1 files changed, 650 insertions, 324 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 579789600a3c..fd6b865cb1ab 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -88,6 +88,9 @@ typedef int __bitwise fpi_t;
  */
 #define FPI_TO_TAIL		((__force fpi_t)BIT(1))
 
+/* Free the page without taking locks. Rely on trylock only. */
+#define FPI_TRYLOCK		((__force fpi_t)BIT(2))
+
 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
 static DEFINE_MUTEX(pcp_batch_high_lock);
 #define MIN_PERCPU_PAGELIST_HIGH_FRACTION (8)
@@ -273,6 +276,7 @@ int min_free_kbytes = 1024;
 int user_min_free_kbytes = -1;
 static int watermark_boost_factor __read_mostly = 15000;
 static int watermark_scale_factor = 10;
+int defrag_mode;
 
 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
 int movable_zone;
@@ -508,9 +512,9 @@ out:
 
 static inline unsigned int order_to_pindex(int migratetype, int order)
 {
-	bool __maybe_unused movable;
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	bool movable;
 	if (order > PAGE_ALLOC_COSTLY_ORDER) {
 		VM_BUG_ON(order != HPAGE_PMD_ORDER);
 
@@ -614,6 +618,10 @@ compaction_capture(struct capture_control *capc, struct page *page,
 	    capc->cc->migratetype != MIGRATE_MOVABLE)
 		return false;
 
+	if (migratetype != capc->cc->migratetype)
+		trace_mm_page_alloc_extfrag(page, capc->cc->order, order,
+					    capc->cc->migratetype, migratetype);
+
 	capc->page = page;
 	return true;
 }
@@ -655,16 +663,20 @@ static inline void __add_to_free_list(struct page *page, struct zone *zone,
 				      bool tail)
 {
 	struct free_area *area = &zone->free_area[order];
+	int nr_pages = 1 << order;
 
 	VM_WARN_ONCE(get_pageblock_migratetype(page) != migratetype,
 		     "page type is %lu, passed migratetype is %d (nr=%d)\n",
-		     get_pageblock_migratetype(page), migratetype, 1 << order);
+		     get_pageblock_migratetype(page), migratetype, nr_pages);
 
 	if (tail)
 		list_add_tail(&page->buddy_list, &area->free_list[migratetype]);
 	else
 		list_add(&page->buddy_list, &area->free_list[migratetype]);
 	area->nr_free++;
+
+	if (order >= pageblock_order && !is_migrate_isolate(migratetype))
+		__mod_zone_page_state(zone, NR_FREE_PAGES_BLOCKS, nr_pages);
 }
 
 /*
@@ -676,24 +688,34 @@ static inline void move_to_free_list(struct page *page, struct zone *zone,
 				     unsigned int order, int old_mt, int new_mt)
 {
 	struct free_area *area = &zone->free_area[order];
+	int nr_pages = 1 << order;
 
 	/* Free page moving can fail, so it happens before the type update */
 	VM_WARN_ONCE(get_pageblock_migratetype(page) != old_mt,
 		     "page type is %lu, passed migratetype is %d (nr=%d)\n",
-		     get_pageblock_migratetype(page), old_mt, 1 << order);
+		     get_pageblock_migratetype(page), old_mt, nr_pages);
 
 	list_move_tail(&page->buddy_list, &area->free_list[new_mt]);
 
-	account_freepages(zone, -(1 << order), old_mt);
-	account_freepages(zone, 1 << order, new_mt);
+	account_freepages(zone, -nr_pages, old_mt);
+	account_freepages(zone, nr_pages, new_mt);
+
+	if (order >= pageblock_order &&
+	    is_migrate_isolate(old_mt) != is_migrate_isolate(new_mt)) {
+		if (!is_migrate_isolate(old_mt))
+			nr_pages = -nr_pages;
+		__mod_zone_page_state(zone, NR_FREE_PAGES_BLOCKS, nr_pages);
+	}
 }
 
 static inline void __del_page_from_free_list(struct page *page, struct zone *zone,
 					     unsigned int order, int migratetype)
 {
+	int nr_pages = 1 << order;
+
         VM_WARN_ONCE(get_pageblock_migratetype(page) != migratetype,
 		     "page type is %lu, passed migratetype is %d (nr=%d)\n",
-		     get_pageblock_migratetype(page), migratetype, 1 << order);
+		     get_pageblock_migratetype(page), migratetype, nr_pages);
 
 	/* clear reported state and update reported page count */
 	if (page_reported(page))
@@ -703,6 +725,9 @@ static inline void __del_page_from_free_list(struct page *page, struct zone *zon
 	__ClearPageBuddy(page);
 	set_page_private(page, 0);
 	zone->free_area[order].nr_free--;
+
+	if (order >= pageblock_order && !is_migrate_isolate(migratetype))
+		__mod_zone_page_state(zone, NR_FREE_PAGES_BLOCKS, -nr_pages);
 }
 
 static inline void del_page_from_free_list(struct page *page, struct zone *zone,
@@ -947,21 +972,34 @@ static int free_tail_page_prepare(struct page *head_page, struct page *page)
 	switch (page - head_page) {
 	case 1:
 		/* the first tail page: these may be in place of ->mapping */
-		if (unlikely(folio_entire_mapcount(folio))) {
-			bad_page(page, "nonzero entire_mapcount");
-			goto out;
-		}
 		if (unlikely(folio_large_mapcount(folio))) {
 			bad_page(page, "nonzero large_mapcount");
 			goto out;
 		}
-		if (unlikely(atomic_read(&folio->_nr_pages_mapped))) {
+		if (IS_ENABLED(CONFIG_PAGE_MAPCOUNT) &&
+		    unlikely(atomic_read(&folio->_nr_pages_mapped))) {
 			bad_page(page, "nonzero nr_pages_mapped");
 			goto out;
 		}
-		if (unlikely(atomic_read(&folio->_pincount))) {
-			bad_page(page, "nonzero pincount");
-			goto out;
+		if (IS_ENABLED(CONFIG_MM_ID)) {
+			if (unlikely(folio->_mm_id_mapcount[0] != -1)) {
+				bad_page(page, "nonzero mm mapcount 0");
+				goto out;
+			}
+			if (unlikely(folio->_mm_id_mapcount[1] != -1)) {
+				bad_page(page, "nonzero mm mapcount 1");
+				goto out;
+			}
+		}
+		if (IS_ENABLED(CONFIG_64BIT)) {
+			if (unlikely(atomic_read(&folio->_entire_mapcount) + 1)) {
+				bad_page(page, "nonzero entire_mapcount");
+				goto out;
+			}
+			if (unlikely(atomic_read(&folio->_pincount))) {
+				bad_page(page, "nonzero pincount");
+				goto out;
+			}
 		}
 		break;
 	case 2:
@@ -970,7 +1008,22 @@ static int free_tail_page_prepare(struct page *head_page, struct page *page)
 			bad_page(page, "on deferred list");
 			goto out;
 		}
+		if (!IS_ENABLED(CONFIG_64BIT)) {
+			if (unlikely(atomic_read(&folio->_entire_mapcount) + 1)) {
+				bad_page(page, "nonzero entire_mapcount");
+				goto out;
+			}
+			if (unlikely(atomic_read(&folio->_pincount))) {
+				bad_page(page, "nonzero pincount");
+				goto out;
+			}
+		}
 		break;
+	case 3:
+		/* the third tail page: hugetlb specifics overlap ->mappings */
+		if (IS_ENABLED(CONFIG_HUGETLB_PAGE))
+			break;
+		fallthrough;
 	default:
 		if (page->mapping != TAIL_MAPPING) {
 			bad_page(page, "corrupted mapping in tail page");
@@ -1041,6 +1094,84 @@ static void kernel_init_pages(struct page *page, int numpages)
 	kasan_enable_current();
 }
 
+#ifdef CONFIG_MEM_ALLOC_PROFILING
+
+/* Should be called only if mem_alloc_profiling_enabled() */
+void __clear_page_tag_ref(struct page *page)
+{
+	union pgtag_ref_handle handle;
+	union codetag_ref ref;
+
+	if (get_page_tag_ref(page, &ref, &handle)) {
+		set_codetag_empty(&ref);
+		update_page_tag_ref(handle, &ref);
+		put_page_tag_ref(handle);
+	}
+}
+
+/* Should be called only if mem_alloc_profiling_enabled() */
+static noinline
+void __pgalloc_tag_add(struct page *page, struct task_struct *task,
+		       unsigned int nr)
+{
+	union pgtag_ref_handle handle;
+	union codetag_ref ref;
+
+	if (get_page_tag_ref(page, &ref, &handle)) {
+		alloc_tag_add(&ref, task->alloc_tag, PAGE_SIZE * nr);
+		update_page_tag_ref(handle, &ref);
+		put_page_tag_ref(handle);
+	}
+}
+
+static inline void pgalloc_tag_add(struct page *page, struct task_struct *task,
+				   unsigned int nr)
+{
+	if (mem_alloc_profiling_enabled())
+		__pgalloc_tag_add(page, task, nr);
+}
+
+/* Should be called only if mem_alloc_profiling_enabled() */
+static noinline
+void __pgalloc_tag_sub(struct page *page, unsigned int nr)
+{
+	union pgtag_ref_handle handle;
+	union codetag_ref ref;
+
+	if (get_page_tag_ref(page, &ref, &handle)) {
+		alloc_tag_sub(&ref, PAGE_SIZE * nr);
+		update_page_tag_ref(handle, &ref);
+		put_page_tag_ref(handle);
+	}
+}
+
+static inline void pgalloc_tag_sub(struct page *page, unsigned int nr)
+{
+	if (mem_alloc_profiling_enabled())
+		__pgalloc_tag_sub(page, nr);
+}
+
+static inline void pgalloc_tag_sub_pages(struct page *page, unsigned int nr)
+{
+	struct alloc_tag *tag;
+
+	if (!mem_alloc_profiling_enabled())
+		return;
+
+	tag = __pgalloc_tag_get(page);
+	if (tag)
+		this_cpu_sub(tag->counters->bytes, PAGE_SIZE * nr);
+}
+
+#else /* CONFIG_MEM_ALLOC_PROFILING */
+
+static inline void pgalloc_tag_add(struct page *page, struct task_struct *task,
+				   unsigned int nr) {}
+static inline void pgalloc_tag_sub(struct page *page, unsigned int nr) {}
+static inline void pgalloc_tag_sub_pages(struct page *page, unsigned int nr) {}
+
+#endif /* CONFIG_MEM_ALLOC_PROFILING */
+
 __always_inline bool free_pages_prepare(struct page *page,
 			unsigned int order)
 {
@@ -1096,8 +1227,12 @@ __always_inline bool free_pages_prepare(struct page *page,
 	if (unlikely(order)) {
 		int i;
 
-		if (compound)
+		if (compound) {
 			page[1].flags &= ~PAGE_FLAGS_SECOND;
+#ifdef NR_PAGES_IN_LARGE_FOLIO
+			folio->_nr_pages = 0;
+#endif
+		}
 		for (i = 1; i < (1 << order); i++) {
 			if (compound)
 				bad += free_tail_page_prepare(page, page + i);
@@ -1249,13 +1384,44 @@ static void split_large_buddy(struct zone *zone, struct page *page,
 	} while (1);
 }
 
+static void add_page_to_zone_llist(struct zone *zone, struct page *page,
+				   unsigned int order)
+{
+	/* Remember the order */
+	page->order = order;
+	/* Add the page to the free list */
+	llist_add(&page->pcp_llist, &zone->trylock_free_pages);
+}
+
 static void free_one_page(struct zone *zone, struct page *page,
 			  unsigned long pfn, unsigned int order,
 			  fpi_t fpi_flags)
 {
+	struct llist_head *llhead;
 	unsigned long flags;
 
-	spin_lock_irqsave(&zone->lock, flags);
+	if (!spin_trylock_irqsave(&zone->lock, flags)) {
+		if (unlikely(fpi_flags & FPI_TRYLOCK)) {
+			add_page_to_zone_llist(zone, page, order);
+			return;
+		}
+		spin_lock_irqsave(&zone->lock, flags);
+	}
+
+	/* The lock succeeded. Process deferred pages. */
+	llhead = &zone->trylock_free_pages;
+	if (unlikely(!llist_empty(llhead) && !(fpi_flags & FPI_TRYLOCK))) {
+		struct llist_node *llnode;
+		struct page *p, *tmp;
+
+		llnode = llist_del_all(llhead);
+		llist_for_each_entry_safe(p, tmp, llnode, pcp_llist) {
+			unsigned int p_order = p->order;
+
+			split_large_buddy(zone, p, page_to_pfn(p), p_order, fpi_flags);
+			__count_vm_events(PGFREE, 1 << p_order);
+		}
+	}
 	split_large_buddy(zone, page, pfn, order, fpi_flags);
 	spin_unlock_irqrestore(&zone->lock, flags);
 
@@ -1427,7 +1593,7 @@ static __always_inline void page_del_and_expand(struct zone *zone,
 
 static void check_new_page_bad(struct page *page)
 {
-	if (unlikely(page->flags & __PG_HWPOISON)) {
+	if (unlikely(PageHWPoison(page))) {
 		/* Don't complain about hwpoisoned pages */
 		if (PageBuddy(page))
 			__ClearPageBuddy(page);
@@ -1825,47 +1991,6 @@ static void change_pageblock_range(struct page *pageblock_page,
 	}
 }
 
-/*
- * When we are falling back to another migratetype during allocation, try to
- * steal extra free pages from the same pageblocks to satisfy further
- * allocations, instead of polluting multiple pageblocks.
- *
- * If we are stealing a relatively large buddy page, it is likely there will
- * be more free pages in the pageblock, so try to steal them all. For
- * reclaimable and unmovable allocations, we steal regardless of page size,
- * as fragmentation caused by those allocations polluting movable pageblocks
- * is worse than movable allocations stealing from unmovable and reclaimable
- * pageblocks.
- */
-static bool can_steal_fallback(unsigned int order, int start_mt)
-{
-	/*
-	 * Leaving this order check is intended, although there is
-	 * relaxed order check in next check. The reason is that
-	 * we can actually steal whole pageblock if this condition met,
-	 * but, below check doesn't guarantee it and that is just heuristic
-	 * so could be changed anytime.
-	 */
-	if (order >= pageblock_order)
-		return true;
-
-	/*
-	 * Movable pages won't cause permanent fragmentation, so when you alloc
-	 * small pages, you just need to temporarily steal unmovable or
-	 * reclaimable pages that are closest to the request size.  After a
-	 * while, memory compaction may occur to form large contiguous pages,
-	 * and the next movable allocation may not need to steal.  Unmovable and
-	 * reclaimable allocations need to actually steal pages.
-	 */
-	if (order >= pageblock_order / 2 ||
-		start_mt == MIGRATE_RECLAIMABLE ||
-		start_mt == MIGRATE_UNMOVABLE ||
-		page_group_by_mobility_disabled)
-		return true;
-
-	return false;
-}
-
 static inline bool boost_watermark(struct zone *zone)
 {
 	unsigned long max_boost;
@@ -1904,30 +2029,99 @@ static inline bool boost_watermark(struct zone *zone)
 }
 
 /*
- * This function implements actual steal behaviour. If order is large enough, we
- * can claim the whole pageblock for the requested migratetype. If not, we check
- * the pageblock for constituent pages; if at least half of the pages are free
- * or compatible, we can still claim the whole block, so pages freed in the
- * future will be put on the correct free list. Otherwise, we isolate exactly
- * the order we need from the fallback block and leave its migratetype alone.
+ * When we are falling back to another migratetype during allocation, should we
+ * try to claim an entire block to satisfy further allocations, instead of
+ * polluting multiple pageblocks?
  */
-static struct page *
-steal_suitable_fallback(struct zone *zone, struct page *page,
-			int current_order, int order, int start_type,
-			unsigned int alloc_flags, bool whole_block)
+static bool should_try_claim_block(unsigned int order, int start_mt)
 {
-	int free_pages, movable_pages, alike_pages;
-	unsigned long start_pfn;
-	int block_type;
+	/*
+	 * Leaving this order check is intended, although there is
+	 * relaxed order check in next check. The reason is that
+	 * we can actually claim the whole pageblock if this condition met,
+	 * but, below check doesn't guarantee it and that is just heuristic
+	 * so could be changed anytime.
+	 */
+	if (order >= pageblock_order)
+		return true;
 
-	block_type = get_pageblock_migratetype(page);
+	/*
+	 * Above a certain threshold, always try to claim, as it's likely there
+	 * will be more free pages in the pageblock.
+	 */
+	if (order >= pageblock_order / 2)
+		return true;
 
 	/*
-	 * This can happen due to races and we want to prevent broken
-	 * highatomic accounting.
+	 * Unmovable/reclaimable allocations would cause permanent
+	 * fragmentations if they fell back to allocating from a movable block
+	 * (polluting it), so we try to claim the whole block regardless of the
+	 * allocation size. Later movable allocations can always steal from this
+	 * block, which is less problematic.
 	 */
-	if (is_migrate_highatomic(block_type))
-		goto single_page;
+	if (start_mt == MIGRATE_RECLAIMABLE || start_mt == MIGRATE_UNMOVABLE)
+		return true;
+
+	if (page_group_by_mobility_disabled)
+		return true;
+
+	/*
+	 * Movable pages won't cause permanent fragmentation, so when you alloc
+	 * small pages, we just need to temporarily steal unmovable or
+	 * reclaimable pages that are closest to the request size. After a
+	 * while, memory compaction may occur to form large contiguous pages,
+	 * and the next movable allocation may not need to steal.
+	 */
+	return false;
+}
+
+/*
+ * Check whether there is a suitable fallback freepage with requested order.
+ * Sets *claim_block to instruct the caller whether it should convert a whole
+ * pageblock to the returned migratetype.
+ * If only_claim is true, this function returns fallback_mt only if
+ * we would do this whole-block claiming. This would help to reduce
+ * fragmentation due to mixed migratetype pages in one pageblock.
+ */
+int find_suitable_fallback(struct free_area *area, unsigned int order,
+			int migratetype, bool only_claim, bool *claim_block)
+{
+	int i;
+	int fallback_mt;
+
+	if (area->nr_free == 0)
+		return -1;
+
+	*claim_block = false;
+	for (i = 0; i < MIGRATE_PCPTYPES - 1 ; i++) {
+		fallback_mt = fallbacks[migratetype][i];
+		if (free_area_empty(area, fallback_mt))
+			continue;
+
+		if (should_try_claim_block(order, migratetype))
+			*claim_block = true;
+
+		if (*claim_block || !only_claim)
+			return fallback_mt;
+	}
+
+	return -1;
+}
+
+/*
+ * This function implements actual block claiming behaviour. If order is large
+ * enough, we can claim the whole pageblock for the requested migratetype. If
+ * not, we check the pageblock for constituent pages; if at least half of the
+ * pages are free or compatible, we can still claim the whole block, so pages
+ * freed in the future will be put on the correct free list.
+ */
+static struct page *
+try_to_claim_block(struct zone *zone, struct page *page,
+		   int current_order, int order, int start_type,
+		   int block_type, unsigned int alloc_flags)
+{
+	int free_pages, movable_pages, alike_pages;
+	unsigned long start_pfn;
 
 	/* Take ownership for orders >= pageblock_order */
 	if (current_order >= pageblock_order) {
@@ -1948,14 +2142,10 @@ steal_suitable_fallback(struct zone *zone, struct page *page,
 	if (boost_watermark(zone) && (alloc_flags & ALLOC_KSWAPD))
 		set_bit(ZONE_BOOSTED_WATERMARK, &zone->flags);
 
-	/* We are not allowed to try stealing from the whole block */
-	if (!whole_block)
-		goto single_page;
-
 	/* moving whole block can fail due to zone boundary conditions */
 	if (!prep_move_freepages_block(zone, page, &start_pfn, &free_pages,
 				       &movable_pages))
-		goto single_page;
+		return NULL;
 
 	/*
 	 * Determine how many pages are compatible with our allocation.
@@ -1988,198 +2178,24 @@ steal_suitable_fallback(struct zone *zone, struct page *page,
 		return __rmqueue_smallest(zone, order, start_type);
 	}
 
-single_page:
-	page_del_and_expand(zone, page, order, current_order, block_type);
-	return page;
-}
-
-/*
- * Check whether there is a suitable fallback freepage with requested order.
- * If only_stealable is true, this function returns fallback_mt only if
- * we can steal other freepages all together. This would help to reduce
- * fragmentation due to mixed migratetype pages in one pageblock.
- */
-int find_suitable_fallback(struct free_area *area, unsigned int order,
-			int migratetype, bool only_stealable, bool *can_steal)
-{
-	int i;
-	int fallback_mt;
-
-	if (area->nr_free == 0)
-		return -1;
-
-	*can_steal = false;
-	for (i = 0; i < MIGRATE_PCPTYPES - 1 ; i++) {
-		fallback_mt = fallbacks[migratetype][i];
-		if (free_area_empty(area, fallback_mt))
-			continue;
-
-		if (can_steal_fallback(order, migratetype))
-			*can_steal = true;
-
-		if (!only_stealable)
-			return fallback_mt;
-
-		if (*can_steal)
-			return fallback_mt;
-	}
-
-	return -1;
-}
-
-/*
- * Reserve the pageblock(s) surrounding an allocation request for
- * exclusive use of high-order atomic allocations if there are no
- * empty page blocks that contain a page with a suitable order
- */
-static void reserve_highatomic_pageblock(struct page *page, int order,
-					 struct zone *zone)
-{
-	int mt;
-	unsigned long max_managed, flags;
-
-	/*
-	 * The number reserved as: minimum is 1 pageblock, maximum is
-	 * roughly 1% of a zone. But if 1% of a zone falls below a
-	 * pageblock size, then don't reserve any pageblocks.
-	 * Check is race-prone but harmless.
-	 */
-	if ((zone_managed_pages(zone) / 100) < pageblock_nr_pages)
-		return;
-	max_managed = ALIGN((zone_managed_pages(zone) / 100), pageblock_nr_pages);
-	if (zone->nr_reserved_highatomic >= max_managed)
-		return;
-
-	spin_lock_irqsave(&zone->lock, flags);
-
-	/* Recheck the nr_reserved_highatomic limit under the lock */
-	if (zone->nr_reserved_highatomic >= max_managed)
-		goto out_unlock;
-
-	/* Yoink! */
-	mt = get_pageblock_migratetype(page);
-	/* Only reserve normal pageblocks (i.e., they can merge with others) */
-	if (!migratetype_is_mergeable(mt))
-		goto out_unlock;
-
-	if (order < pageblock_order) {
-		if (move_freepages_block(zone, page, mt, MIGRATE_HIGHATOMIC) == -1)
-			goto out_unlock;
-		zone->nr_reserved_highatomic += pageblock_nr_pages;
-	} else {
-		change_pageblock_range(page, order, MIGRATE_HIGHATOMIC);
-		zone->nr_reserved_highatomic += 1 << order;
-	}
-
-out_unlock:
-	spin_unlock_irqrestore(&zone->lock, flags);
+	return NULL;
 }
 
 /*
- * Used when an allocation is about to fail under memory pressure. This
- * potentially hurts the reliability of high-order allocations when under
- * intense memory pressure but failed atomic allocations should be easier
- * to recover from than an OOM.
+ * Try finding a free buddy page on the fallback list.
  *
- * If @force is true, try to unreserve pageblocks even though highatomic
- * pageblock is exhausted.
- */
-static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
-						bool force)
-{
-	struct zonelist *zonelist = ac->zonelist;
-	unsigned long flags;
-	struct zoneref *z;
-	struct zone *zone;
-	struct page *page;
-	int order;
-	int ret;
-
-	for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->highest_zoneidx,
-								ac->nodemask) {
-		/*
-		 * Preserve at least one pageblock unless memory pressure
-		 * is really high.
-		 */
-		if (!force && zone->nr_reserved_highatomic <=
-					pageblock_nr_pages)
-			continue;
-
-		spin_lock_irqsave(&zone->lock, flags);
-		for (order = 0; order < NR_PAGE_ORDERS; order++) {
-			struct free_area *area = &(zone->free_area[order]);
-			int mt;
-
-			page = get_page_from_free_area(area, MIGRATE_HIGHATOMIC);
-			if (!page)
-				continue;
-
-			mt = get_pageblock_migratetype(page);
-			/*
-			 * In page freeing path, migratetype change is racy so
-			 * we can counter several free pages in a pageblock
-			 * in this loop although we changed the pageblock type
-			 * from highatomic to ac->migratetype. So we should
-			 * adjust the count once.
-			 */
-			if (is_migrate_highatomic(mt)) {
-				unsigned long size;
-				/*
-				 * It should never happen but changes to
-				 * locking could inadvertently allow a per-cpu
-				 * drain to add pages to MIGRATE_HIGHATOMIC
-				 * while unreserving so be safe and watch for
-				 * underflows.
-				 */
-				size = max(pageblock_nr_pages, 1UL << order);
-				size = min(size, zone->nr_reserved_highatomic);
-				zone->nr_reserved_highatomic -= size;
-			}
-
-			/*
-			 * Convert to ac->migratetype and avoid the normal
-			 * pageblock stealing heuristics. Minimally, the caller
-			 * is doing the work and needs the pages. More
-			 * importantly, if the block was always converted to
-			 * MIGRATE_UNMOVABLE or another type then the number
-			 * of pageblocks that cannot be completely freed
-			 * may increase.
-			 */
-			if (order < pageblock_order)
-				ret = move_freepages_block(zone, page, mt,
-							   ac->migratetype);
-			else {
-				move_to_free_list(page, zone, order, mt,
-						  ac->migratetype);
-				change_pageblock_range(page, order,
-						       ac->migratetype);
-				ret = 1;
-			}
-			/*
-			 * Reserving the block(s) already succeeded,
-			 * so this should not fail on zone boundaries.
-			 */
-			WARN_ON_ONCE(ret == -1);
-			if (ret > 0) {
-				spin_unlock_irqrestore(&zone->lock, flags);
-				return ret;
-			}
-		}
-		spin_unlock_irqrestore(&zone->lock, flags);
-	}
-
-	return false;
-}
-
-/*
- * Try finding a free buddy page on the fallback list and put it on the free
- * list of requested migratetype, possibly along with other pages from the same
- * block, depending on fragmentation avoidance heuristics. Returns true if
- * fallback was found so that __rmqueue_smallest() can grab it.
+ * This will attempt to claim a whole pageblock for the requested type
+ * to ensure grouping of such requests in the future.
+ *
+ * If a whole block cannot be claimed, steal an individual page, regressing to
+ * __rmqueue_smallest() logic to at least break up as little contiguity as
+ * possible.
  *
  * The use of signed ints for order and current_order is a deliberate
  * deviation from the rest of this file, to make the for loop
  * condition simpler.
+ *
+ * Return the stolen page, or NULL if none can be found.
  */
 static __always_inline struct page *
 __rmqueue_fallback(struct zone *zone, int order, int start_migratetype,
@@ -2190,7 +2206,7 @@ __rmqueue_fallback(struct zone *zone, int order, int start_migratetype,
 	int min_order = order;
 	struct page *page;
 	int fallback_mt;
-	bool can_steal;
+	bool claim_block;
 
 	/*
 	 * Do not steal pages from freelists belonging to other pageblocks
@@ -2209,49 +2225,40 @@ __rmqueue_fallback(struct zone *zone, int order, int start_migratetype,
 				--current_order) {
 		area = &(zone->free_area[current_order]);
 		fallback_mt = find_suitable_fallback(area, current_order,
-				start_migratetype, false, &can_steal);
+				start_migratetype, false, &claim_block);
 		if (fallback_mt == -1)
 			continue;
 
-		/*
-		 * We cannot steal all free pages from the pageblock and the
-		 * requested migratetype is movable. In that case it's better to
-		 * steal and split the smallest available page instead of the
-		 * largest available page, because even if the next movable
-		 * allocation falls back into a different pageblock than this
-		 * one, it won't cause permanent fragmentation.
-		 */
-		if (!can_steal && start_migratetype == MIGRATE_MOVABLE
-					&& current_order > order)
-			goto find_smallest;
+		if (!claim_block)
+			break;
 
-		goto do_steal;
+		page = get_page_from_free_area(area, fallback_mt);
+		page = try_to_claim_block(zone, page, current_order, order,
+					  start_migratetype, fallback_mt,
+					  alloc_flags);
+		if (page)
+			goto got_one;
 	}
 
-	return NULL;
+	if (alloc_flags & ALLOC_NOFRAGMENT)
+		return NULL;
 
-find_smallest:
+	/* No luck claiming pageblock. Find the smallest fallback page */
 	for (current_order = order; current_order < NR_PAGE_ORDERS; current_order++) {
 		area = &(zone->free_area[current_order]);
 		fallback_mt = find_suitable_fallback(area, current_order,
-				start_migratetype, false, &can_steal);
-		if (fallback_mt != -1)
-			break;
-	}
-
-	/*
-	 * This should not happen - we already found a suitable fallback
-	 * when looking for the largest page.
-	 */
-	VM_BUG_ON(current_order > MAX_PAGE_ORDER);
+				start_migratetype, false, &claim_block);
+		if (fallback_mt == -1)
+			continue;
 
-do_steal:
-	page = get_page_from_free_area(area, fallback_mt);
+		page = get_page_from_free_area(area, fallback_mt);
+		page_del_and_expand(zone, page, order, current_order, fallback_mt);
+		goto got_one;
+	}
 
-	/* take off list, maybe claim block, expand remainder */
-	page = steal_suitable_fallback(zone, page, current_order, order,
-				       start_migratetype, alloc_flags, can_steal);
+	return NULL;
 
+got_one:
 	trace_mm_page_alloc_extfrag(page, order, current_order,
 		start_migratetype, fallback_mt);
 
@@ -2307,7 +2314,11 @@ static int rmqueue_bulk(struct zone *zone, unsigned int order,
 	unsigned long flags;
 	int i;
 
-	spin_lock_irqsave(&zone->lock, flags);
+	if (!spin_trylock_irqsave(&zone->lock, flags)) {
+		if (unlikely(alloc_flags & ALLOC_TRYLOCK))
+			return 0;
+		spin_lock_irqsave(&zone->lock, flags);
+	}
 	for (i = 0; i < count; ++i) {
 		struct page *page = __rmqueue(zone, order, migratetype,
 								alloc_flags);
@@ -2595,7 +2606,7 @@ static int nr_pcp_high(struct per_cpu_pages *pcp, struct zone *zone,
 
 static void free_frozen_page_commit(struct zone *zone,
 		struct per_cpu_pages *pcp, struct page *page, int migratetype,
-		unsigned int order)
+		unsigned int order, fpi_t fpi_flags)
 {
 	int high, batch;
 	int pindex;
@@ -2630,6 +2641,14 @@ static void free_frozen_page_commit(struct zone *zone,
 	}
 	if (pcp->free_count < (batch << CONFIG_PCP_BATCH_SCALE_MAX))
 		pcp->free_count += (1 << order);
+
+	if (unlikely(fpi_flags & FPI_TRYLOCK)) {
+		/*
+		 * Do not attempt to take a zone lock. Let pcp->count get
+		 * over high mark temporarily.
+		 */
+		return;
+	}
 	high = nr_pcp_high(pcp, zone, batch, free_high);
 	if (pcp->count >= high) {
 		free_pcppages_bulk(zone, nr_pcp_free(pcp, batch, high, free_high),
@@ -2644,7 +2663,8 @@ static void free_frozen_page_commit(struct zone *zone,
 /*
  * Free a pcp page
  */
-void free_frozen_pages(struct page *page, unsigned int order)
+static void __free_frozen_pages(struct page *page, unsigned int order,
+				fpi_t fpi_flags)
 {
 	unsigned long __maybe_unused UP_flags;
 	struct per_cpu_pages *pcp;
@@ -2653,7 +2673,7 @@ void free_frozen_pages(struct page *page, unsigned int order)
 	int migratetype;
 
 	if (!pcp_allowed_order(order)) {
-		__free_pages_ok(page, order, FPI_NONE);
+		__free_pages_ok(page, order, fpi_flags);
 		return;
 	}
 
@@ -2671,23 +2691,33 @@ void free_frozen_pages(struct page *page, unsigned int order)
 	migratetype = get_pfnblock_migratetype(page, pfn);
 	if (unlikely(migratetype >= MIGRATE_PCPTYPES)) {
 		if (unlikely(is_migrate_isolate(migratetype))) {
-			free_one_page(zone, page, pfn, order, FPI_NONE);
+			free_one_page(zone, page, pfn, order, fpi_flags);
 			return;
 		}
 		migratetype = MIGRATE_MOVABLE;
 	}
 
+	if (unlikely((fpi_flags & FPI_TRYLOCK) && IS_ENABLED(CONFIG_PREEMPT_RT)
+		     && (in_nmi() || in_hardirq()))) {
+		add_page_to_zone_llist(zone, page, order);
+		return;
+	}
 	pcp_trylock_prepare(UP_flags);
 	pcp = pcp_spin_trylock(zone->per_cpu_pageset);
 	if (pcp) {
-		free_frozen_page_commit(zone, pcp, page, migratetype, order);
+		free_frozen_page_commit(zone, pcp, page, migratetype, order, fpi_flags);
 		pcp_spin_unlock(pcp);
 	} else {
-		free_one_page(zone, page, pfn, order, FPI_NONE);
+		free_one_page(zone, page, pfn, order, fpi_flags);
 	}
 	pcp_trylock_finish(UP_flags);
 }
 
+void free_frozen_pages(struct page *page, unsigned int order)
+{
+	__free_frozen_pages(page, order, FPI_NONE);
+}
+
 /*
  * Free a batch of folios
  */
@@ -2776,7 +2806,7 @@ void free_unref_folios(struct folio_batch *folios)
 
 		trace_mm_page_free_batched(&folio->page);
 		free_frozen_page_commit(zone, pcp, &folio->page, migratetype,
-				order);
+					order, FPI_NONE);
 	}
 
 	if (pcp) {
@@ -2805,7 +2835,7 @@ void split_page(struct page *page, unsigned int order)
 		set_page_refcounted(page + i);
 	split_page_owner(page, order, 0);
 	pgalloc_tag_split(page_folio(page), order, 0);
-	split_page_memcg(page, order, 0);
+	split_page_memcg(page, order);
 }
 EXPORT_SYMBOL_GPL(split_page);
 
@@ -2907,7 +2937,11 @@ struct page *rmqueue_buddy(struct zone *preferred_zone, struct zone *zone,
 
 	do {
 		page = NULL;
-		spin_lock_irqsave(&zone->lock, flags);
+		if (!spin_trylock_irqsave(&zone->lock, flags)) {
+			if (unlikely(alloc_flags & ALLOC_TRYLOCK))
+				return NULL;
+			spin_lock_irqsave(&zone->lock, flags);
+		}
 		if (alloc_flags & ALLOC_HIGHATOMIC)
 			page = __rmqueue_smallest(zone, order, MIGRATE_HIGHATOMIC);
 		if (!page) {
@@ -3095,6 +3129,142 @@ out:
 	return page;
 }
 
+/*
+ * Reserve the pageblock(s) surrounding an allocation request for
+ * exclusive use of high-order atomic allocations if there are no
+ * empty page blocks that contain a page with a suitable order
+ */
+static void reserve_highatomic_pageblock(struct page *page, int order,
+					 struct zone *zone)
+{
+	int mt;
+	unsigned long max_managed, flags;
+
+	/*
+	 * The number reserved as: minimum is 1 pageblock, maximum is
+	 * roughly 1% of a zone. But if 1% of a zone falls below a
+	 * pageblock size, then don't reserve any pageblocks.
+	 * Check is race-prone but harmless.
+	 */
+	if ((zone_managed_pages(zone) / 100) < pageblock_nr_pages)
+		return;
+	max_managed = ALIGN((zone_managed_pages(zone) / 100), pageblock_nr_pages);
+	if (zone->nr_reserved_highatomic >= max_managed)
+		return;
+
+	spin_lock_irqsave(&zone->lock, flags);
+
+	/* Recheck the nr_reserved_highatomic limit under the lock */
+	if (zone->nr_reserved_highatomic >= max_managed)
+		goto out_unlock;
+
+	/* Yoink! */
+	mt = get_pageblock_migratetype(page);
+	/* Only reserve normal pageblocks (i.e., they can merge with others) */
+	if (!migratetype_is_mergeable(mt))
+		goto out_unlock;
+
+	if (order < pageblock_order) {
+		if (move_freepages_block(zone, page, mt, MIGRATE_HIGHATOMIC) == -1)
+			goto out_unlock;
+		zone->nr_reserved_highatomic += pageblock_nr_pages;
+	} else {
+		change_pageblock_range(page, order, MIGRATE_HIGHATOMIC);
+		zone->nr_reserved_highatomic += 1 << order;
+	}
+
+out_unlock:
+	spin_unlock_irqrestore(&zone->lock, flags);
+}
+
+/*
+ * Used when an allocation is about to fail under memory pressure. This
+ * potentially hurts the reliability of high-order allocations when under
+ * intense memory pressure but failed atomic allocations should be easier
+ * to recover from than an OOM.
+ *
+ * If @force is true, try to unreserve pageblocks even though highatomic
+ * pageblock is exhausted.
+ */
+static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
+						bool force)
+{
+	struct zonelist *zonelist = ac->zonelist;
+	unsigned long flags;
+	struct zoneref *z;
+	struct zone *zone;
+	struct page *page;
+	int order;
+	int ret;
+
+	for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->highest_zoneidx,
+								ac->nodemask) {
+		/*
+		 * Preserve at least one pageblock unless memory pressure
+		 * is really high.
+		 */
+		if (!force && zone->nr_reserved_highatomic <=
+					pageblock_nr_pages)
+			continue;
+
+		spin_lock_irqsave(&zone->lock, flags);
+		for (order = 0; order < NR_PAGE_ORDERS; order++) {
+			struct free_area *area = &(zone->free_area[order]);
+			unsigned long size;
+
+			page = get_page_from_free_area(area, MIGRATE_HIGHATOMIC);
+			if (!page)
+				continue;
+
+			size = max(pageblock_nr_pages, 1UL << order);
+			/*
+			 * It should never happen but changes to
+			 * locking could inadvertently allow a per-cpu
+			 * drain to add pages to MIGRATE_HIGHATOMIC
+			 * while unreserving so be safe and watch for
+			 * underflows.
+			 */
+			if (WARN_ON_ONCE(size > zone->nr_reserved_highatomic))
+				size = zone->nr_reserved_highatomic;
+			zone->nr_reserved_highatomic -= size;
+
+			/*
+			 * Convert to ac->migratetype and avoid the normal
+			 * pageblock stealing heuristics. Minimally, the caller
+			 * is doing the work and needs the pages. More
+			 * importantly, if the block was always converted to
+			 * MIGRATE_UNMOVABLE or another type then the number
+			 * of pageblocks that cannot be completely freed
+			 * may increase.
+			 */
+			if (order < pageblock_order)
+				ret = move_freepages_block(zone, page,
+							   MIGRATE_HIGHATOMIC,
+							   ac->migratetype);
+			else {
+				move_to_free_list(page, zone, order,
+						  MIGRATE_HIGHATOMIC,
+						  ac->migratetype);
+				change_pageblock_range(page, order,
+						       ac->migratetype);
+				ret = 1;
+			}
+			/*
+			 * Reserving the block(s) already succeeded,
+			 * so this should not fail on zone boundaries.
+			 */
+			WARN_ON_ONCE(ret == -1);
+			if (ret > 0) {
+				spin_unlock_irqrestore(&zone->lock, flags);
+				return ret;
+			}
+		}
+		spin_unlock_irqrestore(&zone->lock, flags);
+	}
+
+	return false;
+}
+
 static inline long __zone_watermark_unusable_free(struct zone *z,
 				unsigned int order, unsigned int alloc_flags)
 {
@@ -3298,6 +3468,11 @@ alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask)
 	 */
 	alloc_flags = (__force int) (gfp_mask & __GFP_KSWAPD_RECLAIM);
 
+	if (defrag_mode) {
+		alloc_flags |= ALLOC_NOFRAGMENT;
+		return alloc_flags;
+	}
+
 #ifdef CONFIG_ZONE_DMA32
 	if (!zone)
 		return alloc_flags;
@@ -3389,7 +3564,7 @@ retry:
 				continue;
 		}
 
-		if (no_fallback && nr_online_nodes > 1 &&
+		if (no_fallback && !defrag_mode && nr_online_nodes > 1 &&
 		    zone != zonelist_zone(ac->preferred_zoneref)) {
 			int local_nid;
 
@@ -3500,7 +3675,7 @@ try_this_zone:
 	 * It's possible on a UMA machine to get through all zones that are
 	 * fragmented. If avoiding fragmentation, reset and try again.
 	 */
-	if (no_fallback) {
+	if (no_fallback && !defrag_mode) {
 		alloc_flags &= ~ALLOC_NOFRAGMENT;
 		goto retry;
 	}
@@ -3979,15 +4154,21 @@ static void wake_all_kswapds(unsigned int order, gfp_t gfp_mask,
 	struct zone *zone;
 	pg_data_t *last_pgdat = NULL;
 	enum zone_type highest_zoneidx = ac->highest_zoneidx;
+	unsigned int reclaim_order;
+
+	if (defrag_mode)
+		reclaim_order = max(order, pageblock_order);
+	else
+		reclaim_order = order;
 
 	for_each_zone_zonelist_nodemask(zone, z, ac->zonelist, highest_zoneidx,
 					ac->nodemask) {
 		if (!managed_zone(zone))
 			continue;
-		if (last_pgdat != zone->zone_pgdat) {
-			wakeup_kswapd(zone, gfp_mask, order, highest_zoneidx);
-			last_pgdat = zone->zone_pgdat;
-		}
+		if (last_pgdat == zone->zone_pgdat)
+			continue;
+		wakeup_kswapd(zone, gfp_mask, reclaim_order, highest_zoneidx);
+		last_pgdat = zone->zone_pgdat;
 	}
 }
 
@@ -4037,6 +4218,9 @@ gfp_to_alloc_flags(gfp_t gfp_mask, unsigned int order)
 
 	alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, alloc_flags);
 
+	if (defrag_mode)
+		alloc_flags |= ALLOC_NOFRAGMENT;
+
 	return alloc_flags;
 }
 
@@ -4243,6 +4427,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
 restart:
 	compaction_retries = 0;
 	no_progress_loops = 0;
+	compact_result = COMPACT_SKIPPED;
 	compact_priority = DEF_COMPACT_PRIORITY;
 	cpuset_mems_cookie = read_mems_allowed_begin();
 	zonelist_iter_cookie = zonelist_iter_begin();
@@ -4418,6 +4603,11 @@ retry:
 				&compaction_retries))
 		goto retry;
 
+	/* Reclaim/compaction failed to prevent the fallback */
+	if (defrag_mode && (alloc_flags & ALLOC_NOFRAGMENT)) {
+		alloc_flags &= ~ALLOC_NOFRAGMENT;
+		goto retry;
+	}
 
 	/*
 	 * Deal with possible cpuset update races or zonelist updates to avoid
@@ -4511,7 +4701,12 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order,
 
 	might_alloc(gfp_mask);
 
-	if (should_fail_alloc_page(gfp_mask, order))
+	/*
+	 * Don't invoke should_fail logic, since it may call
+	 * get_random_u32() and printk() which need to spin_lock.
+	 */
+	if (!(*alloc_flags & ALLOC_TRYLOCK) &&
+	    should_fail_alloc_page(gfp_mask, order))
 		return false;
 
 	*alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, *alloc_flags);
@@ -4809,9 +5004,10 @@ unsigned long get_zeroed_page_noprof(gfp_t gfp_mask)
 EXPORT_SYMBOL(get_zeroed_page_noprof);
 
 /**
- * __free_pages - Free pages allocated with alloc_pages().
+ * ___free_pages - Free pages allocated with alloc_pages().
  * @page: The page pointer returned from alloc_pages().
  * @order: The order of the allocation.
+ * @fpi_flags: Free Page Internal flags.
  *
  * This function can free multi-page allocations that are not compound
  * pages.  It does not check that the @order passed in matches that of
@@ -4828,22 +5024,36 @@ EXPORT_SYMBOL(get_zeroed_page_noprof);
  * Context: May be called in interrupt context or while holding a normal
  * spinlock, but not in NMI context or while holding a raw spinlock.
  */
-void __free_pages(struct page *page, unsigned int order)
+static void ___free_pages(struct page *page, unsigned int order,
+			  fpi_t fpi_flags)
 {
 	/* get PageHead before we drop reference */
 	int head = PageHead(page);
-	struct alloc_tag *tag = pgalloc_tag_get(page);
 
 	if (put_page_testzero(page))
-		free_frozen_pages(page, order);
+		__free_frozen_pages(page, order, fpi_flags);
 	else if (!head) {
-		pgalloc_tag_sub_pages(tag, (1 << order) - 1);
+		pgalloc_tag_sub_pages(page, (1 << order) - 1);
 		while (order-- > 0)
-			free_frozen_pages(page + (1 << order), order);
+			__free_frozen_pages(page + (1 << order), order,
+					    fpi_flags);
 	}
 }
+void __free_pages(struct page *page, unsigned int order)
+{
+	___free_pages(page, order, FPI_NONE);
+}
 EXPORT_SYMBOL(__free_pages);
 
+/*
+ * Can be called while holding raw_spin_lock or from IRQ and NMI for any
+ * page type (not only those that came from try_alloc_pages)
+ */
+void free_pages_nolock(struct page *page, unsigned int order)
+{
+	___free_pages(page, order, FPI_TRYLOCK);
+}
+
 void free_pages(unsigned long addr, unsigned int order)
 {
 	if (addr != 0) {
@@ -4864,7 +5074,7 @@ static void *make_alloc_exact(unsigned long addr, unsigned int order,
 
 		split_page_owner(page, order, 0);
 		pgalloc_tag_split(page_folio(page), order, 0);
-		split_page_memcg(page, order, 0);
+		split_page_memcg(page, order);
 		while (page < --last)
 			set_page_refcounted(last);
 
@@ -5827,6 +6037,7 @@ static void calculate_totalreserve_pages(void)
 		}
 	}
 	totalreserve_pages = reserve_pages;
+	trace_mm_calculate_totalreserve_pages(totalreserve_pages);
 }
 
 /*
@@ -5849,14 +6060,15 @@ static void setup_per_zone_lowmem_reserve(void)
 
 			for (j = i + 1; j < MAX_NR_ZONES; j++) {
 				struct zone *upper_zone = &pgdat->node_zones[j];
-				bool empty = !zone_managed_pages(upper_zone);
 
 				managed_pages += zone_managed_pages(upper_zone);
 
-				if (clear || empty)
+				if (clear)
 					zone->lowmem_reserve[j] = 0;
 				else
 					zone->lowmem_reserve[j] = managed_pages / ratio;
+				trace_mm_setup_per_zone_lowmem_reserve(zone, upper_zone,
+								       zone->lowmem_reserve[j]);
 			}
 		}
 	}
@@ -5920,6 +6132,7 @@ static void __setup_per_zone_wmarks(void)
 		zone->_watermark[WMARK_LOW]  = min_wmark_pages(zone) + tmp;
 		zone->_watermark[WMARK_HIGH] = low_wmark_pages(zone) + tmp;
 		zone->_watermark[WMARK_PROMO] = high_wmark_pages(zone) + tmp;
+		trace_mm_setup_per_zone_wmarks(zone);
 
 		spin_unlock_irqrestore(&zone->lock, flags);
 	}
@@ -6193,6 +6406,15 @@ static const struct ctl_table page_alloc_sysctl_table[] = {
 		.extra2		= SYSCTL_THREE_THOUSAND,
 	},
 	{
+		.procname	= "defrag_mode",
+		.data		= &defrag_mode,
+		.maxlen		= sizeof(defrag_mode),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	},
+	{
 		.procname	= "percpu_pagelist_high_fraction",
 		.data		= &percpu_pagelist_high_fraction,
 		.maxlen		= sizeof(percpu_pagelist_high_fraction),
@@ -7004,7 +7226,7 @@ static inline bool has_unaccepted_memory(void)
 
 static bool cond_accept_memory(struct zone *zone, unsigned int order)
 {
-	long to_accept;
+	long to_accept, wmark;
 	bool ret = false;
 
 	if (!has_unaccepted_memory())
@@ -7013,8 +7235,18 @@ static bool cond_accept_memory(struct zone *zone, unsigned int order)
 	if (list_empty(&zone->unaccepted_pages))
 		return false;
 
+	wmark = promo_wmark_pages(zone);
+
+	/*
+	 * Watermarks have not been initialized yet.
+	 *
+	 * Accepting one MAX_ORDER page to ensure progress.
+	 */
+	if (!wmark)
+		return try_to_accept_memory_one(zone);
+
 	/* How much to accept to get to promo watermark? */
-	to_accept = promo_wmark_pages(zone) -
+	to_accept = wmark -
 		    (zone_page_state(zone, NR_FREE_PAGES) -
 		    __zone_watermark_unusable_free(zone, order, 0) -
 		    zone_page_state(zone, NR_UNACCEPTED));
@@ -7071,3 +7303,97 @@ static bool __free_unaccepted(struct page *page)
 }
 
 #endif /* CONFIG_UNACCEPTED_MEMORY */
+
+/**
+ * try_alloc_pages - opportunistic reentrant allocation from any context
+ * @nid: node to allocate from
+ * @order: allocation order size
+ *
+ * Allocates pages of a given order from the given node. This is safe to
+ * call from any context (from atomic, NMI, and also reentrant
+ * allocator -> tracepoint -> try_alloc_pages_noprof).
+ * Allocation is best effort and to be expected to fail easily so nobody should
+ * rely on the success. Failures are not reported via warn_alloc().
+ * See always fail conditions below.
+ *
+ * Return: allocated page or NULL on failure.
+ */
+struct page *try_alloc_pages_noprof(int nid, unsigned int order)
+{
+	/*
+	 * Do not specify __GFP_DIRECT_RECLAIM, since direct claim is not allowed.
+	 * Do not specify __GFP_KSWAPD_RECLAIM either, since wake up of kswapd
+	 * is not safe in arbitrary context.
+	 *
+	 * These two are the conditions for gfpflags_allow_spinning() being true.
+	 *
+	 * Specify __GFP_NOWARN since failing try_alloc_pages() is not a reason
+	 * to warn. Also warn would trigger printk() which is unsafe from
+	 * various contexts. We cannot use printk_deferred_enter() to mitigate,
+	 * since the running context is unknown.
+	 *
+	 * Specify __GFP_ZERO to make sure that call to kmsan_alloc_page() below
+	 * is safe in any context. Also zeroing the page is mandatory for
+	 * BPF use cases.
+	 *
+	 * Though __GFP_NOMEMALLOC is not checked in the code path below,
+	 * specify it here to highlight that try_alloc_pages()
+	 * doesn't want to deplete reserves.
+	 */
+	gfp_t alloc_gfp = __GFP_NOWARN | __GFP_ZERO | __GFP_NOMEMALLOC
+			| __GFP_ACCOUNT;
+	unsigned int alloc_flags = ALLOC_TRYLOCK;
+	struct alloc_context ac = { };
+	struct page *page;
+
+	/*
+	 * In PREEMPT_RT spin_trylock() will call raw_spin_lock() which is
+	 * unsafe in NMI. If spin_trylock() is called from hard IRQ the current
+	 * task may be waiting for one rt_spin_lock, but rt_spin_trylock() will
+	 * mark the task as the owner of another rt_spin_lock which will
+	 * confuse PI logic, so return immediately if called form hard IRQ or
+	 * NMI.
+	 *
+	 * Note, irqs_disabled() case is ok. This function can be called
+	 * from raw_spin_lock_irqsave region.
+	 */
+	if (IS_ENABLED(CONFIG_PREEMPT_RT) && (in_nmi() || in_hardirq()))
+		return NULL;
+	if (!pcp_allowed_order(order))
+		return NULL;
+
+#ifdef CONFIG_UNACCEPTED_MEMORY
+	/* Bailout, since try_to_accept_memory_one() needs to take a lock */
+	if (has_unaccepted_memory())
+		return NULL;
+#endif
+	/* Bailout, since _deferred_grow_zone() needs to take a lock */
+	if (deferred_pages_enabled())
+		return NULL;
+
+	if (nid == NUMA_NO_NODE)
+		nid = numa_node_id();
+
+	prepare_alloc_pages(alloc_gfp, order, nid, NULL, &ac,
+			    &alloc_gfp, &alloc_flags);
+
+	/*
+	 * Best effort allocation from percpu free list.
+	 * If it's empty attempt to spin_trylock zone->lock.
+	 */
+	page = get_page_from_freelist(alloc_gfp, order, alloc_flags, &ac);
+
+	/* Unlike regular alloc_pages() there is no __alloc_pages_slowpath(). */
+
+	if (page)
+		set_page_refcounted(page);
+
+	if (memcg_kmem_online() && page &&
+	    unlikely(__memcg_kmem_charge_page(page, alloc_gfp, order) != 0)) {
+		free_pages_nolock(page, order);
+		page = NULL;
+	}
+	trace_mm_page_alloc(page, order, alloc_gfp, ac.migratetype);
+	kmsan_alloc_page(page, order, alloc_gfp);
+	return page;
+}