linux.git/include/linux/page-flags.h, branch v6.14-rc2

mm: add PG_dropbehind folio flag

2025-01-26T04:22:42+00:00

Add a folio flag that file IO can use to indicate that the cached IO being
done should be dropped from the page cache upon completion.

Link: https://lkml.kernel.org/r/20241220154831.1086649-5-axboe@kernel.dk
Signed-off-by: Jens Axboe 
Reviewed-by: Kirill A. Shutemov 
Cc: Brian Foster 
Cc: Chris Mason 
Cc: Christoph Hellwig 
Cc: Johannes Weiner 
Cc: Matthew Wilcox (Oracle) 
Signed-off-by: Andrew Morton

mm/huge_memory: convert has_hwpoisoned into a pure folio flag

2025-01-26T04:22:41+00:00

Patch series "mm: hugetlb+THP folio and migration cleanups", v2.

Some cleanups around more folio conversion and migration handling that I
collected working on random stuff.


This patch (of 6):

Let's stop setting it on pages, there is no need to anymore.

Link: https://lkml.kernel.org/r/20250113131611.2554758-2-david@redhat.com
Signed-off-by: David Hildenbrand 
Reviewed-by: Matthew Wilcox (Oracle) 
Cc: Muchun Song 
Cc: Baolin Wang 
Cc: Sidhartha Kumar 
Signed-off-by: Andrew Morton

mm: remove PageTransTail()

2025-01-26T04:22:39+00:00

The last caller was removed in October.  Also remove the FALSE definition
of PageTransCompoundMap(); the normal definition was removed a few years
ago.

Link: https://lkml.kernel.org/r/20250109152245.1591914-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) 
Acked-by: David Hildenbrand 
Acked-by: Zi Yan 
Signed-off-by: Andrew Morton

mm: convert partially_mapped set/clear operations to be atomic

2024-12-19T03:04:45+00:00

Other page flags in the 2nd page, like PG_hwpoison and PG_anon_exclusive
can get modified concurrently.  Changes to other page flags might be lost
if they are happening at the same time as non-atomic partially_mapped
operations.  Hence, make partially_mapped operations atomic.

Link: https://lkml.kernel.org/r/20241212183351.1345389-1-usamaarif642@gmail.com
Fixes: 8422acdc97ed ("mm: introduce a pageflag for partially mapped folios")
Reported-by: David Hildenbrand 
Link: https://lore.kernel.org/all/e53b04ad-1827-43a2-a1ab-864c7efecf6e@redhat.com/
Signed-off-by: Usama Arif 
Acked-by: David Hildenbrand 
Acked-by: Johannes Weiner 
Acked-by: Roman Gushchin 
Cc: Barry Song 
Cc: Domenico Cerasuolo 
Cc: Jonathan Corbet 
Cc: Matthew Wilcox 
Cc: Mike Rapoport (Microsoft) 
Cc: Nico Pache 
Cc: Rik van Riel 
Cc: Ryan Roberts 
Cc: Shakeel Butt 
Cc: Yu Zhao 
Cc: 
Signed-off-by: Andrew Morton

mm: open-code PageTail in folio_flags() and const_folio_flags()

2024-12-06T03:54:45+00:00

It is unsafe to call PageTail() in dump_page() as page_is_fake_head() will
almost certainly return true when called on a head page that is copied to
the stack.  That will cause the VM_BUG_ON_PGFLAGS() in const_folio_flags()
to trigger when it shouldn't.  Fortunately, we don't need to call
PageTail() here; it's fine to have a pointer to a virtual alias of the
page's flag word rather than the real page's flag word.

Link: https://lkml.kernel.org/r/20241125201721.2963278-1-willy@infradead.org
Fixes: fae7d834c43c ("mm: add __dump_folio()")
Signed-off-by: Matthew Wilcox (Oracle) 
Cc: Kees Cook 
Cc: 
Signed-off-by: Andrew Morton

Merge tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-11-23T17:58:07+00:00

Pull MM updates from Andrew Morton:

- The series "zram: optimal post-processing target selection" from
Sergey Senozhatsky improves zram's post-processing selection
algorithm. This leads to improved memory savings.

- Wei Yang has gone to town on the mapletree code, contributing several
series which clean up the implementation:
- "refine mas_mab_cp()"
- "Reduce the space to be cleared for maple_big_node"
- "maple_tree: simplify mas_push_node()"
- "Following cleanup after introduce mas_wr_store_type()"
- "refine storing null"

- The series "selftests/mm: hugetlb_fault_after_madv improvements" from
David Hildenbrand fixes this selftest for s390.

- The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
implements some rationaizations and cleanups in the page mapping
code.

- The series "mm: optimize shadow entries removal" from Shakeel Butt
optimizes the file truncation code by speeding up the handling of
shadow entries.

- The series "Remove PageKsm()" from Matthew Wilcox completes the
migration of this flag over to being a folio-based flag.

- The series "Unify hugetlb into arch_get_unmapped_area functions" from
Oscar Salvador implements a bunch of consolidations and cleanups in
the hugetlb code.

- The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
takes away the wp-fault time practice of turning a huge zero page
into small pages. Instead we replace the whole thing with a THP. More
consistent cleaner and potentiall saves a large number of pagefaults.

- The series "percpu: Add a test case and fix for clang" from Andy
Shevchenko enhances and fixes the kernel's built in percpu test code.

- The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
optimizes mremap() by avoiding doing things which we didn't need to
do.

- The series "Improve the tmpfs large folio read performance" from
Baolin Wang teaches tmpfs to copy data into userspace at the folio
size rather than as individual pages. A 20% speedup was observed.

- The series "mm/damon/vaddr: Fix issue in
damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON
splitting.

- The series "memcg-v1: fully deprecate charge moving" from Shakeel
Butt removes the long-deprecated memcgv2 charge moving feature.

- The series "fix error handling in mmap_region() and refactor" from
Lorenzo Stoakes cleanup up some of the mmap() error handling and
addresses some potential performance issues.

- The series "x86/module: use large ROX pages for text allocations"
from Mike Rapoport teaches x86 to use large pages for
read-only-execute module text.

- The series "page allocation tag compression" from Suren Baghdasaryan
is followon maintenance work for the new page allocation profiling
feature.

- The series "page->index removals in mm" from Matthew Wilcox remove
most references to page->index in mm/. A slow march towards shrinking
struct page.

- The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
interface tests" from Andrew Paniakin performs maintenance work for
DAMON's self testing code.

- The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
improves zswap's batching of compression and decompression. It is a
step along the way towards using Intel IAA hardware acceleration for
this zswap operation.

- The series "kasan: migrate the last module test to kunit" from
Sabyrzhan Tasbolatov completes the migration of the KASAN built-in
tests over to the KUnit framework.

- The series "implement lightweight guard pages" from Lorenzo Stoakes
permits userapace to place fault-generating guard pages within a
single VMA, rather than requiring that multiple VMAs be created for
this. Improved efficiencies for userspace memory allocators are
expected.

- The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
tracepoints to provide increased visibility into memcg stats flushing
activity.

- The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
fixes a zram buglet which potentially affected performance.

- The series "mm: add more kernel parameters to control mTHP" from
Maíra Canal enhances our ability to control/configuremultisize THP
from the kernel boot command line.

- The series "kasan: few improvements on kunit tests" from Sabyrzhan
Tasbolatov has a couple of fixups for the KASAN KUnit tests.

- The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
from Kairui Song optimizes list_lru memory utilization when lockdep
is enabled.

* tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits)
cma: enforce non-zero pageblock_order during cma_init_reserved_mem()
mm/kfence: add a new kunit test test_use_after_free_read_nofault()
zram: fix NULL pointer in comp_algorithm_show()
memcg/hugetlb: add hugeTLB counters to memcg
vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event
mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount
zram: ZRAM_DEF_COMP should depend on ZRAM
MAINTAINERS/MEMORY MANAGEMENT: add document files for mm
Docs/mm/damon: recommend academic papers to read and/or cite
mm: define general function pXd_init()
kmemleak: iommu/iova: fix transient kmemleak false positive
mm/list_lru: simplify the list_lru walk callback function
mm/list_lru: split the lock to per-cgroup scope
mm/list_lru: simplify reparenting and initial allocation
mm/list_lru: code clean up for reparenting
mm/list_lru: don't export list_lru_add
mm/list_lru: don't pass unnecessary key parameters
kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller
kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW
kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols
...

Merge tag 'vfs-6.13.pagecache' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2024-11-18T17:54:32+00:00

Pull vfs pagecache updates from Christian Brauner:
 "Cleanup filesystem page flag usage: This continues the work to make
  the mappedtodisk/owner_2 flag available to filesystems which don't use
  buffer heads. Further patches remove uses of Private2. This brings us
  very close to being rid of it entirely"

* tag 'vfs-6.13.pagecache' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  migrate: Remove references to Private2
  ceph: Remove call to PagePrivate2()
  btrfs: Switch from using the private_2 flag to owner_2
  mm: Remove PageMappedToDisk
  nilfs2: Convert nilfs_copy_buffer() to use folios
  fs: Move clearing of mappedtodisk to buffer.c

mm: remove PageKsm()

2024-11-07T04:11:08+00:00

All callers have been converted to use folio_test_ksm() or
PageAnonNotKsm(), so we can remove this wrapper.

Link: https://lkml.kernel.org/r/20241002152533.1350629-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) 
Acked-by: David Hildenbrand 
Cc: Alex Shi 
Signed-off-by: Andrew Morton

mm: add PageAnonNotKsm()

2024-11-07T04:11:08+00:00

Check that this anonymous page is really anonymous, not anonymous-or-KSM. 
This optimises the debug check, but its real purpose is to remove the last
two users of PageKsm().

[willy@infradead.org: fix assertions]
  Link: https://lkml.kernel.org/r/ZwApWPER7caIA_N3@casper.infradead.org
Link: https://lkml.kernel.org/r/20241002152533.1350629-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) 
Acked-by: David Hildenbrand 
Cc: Alex Shi 
Signed-off-by: Andrew Morton

mm: allow set/clear page_type again

2024-10-31T03:14:12+00:00

Some page flags (page->flags) were converted to page types
(page->page_types).  A recent example is PG_hugetlb.

From the exclusive writer's perspective, e.g., a thread doing
__folio_set_hugetlb(), there is a difference between the page flag and
type APIs: the former allows the same non-atomic operation to be repeated
whereas the latter does not.  For example, calling __folio_set_hugetlb()
twice triggers VM_BUG_ON_FOLIO(), since the second call expects the type
(PG_hugetlb) not to be set previously.

Using add_hugetlb_folio() as an example, it calls __folio_set_hugetlb() in
the following error-handling path.  And when that happens, it triggers the
aforementioned VM_BUG_ON_FOLIO().

  if (folio_test_hugetlb(folio)) {
    rc = hugetlb_vmemmap_restore_folio(h, folio);
    if (rc) {
      spin_lock_irq(&hugetlb_lock);
      add_hugetlb_folio(h, folio, false);
      ...

It is possible to make hugeTLB comply with the new requirements from the
page type API.  However, a straightforward fix would be to just allow the
same page type to be set or cleared again inside the API, to avoid any
changes to its callers.

Link: https://lkml.kernel.org/r/20241020042212.296781-1-yuzhao@google.com
Fixes: d99e3140a4d3 ("mm: turn folio_test_hugetlb into a PageType")
Signed-off-by: Yu Zhao 
Cc: Matthew Wilcox (Oracle) 
Cc: Muchun Song 
Cc: 
Signed-off-by: Andrew Morton