Merge tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
   from hotplugged memory rather than only from main memory. Series
   "implement "memmap on memory" feature on s390".

 - More folio conversions from Matthew Wilcox in the series

	"Convert memcontrol charge moving to use folios"
	"mm: convert mm counter to take a folio"

 - Chengming Zhou has optimized zswap's rbtree locking, providing
   significant reductions in system time and modest but measurable
   reductions in overall runtimes. The series is "mm/zswap: optimize the
   scalability of zswap rb-tree".

 - Chengming Zhou has also provided the series "mm/zswap: optimize zswap
   lru list" which provides measurable runtime benefits in some
   swap-intensive situations.

 - And Chengming Zhou further optimizes zswap in the series "mm/zswap:
   optimize for dynamic zswap_pools". Measured improvements are modest.

 - zswap cleanups and simplifications from Yosry Ahmed in the series
   "mm: zswap: simplify zswap_swapoff()".

 - In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
   contributed several DAX cleanups as well as adding a sysfs tunable to
   control the memmap_on_memory setting when the dax device is
   hotplugged as system memory.

 - Johannes Weiner has added the large series "mm: zswap: cleanups",
   which does that.

 - More DAMON work from SeongJae Park in the series

	"mm/damon: make DAMON debugfs interface deprecation unignorable"
	"selftests/damon: add more tests for core functionalities and corner cases"
	"Docs/mm/damon: misc readability improvements"
	"mm/damon: let DAMOS feeds and tame/auto-tune itself"

 - In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
   extension" Rakie Kim has developed a new mempolicy interleaving
   policy wherein we allocate memory across nodes in a weighted fashion
   rather than uniformly. This is beneficial in heterogeneous memory
   environments appearing with CXL.

 - Christophe Leroy has contributed some cleanup and consolidation work
   against the ARM pagetable dumping code in the series "mm: ptdump:
   Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".

 - Luis Chamberlain has added some additional xarray selftesting in the
   series "test_xarray: advanced API multi-index tests".

 - Muhammad Usama Anjum has reworked the selftest code to make its
   human-readable output conform to the TAP ("Test Anything Protocol")
   format. Amongst other things, this opens up the use of third-party
   tools to parse and process out selftesting results.

 - Ryan Roberts has added fork()-time PTE batching of THP ptes in the
   series "mm/memory: optimize fork() with PTE-mapped THP". Mainly
   targeted at arm64, this significantly speeds up fork() when the
   process has a large number of pte-mapped folios.

 - David Hildenbrand also gets in on the THP pte batching game in his
   series "mm/memory: optimize unmap/zap with PTE-mapped THP". It
   implements batching during munmap() and other pte teardown
   situations. The microbenchmark improvements are nice.

 - And in the series "Transparent Contiguous PTEs for User Mappings"
   Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte
   mappings"). Kernel build times on arm64 improved nicely. Ryan's
   series "Address some contpte nits" provides some followup work.

 - In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
   fixed an obscure hugetlb race which was causing unnecessary page
   faults. He has also added a reproducer under the selftest code.

 - In the series "selftests/mm: Output cleanups for the compaction
   test", Mark Brown did what the title claims.

 - Kinsey Ho has added the series "mm/mglru: code cleanup and
   refactoring".

 - Even more zswap material from Nhat Pham. The series "fix and extend
   zswap kselftests" does as claimed.

 - In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
   regression" Mathieu Desnoyers has cleaned up and fixed rather a mess
   in our handling of DAX on archiecctures which have virtually aliasing
   data caches. The arm architecture is the main beneficiary.

 - Lokesh Gidra's series "per-vma locks in userfaultfd" provides
   dramatic improvements in worst-case mmap_lock hold times during
   certain userfaultfd operations.

 - Some page_owner enhancements and maintenance work from Oscar Salvador
   in his series

	"page_owner: print stacks and their outstanding allocations"
	"page_owner: Fixup and cleanup"

 - Uladzislau Rezki has contributed some vmalloc scalability
   improvements in his series "Mitigate a vmap lock contention". It
   realizes a 12x improvement for a certain microbenchmark.

 - Some kexec/crash cleanup work from Baoquan He in the series "Split
   crash out from kexec and clean up related config items".

 - Some zsmalloc maintenance work from Chengming Zhou in the series

	"mm/zsmalloc: fix and optimize objects/page migration"
	"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"

 - Zi Yan has taught the MM to perform compaction on folios larger than
   order=0. This a step along the path to implementaton of the merging
   of large anonymous folios. The series is named "Enable >0 order folio
   memory compaction".

 - Christoph Hellwig has done quite a lot of cleanup work in the
   pagecache writeback code in his series "convert write_cache_pages()
   to an iterator".

 - Some modest hugetlb cleanups and speedups in Vishal Moola's series
   "Handle hugetlb faults under the VMA lock".

 - Zi Yan has changed the page splitting code so we can split huge pages
   into sizes other than order-0 to better utilize large folios. The
   series is named "Split a folio to any lower order folios".

 - David Hildenbrand has contributed the series "mm: remove
   total_mapcount()", a cleanup.

 - Matthew Wilcox has sought to improve the performance of bulk memory
   freeing in his series "Rearrange batched folio freeing".

 - Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
   provides large improvements in bootup times on large machines which
   are configured to use large numbers of hugetlb pages.

 - Matthew Wilcox's series "PageFlags cleanups" does that.

 - Qi Zheng's series "minor fixes and supplement for ptdesc" does that
   also. S390 is affected.

 - Cleanups to our pagemap utility functions from Peter Xu in his series
   "mm/treewide: Replace pXd_large() with pXd_leaf()".

 - Nico Pache has fixed a few things with our hugepage selftests in his
   series "selftests/mm: Improve Hugepage Test Handling in MM
   Selftests".

 - Also, of course, many singleton patches to many things. Please see
   the individual changelogs for details.

* tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits)
  mm/zswap: remove the memcpy if acomp is not sleepable
  crypto: introduce: acomp_is_async to expose if comp drivers might sleep
  memtest: use {READ,WRITE}_ONCE in memory scanning
  mm: prohibit the last subpage from reusing the entire large folio
  mm: recover pud_leaf() definitions in nopmd case
  selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements
  selftests/mm: skip uffd hugetlb tests with insufficient hugepages
  selftests/mm: dont fail testsuite due to a lack of hugepages
  mm/huge_memory: skip invalid debugfs new_order input for folio split
  mm/huge_memory: check new folio order when split a folio
  mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure
  mm: add an explicit smp_wmb() to UFFDIO_CONTINUE
  mm: fix list corruption in put_pages_list
  mm: remove folio from deferred split list before uncharging it
  filemap: avoid unnecessary major faults in filemap_fault()
  mm,page_owner: drop unnecessary check
  mm,page_owner: check for null stack_record before bumping its refcount
  mm: swap: fix race between free_swap_and_cache() and swapoff()
  mm/treewide: align up pXd_leaf() retval across archs
  mm/treewide: drop pXd_large()
  ...

1 files changed, 112 insertions, 7 deletions

diff --git a/mm/internal.h b/mm/internal.h
index 4398f572485f..7e486f2c502c 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -83,6 +83,99 @@ static inline void *folio_raw_mapping(struct folio *folio)
 	return (void *)(mapping & ~PAGE_MAPPING_FLAGS);
 }
 
+#ifdef CONFIG_MMU
+
+/* Flags for folio_pte_batch(). */
+typedef int __bitwise fpb_t;
+
+/* Compare PTEs after pte_mkclean(), ignoring the dirty bit. */
+#define FPB_IGNORE_DIRTY		((__force fpb_t)BIT(0))
+
+/* Compare PTEs after pte_clear_soft_dirty(), ignoring the soft-dirty bit. */
+#define FPB_IGNORE_SOFT_DIRTY		((__force fpb_t)BIT(1))
+
+static inline pte_t __pte_batch_clear_ignored(pte_t pte, fpb_t flags)
+{
+	if (flags & FPB_IGNORE_DIRTY)
+		pte = pte_mkclean(pte);
+	if (likely(flags & FPB_IGNORE_SOFT_DIRTY))
+		pte = pte_clear_soft_dirty(pte);
+	return pte_wrprotect(pte_mkold(pte));
+}
+
+/**
+ * folio_pte_batch - detect a PTE batch for a large folio
+ * @folio: The large folio to detect a PTE batch for.
+ * @addr: The user virtual address the first page is mapped at.
+ * @start_ptep: Page table pointer for the first entry.
+ * @pte: Page table entry for the first page.
+ * @max_nr: The maximum number of table entries to consider.
+ * @flags: Flags to modify the PTE batch semantics.
+ * @any_writable: Optional pointer to indicate whether any entry except the
+ *		  first one is writable.
+ *
+ * Detect a PTE batch: consecutive (present) PTEs that map consecutive
+ * pages of the same large folio.
+ *
+ * All PTEs inside a PTE batch have the same PTE bits set, excluding the PFN,
+ * the accessed bit, writable bit, dirty bit (with FPB_IGNORE_DIRTY) and
+ * soft-dirty bit (with FPB_IGNORE_SOFT_DIRTY).
+ *
+ * start_ptep must map any page of the folio. max_nr must be at least one and
+ * must be limited by the caller so scanning cannot exceed a single page table.
+ *
+ * Return: the number of table entries in the batch.
+ */
+static inline int folio_pte_batch(struct folio *folio, unsigned long addr,
+		pte_t *start_ptep, pte_t pte, int max_nr, fpb_t flags,
+		bool *any_writable)
+{
+	unsigned long folio_end_pfn = folio_pfn(folio) + folio_nr_pages(folio);
+	const pte_t *end_ptep = start_ptep + max_nr;
+	pte_t expected_pte, *ptep;
+	bool writable;
+	int nr;
+
+	if (any_writable)
+		*any_writable = false;
+
+	VM_WARN_ON_FOLIO(!pte_present(pte), folio);
+	VM_WARN_ON_FOLIO(!folio_test_large(folio) || max_nr < 1, folio);
+	VM_WARN_ON_FOLIO(page_folio(pfn_to_page(pte_pfn(pte))) != folio, folio);
+
+	nr = pte_batch_hint(start_ptep, pte);
+	expected_pte = __pte_batch_clear_ignored(pte_advance_pfn(pte, nr), flags);
+	ptep = start_ptep + nr;
+
+	while (ptep < end_ptep) {
+		pte = ptep_get(ptep);
+		if (any_writable)
+			writable = !!pte_write(pte);
+		pte = __pte_batch_clear_ignored(pte, flags);
+
+		if (!pte_same(pte, expected_pte))
+			break;
+
+		/*
+		 * Stop immediately once we reached the end of the folio. In
+		 * corner cases the next PFN might fall into a different
+		 * folio.
+		 */
+		if (pte_pfn(pte) >= folio_end_pfn)
+			break;
+
+		if (any_writable)
+			*any_writable |= writable;
+
+		nr = pte_batch_hint(ptep, pte);
+		expected_pte = pte_advance_pfn(expected_pte, nr);
+		ptep += nr;
+	}
+
+	return min(ptep - start_ptep, max_nr);
+}
+#endif /* CONFIG_MMU */
+
 void __acct_reclaim_writeback(pg_data_t *pgdat, struct folio *folio,
 						int nr_throttled);
 static inline void acct_reclaim_writeback(struct folio *folio)
@@ -103,6 +196,7 @@ static inline void wake_throttle_isolated(pg_data_t *pgdat)
 		wake_up(wqh);
 }
 
+vm_fault_t vmf_anon_prepare(struct vm_fault *vmf);
 vm_fault_t do_swap_page(struct vm_fault *vmf);
 void folio_rotate_reclaimable(struct folio *folio);
 bool __folio_end_writeback(struct folio *folio);
@@ -419,8 +513,7 @@ static inline struct folio *page_rmappable_folio(struct page *page)
 {
 	struct folio *folio = (struct folio *)page;
 
-	if (folio && folio_order(folio) > 1)
-		folio_prep_large_rmappable(folio);
+	folio_prep_large_rmappable(folio);
 	return folio;
 }
 
@@ -447,10 +540,12 @@ extern void prep_compound_page(struct page *page, unsigned int order);
 
 extern void post_alloc_hook(struct page *page, unsigned int order,
 					gfp_t gfp_flags);
+extern bool free_pages_prepare(struct page *page, unsigned int order);
+
 extern int user_min_free_kbytes;
 
-extern void free_unref_page(struct page *page, unsigned int order);
-extern void free_unref_page_list(struct list_head *list);
+void free_unref_page(struct page *page, unsigned int order);
+void free_unref_folios(struct folio_batch *fbatch);
 
 extern void zone_pcp_reset(struct zone *zone);
 extern void zone_pcp_disable(struct zone *zone);
@@ -481,7 +576,7 @@ int split_free_page(struct page *free_page,
  * completes when free_pfn <= migrate_pfn
  */
 struct compact_control {
-	struct list_head freepages;	/* List of free pages to migrate to */
+	struct list_head freepages[NR_PAGE_ORDERS];	/* List of free pages to migrate to */
 	struct list_head migratepages;	/* List of pages being migrated */
 	unsigned int nr_freepages;	/* Number of isolated free pages */
 	unsigned int nr_migratepages;	/* Number of pages to migrate */
@@ -537,7 +632,8 @@ isolate_migratepages_range(struct compact_control *cc,
 			   unsigned long low_pfn, unsigned long end_pfn);
 
 int __alloc_contig_migrate_range(struct compact_control *cc,
-					unsigned long start, unsigned long end);
+					unsigned long start, unsigned long end,
+					int migratetype);
 
 /* Free whole pageblock and set its migration type to MIGRATE_CMA. */
 void init_cma_reserved_pageblock(struct page *page);
@@ -866,7 +962,7 @@ extern unsigned long  __must_check vm_mmap_pgoff(struct file *, unsigned long,
         unsigned long, unsigned long);
 
 extern void set_pageblock_order(void);
-unsigned long reclaim_pages(struct list_head *folio_list);
+unsigned long reclaim_pages(struct list_head *folio_list, bool ignore_references);
 unsigned int reclaim_clean_pages_from_list(struct zone *zone,
 					    struct list_head *folio_list);
 /* The ALLOC_WMARK bits are used as an index to zone->watermark */
@@ -1114,6 +1210,15 @@ static inline bool gup_must_unshare(struct vm_area_struct *vma,
 extern bool mirrored_kernelcore;
 extern bool memblock_has_mirror(void);
 
+static __always_inline void vma_set_range(struct vm_area_struct *vma,
+					  unsigned long start, unsigned long end,
+					  pgoff_t pgoff)
+{
+	vma->vm_start = start;
+	vma->vm_end = end;
+	vma->vm_pgoff = pgoff;
+}
+
 static inline bool vma_soft_dirty_enabled(struct vm_area_struct *vma)
 {
 	/*