linux.git/include/linux/swapops.h, branch v7.3-rc2

mm: include swap.h in swapops.h

2026-08-25T01:43:26+00:00

swapops.h uses MAX_SWAPFILES_SHIFT, SWP_MIGRATION_READ and SWP_PTE_MARKER,
all of which swap.h defines, but does not include swap.h.  It compiles only
where the translation unit pulled swap.h in first.  leafops.h includes
swapops.h on the line above swap.h, so a file whose include list reaches
leafops.h before swap.h gets:

    In file included from include/linux/leafops.h:11:
    include/linux/swapops.h:88:21: error: use of undeclared
    identifier 'MAX_SWAPFILES_SHIFT'

A header that uses a definition has to include the header that provides it.

Link: https://lore.kernel.org/20260818115026.656406-1-kirill@shutemov.name
Signed-off-by: Kiryl Shutsemau (Meta) 
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202608181757.mza9RRj7-lkp@intel.com/
Reviewed-by: Lorenzo Stoakes (ARM) 
Reviewed-by: Barry Song 
Cc: Baoquan He 
Cc: Chris Li 
Cc: Kairui Song 
Cc: Kemeng Shi 
Cc: Nhat Pham 
Signed-off-by: Andrew Morton

mm/huge_memory: update remove_migration_pmd() to accept a folio

2026-08-25T01:42:52+00:00

This function does not need to accept a page and requiring it to is
unnecessary and misleading.

make_[writable, readable]_device_private_entry() must be passed a
PMD-aligned PFN as they immediately used to obtain a softleaf PMD entry
and the same argument applies to folio_add_[anon, file]_rmap_pmd().

While we are here, update a VM_BUG_ON() to a VM_WARN_ON_ONCE().

No functional change intended.

Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-12-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) 
Acked-by: David Hildenbrand (Arm) 
Cc: Adrian Hunter 
Cc: Alexander Deucher 
Cc: Alexander Gordeev 
Cc: Alexander Shishkin 
Cc: Alistair Popple 
Cc: Arnaldo Carvalho de Melo 
Cc: Arnd Bergmann 
Cc: Baolin Wang 
Cc: Baoquan He 
Cc: Barry Song 
Cc: Boris Brezillon 
Cc: Byungchul Park 
Cc: Chengming Zhou 
Cc: Chris Li 
Cc: Christan König 
Cc: Christian Borntraeger 
Cc: Claudio Imbrenda 
Cc: Dave Airlie 
Cc: Dev Jain 
Cc: Gerald Schaefer 
Cc: Greg Kroah-Hartman 
Cc: Gregory Price (Meta) 
Cc: Harry Yoo 
Cc: Heiko Carstens 
Cc: Huang Ray 
Cc: "Huang, Ying" 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jan Kara 
Cc: Jann Horn 
Cc: Janosch Frank 
Cc: Jason Gunthorpe 
Cc: Jiri Olsa 
Cc: John Hubbard 
Cc: Joshua Hahn 
Cc: Kairui Song 
Cc: Kees Cook 
Cc: Kemeng Shi 
Cc: Lance Yang 
Cc: Liam R. Howlett 
Cc: Liviu Dudau 
Cc: Maarten Lankhorst 
Cc: Marc Rutland 
Cc: "Masami Hiramatsu (Google)" 
Cc: Matthew Auld 
Cc: Matthew Brost 
Cc: Matthew Wilcox (Oracle) 
Cc: Maxime Ripard 
Cc: Miaohe Lin 
Cc: Michal Hocko 
Cc: Mike Rapoport 
Cc: Muchun Song 
Cc: Namhyung kim 
Cc: Naoya Horiguchi 
Cc: Nhat Pham 
Cc: Nico Pache 
Cc: Oleg Nesterov 
Cc: Oscar Salvador 
Cc: Pedro Falcato 
Cc: Peter Xu 
Cc: Peter Zijlstra 
Cc: Rakie Kim 
Cc: Rik van Riel 
Cc: Rodrigo Vivi 
Cc: Ryan Roberts 
Cc: Steven Price 
Cc: Suren Baghdasaryan 
Cc: Sven Schnelle 
Cc: Thomas Hellström 
Cc: Thomas Zimemrmann 
Cc: Vasily Gorbik 
Cc: Vlastimil Babka 
Cc: xu xin 
Cc: Zi Yan 
Signed-off-by: Andrew Morton

mm: rename uffd-wp PTE accessors to uffd

2026-08-05T02:18:36+00:00

Userfaultfd RWP will reuse the uffd-wp PTE bit to mark access-tracking
PTEs, alongside the write-protected ones it already marks.  The bit's
meaning now depends on the VMA flag (WP or RWP), not on its name.

Rename the kernel-internal names that describe the bit:

  - pte/pmd/huge_pte accessors (and swap variants)
  - pgtable_supports_uffd() capability query
  - SCAN_PTE_UFFD khugepaged enum

The ftrace string emitted by mm_khugepaged_scan_pmd for this enum is
kept as "pte_uffd_wp" so existing trace-based tooling keeps matching.

Pure mechanical rename -- no behavior change.

Link: https://lore.kernel.org/20260708111417.173443-4-kirill@shutemov.name
Signed-off-by: Kiryl Shutsemau 
Assisted-by: Claude:claude-opus-4-6
Reviewed-by: Mike Rapoport (Microsoft) 
Reviewed-by: SeongJae Park 
Cc: Andrea Arcangeli 
Cc: David Hildenbrand 
Cc: James Houghton 
Cc: Jonathan Corbet 
Cc: Liam Howlett 
Cc: Lorenzo Stoakes 
Cc: Paolo Bonzini 
Cc: Peter Xu 
Cc: Sean Christopherson 
Cc: Suren Baghdasaryan 
Cc: Vlastimil Babka 
Cc: Zi Yan 
Signed-off-by: Andrew Morton

mm: rename ARCH_ENABLE_THP_MIGRATION to ARCH_HAS_PMD_SOFTLEAVES

2026-07-31T02:40:25+00:00

CONFIG_ARCH_ENABLE_THP_MIGRATION gates PMD-level migration entries. 
PMD-level device-private entries use the same migration mechanism and
therefore require the same architecture support.

Upcoming PMD-level swap entries can use the same PMD softleaf helpers
without depending on page migration, so rename the architecture gate to
CONFIG_ARCH_HAS_PMD_SOFTLEAVES.  This describes the PMD entry capability
rather than one current user of it.

This is a pure rename: the set of selecting architectures (x86, arm64,
s390, riscv, loongarch, and powerpc on PPC_BOOK3S_64) and the gating
semantics are unchanged.

No functional change intended.

Link: https://lore.kernel.org/20260706114320.1643046-7-usama.arif@linux.dev
Signed-off-by: Usama Arif 
Reviewed-by: Zi Yan 
Acked-by: David Hildenbrand (Arm) 
Cc: Alexandre Ghiti 
Cc: Baolin Wang 
Cc: Baoquan He 
Cc: Barry Song 
Cc: Chris Li 
Cc: Dev Jain 
Cc: "Huang, Ying" 
Cc: Johannes Weiner 
Cc: Kairui Song 
Cc: Kemeng Shi 
Cc: Kiryl Shutsemau 
Cc: Lance Yang 
Cc: Liam R. Howlett 
Cc: Lorenzo Stoakes 
Cc: Matthew Wilcox (Oracle) 
Cc: Nhat Pham 
Cc: Nico Pache 
Cc: Rik van Riel 
Cc: Ryan Roberts 
Cc: Shakeel Butt 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton

mm: replace remaining pte_to_swp_entry() with softleaf_from_pte()

2025-11-24T23:08:52+00:00

There are straggler invocations of pte_to_swp_entry() lying around,
replace all of these with the software leaf entry equivalent -
softleaf_from_pte().

With those removed, eliminate pte_to_swp_entry() altogether.

No functional change intended.

Link: https://lkml.kernel.org/r/d8ee5ccefe4c42d7c4fe1a2e46f285ac40421cd3.1762812360.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes 
Cc: Alexander Gordeev 
Cc: Alistair Popple 
Cc: Al Viro 
Cc: Arnd Bergmann 
Cc: Axel Rasmussen 
Cc: Baolin Wang 
Cc: Baoquan He 
Cc: Barry Song 
Cc: Byungchul Park 
Cc: Chengming Zhou 
Cc: Chris Li 
Cc: Christian Borntraeger 
Cc: Christian Brauner 
Cc: Claudio Imbrenda 
Cc: David Hildenbrand 
Cc: Dev Jain 
Cc: Gerald Schaefer 
Cc: Gregory Price 
Cc: Heiko Carstens 
Cc: "Huang, Ying" 
Cc: Hugh Dickins 
Cc: Jan Kara 
Cc: Jann Horn 
Cc: Janosch Frank 
Cc: Jason Gunthorpe 
Cc: Joshua Hahn 
Cc: Kairui Song 
Cc: Kemeng Shi 
Cc: Lance Yang 
Cc: Leon Romanovsky 
Cc: Liam Howlett 
Cc: Mathew Brost 
Cc: Matthew Wilcox (Oracle) 
Cc: Miaohe Lin 
Cc: Michal Hocko 
Cc: Mike Rapoport 
Cc: Muchun Song 
Cc: Naoya Horiguchi 
Cc: Nhat Pham 
Cc: Nico Pache 
Cc: Oscar Salvador 
Cc: Pasha Tatashin 
Cc: Peter Xu 
Cc: Rakie Kim 
Cc: Rik van Riel 
Cc: Ryan Roberts 
Cc: SeongJae Park 
Cc: Suren Baghdasaryan 
Cc: Sven Schnelle 
Cc: Vasily Gorbik 
Cc: Vlastimil Babka 
Cc: Wei Xu 
Cc: xu xin 
Cc: Yuanchu Xie 
Cc: Zi Yan 
Signed-off-by: Andrew Morton

mm: eliminate further swapops predicates

2025-11-24T23:08:52+00:00

Having converted so much of the code base to software leaf entries, we can
mop up some remaining cases.

We replace is_pfn_swap_entry(), pfn_swap_entry_to_page(),
is_writable_device_private_entry(), is_device_exclusive_entry(),
is_migration_entry(), is_writable_migration_entry(),
is_readable_migration_entry(), swp_offset_pfn() and pfn_swap_entry_folio()
with softleaf equivalents.

No functional change intended.

Link: https://lkml.kernel.org/r/956bc9c031604811c0070d2f4bf2f1373f230213.1762812360.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes 
Cc: Alexander Gordeev 
Cc: Alistair Popple 
Cc: Al Viro 
Cc: Arnd Bergmann 
Cc: Axel Rasmussen 
Cc: Baolin Wang 
Cc: Baoquan He 
Cc: Barry Song 
Cc: Byungchul Park 
Cc: Chengming Zhou 
Cc: Chris Li 
Cc: Christian Borntraeger 
Cc: Christian Brauner 
Cc: Claudio Imbrenda 
Cc: David Hildenbrand 
Cc: Dev Jain 
Cc: Gerald Schaefer 
Cc: Gregory Price 
Cc: Heiko Carstens 
Cc: "Huang, Ying" 
Cc: Hugh Dickins 
Cc: Jan Kara 
Cc: Jann Horn 
Cc: Janosch Frank 
Cc: Jason Gunthorpe 
Cc: Joshua Hahn 
Cc: Kairui Song 
Cc: Kemeng Shi 
Cc: Lance Yang 
Cc: Leon Romanovsky 
Cc: Liam Howlett 
Cc: Mathew Brost 
Cc: Matthew Wilcox (Oracle) 
Cc: Miaohe Lin 
Cc: Michal Hocko 
Cc: Mike Rapoport 
Cc: Muchun Song 
Cc: Naoya Horiguchi 
Cc: Nhat Pham 
Cc: Nico Pache 
Cc: Oscar Salvador 
Cc: Pasha Tatashin 
Cc: Peter Xu 
Cc: Rakie Kim 
Cc: Rik van Riel 
Cc: Ryan Roberts 
Cc: SeongJae Park 
Cc: Suren Baghdasaryan 
Cc: Sven Schnelle 
Cc: Vasily Gorbik 
Cc: Vlastimil Babka 
Cc: Wei Xu 
Cc: xu xin 
Cc: Yuanchu Xie 
Cc: Zi Yan 
Signed-off-by: Andrew Morton

mm: remove non_swap_entry() and use softleaf helpers instead

2025-11-24T23:08:51+00:00

There is simply no need for the hugely confusing concept of 'non-swap'
swap entries now we have the concept of softleaf entries and relevant
softleaf_xxx() helpers.

Adjust all callers to use these instead and remove non_swap_entry()
altogether.

No functional change intended.

Link: https://lkml.kernel.org/r/2562093f37f4a9cffea0447058014485eb50aaaf.1762812360.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes 
Cc: Alexander Gordeev 
Cc: Alistair Popple 
Cc: Al Viro 
Cc: Arnd Bergmann 
Cc: Axel Rasmussen 
Cc: Baolin Wang 
Cc: Baoquan He 
Cc: Barry Song 
Cc: Byungchul Park 
Cc: Chengming Zhou 
Cc: Chris Li 
Cc: Christian Borntraeger 
Cc: Christian Brauner 
Cc: Claudio Imbrenda 
Cc: David Hildenbrand 
Cc: Dev Jain 
Cc: Gerald Schaefer 
Cc: Gregory Price 
Cc: Heiko Carstens 
Cc: "Huang, Ying" 
Cc: Hugh Dickins 
Cc: Jan Kara 
Cc: Jann Horn 
Cc: Janosch Frank 
Cc: Jason Gunthorpe 
Cc: Joshua Hahn 
Cc: Kairui Song 
Cc: Kemeng Shi 
Cc: Lance Yang 
Cc: Leon Romanovsky 
Cc: Liam Howlett 
Cc: Mathew Brost 
Cc: Matthew Wilcox (Oracle) 
Cc: Miaohe Lin 
Cc: Michal Hocko 
Cc: Mike Rapoport 
Cc: Muchun Song 
Cc: Naoya Horiguchi 
Cc: Nhat Pham 
Cc: Nico Pache 
Cc: Oscar Salvador 
Cc: Pasha Tatashin 
Cc: Peter Xu 
Cc: Rakie Kim 
Cc: Rik van Riel 
Cc: Ryan Roberts 
Cc: SeongJae Park 
Cc: Suren Baghdasaryan 
Cc: Sven Schnelle 
Cc: Vasily Gorbik 
Cc: Vlastimil Babka 
Cc: Wei Xu 
Cc: xu xin 
Cc: Yuanchu Xie 
Cc: Zi Yan 
Signed-off-by: Andrew Morton

mm: introduce pmd_is_huge() and use where appropriate

2025-11-24T23:08:51+00:00

The leaf entry PMD case is confusing as only migration entries and device
private entries are valid at PMD level, not true swap entries.

We repeatedly perform checks of the form is_swap_pmd() || pmd_trans_huge()
which is itself confusing - it implies that leaf entries at PMD level
exist and are different from huge entries.

Address this confusion by introduced pmd_is_huge() which checks for either
case.  Sadly due to header dependency issues (huge_mm.h is included very
early on in headers and cannot really rely on much else) we cannot use
pmd_is_valid_softleaf() here.

However since these are the only valid, handled cases the function is
still achieving what it intends to do.

We then replace all instances of is_swap_pmd() || pmd_trans_huge() with
pmd_is_huge() invocations and adjust logic accordingly to accommodate
this.

No functional change intended.

Link: https://lkml.kernel.org/r/00f79db3b15293cac8f7040a48d69c52d00117e4.1762812360.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes 
Cc: Alexander Gordeev 
Cc: Alistair Popple 
Cc: Al Viro 
Cc: Arnd Bergmann 
Cc: Axel Rasmussen 
Cc: Baolin Wang 
Cc: Baoquan He 
Cc: Barry Song 
Cc: Byungchul Park 
Cc: Chengming Zhou 
Cc: Chris Li 
Cc: Christian Borntraeger 
Cc: Christian Brauner 
Cc: Claudio Imbrenda 
Cc: David Hildenbrand 
Cc: Dev Jain 
Cc: Gerald Schaefer 
Cc: Gregory Price 
Cc: Heiko Carstens 
Cc: "Huang, Ying" 
Cc: Hugh Dickins 
Cc: Jan Kara 
Cc: Jann Horn 
Cc: Janosch Frank 
Cc: Jason Gunthorpe 
Cc: Joshua Hahn 
Cc: Kairui Song 
Cc: Kemeng Shi 
Cc: Lance Yang 
Cc: Leon Romanovsky 
Cc: Liam Howlett 
Cc: Mathew Brost 
Cc: Matthew Wilcox (Oracle) 
Cc: Miaohe Lin 
Cc: Michal Hocko 
Cc: Mike Rapoport 
Cc: Muchun Song 
Cc: Naoya Horiguchi 
Cc: Nhat Pham 
Cc: Nico Pache 
Cc: Oscar Salvador 
Cc: Pasha Tatashin 
Cc: Peter Xu 
Cc: Rakie Kim 
Cc: Rik van Riel 
Cc: Ryan Roberts 
Cc: SeongJae Park 
Cc: Suren Baghdasaryan 
Cc: Sven Schnelle 
Cc: Vasily Gorbik 
Cc: Vlastimil Babka 
Cc: Wei Xu 
Cc: xu xin 
Cc: Yuanchu Xie 
Cc: Zi Yan 
Signed-off-by: Andrew Morton

mm: replace pmd_to_swp_entry() with softleaf_from_pmd()

2025-11-24T23:08:51+00:00

Introduce softleaf_from_pmd() to do the equivalent operation for PMDs that
softleaf_from_pte() fulfils, and cascade changes through code base
accordingly, introducing helpers as necessary.

We are then able to eliminate pmd_to_swp_entry(),
is_pmd_migration_entry(), is_pmd_device_private_entry() and
is_pmd_non_present_folio_entry().

This further establishes the use of leaf operations throughout the code
base and further establishes the foundations for eliminating
is_swap_pmd().

No functional change intended.

[lorenzo.stoakes@oracle.com: check writable, not readable/writable, per Vlastimil]
  Link: https://lkml.kernel.org/r/cd97b6ec-00f9-45a4-9ae0-8f009c212a94@lucifer.local
Link: https://lkml.kernel.org/r/3fb431699639ded8fdc63d2210aa77a38c8891f1.1762812360.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes 
Reviewed-by: SeongJae Park \
Reviewed-by: Vlastimil Babka 
Cc: Alexander Gordeev 
Cc: Alistair Popple 
Cc: Al Viro 
Cc: Arnd Bergmann 
Cc: Axel Rasmussen 
Cc: Baolin Wang 
Cc: Baoquan He 
Cc: Barry Song 
Cc: Byungchul Park 
Cc: Chengming Zhou 
Cc: Chris Li 
Cc: Christian Borntraeger 
Cc: Christian Brauner 
Cc: Claudio Imbrenda 
Cc: David Hildenbrand 
Cc: Dev Jain 
Cc: Gerald Schaefer 
Cc: Gregory Price 
Cc: Heiko Carstens 
Cc: "Huang, Ying" 
Cc: Hugh Dickins 
Cc: Jan Kara 
Cc: Jann Horn 
Cc: Janosch Frank 
Cc: Jason Gunthorpe 
Cc: Joshua Hahn 
Cc: Kairui Song 
Cc: Kemeng Shi 
Cc: Lance Yang 
Cc: Leon Romanovsky 
Cc: Liam Howlett 
Cc: Mathew Brost 
Cc: Matthew Wilcox (Oracle) 
Cc: Miaohe Lin 
Cc: Michal Hocko 
Cc: Mike Rapoport 
Cc: Muchun Song 
Cc: Naoya Horiguchi 
Cc: Nhat Pham 
Cc: Nico Pache 
Cc: Oscar Salvador 
Cc: Pasha Tatashin 
Cc: Peter Xu 
Cc: Rakie Kim 
Cc: Rik van Riel 
Cc: Ryan Roberts 
Cc: Suren Baghdasaryan 
Cc: Sven Schnelle 
Cc: Vasily Gorbik 
Cc: Wei Xu 
Cc: xu xin 
Cc: Yuanchu Xie 
Cc: Zi Yan 
Signed-off-by: Andrew Morton

mm: avoid unnecessary use of is_swap_pmd()

2025-11-24T23:08:51+00:00

PMD 'non-swap' swap entries are currently used for PMD-level migration
entries and device private entries.

To add to the confusion in this terminology we use is_swap_pmd() in an
inconsistent way similar to how is_swap_pte() was being used - sometimes
adopting the convention that !pmd_none(), !pmd_present() implies PMD 'swap'
entry, sometimes not.

This patch handles the low-hanging fruit of cases where we can simply
substitute other predicates for is_swap_pmd().

No functional change intended.

Link: https://lkml.kernel.org/r/8a1704b36a009c18032d5bea4cb68e71448fbbe5.1762812360.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes 
Reviewed-by: Vlastimil Babka 
Cc: Alexander Gordeev 
Cc: Alistair Popple 
Cc: Al Viro 
Cc: Arnd Bergmann 
Cc: Axel Rasmussen 
Cc: Baolin Wang 
Cc: Baoquan He 
Cc: Barry Song 
Cc: Byungchul Park 
Cc: Chengming Zhou 
Cc: Chris Li 
Cc: Christian Borntraeger 
Cc: Christian Brauner 
Cc: Claudio Imbrenda 
Cc: David Hildenbrand 
Cc: Dev Jain 
Cc: Gerald Schaefer 
Cc: Gregory Price 
Cc: Heiko Carstens 
Cc: "Huang, Ying" 
Cc: Hugh Dickins 
Cc: Jan Kara 
Cc: Jann Horn 
Cc: Janosch Frank 
Cc: Jason Gunthorpe 
Cc: Joshua Hahn 
Cc: Kairui Song 
Cc: Kemeng Shi 
Cc: Lance Yang 
Cc: Leon Romanovsky 
Cc: Liam Howlett 
Cc: Mathew Brost 
Cc: Matthew Wilcox (Oracle) 
Cc: Miaohe Lin 
Cc: Michal Hocko 
Cc: Mike Rapoport 
Cc: Muchun Song 
Cc: Naoya Horiguchi 
Cc: Nhat Pham 
Cc: Nico Pache 
Cc: Oscar Salvador 
Cc: Pasha Tatashin 
Cc: Peter Xu 
Cc: Rakie Kim 
Cc: Rik van Riel 
Cc: Ryan Roberts 
Cc: SeongJae Park 
Cc: Suren Baghdasaryan 
Cc: Sven Schnelle 
Cc: Vasily Gorbik 
Cc: Vlastimil Babka 
Cc: Wei Xu 
Cc: xu xin 
Cc: Yuanchu Xie 
Cc: Zi Yan 
Signed-off-by: Andrew Morton