Merge tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull mm updates from Andrew Morton:
 "The usual shower of singleton fixes and minor series all over MM,
  documented (hopefully adequately) in the respective changelogs.
  Notable series include:

   - Lucas Stach has provided some page-mapping cleanup/consolidation/
     maintainability work in the series "mm/treewide: Remove pXd_huge()
     API".

   - In the series "Allow migrate on protnone reference with
     MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
     MPOL_PREFERRED_MANY mode, yielding almost doubled performance in
     one test.

   - In their series "Memory allocation profiling" Kent Overstreet and
     Suren Baghdasaryan have contributed a means of determining (via
     /proc/allocinfo) whereabouts in the kernel memory is being
     allocated: number of calls and amount of memory.

   - Matthew Wilcox has provided the series "Various significant MM
     patches" which does a number of rather unrelated things, but in
     largely similar code sites.

   - In his series "mm: page_alloc: freelist migratetype hygiene"
     Johannes Weiner has fixed the page allocator's handling of
     migratetype requests, with resulting improvements in compaction
     efficiency.

   - In the series "make the hugetlb migration strategy consistent"
     Baolin Wang has fixed a hugetlb migration issue, which should
     improve hugetlb allocation reliability.

   - Liu Shixin has hit an I/O meltdown caused by readahead in a
     memory-tight memcg. Addressed in the series "Fix I/O high when
     memory almost met memcg limit".

   - In the series "mm/filemap: optimize folio adding and splitting"
     Kairui Song has optimized pagecache insertion, yielding ~10%
     performance improvement in one test.

   - Baoquan He has cleaned up and consolidated the early zone
     initialization code in the series "mm/mm_init.c: refactor
     free_area_init_core()".

   - Baoquan has also redone some MM initializatio code in the series
     "mm/init: minor clean up and improvement".

   - MM helper cleanups from Christoph Hellwig in his series "remove
     follow_pfn".

   - More cleanups from Matthew Wilcox in the series "Various
     page->flags cleanups".

   - Vlastimil Babka has contributed maintainability improvements in the
     series "memcg_kmem hooks refactoring".

   - More folio conversions and cleanups in Matthew Wilcox's series:
	"Convert huge_zero_page to huge_zero_folio"
	"khugepaged folio conversions"
	"Remove page_idle and page_young wrappers"
	"Use folio APIs in procfs"
	"Clean up __folio_put()"
	"Some cleanups for memory-failure"
	"Remove page_mapping()"
	"More folio compat code removal"

   - David Hildenbrand chipped in with "fs/proc/task_mmu: convert
     hugetlb functions to work on folis".

   - Code consolidation and cleanup work related to GUP's handling of
     hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".

   - Rick Edgecombe has developed some fixes to stack guard gaps in the
     series "Cover a guard gap corner case".

   - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the
     series "mm/ksm: fix ksm exec support for prctl".

   - Baolin Wang has implemented NUMA balancing for multi-size THPs.
     This is a simple first-cut implementation for now. The series is
     "support multi-size THP numa balancing".

   - Cleanups to vma handling helper functions from Matthew Wilcox in
     the series "Unify vma_address and vma_pgoff_address".

   - Some selftests maintenance work from Dev Jain in the series
     "selftests/mm: mremap_test: Optimizations and style fixes".

   - Improvements to the swapping of multi-size THPs from Ryan Roberts
     in the series "Swap-out mTHP without splitting".

   - Kefeng Wang has significantly optimized the handling of arm64's
     permission page faults in the series
	"arch/mm/fault: accelerate pagefault when badaccess"
	"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"

   - GUP cleanups from David Hildenbrand in "mm/gup: consistently call
     it GUP-fast".

   - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault
     path to use struct vm_fault".

   - selftests build fixes from John Hubbard in the series "Fix
     selftests/mm build without requiring "make headers"".

   - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
     series "Improved Memory Tier Creation for CPUless NUMA Nodes".
     Fixes the initialization code so that migration between different
     memory types works as intended.

   - David Hildenbrand has improved follow_pte() and fixed an errant
     driver in the series "mm: follow_pte() improvements and acrn
     follow_pte() fixes".

   - David also did some cleanup work on large folio mapcounts in his
     series "mm: mapcount for large folios + page_mapcount() cleanups".

   - Folio conversions in KSM in Alex Shi's series "transfer page to
     folio in KSM".

   - Barry Song has added some sysfs stats for monitoring multi-size
     THP's in the series "mm: add per-order mTHP alloc and swpout
     counters".

   - Some zswap cleanups from Yosry Ahmed in the series "zswap
     same-filled and limit checking cleanups".

   - Matthew Wilcox has been looking at buffer_head code and found the
     documentation to be lacking. The series is "Improve buffer head
     documentation".

   - Multi-size THPs get more work, this time from Lance Yang. His
     series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free"
     optimizes the freeing of these things.

   - Kemeng Shi has added more userspace-visible writeback
     instrumentation in the series "Improve visibility of writeback".

   - Kemeng Shi then sent some maintenance work on top in the series
     "Fix and cleanups to page-writeback".

   - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in
     the series "Improve anon_vma scalability for anon VMAs". Intel's
     test bot reported an improbable 3x improvement in one test.

   - SeongJae Park adds some DAMON feature work in the series
	"mm/damon: add a DAMOS filter type for page granularity access recheck"
	"selftests/damon: add DAMOS quota goal test"

   - Also some maintenance work in the series
	"mm/damon/paddr: simplify page level access re-check for pageout"
	"mm/damon: misc fixes and improvements"

   - David Hildenbrand has disabled some known-to-fail selftests ni the
     series "selftests: mm: cow: flag vmsplice() hugetlb tests as
     XFAIL".

   - memcg metadata storage optimizations from Shakeel Butt in "memcg:
     reduce memory consumption by memcg stats".

   - DAX fixes and maintenance work from Vishal Verma in the series
     "dax/bus.c: Fixups for dax-bus locking""

* tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits)
  memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order
  selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp
  mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault
  selftests: cgroup: add tests to verify the zswap writeback path
  mm: memcg: make alloc_mem_cgroup_per_node_info() return bool
  mm/damon/core: fix return value from damos_wmark_metric_value
  mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED
  selftests: cgroup: remove redundant enabling of memory controller
  Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree
  Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT
  Docs/mm/damon/design: use a list for supported filters
  Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
  Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
  selftests/damon: classify tests for functionalities and regressions
  selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None'
  selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts
  selftests/damon/_damon_sysfs: check errors from nr_schemes file reads
  mm/damon/core: initialize ->esz_bp from damos_quota_init_priv()
  selftests/damon: add a test for DAMOS quota goal
  ...

1 files changed, 34 insertions, 9 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index 73a052a382f1..dd04f578c19c 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -113,7 +113,7 @@ bool isolate_movable_page(struct page *page, isolate_mode_t mode)
 	if (!mops->isolate_page(&folio->page, mode))
 		goto out_no_isolated;
 
-	/* Driver shouldn't use PG_isolated bit of page->flags */
+	/* Driver shouldn't use the isolated flag */
 	WARN_ON_ONCE(folio_test_isolated(folio));
 	folio_set_isolated(folio);
 	folio_unlock(folio);
@@ -616,7 +616,7 @@ void folio_migrate_flags(struct folio *newfolio, struct folio *folio)
 	folio_migrate_ksm(newfolio, folio);
 	/*
 	 * Please do not reorder this without considering how mm/ksm.c's
-	 * get_ksm_page() depends upon ksm_migrate_page() and PageSwapCache().
+	 * ksm_get_folio() depends upon ksm_migrate_page() and PageSwapCache().
 	 */
 	if (folio_test_swapcache(folio))
 		folio_clear_swapcache(folio);
@@ -1425,7 +1425,7 @@ static int unmap_and_move_huge_page(new_folio_t get_new_folio,
 			 * semaphore in write mode here and set TTU_RMAP_LOCKED
 			 * to let lower levels know we have taken the lock.
 			 */
-			mapping = hugetlb_page_mapping_lock_write(&src->page);
+			mapping = hugetlb_folio_mapping_lock_write(src);
 			if (unlikely(!mapping))
 				goto unlock_put_anon;
 
@@ -1653,6 +1653,29 @@ static int migrate_pages_batch(struct list_head *from,
 			cond_resched();
 
 			/*
+			 * The rare folio on the deferred split list should
+			 * be split now. It should not count as a failure.
+			 * Only check it without removing it from the list.
+			 * Since the folio can be on deferred_split_scan()
+			 * local list and removing it can cause the local list
+			 * corruption. Folio split process below can handle it
+			 * with the help of folio_ref_freeze().
+			 *
+			 * nr_pages > 2 is needed to avoid checking order-1
+			 * page cache folios. They exist, in contrast to
+			 * non-existent order-1 anonymous folios, and do not
+			 * use _deferred_list.
+			 */
+			if (nr_pages > 2 &&
+			   !list_empty(&folio->_deferred_list)) {
+				if (try_split_folio(folio, split_folios) == 0) {
+					stats->nr_thp_split += is_thp;
+					stats->nr_split++;
+					continue;
+				}
+			}
+
+			/*
 			 * Large folio migration might be unsupported or
 			 * the allocation might be failed so we should retry
 			 * on the same folio with the large folio split
@@ -2022,7 +2045,8 @@ struct folio *alloc_migration_target(struct folio *src, unsigned long private)
 
 		gfp_mask = htlb_modify_alloc_mask(h, gfp_mask);
 		return alloc_hugetlb_folio_nodemask(h, nid,
-						mtc->nmask, gfp_mask);
+						mtc->nmask, gfp_mask,
+						htlb_allow_alloc_fallback(mtc->reason));
 	}
 
 	if (folio_test_large(src)) {
@@ -2060,6 +2084,7 @@ static int do_move_pages_to_node(struct list_head *pagelist, int node)
 	struct migration_target_control mtc = {
 		.nid = node,
 		.gfp_mask = GFP_HIGHUSER_MOVABLE | __GFP_THISNODE,
+		.reason = MR_SYSCALL,
 	};
 
 	err = migrate_pages(pagelist, alloc_migration_target, NULL,
@@ -2115,7 +2140,7 @@ static int add_page_for_migration(struct mm_struct *mm, const void __user *p,
 		goto out_putfolio;
 
 	err = -EACCES;
-	if (page_mapcount(page) > 1 && !migrate_all)
+	if (folio_likely_mapped_shared(folio) && !migrate_all)
 		goto out_putfolio;
 
 	err = -EBUSY;
@@ -2568,11 +2593,11 @@ int migrate_misplaced_folio(struct folio *folio, struct vm_area_struct *vma,
 	/*
 	 * Don't migrate file folios that are mapped in multiple processes
 	 * with execute permissions as they are probably shared libraries.
-	 * To check if the folio is shared, ideally we want to make sure
-	 * every page is mapped to the same process. Doing that is very
-	 * expensive, so check the estimated mapcount of the folio instead.
+	 *
+	 * See folio_likely_mapped_shared() on possible imprecision when we
+	 * cannot easily detect if a folio is shared.
 	 */
-	if (folio_estimated_sharers(folio) != 1 && folio_is_file_lru(folio) &&
+	if (folio_likely_mapped_shared(folio) && folio_is_file_lru(folio) &&
 	    (vma->vm_flags & VM_EXEC))
 		goto out;