak uses x86 named address space qualifiers to provide
   compile-time checking of percpu area accesses.

   This has caused a small amount of fallout - two or three issues were
   reported. In all cases the calling code was found to be incorrect.

 - The series "Some cleanup for memcg" from Chen Ridong implements some
   relatively monir cleanups for the memcontrol code.

 - The series "mm: fixes for device-exclusive entries (hmm)" from David
   Hildenbrand fixes a boatload of issues which David found then using
   device-exclusive PTE entries when THP is enabled. More work is
   needed, but this makes thins better - our own HMM selftests now
   succeed.

 - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed
   remove the z3fold and zbud implementations. They have been deprecated
   for half a year and nobody has complained.

 - The series "mm: further simplify VMA merge operation" from Lorenzo
   Stoakes implements numerous simplifications in this area. No runtime
   effects are anticipated.

 - The series "mm/madvise: remove redundant mmap_lock operations from
   process_madvise()" from SeongJae Park rationalizes the locking in the
   madvise() implementation. Performance gains of 20-25% were observed
   in one MADV_DONTNEED microbenchmark.

 - The series "Tiny cleanup and improvements about SWAP code" from
   Baoquan He contains a number of touchups to issues which Baoquan
   noticed when working on the swap code.

 - The series "mm: kmemleak: Usability improvements" from Catalin
   Marinas implements a couple of improvements to the kmemleak
   user-visible output.

 - The series "mm/damon/paddr: fix large folios access and schemes
   handling" from Usama Arif provides a couple of fixes for DAMON's
   handling of large folios.

 - The series "mm/damon/core: fix wrong and/or useless damos_walk()
   behaviors" from SeongJae Park fixes a few issues with the accuracy of
   kdamond's walking of DAMON regions.

 - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo
   Stoakes changes the interaction between framebuffer deferred-io and
   core MM. No functional changes are anticipated - this is preparatory
   work for the future removal of page structure fields.

 - The series "mm/damon: add support for hugepage_size DAMOS filter"
   from Usama Arif adds a DAMOS filter which permits the filtering by
   huge page sizes.

 - The series "mm: permit guard regions for file-backed/shmem mappings"
   from Lorenzo Stoakes extends the guard region feature from its
   present "anon mappings only" state. The feature now covers shmem and
   file-backed mappings.

 - The series "mm: batched unmap lazyfree large folios during
   reclamation" from Barry Song cleans up and speeds up the unmapping
   for pte-mapped large folios.

 - The series "reimplement per-vma lock as a refcount" from Suren
   Baghdasaryan puts the vm_lock back into the vma. Our reasons for
   pulling it out were largely bogus and that change made the code more
   messy. This patchset provides small (0-10%) improvements on one
   microbenchmark.

 - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and
   improves" from SeongJae Park does some maintenance work on the DAMON
   docs.

 - The series "hugetlb/CMA improvements for large systems" from Frank
   van der Linden addresses a pile of issues which have been observed
   when using CMA on large machines.

 - The series "mm/damon: introduce DAMOS filter type for unmapped pages"
   from SeongJae Park enables users of DMAON/DAMOS to filter my the
   page's mapped/unmapped status.

 - The series "zsmalloc/zram: there be preemption" from Sergey
   Senozhatsky teaches zram to run its compression and decompression
   operations preemptibly.

 - The series "selftests/mm: Some cleanups from trying to run them" from
   Brendan Jackman fixes a pile of unrelated issues which Brendan
   encountered while runnimg our selftests.

 - The series "fs/proc/task_mmu: add guard region bit to pagemap" from
   Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to
   determine whether a particular page is a guard page.

 - The series "mm, swap: remove swap slot cache" from Kairui Song
   removes the swap slot cache from the allocation path - it simply
   wasn't being effective.

 - The series "mm: cleanups for device-exclusive entries (hmm)" from
   David Hildenbrand implements a number of unrelated cleanups in this
   code.

 - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual
   implements a number of preparatoty cleanups to the GENERIC_PTDUMP
   Kconfig logic.

 - The series "mm/damon: auto-tune aggregation interval" from SeongJae
   Park implements a feedback-driven automatic tuning feature for
   DAMON's aggregation interval tuning.

 - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in
   powerpc, sparc and x86 lazy MMU implementations. Ryan did this in
   preparation for implementing lazy mmu mode for arm64 to optimize
   vmalloc.

 - The series "mm/page_alloc: Some clarifications for migratetype
   fallback" from Brendan Jackman reworks some commentary to make the
   code easier to follow.

 - The series "page_counter cleanup and size reduction" from Shakeel
   Butt cleans up the page_counter code and fixes a size increase which
   we accidentally added late last year.

 - The series "Add a command line option that enables control of how
   many threads should be used to allocate huge pages" from Thomas
   Prescher does that. It allows the careful operator to significantly
   reduce boot time by tuning the parallalization of huge page
   initialization.

 - The series "Fix calculations in trace_balance_dirty_pages() for cgwb"
   from Tang Yizhou fixes the tracing output from the dirty page
   balancing code.

 - The series "mm/damon: make allow filters after reject filters useful
   and intuitive" from SeongJae Park improves the handling of allow and
   reject filters. Behaviour is made more consistent and the documention
   is updated accordingly.

 - The series "Switch zswap to object read/write APIs" from Yosry Ahmed
   updates zswap to the new object read/write APIs and thus permits the
   removal of some legacy code from zpool and zsmalloc.

 - The series "Some trivial cleanups for shmem" from Baolin Wang does as
   it claims.

 - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from
   Alistair Popple regularizes the weird ZONE_DEVICE page refcount
   handling in DAX, permittig the removal of a number of special-case
   checks.

 - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a
   preparatoty refactoring and cleanup of the mremap() code.

 - The series "mm: MM owner tracking for large folios (!hugetlb) +
   CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in
   which we determine whether a large folio is known to be mapped
   exclusively into a single MM.

 - The series "mm/damon: add sysfs dirs for managing DAMOS filters based
   on handling layers" from SeongJae Park adds a couple of new sysfs
   directories to ease the management of DAMON/DAMOS filters.

 - The series "arch, mm: reduce code duplication in mem_init()" from
   Mike Rapoport consolidates many per-arch implementations of
   mem_init() into code generic code, where that is practical.

 - The series "mm/damon/sysfs: commit parameters online via
   damon_call()" from SeongJae Park continues the cleaning up of sysfs
   access to DAMON internal data.

 - The series "mm: page_ext: Introduce new iteration API" from Luiz
   Capitulino reworks the page_ext initialization to fix a boot-time
   crash which was observed with an unusual combination of compile and
   cmdline options.

 - The series "Buddy allocator like (or non-uniform) folio split" from
   Zi Yan reworks the code to split a folio into smaller folios. The
   main benefit is lessened memory consumption: fewer post-split folios
   are generated.

 - The series "Minimize xa_node allocation during xarry split" from Zi
   Yan reduces the number of xarray xa_nodes which are generated during
   an xarray split.

 - The series "drivers/base/memory: Two cleanups" from Gavin Shan
   performs some maintenance work on the drivers/base/memory code.

 - The series "Add tracepoints for lowmem reserves, watermarks and
   totalreserve_pages" from Martin Liu adds some more tracepoints to the
   page allocator code.

 - The series "mm/madvise: cleanup requests validations and
   classifications" from SeongJae Park cleans up some warts which
   SeongJae observed during his earlier madvise work.

 - The series "mm/hwpoison: Fix regressions in memory failure handling"
   from Shuai Xue addresses two quite serious regressions which Shuai
   has observed in the memory-failure implementation.

 - The series "mm: reliable huge page allocator" from Johannes Weiner
   makes huge page allocations cheaper and more reliable by reducing
   fragmentation.

 - The series "Minor memcg cleanups & prep for memdescs" from Matthew
   Wilcox is preparatory work for the future implementation of memdescs.

 - The series "track memory used by balloon drivers" from Nico Pache
   introduces a way to track memory used by our various balloon drivers.

 - The series "mm/damon: introduce DAMOS filter type for active pages"
   from Nhat Pham permits users to filter for active/inactive pages,
   separately for file and anon pages.

 - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia
   separates the proactive reclaim statistics from the direct reclaim
   statistics.

 - The series "mm/vmscan: don't try to reclaim hwpoison folio" from
   Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim
   code.

* tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits)
  mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex()
  x86/mm: restore early initialization of high_memory for 32-bits
  mm/vmscan: don't try to reclaim hwpoison folio
  mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper
  cgroup: docs: add pswpin and pswpout items in cgroup v2 doc
  mm: vmscan: split proactive reclaim statistics from direct reclaim statistics
  selftests/mm: speed up split_huge_page_test
  selftests/mm: uffd-unit-tests support for hugepages > 2M
  docs/mm/damon/design: document active DAMOS filter type
  mm/damon: implement a new DAMOS filter type for active pages
  fs/dax: don't disassociate zero page entries
  MM documentation: add "Unaccepted" meminfo entry
  selftests/mm: add commentary about 9pfs bugs
  fork: use __vmalloc_node() for stack allocation
  docs/mm: Physical Memory: Populate the "Zones" section
  xen: balloon: update the NR_BALLOON_PAGES state
  hv_balloon: update the NR_BALLOON_PAGES state
  balloon_compaction: update the NR_BALLOON_PAGES state
  meminfo: add a per node counter for balloon drivers
  mm: remove references to folio in __memcg_kmem_uncharge_page()
  ...

1 files changed, 130 insertions, 164 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 83c2df73e4b6..421740f1bcdc 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -315,6 +315,7 @@ static const unsigned int memcg_node_stat_items[] = {
 	PGDEMOTE_KSWAPD,
 	PGDEMOTE_DIRECT,
 	PGDEMOTE_KHUGEPAGED,
+	PGDEMOTE_PROACTIVE,
 #ifdef CONFIG_HUGETLB_PAGE
 	NR_HUGETLB,
 #endif
@@ -431,9 +432,11 @@ static const unsigned int memcg_vm_event_stat[] = {
 	PGSCAN_KSWAPD,
 	PGSCAN_DIRECT,
 	PGSCAN_KHUGEPAGED,
+	PGSCAN_PROACTIVE,
 	PGSTEAL_KSWAPD,
 	PGSTEAL_DIRECT,
 	PGSTEAL_KHUGEPAGED,
+	PGSTEAL_PROACTIVE,
 	PGFAULT,
 	PGMAJFAULT,
 	PGREFILL,
@@ -706,6 +709,7 @@ void __mod_memcg_state(struct mem_cgroup *memcg, enum memcg_stat_item idx,
 	trace_mod_memcg_state(memcg, idx, val);
 }
 
+#ifdef CONFIG_MEMCG_V1
 /* idx can be of type enum memcg_stat_item or node_stat_item. */
 unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx)
 {
@@ -722,6 +726,7 @@ unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx)
 #endif
 	return x;
 }
+#endif
 
 static void __mod_memcg_lruvec_state(struct lruvec *lruvec,
 				     enum node_stat_item idx,
@@ -869,6 +874,7 @@ unsigned long memcg_events(struct mem_cgroup *memcg, int event)
 	return READ_ONCE(memcg->vmstats->events[i]);
 }
 
+#ifdef CONFIG_MEMCG_V1
 unsigned long memcg_events_local(struct mem_cgroup *memcg, int event)
 {
 	int i = memcg_events_index(event);
@@ -878,6 +884,7 @@ unsigned long memcg_events_local(struct mem_cgroup *memcg, int event)
 
 	return READ_ONCE(memcg->vmstats->events_local[i]);
 }
+#endif
 
 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
 {
@@ -1390,6 +1397,7 @@ static const struct memory_stat memory_stats[] = {
 	{ "pgdemote_kswapd",		PGDEMOTE_KSWAPD		},
 	{ "pgdemote_direct",		PGDEMOTE_DIRECT		},
 	{ "pgdemote_khugepaged",	PGDEMOTE_KHUGEPAGED	},
+	{ "pgdemote_proactive",		PGDEMOTE_PROACTIVE	},
 #ifdef CONFIG_NUMA_BALANCING
 	{ "pgpromote_success",		PGPROMOTE_SUCCESS	},
 #endif
@@ -1432,6 +1440,7 @@ static int memcg_page_state_output_unit(int item)
 	case PGDEMOTE_KSWAPD:
 	case PGDEMOTE_DIRECT:
 	case PGDEMOTE_KHUGEPAGED:
+	case PGDEMOTE_PROACTIVE:
 #ifdef CONFIG_NUMA_BALANCING
 	case PGPROMOTE_SUCCESS:
 #endif
@@ -1447,11 +1456,13 @@ unsigned long memcg_page_state_output(struct mem_cgroup *memcg, int item)
 		memcg_page_state_output_unit(item);
 }
 
+#ifdef CONFIG_MEMCG_V1
 unsigned long memcg_page_state_local_output(struct mem_cgroup *memcg, int item)
 {
 	return memcg_page_state_local(memcg, item) *
 		memcg_page_state_output_unit(item);
 }
+#endif
 
 #ifdef CONFIG_HUGETLB_PAGE
 static bool memcg_accounts_hugetlb(void)
@@ -1503,10 +1514,12 @@ static void memcg_stat_format(struct mem_cgroup *memcg, struct seq_buf *s)
 	seq_buf_printf(s, "pgscan %lu\n",
 		       memcg_events(memcg, PGSCAN_KSWAPD) +
 		       memcg_events(memcg, PGSCAN_DIRECT) +
+		       memcg_events(memcg, PGSCAN_PROACTIVE) +
 		       memcg_events(memcg, PGSCAN_KHUGEPAGED));
 	seq_buf_printf(s, "pgsteal %lu\n",
 		       memcg_events(memcg, PGSTEAL_KSWAPD) +
 		       memcg_events(memcg, PGSTEAL_DIRECT) +
+		       memcg_events(memcg, PGSTEAL_PROACTIVE) +
 		       memcg_events(memcg, PGSTEAL_KHUGEPAGED));
 
 	for (i = 0; i < ARRAY_SIZE(memcg_vm_event_stat); i++) {
@@ -1566,16 +1579,23 @@ void mem_cgroup_print_oom_meminfo(struct mem_cgroup *memcg)
 	/* Use static buffer, for the caller is holding oom_lock. */
 	static char buf[SEQ_BUF_SIZE];
 	struct seq_buf s;
+	unsigned long memory_failcnt;
 
 	lockdep_assert_held(&oom_lock);
 
+	if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
+		memory_failcnt = atomic_long_read(&memcg->memory_events[MEMCG_MAX]);
+	else
+		memory_failcnt = memcg->memory.failcnt;
+
 	pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
 		K((u64)page_counter_read(&memcg->memory)),
-		K((u64)READ_ONCE(memcg->memory.max)), memcg->memory.failcnt);
+		K((u64)READ_ONCE(memcg->memory.max)), memory_failcnt);
 	if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
 		pr_info("swap: usage %llukB, limit %llukB, failcnt %lu\n",
 			K((u64)page_counter_read(&memcg->swap)),
-			K((u64)READ_ONCE(memcg->swap.max)), memcg->swap.failcnt);
+			K((u64)READ_ONCE(memcg->swap.max)),
+			atomic_long_read(&memcg->memory_events[MEMCG_SWAP_MAX]));
 #ifdef CONFIG_MEMCG_V1
 	else {
 		pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",
@@ -2224,8 +2244,8 @@ out:
 	css_put(&memcg->css);
 }
 
-int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
-		     unsigned int nr_pages)
+static int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
+			    unsigned int nr_pages)
 {
 	unsigned int batch = max(MEMCG_CHARGE_BATCH, nr_pages);
 	int nr_retries = MAX_RECLAIM_RETRIES;
@@ -2418,6 +2438,15 @@ done_restock:
 	return 0;
 }
 
+static inline int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
+			     unsigned int nr_pages)
+{
+	if (mem_cgroup_is_root(memcg))
+		return 0;
+
+	return try_charge_memcg(memcg, gfp_mask, nr_pages);
+}
+
 static void commit_charge(struct folio *folio, struct mem_cgroup *memcg)
 {
 	VM_BUG_ON_FOLIO(folio_memcg_charged(folio), folio);
@@ -2642,7 +2671,8 @@ static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg,
 
 	mod_memcg_state(memcg, MEMCG_KMEM, -nr_pages);
 	memcg1_account_kmem(memcg, -nr_pages);
-	refill_stock(memcg, nr_pages);
+	if (!mem_cgroup_is_root(memcg))
+		refill_stock(memcg, nr_pages);
 
 	css_put(&memcg->css);
 }
@@ -2675,6 +2705,23 @@ out:
 	return ret;
 }
 
+static struct obj_cgroup *page_objcg(const struct page *page)
+{
+	unsigned long memcg_data = page->memcg_data;
+
+	if (mem_cgroup_disabled() || !memcg_data)
+		return NULL;
+
+	VM_BUG_ON_PAGE((memcg_data & OBJEXTS_FLAGS_MASK) != MEMCG_DATA_KMEM,
+			page);
+	return (struct obj_cgroup *)(memcg_data - MEMCG_DATA_KMEM);
+}
+
+static void page_set_objcg(struct page *page, const struct obj_cgroup *objcg)
+{
+	page->memcg_data = (unsigned long)objcg | MEMCG_DATA_KMEM;
+}
+
 /**
  * __memcg_kmem_charge_page: charge a kmem page to the current memory cgroup
  * @page: page to charge
@@ -2693,8 +2740,7 @@ int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order)
 		ret = obj_cgroup_charge_pages(objcg, gfp, 1 << order);
 		if (!ret) {
 			obj_cgroup_get(objcg);
-			page->memcg_data = (unsigned long)objcg |
-				MEMCG_DATA_KMEM;
+			page_set_objcg(page, objcg);
 			return 0;
 		}
 	}
@@ -2708,19 +2754,31 @@ int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order)
  */
 void __memcg_kmem_uncharge_page(struct page *page, int order)
 {
-	struct folio *folio = page_folio(page);
-	struct obj_cgroup *objcg;
+	struct obj_cgroup *objcg = page_objcg(page);
 	unsigned int nr_pages = 1 << order;
 
-	if (!folio_memcg_kmem(folio))
+	if (!objcg)
 		return;
 
-	objcg = __folio_objcg(folio);
 	obj_cgroup_uncharge_pages(objcg, nr_pages);
-	folio->memcg_data = 0;
+	page->memcg_data = 0;
 	obj_cgroup_put(objcg);
 }
 
+/* Replace the stock objcg with objcg, return the old objcg */
+static struct obj_cgroup *replace_stock_objcg(struct memcg_stock_pcp *stock,
+					     struct obj_cgroup *objcg)
+{
+	struct obj_cgroup *old = NULL;
+
+	old = drain_obj_stock(stock);
+	obj_cgroup_get(objcg);
+	stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes)
+			? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0;
+	WRITE_ONCE(stock->cached_objcg, objcg);
+	return old;
+}
+
 static void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
 		     enum node_stat_item idx, int nr)
 {
@@ -2738,11 +2796,7 @@ static void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
 	 * changes.
 	 */
 	if (READ_ONCE(stock->cached_objcg) != objcg) {
-		old = drain_obj_stock(stock);
-		obj_cgroup_get(objcg);
-		stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes)
-				? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0;
-		WRITE_ONCE(stock->cached_objcg, objcg);
+		old = replace_stock_objcg(stock, objcg);
 		stock->cached_pgdat = pgdat;
 	} else if (stock->cached_pgdat != pgdat) {
 		/* Flush the existing cached vmstat data */
@@ -2896,11 +2950,7 @@ static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes,
 
 	stock = this_cpu_ptr(&memcg_stock);
 	if (READ_ONCE(stock->cached_objcg) != objcg) { /* reset if necessary */
-		old = drain_obj_stock(stock);
-		obj_cgroup_get(objcg);
-		WRITE_ONCE(stock->cached_objcg, objcg);
-		stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes)
-				? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0;
+		old = replace_stock_objcg(stock, objcg);
 		allow_uncharge = true;	/* Allow uncharge when objcg changes */
 	}
 	stock->nr_bytes += nr_bytes;
@@ -3058,25 +3108,33 @@ void __memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
 }
 
 /*
- * Because folio_memcg(head) is not set on tails, set it now.
+ * The objcg is only set on the first page, so transfer it to all the
+ * other pages.
  */
-void split_page_memcg(struct page *head, int old_order, int new_order)
+void split_page_memcg(struct page *page, unsigned order)
 {
-	struct folio *folio = page_folio(head);
-	int i;
-	unsigned int old_nr = 1 << old_order;
-	unsigned int new_nr = 1 << new_order;
+	struct obj_cgroup *objcg = page_objcg(page);
+	unsigned int i, nr = 1 << order;
 
-	if (mem_cgroup_disabled() || !folio_memcg_charged(folio))
+	if (!objcg)
 		return;
 
-	for (i = new_nr; i < old_nr; i += new_nr)
-		folio_page(folio, i)->memcg_data = folio->memcg_data;
+	for (i = 1; i < nr; i++)
+		page_set_objcg(&page[i], objcg);
 
-	if (folio_memcg_kmem(folio))
-		obj_cgroup_get_many(__folio_objcg(folio), old_nr / new_nr - 1);
-	else
-		css_get_many(&folio_memcg(folio)->css, old_nr / new_nr - 1);
+	obj_cgroup_get_many(objcg, nr - 1);
+}
+
+void folio_split_memcg_refs(struct folio *folio, unsigned old_order,
+		unsigned new_order)
+{
+	unsigned new_refs;
+
+	if (mem_cgroup_disabled() || !folio_memcg_charged(folio))
+		return;
+
+	new_refs = (1 << (old_order - new_order)) - 1;
+	css_get_many(&__folio_memcg(folio)->css, new_refs);
 }
 
 unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
@@ -3404,7 +3462,7 @@ void __maybe_unused mem_cgroup_id_get_many(struct mem_cgroup *memcg,
 	refcount_add(n, &memcg->id.ref);
 }
 
-void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n)
+static void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n)
 {
 	if (refcount_sub_and_test(n, &memcg->id.ref)) {
 		mem_cgroup_id_remove(memcg);
@@ -3419,6 +3477,24 @@ static inline void mem_cgroup_id_put(struct mem_cgroup *memcg)
 	mem_cgroup_id_put_many(memcg, 1);
 }
 
+struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg)
+{
+	while (!refcount_inc_not_zero(&memcg->id.ref)) {
+		/*
+		 * The root cgroup cannot be destroyed, so it's refcount must
+		 * always be >= 1.
+		 */
+		if (WARN_ON_ONCE(mem_cgroup_is_root(memcg))) {
+			VM_BUG_ON(1);
+			break;
+		}
+		memcg = parent_mem_cgroup(memcg);
+		if (!memcg)
+			memcg = root_mem_cgroup;
+	}
+	return memcg;
+}
+
 /**
  * mem_cgroup_from_id - look up a memcg from a memcg id
  * @id: the memcg id to look up
@@ -3454,6 +3530,16 @@ struct mem_cgroup *mem_cgroup_get_from_ino(unsigned long ino)
 }
 #endif
 
+static void free_mem_cgroup_per_node_info(struct mem_cgroup_per_node *pn)
+{
+	if (!pn)
+		return;
+
+	free_percpu(pn->lruvec_stats_percpu);
+	kfree(pn->lruvec_stats);
+	kfree(pn);
+}
+
 static bool alloc_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node)
 {
 	struct mem_cgroup_per_node *pn;
@@ -3478,23 +3564,10 @@ static bool alloc_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node)
 	memcg->nodeinfo[node] = pn;
 	return true;
 fail:
-	kfree(pn->lruvec_stats);
-	kfree(pn);
+	free_mem_cgroup_per_node_info(pn);
 	return false;
 }
 
-static void free_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node)
-{
-	struct mem_cgroup_per_node *pn = memcg->nodeinfo[node];
-
-	if (!pn)
-		return;
-
-	free_percpu(pn->lruvec_stats_percpu);
-	kfree(pn->lruvec_stats);
-	kfree(pn);
-}
-
 static void __mem_cgroup_free(struct mem_cgroup *memcg)
 {
 	int node;
@@ -3502,7 +3575,7 @@ static void __mem_cgroup_free(struct mem_cgroup *memcg)
 	obj_cgroup_put(memcg->orig_objcg);
 
 	for_each_node(node)
-		free_mem_cgroup_per_node_info(memcg, node);
+		free_mem_cgroup_per_node_info(memcg->nodeinfo[node]);
 	memcg1_free_events(memcg);
 	kfree(memcg->vmstats);
 	free_percpu(memcg->vmstats_percpu);
@@ -3595,6 +3668,7 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
 {
 	struct mem_cgroup *parent = mem_cgroup_from_css(parent_css);
 	struct mem_cgroup *memcg, *old_memcg;
+	bool memcg_on_dfl = cgroup_subsys_on_dfl(memory_cgrp_subsys);
 
 	old_memcg = set_active_memcg(parent);
 	memcg = mem_cgroup_alloc(parent);
@@ -3612,9 +3686,10 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
 	if (parent) {
 		WRITE_ONCE(memcg->swappiness, mem_cgroup_swappiness(parent));
 
-		page_counter_init(&memcg->memory, &parent->memory, true);
+		page_counter_init(&memcg->memory, &parent->memory, memcg_on_dfl);
 		page_counter_init(&memcg->swap, &parent->swap, false);
 #ifdef CONFIG_MEMCG_V1
+		memcg->memory.track_failcnt = !memcg_on_dfl;
 		WRITE_ONCE(memcg->oom_kill_disable, READ_ONCE(parent->oom_kill_disable));
 		page_counter_init(&memcg->kmem, &parent->kmem, false);
 		page_counter_init(&memcg->tcpmem, &parent->tcpmem, false);
@@ -3632,7 +3707,7 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
 		return &memcg->css;
 	}
 
-	if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
+	if (memcg_on_dfl && !cgroup_memory_nosocket)
 		static_branch_inc(&memcg_sockets_enabled_key);
 
 	if (!cgroup_memory_nobpf)
@@ -4034,7 +4109,7 @@ static ssize_t peak_write(struct kernfs_open_file *of, char *buf, size_t nbytes,
 			WRITE_ONCE(peer_ctx->value, usage);
 
 	/* initial write, register watcher */
-	if (ofp->value == -1)
+	if (ofp->value == OFP_PEAK_UNSET)
 		list_add(&ofp->list, watchers);
 
 	WRITE_ONCE(ofp->value, usage);
@@ -4607,40 +4682,6 @@ int mem_cgroup_swapin_charge_folio(struct folio *folio, struct mm_struct *mm,
 	return ret;
 }
 
-/*
- * mem_cgroup_swapin_uncharge_swap - uncharge swap slot
- * @entry: the first swap entry for which the pages are charged
- * @nr_pages: number of pages which will be uncharged
- *
- * Call this function after successfully adding the charged page to swapcache.
- *
- * Note: This function assumes the page for which swap slot is being uncharged
- * is order 0 page.
- */
-void mem_cgroup_swapin_uncharge_swap(swp_entry_t entry, unsigned int nr_pages)
-{
-	/*
-	 * Cgroup1's unified memory+swap counter has been charged with the
-	 * new swapcache page, finish the transfer by uncharging the swap
-	 * slot. The swap slot would also get uncharged when it dies, but
-	 * it can stick around indefinitely and we'd count the page twice
-	 * the entire time.
-	 *
-	 * Cgroup2 has separate resource counters for memory and swap,
-	 * so this is a non-issue here. Memory and swap charge lifetimes
-	 * correspond 1:1 to page and swap slot lifetimes: we charge the
-	 * page to memory here, and uncharge swap when the slot is freed.
-	 */
-	if (do_memsw_account()) {
-		/*
-		 * The swap entry might not get freed for a long time,
-		 * let's not wait for it.  The page already received a
-		 * memory+swap charge, drop the swap entry duplicate.
-		 */
-		mem_cgroup_uncharge_swap(entry, nr_pages);
-	}
-}
-
 struct uncharge_gather {
 	struct mem_cgroup *memcg;
 	unsigned long nr_memory;
@@ -4891,7 +4932,7 @@ bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
 	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
 		return memcg1_charge_skmem(memcg, nr_pages, gfp_mask);
 
-	if (try_charge(memcg, gfp_mask, nr_pages) == 0) {
+	if (try_charge_memcg(memcg, gfp_mask, nr_pages) == 0) {
 		mod_memcg_state(memcg, MEMCG_SOCK, nr_pages);
 		return true;
 	}
@@ -4966,81 +5007,6 @@ static int __init mem_cgroup_init(void)
 subsys_initcall(mem_cgroup_init);
 
 #ifdef CONFIG_SWAP
-static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg)
-{
-	while (!refcount_inc_not_zero(&memcg->id.ref)) {
-		/*
-		 * The root cgroup cannot be destroyed, so it's refcount must
-		 * always be >= 1.
-		 */
-		if (WARN_ON_ONCE(mem_cgroup_is_root(memcg))) {
-			VM_BUG_ON(1);
-			break;
-		}
-		memcg = parent_mem_cgroup(memcg);
-		if (!memcg)
-			memcg = root_mem_cgroup;
-	}
-	return memcg;
-}
-
-/**
- * mem_cgroup_swapout - transfer a memsw charge to swap
- * @folio: folio whose memsw charge to transfer
- * @entry: swap entry to move the charge to
- *
- * Transfer the memsw charge of @folio to @entry.
- */
-void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry)
-{
-	struct mem_cgroup *memcg, *swap_memcg;
-	unsigned int nr_entries;
-
-	VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);
-	VM_BUG_ON_FOLIO(folio_ref_count(folio), folio);
-
-	if (mem_cgroup_disabled())
-		return;
-
-	if (!do_memsw_account())
-		return;
-
-	memcg = folio_memcg(folio);
-
-	VM_WARN_ON_ONCE_FOLIO(!memcg, folio);
-	if (!memcg)
-		return;
-
-	/*
-	 * In case the memcg owning these pages has been offlined and doesn't
-	 * have an ID allocated to it anymore, charge the closest online
-	 * ancestor for the swap instead and transfer the memory+swap charge.
-	 */
-	swap_memcg = mem_cgroup_id_get_online(memcg);
-	nr_entries = folio_nr_pages(folio);
-	/* Get references for the tail pages, too */
-	if (nr_entries > 1)
-		mem_cgroup_id_get_many(swap_memcg, nr_entries - 1);
-	mod_memcg_state(swap_memcg, MEMCG_SWAP, nr_entries);
-
-	swap_cgroup_record(folio, mem_cgroup_id(swap_memcg), entry);
-
-	folio_unqueue_deferred_split(folio);
-	folio->memcg_data = 0;
-
-	if (!mem_cgroup_is_root(memcg))
-		page_counter_uncharge(&memcg->memory, nr_entries);
-
-	if (memcg != swap_memcg) {
-		if (!mem_cgroup_is_root(swap_memcg))
-			page_counter_charge(&swap_memcg->memsw, nr_entries);
-		page_counter_uncharge(&memcg->memsw, nr_entries);
-	}
-
-	memcg1_swapout(folio, memcg);
-	css_put(&memcg->css);
-}
-
 /**
  * __mem_cgroup_try_charge_swap - try charging swap space for a folio
  * @folio: folio being added to swap