Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
   linux-next for a couple of months without, to my knowledge, any
   negative reports (or any positive ones, come to that).

 - Also the Maple Tree from Liam Howlett. An overlapping range-based
   tree for vmas. It it apparently slightly more efficient in its own
   right, but is mainly targeted at enabling work to reduce mmap_lock
   contention.

   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.

   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   at [1]. This has yet to be addressed due to Liam's unfortunately
   timed vacation. He is now back and we'll get this fixed up.

 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
   clang-generated instrumentation to detect used-unintialized bugs down
   to the single bit level.

   KMSAN keeps finding bugs. New ones, as well as the legacy ones.

 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.

 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
   support file/shmem-backed pages.

 - userfaultfd updates from Axel Rasmussen

 - zsmalloc cleanups from Alexey Romanov

 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
   memory-failure

 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.

 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.

 - memcg cleanups from Kairui Song.

 - memcg fixes and cleanups from Johannes Weiner.

 - Vishal Moola provides more folio conversions

 - Zhang Yi removed ll_rw_block() :(

 - migration enhancements from Peter Xu

 - migration error-path bugfixes from Huang Ying

 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths. For optimizations by PMEM drivers, DRM
   drivers, etc.

 - vma merging improvements from Jakub Matěn.

 - NUMA hinting cleanups from David Hildenbrand.

 - xu xin added aditional userspace visibility into KSM merging
   activity.

 - THP & KSM code consolidation from Qi Zheng.

 - more folio work from Matthew Wilcox.

 - KASAN updates from Andrey Konovalov.

 - DAMON cleanups from Kaixu Xia.

 - DAMON work from SeongJae Park: fixes, cleanups.

 - hugetlb sysfs cleanups from Muchun Song.

 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.

Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]

* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
  hugetlb: allocate vma lock for all sharable vmas
  hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
  hugetlb: fix vma lock handling during split vma and range unmapping
  mglru: mm/vmscan.c: fix imprecise comments
  mm/mglru: don't sync disk for each aging cycle
  mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
  mm: memcontrol: use do_memsw_account() in a few more places
  mm: memcontrol: deprecate swapaccounting=0 mode
  mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
  mm/secretmem: remove reduntant return value
  mm/hugetlb: add available_huge_pages() func
  mm: remove unused inline functions from include/linux/mm_inline.h
  selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
  selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
  selftests/vm: add thp collapse shmem testing
  selftests/vm: add thp collapse file and tmpfs testing
  selftests/vm: modularize thp collapse memory operations
  selftests/vm: dedup THP helpers
  mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
  mm/madvise: add file and shmem support to MADV_COLLAPSE
  ...

1 files changed, 11 insertions, 11 deletions

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 907c9b1e1e61..525758713a55 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -472,12 +472,12 @@ static inline struct page *get_first_page(struct zspage *zspage)
 	return first_page;
 }
 
-static inline int get_first_obj_offset(struct page *page)
+static inline unsigned int get_first_obj_offset(struct page *page)
 {
 	return page->page_type;
 }
 
-static inline void set_first_obj_offset(struct page *page, int offset)
+static inline void set_first_obj_offset(struct page *page, unsigned int offset)
 {
 	page->page_type = offset;
 }
@@ -1555,6 +1555,13 @@ static void zs_object_copy(struct size_class *class, unsigned long dst,
 		d_off += size;
 		d_size -= size;
 
+		/*
+		 * Calling kunmap_atomic(d_addr) is necessary. kunmap_atomic()
+		 * calls must occurs in reverse order of calls to kmap_atomic().
+		 * So, to call kunmap_atomic(s_addr) we should first call
+		 * kunmap_atomic(d_addr). For more details see
+		 * Documentation/mm/highmem.rst.
+		 */
 		if (s_off >= PAGE_SIZE) {
 			kunmap_atomic(d_addr);
 			kunmap_atomic(s_addr);
@@ -1585,7 +1592,7 @@ static void zs_object_copy(struct size_class *class, unsigned long dst,
 static unsigned long find_alloced_obj(struct size_class *class,
 					struct page *page, int *obj_idx)
 {
-	int offset = 0;
+	unsigned int offset;
 	int index = *obj_idx;
 	unsigned long handle = 0;
 	void *addr = kmap_atomic(page);
@@ -1839,7 +1846,7 @@ static int zs_page_migrate(struct page *newpage, struct page *page,
 	struct zspage *zspage;
 	struct page *dummy;
 	void *s_addr, *d_addr, *addr;
-	int offset;
+	unsigned int offset;
 	unsigned long handle;
 	unsigned long old_obj, new_obj;
 	unsigned int obj_idx;
@@ -2103,8 +2110,6 @@ unsigned long zs_compact(struct zs_pool *pool)
 
 	for (i = ZS_SIZE_CLASSES - 1; i >= 0; i--) {
 		class = pool->size_class[i];
-		if (!class)
-			continue;
 		if (class->index != i)
 			continue;
 		pages_freed += __zs_compact(pool, class);
@@ -2149,8 +2154,6 @@ static unsigned long zs_shrinker_count(struct shrinker *shrinker,
 
 	for (i = ZS_SIZE_CLASSES - 1; i >= 0; i--) {
 		class = pool->size_class[i];
-		if (!class)
-			continue;
 		if (class->index != i)
 			continue;
 
@@ -2308,9 +2311,6 @@ void zs_destroy_pool(struct zs_pool *pool)
 		int fg;
 		struct size_class *class = pool->size_class[i];
 
-		if (!class)
-			continue;
-
 		if (class->index != i)
 			continue;