Merge tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Almost all of MM here. A few things are still getting finished off,
  reviewed, etc.

   - Yang Shi has improved the behaviour of khugepaged collapsing of
     readonly file-backed transparent hugepages.

   - Johannes Weiner has arranged for zswap memory use to be tracked and
     managed on a per-cgroup basis.

   - Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for
     runtime enablement of the recent huge page vmemmap optimization
     feature.

   - Baolin Wang contributes a series to fix some issues around hugetlb
     pagetable invalidation.

   - Zhenwei Pi has fixed some interactions between hwpoisoned pages and
     virtualization.

   - Tong Tiangen has enabled the use of the presently x86-only
     page_table_check debugging feature on arm64 and riscv.

   - David Vernet has done some fixup work on the memcg selftests.

   - Peter Xu has taught userfaultfd to handle write protection faults
     against shmem- and hugetlbfs-backed files.

   - More DAMON development from SeongJae Park - adding online tuning of
     the feature and support for monitoring of fixed virtual address
     ranges. Also easier discovery of which monitoring operations are
     available.

   - Nadav Amit has done some optimization of TLB flushing during
     mprotect().

   - Neil Brown continues to labor away at improving our swap-over-NFS
     support.

   - David Hildenbrand has some fixes to anon page COWing versus
     get_user_pages().

   - Peng Liu fixed some errors in the core hugetlb code.

   - Joao Martins has reduced the amount of memory consumed by
     device-dax's compound devmaps.

   - Some cleanups of the arch-specific pagemap code from Anshuman
     Khandual.

   - Muchun Song has found and fixed some errors in the TLB flushing of
     transparent hugepages.

   - Roman Gushchin has done more work on the memcg selftests.

  ... and, of course, many smaller fixes and cleanups. Notably, the
  customary million cleanup serieses from Miaohe Lin"

* tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (381 commits)
  mm: kfence: use PAGE_ALIGNED helper
  selftests: vm: add the "settings" file with timeout variable
  selftests: vm: add "test_hmm.sh" to TEST_FILES
  selftests: vm: check numa_available() before operating "merge_across_nodes" in ksm_tests
  selftests: vm: add migration to the .gitignore
  selftests/vm/pkeys: fix typo in comment
  ksm: fix typo in comment
  selftests: vm: add process_mrelease tests
  Revert "mm/vmscan: never demote for memcg reclaim"
  mm/kfence: print disabling or re-enabling message
  include/trace/events/percpu.h: cleanup for "percpu: improve percpu_alloc_percpu event trace"
  include/trace/events/mmflags.h: cleanup for "tracing: incorrect gfp_t conversion"
  mm: fix a potential infinite loop in start_isolate_page_range()
  MAINTAINERS: add Muchun as co-maintainer for HugeTLB
  zram: fix Kconfig dependency warning
  mm/shmem: fix shmem folio swapoff hang
  cgroup: fix an error handling path in alloc_pagecache_max_30M()
  mm: damon: use HPAGE_PMD_SIZE
  tracing: incorrect isolate_mote_t cast in mm_vmscan_lru_isolate
  nodemask.h: fix compilation error with GCC12
  ...

1 files changed, 52 insertions, 10 deletions

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index af10149a6c31..e66f7aa3191d 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -142,6 +142,15 @@ enum pageflags {
 
 	PG_readahead = PG_reclaim,
 
+	/*
+	 * Depending on the way an anonymous folio can be mapped into a page
+	 * table (e.g., single PMD/PUD/CONT of the head page vs. PTE-mapped
+	 * THP), PG_anon_exclusive may be set only for the head page or for
+	 * tail pages of an anonymous folio. For now, we only expect it to be
+	 * set on tail pages for PTE-mapped THP.
+	 */
+	PG_anon_exclusive = PG_mappedtodisk,
+
 	/* Filesystems */
 	PG_checked = PG_owner_priv_1,
 
@@ -176,7 +185,7 @@ enum pageflags {
 	 * Indicates that at least one subpage is hwpoisoned in the
 	 * THP.
 	 */
-	PG_has_hwpoisoned = PG_mappedtodisk,
+	PG_has_hwpoisoned = PG_error,
 #endif
 
 	/* non-lru isolated movable page */
@@ -190,18 +199,18 @@ enum pageflags {
 
 #ifndef __GENERATING_BOUNDS_H
 
-#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
-DECLARE_STATIC_KEY_MAYBE(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON,
-			 hugetlb_free_vmemmap_enabled_key);
+#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
+DECLARE_STATIC_KEY_MAYBE(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON,
+			 hugetlb_optimize_vmemmap_key);
 
-static __always_inline bool hugetlb_free_vmemmap_enabled(void)
+static __always_inline bool hugetlb_optimize_vmemmap_enabled(void)
 {
-	return static_branch_maybe(CONFIG_HUGETLB_PAGE_FREE_VMEMMAP_DEFAULT_ON,
-				   &hugetlb_free_vmemmap_enabled_key);
+	return static_branch_maybe(CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP_DEFAULT_ON,
+				   &hugetlb_optimize_vmemmap_key);
 }
 
 /*
- * If the feature of freeing some vmemmap pages associated with each HugeTLB
+ * If the feature of optimizing vmemmap pages associated with each HugeTLB
  * page is enabled, the head vmemmap page frame is reused and all of the tail
  * vmemmap addresses map to the head vmemmap page frame (furture details can
  * refer to the figure at the head of the mm/hugetlb_vmemmap.c).  In other
@@ -218,7 +227,7 @@ static __always_inline bool hugetlb_free_vmemmap_enabled(void)
  */
 static __always_inline const struct page *page_fixed_fake_head(const struct page *page)
 {
-	if (!hugetlb_free_vmemmap_enabled())
+	if (!hugetlb_optimize_vmemmap_enabled())
 		return page;
 
 	/*
@@ -247,7 +256,7 @@ static inline const struct page *page_fixed_fake_head(const struct page *page)
 	return page;
 }
 
-static inline bool hugetlb_free_vmemmap_enabled(void)
+static inline bool hugetlb_optimize_vmemmap_enabled(void)
 {
 	return false;
 }
@@ -641,6 +650,11 @@ __PAGEFLAG(Reported, reported, PF_NO_COMPOUND)
 #define PAGE_MAPPING_KSM	(PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE)
 #define PAGE_MAPPING_FLAGS	(PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE)
 
+static __always_inline bool folio_mapping_flags(struct folio *folio)
+{
+	return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) != 0;
+}
+
 static __always_inline int PageMappingFlags(struct page *page)
 {
 	return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != 0;
@@ -1002,6 +1016,34 @@ extern bool is_free_buddy_page(struct page *page);
 
 PAGEFLAG(Isolated, isolated, PF_ANY);
 
+static __always_inline int PageAnonExclusive(struct page *page)
+{
+	VM_BUG_ON_PGFLAGS(!PageAnon(page), page);
+	VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page);
+	return test_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags);
+}
+
+static __always_inline void SetPageAnonExclusive(struct page *page)
+{
+	VM_BUG_ON_PGFLAGS(!PageAnon(page) || PageKsm(page), page);
+	VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page);
+	set_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags);
+}
+
+static __always_inline void ClearPageAnonExclusive(struct page *page)
+{
+	VM_BUG_ON_PGFLAGS(!PageAnon(page) || PageKsm(page), page);
+	VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page);
+	clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags);
+}
+
+static __always_inline void __ClearPageAnonExclusive(struct page *page)
+{
+	VM_BUG_ON_PGFLAGS(!PageAnon(page), page);
+	VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page);
+	__clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags);
+}
+
 #ifdef CONFIG_MMU
 #define __PG_MLOCKED		(1UL << PG_mlocked)
 #else