Balbir Singh [Wed, 1 Oct 2025 06:57:07 +0000 (16:57 +1000)]
gpu/drm/nouveau: enable THP support for GPU memory migration
Enable MIGRATE_VMA_SELECT_COMPOUND support in nouveau driver to take
advantage of THP zone device migration capabilities.
Update migration and eviction code paths to handle compound page sizes
appropriately, improving memory bandwidth utilization and reducing
migration overhead for large GPU memory allocations.
Link: https://lkml.kernel.org/r/20251001065707.920170-17-balbirs@nvidia.com Signed-off-by: Balbir Singh <balbirs@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Lyude Paul <lyude@redhat.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: David Airlie <airlied@gmail.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Mika Penttilä <mpenttil@redhat.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Francois Dugast <francois.dugast@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Balbir Singh [Wed, 1 Oct 2025 06:57:03 +0000 (16:57 +1000)]
lib/test_hmm: add large page allocation failure testing
Add HMM_DMIRROR_FLAG_FAIL_ALLOC flag to simulate large page allocation
failures, enabling testing of split migration code paths.
This test flag allows validation of the fallback behavior when destination
device cannot allocate compound pages. This is useful for testing the
split migration functionality.
Link: https://lkml.kernel.org/r/20251001065707.920170-13-balbirs@nvidia.com Signed-off-by: Balbir Singh <balbirs@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Lyude Paul <lyude@redhat.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: David Airlie <airlied@gmail.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Mika Penttilä <mpenttil@redhat.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Francois Dugast <francois.dugast@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Balbir Singh [Wed, 1 Oct 2025 06:57:02 +0000 (16:57 +1000)]
mm/migrate_device: add THP splitting during migration
Implement migrate_vma_split_pages() to handle THP splitting during the
migration process when destination cannot allocate compound pages.
This addresses the common scenario where migrate_vma_setup() succeeds with
MIGRATE_PFN_COMPOUND pages, but the destination device cannot allocate
large pages during the migration phase.
Key changes:
- migrate_vma_split_pages(): Split already-isolated pages during migration
- Enhanced folio_split() and __split_unmapped_folio() with isolated
parameter to avoid redundant unmap/remap operations
This provides a fallback mechansim to ensure migration succeeds even when
large page allocation fails at the destination.
Link: https://lkml.kernel.org/r/20251001065707.920170-12-balbirs@nvidia.com Signed-off-by: Balbir Singh <balbirs@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Lyude Paul <lyude@redhat.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: David Airlie <airlied@gmail.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Mika Penttilä <mpenttil@redhat.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Francois Dugast <francois.dugast@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Balbir Singh [Wed, 1 Oct 2025 06:57:01 +0000 (16:57 +1000)]
mm/memremap: add driver callback support for folio splitting
When a zone device page is split (via huge pmd folio split). The driver
callback for folio_split is invoked to let the device driver know that the
folio size has been split into a smaller order.
Provide a default implementation for drivers that do not provide this
callback that copies the pgmap and mapping fields for the split folios.
Update the HMM test driver to handle the split.
Link: https://lkml.kernel.org/r/20251001065707.920170-11-balbirs@nvidia.com Signed-off-by: Balbir Singh <balbirs@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Lyude Paul <lyude@redhat.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: David Airlie <airlied@gmail.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Mika Penttilä <mpenttil@redhat.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Francois Dugast <francois.dugast@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Balbir Singh [Wed, 1 Oct 2025 06:57:00 +0000 (16:57 +1000)]
lib/test_hmm: add zone device private THP test infrastructure
Enhance the hmm test driver (lib/test_hmm) with support for THP pages.
A new pool of free_folios() has now been added to the dmirror device,
which can be allocated when a request for a THP zone device private page
is made.
Add compound page awareness to the allocation function during normal
migration and fault based migration. These routines also copy
folio_nr_pages() when moving data between system memory and device memory.
args.src and args.dst used to hold migration entries are now dynamically
allocated (as they need to hold HPAGE_PMD_NR entries or more).
Split and migrate support will be added in future patches in this series.
Link: https://lkml.kernel.org/r/20251001065707.920170-10-balbirs@nvidia.com Signed-off-by: Balbir Singh <balbirs@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Lyude Paul <lyude@redhat.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: David Airlie <airlied@gmail.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Mika Penttilä <mpenttil@redhat.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Francois Dugast <francois.dugast@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Balbir Singh [Wed, 1 Oct 2025 06:56:59 +0000 (16:56 +1000)]
mm/memory/fault: add THP fault handling for zone device private pages
Implement CPU fault handling for zone device THP entries through
do_huge_pmd_device_private(), enabling transparent migration of
device-private large pages back to system memory on CPU access.
When the CPU accesses a zone device THP entry, the fault handler calls the
device driver's migrate_to_ram() callback to migrate the entire large page
back to system memory.
Link: https://lkml.kernel.org/r/20251001065707.920170-9-balbirs@nvidia.com Signed-off-by: Balbir Singh <balbirs@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Lyude Paul <lyude@redhat.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: David Airlie <airlied@gmail.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Mika Penttilä <mpenttil@redhat.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Francois Dugast <francois.dugast@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Balbir Singh [Wed, 1 Oct 2025 06:56:58 +0000 (16:56 +1000)]
mm/migrate_device: implement THP migration of zone device pages
MIGRATE_VMA_SELECT_COMPOUND will be used to select THP pages during
migrate_vma_setup() and MIGRATE_PFN_COMPOUND will make migrating device
pages as compound pages during device pfn migration.
migrate_device code paths go through the collect, setup and finalize
phases of migration.
The entries in src and dst arrays passed to these functions still remain
at a PAGE_SIZE granularity. When a compound page is passed, the first
entry has the PFN along with MIGRATE_PFN_COMPOUND and other flags set
(MIGRATE_PFN_MIGRATE, MIGRATE_PFN_VALID), the remaining entries
(HPAGE_PMD_NR - 1) are filled with 0's. This representation allows for
the compound page to be split into smaller page sizes.
migrate_vma_collect_hole(), migrate_vma_collect_pmd() are now THP page
aware. Two new helper functions migrate_vma_collect_huge_pmd() and
migrate_vma_insert_huge_pmd_page() have been added.
migrate_vma_collect_huge_pmd() can collect THP pages, but if for some
reason this fails, there is fallback support to split the folio and
migrate it.
migrate_vma_insert_huge_pmd_page() closely follows the logic of
migrate_vma_insert_page()
Support for splitting pages as needed for migration will follow in later
patches in this series.
Link: https://lkml.kernel.org/r/20251001065707.920170-8-balbirs@nvidia.com Signed-off-by: Balbir Singh <balbirs@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Lyude Paul <lyude@redhat.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: David Airlie <airlied@gmail.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Mika Penttilä <mpenttil@redhat.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Francois Dugast <francois.dugast@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Balbir Singh [Wed, 1 Oct 2025 06:56:57 +0000 (16:56 +1000)]
mm/migrate_device: handle partially mapped folios during collection
Extend migrate_vma_collect_pmd() to handle partially mapped large folios
that require splitting before migration can proceed.
During PTE walk in the collection phase, if a large folio is only
partially mapped in the migration range, it must be split to ensure the
folio is correctly migrated.
Link: https://lkml.kernel.org/r/20251001065707.920170-7-balbirs@nvidia.com Signed-off-by: Balbir Singh <balbirs@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Lyude Paul <lyude@redhat.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: David Airlie <airlied@gmail.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Mika Penttilä <mpenttil@redhat.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Francois Dugast <francois.dugast@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add support for splitting device-private THP folios, enabling fallback
to smaller page sizes when large page allocation or migration fails.
Key changes:
- split_huge_pmd(): Handle device-private PMD entries during splitting
- Preserve RMAP_EXCLUSIVE semantics for anonymous exclusive folios
- Skip RMP_USE_SHARED_ZEROPAGE for device-private entries as they
don't support shared zero page semantics
Link: https://lkml.kernel.org/r/20251001065707.920170-6-balbirs@nvidia.com Signed-off-by: Balbir Singh <balbirs@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Lyude Paul <lyude@redhat.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: David Airlie <airlied@gmail.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Mika Penttilä <mpenttil@redhat.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Francois Dugast <francois.dugast@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Balbir Singh [Wed, 1 Oct 2025 06:56:54 +0000 (16:56 +1000)]
mm/huge_memory: add device-private THP support to PMD operations
Extend core huge page management functions to handle device-private THP
entries. This enables proper handling of large device-private folios in
fundamental MM operations.
The following functions have been updated:
- copy_huge_pmd(): Handle device-private entries during fork/clone
- zap_huge_pmd(): Properly free device-private THP during munmap
- change_huge_pmd(): Support protection changes on device-private THP
- __pte_offset_map(): Add device-private entry awareness
Link: https://lkml.kernel.org/r/20251001065707.920170-4-balbirs@nvidia.com Signed-off-by: Matthew Brost <matthew.brost@intel.com> Signed-off-by: Balbir Singh <balbirs@nvidia.com> Acked-by: Zi Yan <ziy@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Lyude Paul <lyude@redhat.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: David Airlie <airlied@gmail.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Mika Penttilä <mpenttil@redhat.com> Cc: Francois Dugast <francois.dugast@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Balbir Singh [Wed, 1 Oct 2025 06:56:53 +0000 (16:56 +1000)]
mm/zone_device: rename page_free callback to folio_free
Change page_free to folio_free to make the folio support for
zone device-private more consistent. The PCI P2PDMA callback
has also been updated and changed to folio_free() as a result.
For drivers that do not support folios (yet), the folio is
converted back into page via &folio->page and the page is used
as is, in the current callback implementation.
Link: https://lkml.kernel.org/r/20251001065707.920170-3-balbirs@nvidia.com Signed-off-by: Balbir Singh <balbirs@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Lyude Paul <lyude@redhat.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: David Airlie <airlied@gmail.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Mika Penttilä <mpenttil@redhat.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Francois Dugast <francois.dugast@intel.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Felix Kuehling <Felix.Kuehling@amd.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: "Christian König" <christian.koenig@amd.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Balbir Singh [Wed, 1 Oct 2025 06:56:52 +0000 (16:56 +1000)]
mm/zone_device: support large zone device private folios
Patch series "mm: support device-private THP", v7.
This patch series introduces support for Transparent Huge Page (THP)
migration in zone device-private memory. The implementation enables
efficient migration of large folios between system memory and
device-private memory
Background
Current zone device-private memory implementation only supports PAGE_SIZE
granularity, leading to:
- Increased TLB pressure
- Inefficient migration between CPU and device memory
This series extends the existing zone device-private infrastructure to
support THP, leading to:
- Reduced page table overhead
- Improved memory bandwidth utilization
- Seamless fallback to base pages when needed
In my local testing (using lib/test_hmm) and a throughput test, the series
shows a 350% improvement in data transfer throughput and a 80% improvement
in latency
These patches build on the earlier posts by Ralph Campbell [1]
Two new flags are added in vma_migration to select and mark compound
pages. migrate_vma_setup(), migrate_vma_pages() and
migrate_vma_finalize() support migration of these pages when
MIGRATE_VMA_SELECT_COMPOUND is passed in as arguments.
The series also adds zone device awareness to (m)THP pages along with
fault handling of large zone device private pages. page vma walk and the
rmap code is also zone device aware. Support has also been added for
folios that might need to be split in the middle of migration (when the
src and dst do not agree on MIGRATE_PFN_COMPOUND), that occurs when src
side of the migration can migrate large pages, but the destination has not
been able to allocate large pages. The code supported and used
folio_split() when migrating THP pages, this is used when
MIGRATE_VMA_SELECT_COMPOUND is not passed as an argument to
migrate_vma_setup().
The test infrastructure lib/test_hmm.c has been enhanced to support THP
migration. A new ioctl to emulate failure of large page allocations has
been added to test the folio split code path. hmm-tests.c has new test
cases for huge page migration and to test the folio split path. A new
throughput test has been added as well.
The nouveau dmem code has been enhanced to use the new THP migration
capability.
mTHP support:
The patches hard code, HPAGE_PMD_NR in a few places, but the code has been
kept generic to support various order sizes. With additional refactoring
of the code support of different order sizes should be possible.
The future plan is to post enhancements to support mTHP with a rough
design as follows:
1. Add the notion of allowable thp orders to the HMM based test driver
2. For non PMD based THP paths in migrate_device.c, check to see if
a suitable order is found and supported by the driver
3. Iterate across orders to check the highest supported order for migration
4. Migrate and finalize
The mTHP patches can be built on top of this series, the key design
elements that need to be worked out are infrastructure and driver support
for multiple ordered pages and their migration.
HMM support for large folios was added in 10b9feee2d0d ("mm/hmm:
populate PFNs from PMD swap entry").
This patch (of 16)
Add routines to support allocation of large order zone device folios and
helper functions for zone device folios, to check if a folio is device
private and helpers for setting zone device data.
When large folios are used, the existing page_free() callback in pgmap is
called when the folio is freed, this is true for both PAGE_SIZE and higher
order pages.
Zone device private large folios do not support deferred split and scan
like normal THP folios.
Link: https://lkml.kernel.org/r/20251001065707.920170-1-balbirs@nvidia.com Link: https://lkml.kernel.org/r/20251001065707.920170-2-balbirs@nvidia.com Link: https://lore.kernel.org/linux-mm/20201106005147.20113-1-rcampbell@nvidia.com/ Signed-off-by: Balbir Singh <balbirs@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Lyude Paul <lyude@redhat.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: David Airlie <airlied@gmail.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Mika Penttilä <mpenttil@redhat.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Francois Dugast <francois.dugast@intel.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Felix Kuehling <Felix.Kuehling@amd.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: "Christian König" <christian.koenig@amd.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Mauricio Faria de Oliveira [Wed, 1 Oct 2025 17:56:11 +0000 (14:56 -0300)]
mm/page_owner: update Documentation with 'show_handles' and 'show_stacks_handles'
Describe and provide examples for 'show_handles' and 'show_stacks_handles'.
Link: https://lkml.kernel.org/r/20251001175611.575861-6-mfo@igalia.com Signed-off-by: Mauricio Faria de Oliveira <mfo@igalia.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add the file 'show_stacks_handles' to show just stack traces and their
handles, in order to resolve stack traces and handles (i.e., to identify
the stack traces for handles in previous reads from 'show_handles').
All stacks/handles must show up, regardless of their number of pages, that
might have become zero or no longer make 'count_threshold', but made it in
previous reads from 'show_handles' -- and need to be resolved later.
P.S.: now, print the extra newline independently of the number of pages.
Link: https://lkml.kernel.org/r/20251001175611.575861-5-mfo@igalia.com Signed-off-by: Mauricio Faria de Oliveira <mfo@igalia.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Mauricio Faria de Oliveira [Wed, 1 Oct 2025 17:56:09 +0000 (14:56 -0300)]
mm/page_owner: add debugfs file 'show_handles'
Add the flag STACK_PRINT_FLAG_HANDLE to print a stack's handle number from
stackdepot, and add the file 'show_handles' to show just handles and their
number of pages.
This is similar to 'show_stacks', with handles instead of stack traces.
Link: https://lkml.kernel.org/r/20251001175611.575861-4-mfo@igalia.com Signed-off-by: Mauricio Faria de Oliveira <mfo@igalia.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Mauricio Faria de Oliveira [Wed, 1 Oct 2025 17:56:08 +0000 (14:56 -0300)]
mm/page_owner: add struct stack_print_ctx.flags
Add the flags field to stack_print_ctx, and define two flags for current
behavior (printing stack traces and their number of base pages).
The plumbing of flags is debugfs_create_file(data) -> inode.i_private ->
page_owner_stack_open() -> stack_print_ctx.flags -> stack_print().
No behavior change intended.
Link: https://lkml.kernel.org/r/20251001175611.575861-3-mfo@igalia.com Signed-off-by: Mauricio Faria de Oliveira <mfo@igalia.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Mauricio Faria de Oliveira [Wed, 1 Oct 2025 17:56:07 +0000 (14:56 -0300)]
mm/page_owner: introduce struct stack_print_ctx
Patch series "mm/page_owner: add debugfs files 'show_handles' and
'show_stacks_handles'", v2.
Context:
The page_owner debug feature can help understand a particular situation in
in a point in time (e.g., identify biggest memory consumers; verify memory
counters that do not add up).
Another useful usecase is to collect data repeatedly over time, and use it
for profiling, monitoring, and even comparing different kernel versions,
at the stack trace level (e.g., watch for trends, leaks, correlations, and
regressions).
For this usecase, userspace periorically collects the data from page_owner
and organizes it in data structures appropriate for access per-stack
trace.
Problem:
The usecase of tracking memory usage per stack trace (or tracking it for a
particular stack trace) requires uniquely identifying each stack trace
(i.e., keys to store their memory usage over periodic data collections).
This has to be done for every stack trace in every sample/data collection,
even if tracking only one stack trace (to identify it among all others).
Therefore, an approach like hashing the stack traces in userspace to
create unique keys/identifiers for them during post-processing can quickly
become expensive, considering the repetition and a growing number of stack
traces.
Solution:
Fortunately, the kernel can provide a unique identifier for stack traces
in page_owner, which is the handle number in stackdepot. This eliminates
the need for creating keys (hashing) in userspace during post-processing.
Additionally, with that information, the stack traces themselves are not
needed until the memory usage should be resolved from a handle to a stack
trace (say, to look at the stack traces of a few top consumers). This can
reduce the amount of text emitted/copied by the kernel to userspace, and
save userspace from matching and discarding stack traces when not needed.
Changes:
This patchset adds 2 files to provide information, like 'show_stacks':
- show_handles: print handle number and number of pages (no stack traces)
- show_stacks_handles: print handle numbers and stack traces (no pages)
Now, it's possible to periodically collect data with handle numbers (keys)
and without stack traces (lower overhead) from 'show_handles', and later
do a final collection with handles and stack traces from
'show_stacks_handles' to resolve the handles to their stack traces.
The output format follows the existing 'show_stacks' file, for simplicity,
but it can certainly be changed if a different format is more convenient.
Example:
The number of base pages collected can be stored per-handle number over
the periodic data collections, and finally resolved to stack traces
per-handle number as well with a final collection.
Later, one can, for example, identify the biggest consumers and watch
their trends or correlate increases/decreases with other events in the
system, or watch a particular stack trace(s) of interest during
development.
Currently, struct seq_file.private is used as an iterator in stack_list by
stack_start|next(), for stack_print().
Create a context struct for this, in order to add another field next.
No behavior change intended.
P.S.: page_owner_stack_open() is expanded with separate statements for
variable definition and return just in preparation for the next patch.
Link: https://lkml.kernel.org/r/20251001175611.575861-1-mfo@igalia.com Link: https://lkml.kernel.org/r/20251001175611.575861-2-mfo@igalia.com Signed-off-by: Mauricio Faria de Oliveira <mfo@igalia.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Anshuman Khandual [Mon, 6 Oct 2025 05:52:14 +0000 (06:52 +0100)]
mm/dirty: replace READ_ONCE() with pudp_get()
Replace READ_ONCE() with a standard page table accessor i.e pudp_get() that
anyways defaults into READ_ONCE() in cases where platform does not override
Link: https://lkml.kernel.org/r/20251006055214.1845342-1-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Lance Yang <lance.yang@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Wei Yang [Thu, 2 Oct 2025 03:31:40 +0000 (03:31 +0000)]
mm/compaction: fix the range to pageblock_pfn_to_page()
The function pageblock_pfn_to_page() must confirm that the target range is
contained entirely within the current zone.
Originally, when pageblock_pfn_to_page() was introduced by commit 7d49d8868336, it operated on a single range, [pfn, block_end_pfn], for
both range checking and isolation.
However, commit e1409c325fdc ("mm/compaction: pass only pageblock aligned
range to pageblock_pfn_to_page") changed this behavior, causing the
function to operate on two different ranges:
[block_start_pfn, block_end_pfn] is used to check if the range is in the
same zone.
[pfn, block_end_pfn] is used for page isolation.
This split logic fails when start_pfn < zone_start_pfn, even if both are
within the same pageblock. In this scenario, the checking range
[block_start_pfn, block_end_pfn] is used, which incorrectly misses the
pages before zone_start_pfn.
This oversight allows the range check to pass, even though the isolation
step ([pfn, block_end_pfn]) may attempt to isolate pages belonging to two
different zones.
To fix this, we should revert to using the same range ([block_start_pfn,
block_end_pfn]) for both checking and isolation in each iteration.
Link: https://lkml.kernel.org/r/20251002033140.24462-3-richard.weiyang@gmail.com Fixes: e1409c325fdc ("mm/compaction: pass only pageblock aligned range to pageblock_pfn_to_page") Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Wei Yang [Thu, 2 Oct 2025 03:31:39 +0000 (03:31 +0000)]
mm/compaction: check the range to pageblock_pfn_to_page() is within the zone first
While reviewing isolate_migratepages_range(), I noticed a discrepancy: the
page range passed to pageblock_pfn_to_page() is different from the range
passed to isolate_migratepages_block().
This difference creates a potential issue: pageblock_pfn_to_page() might
incorrectly confirm that the range is entirely within the same zone, but
isolate_migratepages_block() could then proceed to isolate pages that span
two different zones. This is unexpected behavior.
Further investigation revealed that pageblock_pfn_to_page() contains an
optimization for zones marked as contiguous. This optimization is buggy,
as it causes the function to assume a range is within the same zone even
if the PFNs actually cross a zone boundary.
To resolve these issues, two patches are introduced:
Patch 1: Check the range belongs to the zone first.
Patch 2: Pass the correct range to pageblock_pfn_to_page() to ensure
consistency between the check and the isolation steps.
This patch (of 2):
The function pageblock_pfn_to_page() was introduced by commit 7d49d8868336
("mm, compaction: reduce zone checking frequency in the migration
scanner"). At that time, it had no requirement that start_pfn and end_pfn
had to be contained within the zone boundary; the only requirement was
that they were in the same pageblock. Therefore, pageblock_pfn_to_page()
would be called with a PFN (Page Frame Number) that wasn't checked against
the zone boundary.
However, after commit 7cf91a98e607 ("mm/compaction: speed up
pageblock_pfn_to_page() when zone is contiguous"), pageblock_pfn_to_page()
may incorrectly assume a range is valid and belongs to a contiguous zone,
even if the range is outside that zone's actual boundaries.
For instance, in fast_isolate_freepages(), min_pfn is assigned using
pageblock_start_pfn() and passed to pageblock_pfn_to_page() without
checking it against zone_start_pfn. Similarly, end_pfn is often not
checked against zone_end_pfn().
To make this function robust, the range must be checked to ensure it is
within the zone boundary first.
Link: https://lkml.kernel.org/r/20251002033140.24462-1-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20251002033140.24462-2-richard.weiyang@gmail.com Fixes: 7cf91a98e607 ("mm/compaction: speed up pageblock_pfn_to_page() when zone is contiguous") Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Ryan Roberts [Fri, 3 Oct 2025 15:53:04 +0000 (16:53 +0100)]
mm: consistently use current->mm in mm_get_unmapped_area()
mm_get_unmapped_area() is a wrapper around arch_get_unmapped_area() /
arch_get_unmapped_area_topdown(), both of which search current->mm for
some free space. Neither take an mm_struct - they implicitly operate on
current->mm.
But the wrapper takes an mm_struct and uses it to decide whether to search
bottom up or top down. All callers pass in current->mm for this, so
everything is working consistently. But it feels like an accident waiting
to happen; eventually someone will call that function with a different mm,
expecting to find free space in it, but what gets returned is free space
in the current mm.
So let's simplify by removing the parameter and have the wrapper use
current->mm to decide which end to start at. Now everything is consistent
and self-documenting.
Link: https://lkml.kernel.org/r/20251003155306.2147572-1-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
SeongJae Park [Fri, 3 Oct 2025 20:38:48 +0000 (13:38 -0700)]
mm/zswap: remove unnecessary dlen writes for incompressible pages
Patch series "mm/zswap: misc cleanup of code and documentations".
Clean up an unnecessary local variable write in incompressible pages
handling, typos (s/zwap/zswap/) and outdated comments/documentations about
the zswap's red-black tree, which is replaced by xarray.
This patch (of 4):
Incompressible pages handling logic in zswap_compress() is setting 'dlen'
as PAGE_SIZE twice. Once before deciding whether to save the content as
is, and once again after it is decided to save it as is. But the value of
'dlen' is used only if it is decided to save the content as is, so the
first write is unnecessary. It is not causing real user issues, but
making code confusing to read. Remove the unnecessary write operation.
Link: https://lkml.kernel.org/r/20251003203851.43128-1-sj@kernel.org Link: https://lkml.kernel.org/r/20251003203851.43128-2-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Acked-by: Yosry Ahmed <yosry.ahmed@linux.dev> Acked-by: Nhat Pham <nphamcs@gmail.com> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Cc: David Hildenbrand <david@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Chris Li <chrisl@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fushuai Wang [Mon, 6 Oct 2025 01:49:48 +0000 (09:49 +0800)]
mm/vmscan: remove redundant __GFP_NOWARN
The __GFP_NOWARN flag was included in GFP_NOWAIT since commit 16f5dfbc851b
("gfp: include __GFP_NOWARN in GFP_NOWAIT"). So remove the redundant
__GFP_NOWARN flag.
Link: https://lkml.kernel.org/r/20251006014948.44695-1-wangfushuai@baidu.com Signed-off-by: Fushuai Wang <wangfushuai@baidu.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Roman Gushchin [Mon, 6 Oct 2025 17:51:06 +0000 (10:51 -0700)]
mm: readahead: make thp readahead conditional to mmap_miss logic
Commit 4687fdbb805a ("mm/filemap: Support VM_HUGEPAGE for file mappings")
introduced a special handling for VM_HUGEPAGE mappings: even if the
readahead is disabled, 1 or 2 HPAGE_PMD_ORDER pages are allocated.
This change causes a significant regression for containers with a tight
memory.max limit, if VM_HUGEPAGE is widely used. Prior to this commit,
mmap_miss logic would eventually lead to the readahead disablement,
effectively reducing the memory pressure in the cgroup. With this change
the kernel is trying to allocate 1-2 huge pages for each fault, no matter
if these pages are used or not before being evicted, increasing the memory
pressure multi-fold.
To fix the regression, let's make the new VM_HUGEPAGE conditional to the
mmap_miss check, but keep independent from the ra->ra_pages. This way the
main intention of commit 4687fdbb805a ("mm/filemap: Support VM_HUGEPAGE
for file mappings") stays intact, but the regression is resolved.
The logic behind this changes is simple: even if a user explicitly
requests using huge pages to back the file mapping (using VM_HUGEPAGE
flag), under a very strong memory pressure it's better to fall back to
ordinary pages.
Link: https://lkml.kernel.org/r/20251006175106.377411-1-roman.gushchin@linux.dev Fixes: 4687fdbb805a ("mm/filemap: Support VM_HUGEPAGE for file mappings") Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kairui Song [Mon, 6 Oct 2025 20:02:36 +0000 (04:02 +0800)]
mm/migrate, swap: drop usage of folio_index
This helper was used when swap cache was mixed with page cache. Now they
are completely separate from each other, access to the swap cache is all
wrapped by the swap_cache_* helpers, which expect the folio's swap entry
as a parameter.
This helper is no longer used, remove the last redundant user and drop it.
Link: https://lkml.kernel.org/r/20251007-swap-clean-after-swap-table-p1-v1-4-74860ef8ba74@tencent.com Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Chris Li <chrisl@kernel.org> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/CAMgjq7DGy_ZmPqcqUO6s5BN381Zuee_g3KWjVqM3amLhpwE=2g@mail.gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nhat Pham <nphamcs@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kairui Song [Mon, 6 Oct 2025 20:02:35 +0000 (04:02 +0800)]
mm, swap: cleanup swap entry allocation parameter
We no longer need this GFP parameter after commit 8578e0c00dcf ("mm, swap:
use the swap table for the swap cache and switch API"). Before that
commit the GFP parameter is already almost identical for all callers, so
nothing changed by that commit. Swap table just moved the GFP to lower
layer and make it more defined and changes depend on atomic or sleep
allocation.
Now this parameter is no longer used, just remove it. No behavior change.
Link: https://lkml.kernel.org/r/20251007-swap-clean-after-swap-table-p1-v1-3-74860ef8ba74@tencent.com Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Chris Li <chrisl@kernel.org> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kairui Song [Mon, 6 Oct 2025 20:02:34 +0000 (04:02 +0800)]
mm, swap: rename helper for setup bad slots
The name inc_cluster_info_page is very confusing, as this helper is only
used during swapon to mark bad slots. Rename it properly and turn the
VM_BUG_ON in it into WARN_ON to expose more potential issues. Swapon is a
cold path, so adding more checks should be a good idea.
No feature change except new WARN_ON.
Link: https://lkml.kernel.org/r/20251007-swap-clean-after-swap-table-p1-v1-2-74860ef8ba74@tencent.com Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Chris Li <chrisl@kernel.org> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kairui Song [Mon, 6 Oct 2025 20:02:33 +0000 (04:02 +0800)]
mm, swap: do not perform synchronous discard during allocation
Patch series "mm, swap: misc cleanup and bugfix".
A few cleanups and a bugfix that are either suitable after the swap table
phase I or found during code review.
Patch 1 is a bugfix and needs to be included in the stable branch, the
rest have no behavior change.
This patch (of 4):
Since commit 1b7e90020eb77 ("mm, swap: use percpu cluster as allocation
fast path"), swap allocation is protected by a local lock, which means we
can't do any sleeping calls during allocation.
However, the discard routine is not taken well care of. When the swap
allocator failed to find any usable cluster, it would look at the pending
discard cluster and try to issue some blocking discards. It may not
necessarily sleep, but the cond_resched at the bio layer indicates this is
wrong when combined with a local lock. And the bio GFP flag used for
discard bio is also wrong (not atomic).
It's arguable whether this synchronous discard is helpful at all. In most
cases, the async discard is good enough. And the swap allocator is doing
very differently at organizing the clusters since the recent change, so it
is very rare to see discard clusters piling up.
So far, no issues have been observed or reported with typical SSD setups
under months of high pressure. This issue was found during my code
review. But by hacking the kernel a bit: adding a mdelay(100) in the
async discard path, this issue will be observable with WARNING triggered
by the wrong GFP and cond_resched in the bio layer.
So let's fix this issue in a safe way: remove the synchronous discard in
the swap allocation path. And when order 0 is failing with all cluster
list drained on all swap devices, try to do a discard following the swap
device priority list. If any discards released some cluster, try the
allocation again. This way, we can still avoid OOM due to swap failure if
the hardware is very slow and memory pressure is extremely high.
Link: https://lkml.kernel.org/r/20251007-swap-clean-after-swap-table-p1-v1-0-74860ef8ba74@tencent.com Link: https://lkml.kernel.org/r/20251007-swap-clean-after-swap-table-p1-v1-1-74860ef8ba74@tencent.com Fixes: 1b7e90020eb7 ("mm, swap: use percpu cluster as allocation fast path") Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Nhat Pham <nphamcs@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
xu xin [Tue, 7 Oct 2025 10:29:35 +0000 (18:29 +0800)]
selftests: update ksm inheritance tests for prctl fork/exec
To reproduce the issue mentioned by [1], this add a setting of
pages_to_scan and sleep_millisecs at the start of test_prctl_fork_exec().
The main change is just raise the scanning frequency of ksmd.
Link: https://lkml.kernel.org/r/20251007182935207jm31wCIgLpZg5XbXQY64S@zte.com.cn Signed-off-by: xu xin <xu.xin16@zte.com.cn> Cc: David Hildenbrand <david@redhat.com> Cc: Jinjiang Tu <tujinjiang@huawei.com> Cc: Stefan Roesch <shr@devkernel.io> Cc: Wang Yaxin <wang.yaxin@zte.com.cn> Cc: Yang Yang <yang.yang29@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
xu xin [Tue, 7 Oct 2025 10:28:21 +0000 (18:28 +0800)]
mm/ksm: fix exec/fork inheritance support for prctl
Patch series "ksm: fix exec/fork inheritance", v2.
This series fixes exec/fork inheritance. See the detailed description of
the issue below.
This patch (of 2):
Background
==========
commit d7597f59d1d33 ("mm: add new api to enable ksm per process")
introduced MMF_VM_MERGE_ANY for mm->flags, and allowed user to set it by
prctl() so that the process's VMAs are forcibly scanned by ksmd.
Subsequently, the 3c6f33b7273a ("mm/ksm: support fork/exec for prctl")
supported inheriting the MMF_VM_MERGE_ANY flag when a task calls execve().
Finally, commit 3a9e567ca45fb ("mm/ksm: fix ksm exec support for prctl")
fixed the issue that ksmd doesn't scan the mm_struct with MMF_VM_MERGE_ANY
by adding the mm_slot to ksm_mm_head in __bprm_mm_init().
Problem
=======
In some extreme scenarios, however, this inheritance of MMF_VM_MERGE_ANY
during exec/fork can fail. For example, when the scanning frequency of
ksmd is tuned extremely high, a process carrying MMF_VM_MERGE_ANY may
still fail to pass it to the newly exec'd process. This happens because
ksm_execve() is executed too early in the do_execve flow (prematurely
adding the new mm_struct to the ksm_mm_slot list).
As a result, before do_execve completes, ksmd may have already performed a
scan and found that this new mm_struct has no VM_MERGEABLE VMAs, thus
clearing its MMF_VM_MERGE_ANY flag. Consequently, when the new program
executes, the flag MMF_VM_MERGE_ANY inheritance missed.
Root reason
===========
commit d7597f59d1d33 ("mm: add new api to enable ksm per process") clear
the flag MMF_VM_MERGE_ANY when ksmd found no VM_MERGEABLE VMAs.
Solution
========
Firstly, Don't clear MMF_VM_MERGE_ANY when ksmd found no VM_MERGEABLE
VMAs, because perhaps their mm_struct has just been added to ksm_mm_slot
list, and its process has not yet officially started running or has not
yet performed mmap/brk to allocate anonymous VMAS.
Secondly, recheck MMF_VM_MERGEABLE again if a process takes
MMF_VM_MERGE_ANY, and create a mm_slot and join it into ksm_scan_list
again.
Link: https://lkml.kernel.org/r/20251007182504440BJgK8VXRHh8TD7IGSUIY4@zte.com.cn Link: https://lkml.kernel.org/r/20251007182821572h_SoFqYZXEP1mvWI4n9VL@zte.com.cn Fixes: 3c6f33b7273a ("mm/ksm: support fork/exec for prctl") Fixes: d7597f59d1d3 ("mm: add new api to enable ksm per process") Signed-off-by: xu xin <xu.xin16@zte.com.cn> Cc: Stefan Roesch <shr@devkernel.io> Cc: David Hildenbrand <david@redhat.com> Cc: Jinjiang Tu <tujinjiang@huawei.com> Cc: Wang Yaxin <wang.yaxin@zte.com.cn> Cc: Yang Yang <yang.yang29@zte.com.cn> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: kvmalloc: add non-blocking support for vmalloc
Extend __kvmalloc_node_noprof() to handle non-blocking GFP flags
(GFP_NOWAIT and GFP_ATOMIC). Previously such flags were rejected,
returning NULL. With this change:
- kvmalloc() can fall back to vmalloc() if non-blocking contexts;
- for non-blocking allocations the VM_ALLOW_HUGE_VMAP option is
disabled, since the huge mapping path still contains might_sleep();
- documentation update to reflect that GFP_NOWAIT and GFP_ATOMIC
are now supported.
Link: https://lkml.kernel.org/r/20251007122035.56347-11-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Marco Elver <elver@google.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm: skip might_alloc() warnings when PF_MEMALLOC is set
might_alloc() catches invalid blocking allocations in contexts where
sleeping is not allowed.
However when PF_MEMALLOC is set, the page allocator already skips reclaim
and other blocking paths. In such cases, a blocking gfp_mask does not
actually lead to blocking, so triggering might_alloc() splats is
misleading.
Adjust might_alloc() to skip warnings when the current task has
PF_MEMALLOC set, matching the allocator's actual blocking behaviour.
Link: https://lkml.kernel.org/r/20251007122035.56347-9-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Marco Elver <elver@google.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kmsan_vmap_pages_range_noflush() allocates its temp s_pages/o_pages arrays
with GFP_KERNEL, which may sleep. This is inconsistent with vmalloc() as
it will support non-blocking requests later.
Plumb gfp_mask through the kmsan_vmap_pages_range_noflush(), so it can use
it internally for its demand.
Please note, the subsequent __vmap_pages_range_noflush() still uses
GFP_KERNEL and can sleep. If a caller runs under reclaim constraints,
sleeping is forbidden, it must establish the appropriate memalloc scope
API.
Link: https://lkml.kernel.org/r/20251007122035.56347-8-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Marco Elver <elver@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/vmalloc: handle non-blocking GFP in __vmalloc_area_node()
Make __vmalloc_area_node() respect non-blocking GFP masks such as
GFP_ATOMIC and GFP_NOWAIT.
- Add memalloc_apply_gfp_scope()/memalloc_restore_scope()
helpers to apply a proper scope.
- Apply memalloc_apply_gfp_scope()/memalloc_restore_scope()
around vmap_pages_range() for page table setup.
- Set "nofail" to false if a non-blocking mask is used, as
they are mutually exclusive.
This is particularly important for page table allocations that internally
use GFP_PGTABLE_KERNEL, which may sleep unless such scope restrictions are
applied. For example:
Note: in most cases, PTE entries are established only up to the level
required by current vmap space usage, meaning the page tables are
typically fully populated during the mapping process.
Link: https://lkml.kernel.org/r/20251007122035.56347-6-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Marco Elver <elver@google.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
__vmalloc_area_node() may call free_vmap_area() or vfree() on error paths,
both of which can sleep. This becomes problematic if the function is
invoked from an atomic context, such as when GFP_ATOMIC or GFP_NOWAIT is
passed via gfp_mask.
To fix this, unify error paths and defer the cleanup of partly initialized
vm_struct objects to a workqueue. This ensures that freeing happens in a
process context and avoids invalid sleeps in atomic regions.
Link: https://lkml.kernel.org/r/20251007122035.56347-5-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Marco Elver <elver@google.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/vmalloc: support non-blocking GFP flags in alloc_vmap_area()
alloc_vmap_area() currently assumes that sleeping is allowed during
allocation. This is not true for callers which pass non-blocking GFP
flags, such as GFP_ATOMIC or GFP_NOWAIT.
This patch adds logic to detect whether the given gfp_mask permits
blocking. It avoids invoking might_sleep() or falling back to reclaim
path if blocking is not allowed.
This makes alloc_vmap_area() safer for use in non-sleeping contexts, where
previously it could hit unexpected sleeps, trigger warnings.
It is a preparation and adjustment step to later allow both GFP_ATOMIC and
GFP_NOWAIT allocations in this series.
Link: https://lkml.kernel.org/r/20251007122035.56347-4-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Marco Elver <elver@google.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
A test marked with "xfail = true" is expected to fail but that does not
mean it is predetermined to fail. Remove "xfail" condition check for
tests which pass successfully.
Link: https://lkml.kernel.org/r/20251007122035.56347-3-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Marco Elver <elver@google.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "__vmalloc()/kvmalloc() and no-block support", v4.
This patch (of 10):
Introduce a new test case "no_block_alloc_test" that verifies non-blocking
allocations using __vmalloc() with GFP_ATOMIC and GFP_NOWAIT flags.
It is recommended to build kernel with CONFIG_DEBUG_ATOMIC_SLEEP enabled
to help catch "sleeping while atomic" issues. This test ensures that
memory allocation logic under atomic constraints does not inadvertently
sleep.
Link: https://lkml.kernel.org/r/20251007122035.56347-2-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Marco Elver <elver@google.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Anshuman Khandual [Wed, 1 Oct 2025 04:25:02 +0000 (05:25 +0100)]
mm/ptdump: replace READ_ONCE() with standard page table accessors
Replace READ_ONCE() with standard page table accessors i.e pxdp_get()
which anyways default into READ_ONCE() in cases where platform does not
override. Also convert ptep_get_lockless() into ptep_get() as well.
Link: https://lkml.kernel.org/r/20251001042502.1400726-1-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Acked-by: Lance Yang <lance.yang@linux.dev> Acked-by: SeongJae Park <sj@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20250929002608.1633825-1-jianyungao89@gmail.com Signed-off-by: jianyun.gao <jianyungao89@gmail.com> Reviewed-by: SeongJae Park <sj@kernel.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Acked-by: Chris Li <chrisl@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
follow_devmap_pmd() has already been dropped by the commit fd2825b0760a
("mm/gup: remove pXX_devmap usage from get_user_pages()"). The fallback
stub in the header which is now redundant, can be dropped off as well.
Link: https://lkml.kernel.org/r/20250929104643.1100421-1-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lorenzo Stoakes [Wed, 17 Sep 2025 19:11:16 +0000 (20:11 +0100)]
mm: update resctl to use mmap_prepare
Make use of the ability to specify a remap action within mmap_prepare to
update the resctl pseudo-lock to use mmap_prepare in favour of the
deprecated mmap hook.
Link: https://lkml.kernel.org/r/ed05dfdff6f77e33628784b6492f66f347673b50.1758135681.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lorenzo Stoakes [Wed, 17 Sep 2025 19:11:15 +0000 (20:11 +0100)]
mm: update mem char driver to use mmap_prepare
Update the mem char driver (backing /dev/mem and /dev/zero) to use
f_op->mmap_prepare hook rather than the deprecated f_op->mmap.
The /dev/zero implementation has a very unique and rather concerning
characteristic in that it converts MAP_PRIVATE mmap() mappings anonymous
when they are, in fact, not.
The new f_op->mmap_prepare() can support this, but rather than introducing
a helper function to perform this hack (and risk introducing other users),
utilise the success hook to do so.
We utilise the newly introduced shmem_zero_setup_desc() to allow for the
shared mapping case via an f_op->mmap_prepare() hook.
We also use the desc->action_error_hook to filter the remap error to
-EAGAIN to keep behaviour consistent.
Link: https://lkml.kernel.org/r/14cdf181c4145a298a2249946b753276bdc11167.1758135681.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lorenzo Stoakes [Wed, 17 Sep 2025 19:11:13 +0000 (20:11 +0100)]
mm/hugetlbfs: update hugetlbfs to use mmap_prepare
Since we can now perform actions after the VMA is established via
mmap_prepare, use desc->action_success_hook to set up the hugetlb lock
once the VMA is setup.
We also make changes throughout hugetlbfs to make this possible.
Link: https://lkml.kernel.org/r/e5532a0aff1991a1b5435dcb358b7d35abc80f3b.1758135681.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lorenzo Stoakes [Wed, 17 Sep 2025 19:11:12 +0000 (20:11 +0100)]
doc: update porting, vfs documentation for mmap_prepare actions
Now we have introduced the ability to specify that actions should be taken
after a VMA is established via the vm_area_desc->action field as specified
in mmap_prepare, update both the VFS documentation and the porting guide
to describe this.
Link: https://lkml.kernel.org/r/269f7675d0924fff58c427bc8f4e37487e985539.1758135681.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lorenzo Stoakes [Wed, 17 Sep 2025 19:11:11 +0000 (20:11 +0100)]
mm: add ability to take further action in vm_area_desc
Some drivers/filesystems need to perform additional tasks after the VMA is
set up. This is typically in the form of pre-population.
The forms of pre-population most likely to be performed are a PFN remap
or the insertion of normal folios and PFNs into a mixed map.
We start by implementing the PFN remap functionality, ensuring that we
perform the appropriate actions at the appropriate time - that is setting
flags at the point of .mmap_prepare, and performing the actual remap at the
point at which the VMA is fully established.
This prevents the driver from doing anything too crazy with a VMA at any
stage, and we retain complete control over how the mm functionality is
applied.
Unfortunately callers still do often require some kind of custom action,
so we add an optional success/error _hook to allow the caller to do
something after the action has succeeded or failed.
This is done at the point when the VMA has already been established, so
the harm that can be done is limited.
The error hook can be used to filter errors if necessary.
If any error arises on these final actions, we simply unmap the VMA
altogether.
Also update the stacked filesystem compatibility layer to utilise the
action behaviour, and update the VMA tests accordingly.
While we're here, rename __compat_vma_mmap_prepare() to __compat_vma_mmap()
as we are now performing actions invoked by the mmap_prepare in addition to
just the mmap_prepare hook.
[lorenzo.stoakes@oracle.com: return error on broken path, update vma_internal.h] Link: https://lkml.kernel.org/r/20f1c97d-b958-474c-b3a1-8ea9a177e096@lucifer.local Link: https://lkml.kernel.org/r/777c55010d2c94cc90913eb5aaeb703e912f99e0.1758135681.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lorenzo Stoakes [Wed, 17 Sep 2025 19:11:09 +0000 (20:11 +0100)]
mm: abstract io_remap_pfn_range() based on PFN
The only instances in which we customise this function are ones in which we
customise the PFN used, other than the fact that, when a custom
io_remap_pfn_range() function is provided, the prot value passed is not
filtered through pgprot_decrypted().
Use this fact to simplify the use of io_remap_pfn_range(), by abstracting
the PFN function as io_remap_pfn_range_pfn(), and simply have the
convention that, should a custom handler be specified, we do not utilise
pgprot_decrypted().
If we require in future prot customisation, we can make
io_remap_pfn_range_prot() available for override.
[lorenzo.stoakes@oracle.com: simplify io_remap_pfn_range_pfn definition] Link: https://lkml.kernel.org/r/96e4a163-a791-4b08-a006-bdd7ebbecaf9@lucifer.local Link: https://lkml.kernel.org/r/4f01f4d82300444dee4af4f8d1333e52db402a45.1758135681.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We need the ability to split PFN remap between updating the VMA and
performing the actual remap, in order to do away with the legacy f_op->mmap
hook.
To do so, update the PFN remap code to provide shared logic, and also make
remap_pfn_range_notrack() static, as its one user, io_mapping_map_user()
was removed in commit 9a4f90e24661 ("mm: remove mm/io-mapping.c").
Then, introduce remap_pfn_range_prepare(), which accepts VMA descriptor
and PFN parameters, and remap_pfn_range_complete() which accepts the same
parameters as remap_pfn_rangte().
remap_pfn_range_prepare() will set the cow vma->vm_pgoff if necessary, so
it must be supplied with a correct PFN to do so.
While we're here, also clean up the duplicated #ifdef
__HAVE_PFNMAP_TRACKING check and put into a single #ifdef/#else block.
We keep these internal to mm as they should only be used by internal
helpers.
[akpm@linux-foundation.org: restore inadvertently-removed newline] Link: https://lkml.kernel.org/r/ad9b7ea2744a05d64f7d9928ed261202b7c0fa46.1758135681.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Pedro Falcato <pfalcato@suse.de> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lorenzo Stoakes [Wed, 17 Sep 2025 19:11:07 +0000 (20:11 +0100)]
mm/vma: rename __mmap_prepare() function to avoid confusion
Now we have the f_op->mmap_prepare() hook, having a static function called
__mmap_prepare() that has nothing to do with it is confusing, so rename
the function to __mmap_setup().
Link: https://lkml.kernel.org/r/24cdbee385fd734d9b1c5aa547d5bbf7a573f292.1758135681.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lorenzo Stoakes [Wed, 17 Sep 2025 19:11:05 +0000 (20:11 +0100)]
mm: add vma_desc_size(), vma_desc_pages() helpers
It's useful to be able to determine the size of a VMA descriptor range
used on f_op->mmap_prepare, expressed both in bytes and pages, so add
helpers for both and update code that could make use of it to do so.
Link: https://lkml.kernel.org/r/5fa007dc4905c863abe6fe97de1238c30b1958ff.1758135681.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lorenzo Stoakes [Wed, 17 Sep 2025 19:11:03 +0000 (20:11 +0100)]
mm/shmem: update shmem to use mmap_prepare
Patch series "expand mmap_prepare functionality, port more users", v4.
Since commit c84bf6dd2b83 ("mm: introduce new .mmap_prepare() file
callback"), The f_op->mmap hook has been deprecated in favour of
f_op->mmap_prepare.
This was introduced in order to make it possible for us to eventually
eliminate the f_op->mmap hook which is highly problematic as it allows
drivers and filesystems raw access to a VMA which is not yet correctly
initialised.
This hook also introduced complexity for the memory mapping operation, as
we must correctly unwind what we do should an error arises.
Overall this interface being so open has caused significant problems for
us, including security issues, it is important for us to simply eliminate
this as a source of problems.
Therefore this series continues what was established by extending the
functionality further to permit more drivers and filesystems to use
mmap_prepare.
We start by udpating some existing users who can use the mmap_prepare
functionality as-is.
We then introduce the concept of an mmap 'action', which a user, on
mmap_prepare, can request to be performed upon the VMA:
By setting the action in mmap_prepare, this allows us to dynamically decide
what to do next, so if a driver/filesystem needs to determine whether to
e.g. remap or use a mixed map, it can do so then change which is done.
This significantly expands the capabilities of the mmap_prepare hook, while
maintaining as much control as possible in the mm logic.
We split [io_]remap_pfn_range*() functions which allow for PFN remap (a
typical mapping prepopulation operation) split between a prepare/complete
step, as well as io_mremap_pfn_range_prepare, complete for a similar
purpose.
From there we update various mm-adjacent logic to use this functionality as
a first set of changes.
We also add success and error hooks for post-action processing for e.g.
output debug log on success and filtering error codes.
This patch (of 14):
This simply assigns the vm_ops so is easily updated - do so.
Link: https://lkml.kernel.org/r/cover.1758135681.git.lorenzo.stoakes@oracle.com Link: https://lkml.kernel.org/r/86029a4f59733826c8419e48f6ad4000932a6d08.1758135681.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Baolin Wang [Thu, 18 Sep 2025 03:46:54 +0000 (11:46 +0800)]
mm: vmscan: simplify the folio refcount check in pageout()
Since we no longer attempt to write back filesystem folios in pageout()
(they will be filtered out by the following check in pageout()), and only
tmpfs/shmem folios and anonymous swapcache folios can be written back, we
can remove the redundant folio_test_private() when checking the folio's
refcount, as tmpfs/shmem and swapcache folios do not use the PG_private
flag.
While we're at it, we can open-code the folio refcount check instead of
adding a simple helper that has only one user.
Link: https://lkml.kernel.org/r/4cbbec5bb92397aa4597105f1f499aabf7a1901c.1758166683.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Baolin Wang [Thu, 18 Sep 2025 03:46:53 +0000 (11:46 +0800)]
mm: vmscan: remove folio_test_private() check in pageout()
Patch series "some cleanups for pageout()", v2.
Since we no longer attempt to write back filesystem folios in pageout(),
and only tmpfs/shmem folios and anonymous swapcache folios can be written
back, we can remove the redundant folio_test_private() related logic to
simplify the logic of pageout(), as tmpfs/shmem and swapcache folios do
not use the PG_private flag.
This patch (of 2):
The folio_test_private() check in pageout() was introduced by commit ce91b575332b ("orphaned pagecache memleak fix") in 2005 (checked from a
history tree[1]). As the commit message mentioned, it was to address the
issue where reiserfs pagecache may be truncated while still pinned. To
further explain, the truncation removes the page->mapping, but the page is
still listed in the VM queues because it still has buffers.
In 2008, commit a2b345642f530 ("Fix dirty page accounting leak with ext3
data=journal") seems to be dealing with a similar issue, where the page
becomes dirty after truncation, and it provides a very useful call stack:
In this commit a2b345642f530, we forcefully clear the page's dirty flag
during truncation (in truncate_complete_page()).
Now it seems this was just a peculiar usage specific to reiserfs. Maybe
reiserfs had some extra refcount on these pages, which caused them to pass
the is_page_cache_freeable() check.
With the fix provided by commit a2b345642f530 and reiserfs being removed
in 2024 by commit fb6f20ecb121 ("reiserfs: The last commit"), such a case
is unlikely to occur again. So let's remove the redundant
folio_test_private() checks and related buffer_head release logic, and
just leave a warning here to catch such a bug.
mm/memory-failure: support disabling soft offline for HugeTLB pages
Some BIOS suppress ("cloak") corrected memory errors until a threshold
is reached. Once that threshold is reached, BIOS reports a CPER with
the "error threshold exceeded" bit set via GHES and the corresponding
page is soft offlined.
BIOS does not know the page type of the corresponding page. If the
corresponding page happens to be a HugeTLB page, it will be dissolved,
permanently reducing the HugeTLB page pool. This can be problematic
for workloads that depend on a fixed number of HugeTLB pages.
Currently, soft offline must be disabled to prevent HugeTLB pages from
being soft offlined.
This patch provides a middle ground. Soft offline can be disabled for
HugeTLB pages while remaining enabled for non-HugeTLB pages, preserving
the benefits of soft offline without the risk of BIOS soft offlining
HugeTLB pages.
Commit 56374430c5dfc ("mm/memory-failure: userspace controls
soft-offlining pages") introduced the following sysctl interface to
control soft offline:
/proc/sys/vm/enable_soft_offline
The interface does not distinguish between page types:
0 - Soft offline is disabled
1 - Soft offline is enabled
Convert enable_soft_offline to a bitmask and support disabling soft
offline for HugeTLB pages:
0 - Soft offline is disabled
1 - Soft offline is enabled
3 - Soft offline is enabled (disabled for HugeTLB pages)
Existing behavior is preserved.
Update documentation and HugeTLB soft offline self tests.
Tony said:
: Recap of original problem is that some BIOS keep track of error
: threshold per-rank and use this GHES mechanism to report threshold
: exceeded on the rank.
:
: Systems that stay up a long time can accumulate enough soft errors to
: trigger this threshold. But the action of taking a page offline isn't
: going to help. For a 4K page this is merely annoying. For 1G page it
: can mess things up badly.
:
: My original patch for this just skipped the GHES->offline process for
: huge pages. But I wasn't aware of the sysctl control. That provides a
: better solution.
Link: https://lkml.kernel.org/r/aMiu_Uku6Y5ZbuhM@hpe.com Signed-off-by: Kyle Meyer <kyle.meyer@hpe.com> Reported-by: Shawn Fan <shawn.fan@intel.com> Suggested-by: Tony Luck <tony.luck@intel.com> Cc: Borislav Betkov <bp@alien8.de> Cc: David Hildenbrand <david@redhat.com> Cc: Jane Chu <jane.chu@oracle.com> Cc: Jan Kara <jack@suse.cz> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Clapinski <mclapinski@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Russ Anderson <russ.anderson@hpe.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yafang <laoar.shao@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
SeongJae Park [Tue, 14 Oct 2025 00:18:44 +0000 (17:18 -0700)]
mm/damon/core: use damos_commit_quota_goal() for new goal commit
When damos_commit_quota_goals() is called for adding new DAMOS quota goals
of DAMOS_QUOTA_USER_INPUT metric, current_value fields of the new goals
should be also set as requested.
However, damos_commit_quota_goals() is not updating the field for the
case, since it is setting only metrics and target values using
damos_new_quota_goal(), and metric-optional union fields using
damos_commit_quota_goal_union(). As a result, users could see the first
current_value parameter that committed online with a new quota goal is
ignored. Users are assumed to commit the current_value for
DAMOS_QUOTA_USER_INPUT quota goals, since it is being used as a feedback.
Hence the real impact would be subtle. That said, this is obviously not
intended behavior.
Fix the issue by using damos_commit_quota_goal() which sets all quota goal
parameters, instead of damos_commit_quota_goal_union(), which sets only
the union fields.
Link: https://lkml.kernel.org/r/20251014001846.279282-1-sj@kernel.org Fixes: 1aef9df0ee90 ("mm/damon/core: commit damos_quota_goal->nid") Signed-off-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> [6.16+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Enze Li [Tue, 14 Oct 2025 08:42:25 +0000 (16:42 +0800)]
mm/damon/core: fix potential memory leak by cleaning ops_filter in damon_destroy_scheme
Currently, damon_destroy_scheme() only cleans up the filter list but
leaves ops_filter untouched, which could lead to memory leaks when a
scheme is destroyed.
This patch ensures both filter and ops_filter are properly freed in
damon_destroy_scheme(), preventing potential memory leaks.
Link: https://lkml.kernel.org/r/20251014084225.313313-1-lienze@kylinos.cn Fixes: ab82e57981d0 ("mm/damon/core: introduce damos->ops_filters") Signed-off-by: Enze Li <lienze@kylinos.cn> Reviewed-by: SeongJae Park <sj@kernel.org> Tested-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Deepanshu Kartikey [Tue, 14 Oct 2025 11:33:44 +0000 (17:03 +0530)]
hugetlbfs: move lock assertions after early returns in huge_pmd_unshare()
When hugetlb_vmdelete_list() processes VMAs during truncate operations, it
may encounter VMAs where huge_pmd_unshare() is called without the required
shareable lock. This triggers an assertion failure in
hugetlb_vma_assert_locked().
The previous fix in commit dd83609b8898 ("hugetlbfs: skip VMAs without
shareable locks in hugetlb_vmdelete_list") skipped entire VMAs without
shareable locks to avoid the assertion. However, this prevented pages
from being unmapped and freed, causing a regression in
fallocate(PUNCH_HOLE) operations where pages were not freed immediately,
as reported by Mark Brown.
Instead of checking locks in the caller or skipping VMAs, move the lock
assertions in huge_pmd_unshare() to after the early return checks. The
assertions are only needed when actual PMD unsharing work will be
performed. If the function returns early because sz != PMD_SIZE or the
PMD is not shared, no locks are required and assertions should not fire.
This approach reverts the VMA skipping logic from commit dd83609b8898
("hugetlbfs: skip VMAs without shareable locks in hugetlb_vmdelete_list")
while moving the assertions to avoid the assertion failure, keeping all
the logic within huge_pmd_unshare() itself and allowing page unmapping and
freeing to proceed for all VMAs.
Link: https://lkml.kernel.org/r/20251014113344.21194-1-kartikey406@gmail.com Fixes: dd83609b8898 ("hugetlbfs: skip VMAs without shareable locks in hugetlb_vmdelete_list") Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com> Reported-by: <syzbot+f26d7c75c26ec19790e7@syzkaller.appspotmail.com> Reported-by: Mark Brown <broonie@kernel.org> Closes: https://syzkaller.appspot.com/bug?extid=f26d7c75c26ec19790e7 Suggested-by: David Hildenbrand <david@redhat.com> Suggested-by: Oscar Salvador <osalvador@suse.de> Tested-by: <syzbot+f26d7c75c26ec19790e7@syzkaller.appspotmail.com> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Tue, 14 Oct 2025 12:44:55 +0000 (14:44 +0200)]
vmw_balloon: indicate success when effectively deflating during migration
When migrating a balloon page, we first deflate the old page to then
inflate the new page.
However, if inflating the new page succeeded, we effectively deflated the
old page, reducing the balloon size.
In that case, the migration actually worked: similar to migrating+
immediately deflating the new page. The old page will be freed back to
the buddy.
Right now, the core will leave the page be marked as isolated (as we
returned an error). When later trying to putback that page, we will run
into the WARN_ON_ONCE() in balloon_page_putback().
That handling was changed in commit 3544c4faccb8 ("mm/balloon_compaction:
stop using __ClearPageMovable()"); before that change, we would have
tolerated that way of handling it.
To fix it, let's just return 0 in that case, making the core effectively
just clear the "isolated" flag + freeing it back to the buddy as if the
migration succeeded. Note that the new page will also get freed when the
core puts the last reference.
Note that this also makes it all be more consistent: we will no longer
unisolate the page in the balloon driver while keeping it marked as being
isolated in migration core.
This was found by code inspection.
Link: https://lkml.kernel.org/r/20251014124455.478345-1-david@redhat.com Fixes: 3544c4faccb8 ("mm/balloon_compaction: stop using __ClearPageMovable()") Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Broadcom internal kernel review list <bcm-kernel-feedback-list@broadcom.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
SeongJae Park [Tue, 14 Oct 2025 20:59:36 +0000 (13:59 -0700)]
mm/damon/core: fix list_add_tail() call on damon_call()
Each damon_ctx maintains callback requests using a linked list
(damon_ctx->call_controls). When a new callback request is received via
damon_call(), the new request should be added to the list. However, the
function is making a mistake at list_add_tail() invocation: putting the
new item to add and the list head to add it before, in the opposite order.
Because of the linked list manipulation implementation, the new request
can still be reached from the context's list head. But the list items
that were added before the new request are dropped from the list.
As a result, the callbacks are unexpectedly not invocated. Worse yet, if
the dropped callback requests were dynamically allocated, the memory is
leaked. Actually DAMON sysfs interface is using a dynamically allocated
repeat-mode callback request for automatic essential stats update. And
because the online DAMON parameters commit is using a non-repeat-mode
callback request, the issue can easily be reproduced, like below.
# damo start --damos_action stat --refresh_stat 1s
# damo tune --damos_action stat --refresh_stat 1s
The first command dynamically allocates the repeat-mode callback request
for automatic essential stat update. Users can see the essential stats
are automatically updated for every second, using the sysfs interface.
The second command calls damon_commit() with a new callback request that
was made for the commit. As a result, the previously added repeat-mode
callback request is dropped from the list. The automatic stats refresh
stops working, and the memory for the repeat-mode callback request is
leaked. It can be confirmed using kmemleak.
Fix the mistake on the list_add_tail() call.
Link: https://lkml.kernel.org/r/20251014205939.1206-1-sj@kernel.org Fixes: 004ded6bee11 ("mm/damon: accept parallel damon_call() requests") Signed-off-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> [6.17+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lorenzo Stoakes [Mon, 13 Oct 2025 16:58:36 +0000 (17:58 +0100)]
mm/mremap: correctly account old mapping after MREMAP_DONTUNMAP remap
Commit b714ccb02a76 ("mm/mremap: complete refactor of move_vma()")
mistakenly introduced a new behaviour - clearing the VM_ACCOUNT flag of
the old mapping when a mapping is mremap()'d with the MREMAP_DONTUNMAP
flag set.
While we always clear the VM_LOCKED and VM_LOCKONFAULT flags for the old
mapping (the page tables have been moved, so there is no data that could
possibly be locked in memory), there is no reason to touch any other VMA
flags.
This is because after the move the old mapping is in a state as if it were
freshly mapped. This implies that the attributes of the mapping ought to
remain the same, including whether or not the mapping is accounted.
Link: https://lkml.kernel.org/r/20251013165836.273113-1-lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Fixes: b714ccb02a76 ("mm/mremap: complete refactor of move_vma()") Reviewed-by: Pedro Falcato <pfalcato@suse.de> Cc: Jann Horn <jannh@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Qiuxu Zhuo [Sat, 11 Oct 2025 07:55:19 +0000 (15:55 +0800)]
mm: prevent poison consumption when splitting THP
When performing memory error injection on a THP (Transparent Huge Page)
mapped to userspace on an x86 server, the kernel panics with the following
trace. The expected behavior is to terminate the affected process instead
of panicking the kernel, as the x86 Machine Check code can recover from an
in-userspace #MC.
mce: [Hardware Error]: CPU 0: Machine Check Exception: f Bank 3: bd80000000070134
mce: [Hardware Error]: RIP 10:<ffffffff8372f8bc> {memchr_inv+0x4c/0xf0}
mce: [Hardware Error]: TSC afff7bbff88a ADDR 1d301b000 MISC 80 PPIN 1e741e77539027db
mce: [Hardware Error]: PROCESSOR 0:d06d0 TIME 1758093249 SOCKET 0 APIC 0 microcode 80000320
mce: [Hardware Error]: Run the above through 'mcelog --ascii'
mce: [Hardware Error]: Machine check: Data load in unrecoverable area of kernel
Kernel panic - not syncing: Fatal local machine check
The root cause of this panic is that handling a memory failure triggered
by an in-userspace #MC necessitates splitting the THP. The splitting
process employs a mechanism, implemented in
try_to_map_unused_to_zeropage(), which reads the sub-pages of the THP to
identify zero-filled pages. However, reading the sub-pages results in a
second in-kernel #MC, occurring before the initial memory_failure()
completes, ultimately leading to a kernel panic. See the kernel panic
call trace on the two #MCs.
[1] Triggered by accessing a hardware-poisoned THP in userspace, which is
typically recoverable by terminating the affected process.
[2] Call folio_set_has_hwpoisoned() before try_to_split_thp_page().
[3] Pass the RMP_USE_SHARED_ZEROPAGE remap flag to remap_page().
[4] Try to map the unused THP to zeropage.
[5] Re-access sub-pages of the hw-poisoned THP in the kernel.
[6] Triggered in-kernel, leading to a panic kernel.
In Step[2], memory_failure() sets the poisoned flag on the sub-page of the
THP by TestSetPageHWPoison() before calling try_to_split_thp_page().
As suggested by David Hildenbrand, fix this panic by not accessing to the
poisoned sub-page of the THP during zeropage identification, while
continuing to scan unaffected sub-pages of the THP for possible zeropage
mapping. This prevents a second in-kernel #MC that would cause kernel
panic in Step[4].
[ Credits to Andrew Zaborowski <andrew.zaborowski@intel.com> for his
original fix that prevents passing the RMP_USE_SHARED_ZEROPAGE flag
to remap_page() in Step[3] if the THP has the has_hwpoisoned flag set,
avoiding access to the entire THP for zero-page identification. ]
Link: https://lkml.kernel.org/r/20251011075520.320862-1-qiuxu.zhuo@intel.com Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com> Reported-by: Farrah Chen <farrah.chen@intel.com> Suggested-by: David Hildenbrand <david@redhat.com> Tested-by: Farrah Chen <farrah.chen@intel.com> Tested-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com> Acked-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Mariano Pache <npache@redhat.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Deepanshu Kartikey [Thu, 9 Oct 2025 15:49:03 +0000 (21:19 +0530)]
ocfs2: clear extent cache after moving/defragmenting extents
The extent map cache can become stale when extents are moved or
defragmented, causing subsequent operations to see outdated extent flags.
This triggers a BUG_ON in ocfs2_refcount_cal_cow_clusters().
The problem occurs when:
1. copy_file_range() creates a reflinked extent with OCFS2_EXT_REFCOUNTED
2. ioctl(FITRIM) triggers ocfs2_move_extents()
3. __ocfs2_move_extents_range() reads and caches the extent (flags=0x2)
4. ocfs2_move_extent()/ocfs2_defrag_extent() calls __ocfs2_move_extent()
which clears OCFS2_EXT_REFCOUNTED flag on disk (flags=0x0)
5. The extent map cache is not invalidated after the move
6. Later write() operations read stale cached flags (0x2) but disk has
updated flags (0x0), causing a mismatch
7. BUG_ON(!(rec->e_flags & OCFS2_EXT_REFCOUNTED)) triggers
Fix by clearing the extent map cache after each extent move/defrag
operation in __ocfs2_move_extents_range(). This ensures subsequent
operations read fresh extent data from disk.
Link: https://lore.kernel.org/all/20251009142917.517229-1-kartikey406@gmail.com/T/ Link: https://lkml.kernel.org/r/20251009154903.522339-1-kartikey406@gmail.com Fixes: 53069d4e7695 ("Ocfs2/move_extents: move/defrag extents within a certain range.") Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com> Reported-by: syzbot+6fdd8fa3380730a4b22c@syzkaller.appspotmail.com Tested-by: syzbot+6fdd8fa3380730a4b22c@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?id=2959889e1f6e216585ce522f7e8bc002b46ad9e7 Reviewed-by: Mark Fasheh <mark@fasheh.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Jun Piao <piaojun@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
replace is_swiotlb_allocated() with is_swiotlb_active(), per Catalin
Link: https://lkml.kernel.org/r/20251010173009.3916215-1-m.szyprowski@samsung.com Fixes: 370645f41e6e ("dma-mapping: force bouncing if the kmalloc() size is not cache-line-aligned") Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "Isaac J. Manjarres" <isaacmanjarres@google.com> Cc: Robin Murohy <robin.murphy@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Marek Szyprowski [Thu, 9 Oct 2025 14:15:08 +0000 (16:15 +0200)]
dma-debug: don't report false positives with DMA_BOUNCE_UNALIGNED_KMALLOC
Commit 370645f41e6e ("dma-mapping: force bouncing if the kmalloc() size is
not cache-line-aligned") introduced DMA_BOUNCE_UNALIGNED_KMALLOC feature
and permitted architecture specific code configure kmalloc slabs with
sizes smaller than the value of dma_get_cache_alignment().
When that feature is enabled, the physical address of some small
kmalloc()-ed buffers might be not aligned to the CPU cachelines, thus not
really suitable for typical DMA. To properly handle that case a SWIOTLB
buffer bouncing is used, so no CPU cache corruption occurs. When that
happens, there is no point reporting a false-positive DMA-API warning that
the buffer is not properly aligned, as this is not a client driver fault.
Link: https://lkml.kernel.org/r/20251009141508.2342138-1-m.szyprowski@samsung.com Fixes: 370645f41e6e ("dma-mapping: force bouncing if the kmalloc() size is not cache-line-aligned") Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Inki Dae <m.szyprowski@samsung.com> Cc: Robin Murohy <robin.murphy@arm.com> Cc: "Isaac J. Manjarres" <isaacmanjarres@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
SeongJae Park [Fri, 3 Oct 2025 20:14:55 +0000 (13:14 -0700)]
mm/damon/sysfs: dealloc commit test ctx always
The damon_ctx for testing online DAMON parameters commit inputs is
deallocated only when the test fails. This means memory is leaked for
every successful online DAMON parameters commit. Fix the leak by always
deallocating it.
Link: https://lkml.kernel.org/r/20251003201455.41448-3-sj@kernel.org Fixes: 4c9ea539ad59 ("mm/damon/sysfs: validate user inputs from damon_sysfs_commit_input()") Signed-off-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> [6.15+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
SeongJae Park [Fri, 3 Oct 2025 20:14:54 +0000 (13:14 -0700)]
mm/damon/sysfs: catch commit test ctx alloc failure
Patch series "mm/damon/sysfs: fix commit test damon_ctx [de]allocation".
DAMON sysfs interface dynamically allocates and uses a damon_ctx object
for testing if given inputs for online DAMON parameters update is valid.
The object is being used without an allocation failure check, and leaked
when the test succeeds. Fix the two bugs.
This patch (of 2):
The damon_ctx for testing online DAMON parameters commit inputs is used
without its allocation failure check. This could result in an invalid
memory access. Fix it by directly returning an error when the allocation
failed.
Dmitry Ilvokhin [Mon, 6 Oct 2025 13:25:26 +0000 (13:25 +0000)]
mm: skip folio_activate() for mlocked folios
__mlock_folio() does not move folio to unevicable LRU, when
folio_activate() removes folio from LRU.
To prevent this case also check for folio_test_mlocked() in
folio_mark_accessed(). If folio is not yet marked as unevictable, but
already marked as mlocked, then skip folio_activate() call to allow
__mlock_folio() to make all necessary updates. It should be safe to skip
folio_activate() here, because mlocked folio should end up in unevictable
LRU eventually anyway.
The user-visible effect is that we unnecessary postpone moving pages to
unevictable LRU that lead to unexpected stats: Mlocked > Unevictable.
To observe the problem mmap() and mlock() big file and check Unevictable
and Mlocked values from /proc/meminfo. On freshly booted system without
any other mlocked memory we expect them to match or be quite close.
See below for more detailed reproduction steps. Source code of stat.c is
available at [1].
Lance Yang [Tue, 9 Sep 2025 14:52:43 +0000 (22:52 +0800)]
hung_task: fix warnings caused by unaligned lock pointers
The blocker tracking mechanism assumes that lock pointers are at least
4-byte aligned to use their lower bits for type encoding.
However, as reported by Eero Tamminen, some architectures like m68k
only guarantee 2-byte alignment of 32-bit values. This breaks the
assumption and causes two related WARN_ON_ONCE checks to trigger.
To fix this, the runtime checks are adjusted to silently ignore any lock
that is not 4-byte aligned, effectively disabling the feature in such
cases and avoiding the related warnings.
Thanks to Geert Uytterhoeven for bisecting!
Link: https://lkml.kernel.org/r/20250909145243.17119-1-lance.yang@linux.dev Fixes: e711faaafbe5 ("hung_task: replace blocker_mutex with encoded blocker") Signed-off-by: Lance Yang <lance.yang@linux.dev> Reported-by: Eero Tamminen <oak@helsinkinet.fi> Closes: https://lore.kernel.org/lkml/CAMuHMdW7Ab13DdGs2acMQcix5ObJK0O2dG_Fxzr8_g58Rc1_0g@mail.gmail.com Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Anna Schumaker <anna.schumaker@oracle.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Finn Thain <fthain@linux-m68k.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joel Granados <joel.granados@kernel.org> Cc: John Stultz <jstultz@google.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Lance Yang <lance.yang@linux.dev> Cc: Mingzhe Yang <mingzhe.yang@ly.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tomasz Figa <tfiga@chromium.org> Cc: Waiman Long <longman@redhat.com> Cc: Will Deacon <will@kernel.org> Cc: Yongliang Gao <leonylgao@tencent.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Linus Torvalds [Sun, 12 Oct 2025 20:27:56 +0000 (13:27 -0700)]
Merge tag 'i2c-for-6.18-rc1-hotfix' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c fix from Wolfram Sang:
"One revert because of a regression in the I2C core which has sadly not
showed up during its time in -next"
* tag 'i2c-for-6.18-rc1-hotfix' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
Revert "i2c: boardinfo: Annotate code used in init phase only"
Linus Torvalds [Sun, 12 Oct 2025 15:45:52 +0000 (08:45 -0700)]
Merge tag 'irq_urgent_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Borislav Petkov:
- Skip interrupt ID 0 in sifive-plic during suspend/resume because
ID 0 is reserved and accessing reserved register space could result
in undefined behavior
- Fix a function's retval check in aspeed-scu-ic
* tag 'irq_urgent_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/sifive-plic: Avoid interrupt ID 0 handling during suspend/resume
irqchip/aspeed-scu-ic: Fix an IS_ERR() vs NULL check
Linus Torvalds [Sat, 11 Oct 2025 23:06:04 +0000 (16:06 -0700)]
Merge tag 'trace-v6.18-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
"The previous fix to trace_marker required updating trace_marker_raw as
well. The difference between trace_marker_raw from trace_marker is
that the raw version is for applications to write binary structures
directly into the ring buffer instead of writing ASCII strings. This
is for applications that will read the raw data from the ring buffer
and get the data structures directly. It's a bit quicker than using
the ASCII version.
Unfortunately, it appears that our test suite has several tests that
test writes to the trace_marker file, but lacks any tests to the
trace_marker_raw file (this needs to be remedied). Two issues came
about the update to the trace_marker_raw file that syzbot found:
- Fix tracing_mark_raw_write() to use per CPU buffer
The fix to use the per CPU buffer to copy from user space was
needed for both the trace_maker and trace_maker_raw file.
The fix for reading from user space into per CPU buffers properly
fixed the trace_marker write function, but the trace_marker_raw
file wasn't fixed properly. The user space data was correctly
written into the per CPU buffer, but the code that wrote into the
ring buffer still used the user space pointer and not the per CPU
buffer that had the user space data already written.
- Stop the fortify string warning from writing into trace_marker_raw
After converting the copy_from_user_nofault() into a memcpy(),
another issue appeared. As writes to the trace_marker_raw expects
binary data, the first entry is a 4 byte identifier. The entry
structure is defined as:
struct {
struct trace_entry ent;
int id;
char buf[];
};
The size of this structure is reserved on the ring buffer with:
size = sizeof(*entry) + cnt;
Then it is copied from the buffer into the ring buffer with:
memcpy(&entry->id, buf, cnt);
This use to be a copy_from_user_nofault(), but now converting it to
a memcpy() triggers the fortify-string code, and causes a warning.
The allocated space is actually more than what is copied, as the
cnt used also includes the entry->id portion. Allocating
sizeof(*entry) plus cnt is actually allocating 4 bytes more than
what is needed.
* tag 'trace-v6.18-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Stop fortify-string from warning in tracing_mark_raw_write()
tracing: Fix tracing_mark_raw_write() to use buf and not ubuf
Linus Torvalds [Sat, 11 Oct 2025 22:47:12 +0000 (15:47 -0700)]
Merge tag 'kbuild-fixes-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux
Pull Kbuild fixes from Nathan Chancellor:
- Fix UAPI types check in headers_check.pl
- Only enable -Werror for hostprogs with CONFIG_WERROR / W=e
- Ignore fsync() error when output of gen_init_cpio is a pipe
- Several little build fixes for recent modules.builtin.modinfo series
* tag 'kbuild-fixes-6.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux:
kbuild: Use '--strip-unneeded-symbol' for removing module device table symbols
s390/vmlinux.lds.S: Move .vmlinux.info to end of allocatable sections
kbuild: Add '.rel.*' strip pattern for vmlinux
kbuild: Restore pattern to avoid stripping .rela.dyn from vmlinux
gen_init_cpio: Ignore fsync() returning EINVAL on pipes
scripts/Makefile.extrawarn: Respect CONFIG_WERROR / W=e for hostprogs
kbuild: uapi: Strip comments before size type check
Reported-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com> Closes: https://lore.kernel.org/r/29ec0082-4dd4-4120-acd2-44b35b4b9487@oss.qualcomm.com Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Linus Torvalds [Sat, 11 Oct 2025 18:56:47 +0000 (11:56 -0700)]
Merge tag 'rtc-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux
Pull RTC updates from Alexandre Belloni:
"This cycle, we have a new RTC driver, for the SpacemiT P1. The optee
driver gets alarm support. We also get a fix for a race condition that
was fairly rare unless while stress testing the alarms.
Subsystem:
- Fix race when setting alarm
- Ensure alarm irq is enabled when UIE is enabled
- remove unneeded 'fast_io' parameter in regmap_config
New driver:
- SpacemiT P1 RTC
Drivers:
- efi: Remove wakeup functionality
- optee: add alarms support
- s3c: Drop support for S3C2410
- zynqmp: Restore alarm functionality after kexec transition"
* tag 'rtc-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (29 commits)
rtc: interface: Ensure alarm irq is enabled when UIE is enabled
rtc: tps6586x: Fix initial enable_irq/disable_irq balance
rtc: cpcap: Fix initial enable_irq/disable_irq balance
rtc: isl12022: Fix initial enable_irq/disable_irq balance
rtc: interface: Fix long-standing race when setting alarm
rtc: pcf2127: fix watchdog interrupt mask on pcf2131
rtc: zynqmp: Restore alarm functionality after kexec transition
rtc: amlogic-a4: Optimize global variables
rtc: sd2405al: Add I2C address.
rtc: Kconfig: move symbols to proper section
rtc: optee: make optee_rtc_pm_ops static
rtc: optee: Fix error code in optee_rtc_read_alarm()
rtc: optee: fix error code in probe()
dt-bindings: rtc: Convert apm,xgene-rtc to DT schema
rtc: spacemit: support the SpacemiT P1 RTC
rtc: optee: add alarm related rtc ops to optee rtc driver
rtc: optee: remove unnecessary memory operations
rtc: optee: fix memory leak on driver removal
rtc: x1205: Fix Xicor X1205 vendor prefix
dt-bindings: rtc: Fix Xicor X1205 vendor prefix
...
Linus Torvalds [Sat, 11 Oct 2025 18:49:00 +0000 (11:49 -0700)]
Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"Fixes only in drivers (ufs, mvsas, qla2xxx, target) that came in just
before or during the merge window.
The most important one is the qla2xxx which reverts a conversion to
fix flexible array member warnings, that went up in this merge window
but which turned out on further testing to be causing data corruption"
* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: ufs: core: Include UTP error in INT_FATAL_ERRORS
scsi: ufs: sysfs: Make HID attributes visible
scsi: mvsas: Fix use-after-free bugs in mvs_work_queue
scsi: ufs: core: Fix PM QoS mutex initialization
scsi: ufs: core: Fix runtime suspend error deadlock
Revert "scsi: qla2xxx: Fix memcpy() field-spanning write issue"
scsi: target: target_core_configfs: Add length check to avoid buffer overflow
Linus Torvalds [Sat, 11 Oct 2025 18:19:16 +0000 (11:19 -0700)]
Merge tag 'x86_core_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull more x86 updates from Borislav Petkov:
- Remove a bunch of asm implementing condition flags testing in KVM's
emulator in favor of int3_emulate_jcc() which is written in C
- Replace KVM fastops with C-based stubs which avoids problems with the
fastop infra related to latter not adhering to the C ABI due to their
special calling convention and, more importantly, bypassing compiler
control-flow integrity checking because they're written in asm
- Remove wrongly used static branches and other ugliness accumulated
over time in hyperv's hypercall implementation with a proper static
function call to the correct hypervisor call variant
- Add some fixes and modifications to allow running FRED-enabled
kernels in KVM even on non-FRED hardware
- Add kCFI improvements like validating indirect calls and prepare for
enabling kCFI with GCC. Add cmdline params documentation and other
code cleanups
- Use the single-byte 0xd6 insn as the official #UD single-byte
undefined opcode instruction as agreed upon by both x86 vendors
- Other smaller cleanups and touchups all over the place
* tag 'x86_core_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
x86,retpoline: Optimize patch_retpoline()
x86,ibt: Use UDB instead of 0xEA
x86/cfi: Remove __noinitretpoline and __noretpoline
x86/cfi: Add "debug" option to "cfi=" bootparam
x86/cfi: Standardize on common "CFI:" prefix for CFI reports
x86/cfi: Document the "cfi=" bootparam options
x86/traps: Clarify KCFI instruction layout
compiler_types.h: Move __nocfi out of compiler-specific header
objtool: Validate kCFI calls
x86/fred: KVM: VMX: Always use FRED for IRQs when CONFIG_X86_FRED=y
x86/fred: Play nice with invoking asm_fred_entry_from_kvm() on non-FRED hardware
x86/fred: Install system vector handlers even if FRED isn't fully enabled
x86/hyperv: Use direct call to hypercall-page
x86/hyperv: Clean up hv_do_hypercall()
KVM: x86: Remove fastops
KVM: x86: Convert em_salc() to C
KVM: x86: Introduce EM_ASM_3WCL
KVM: x86: Introduce EM_ASM_1SRC2
KVM: x86: Introduce EM_ASM_2CL
KVM: x86: Introduce EM_ASM_2W
...
Linus Torvalds [Sat, 11 Oct 2025 17:51:14 +0000 (10:51 -0700)]
Merge tag 'x86_cleanups_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cleanups from Borislav Petkov:
- Simplify inline asm flag output operands now that the minimum
compiler version supports the =@ccCOND syntax
- Remove a bunch of AS_* Kconfig symbols which detect assembler support
for various instruction mnemonics now that the minimum assembler
version supports them all
- The usual cleanups all over the place
* tag 'x86_cleanups_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/asm: Remove code depending on __GCC_ASM_FLAG_OUTPUTS__
x86/sgx: Use ENCLS mnemonic in <kernel/cpu/sgx/encls.h>
x86/mtrr: Remove license boilerplate text with bad FSF address
x86/asm: Use RDPKRU and WRPKRU mnemonics in <asm/special_insns.h>
x86/idle: Use MONITORX and MWAITX mnemonics in <asm/mwait.h>
x86/entry/fred: Push __KERNEL_CS directly
x86/kconfig: Remove CONFIG_AS_AVX512
crypto: x86 - Remove CONFIG_AS_VPCLMULQDQ
crypto: X86 - Remove CONFIG_AS_VAES
crypto: x86 - Remove CONFIG_AS_GFNI
x86/kconfig: Drop unused and needless config X86_64_SMP
Linus Torvalds [Sat, 11 Oct 2025 17:40:24 +0000 (10:40 -0700)]
Merge tag 'slab-for-6.18-rc1-hotfix' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull slab fix from Vlastimil Babka:
"A NULL pointer deref hotfix"
* tag 'slab-for-6.18-rc1-hotfix' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
slab: fix barn NULL pointer dereference on memoryless nodes
- Fix metadata_dst leak in __bpf_redirect_neigh_v{4,6}() (Daniel
Borkmann)
- Fix undefined behavior in {get,put}_unaligned_be32() (Eric Biggers)
- Use correct context to unpin bpf hash map with special types (KaFai
Wan)
* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
selftests/bpf: Add test for unpinning htab with internal timer struct
bpf: Avoid RCU context warning when unpinning htab with internal structs
xsk: Harden userspace-supplied xdp_desc validation
bpf: Fix metadata_dst leak __bpf_redirect_neigh_v{4,6}
libbpf: Fix undefined behavior in {get,put}_unaligned_be32()
bpf: Finish constification of 1st parameter of bpf_d_path()
Linus Torvalds [Sat, 11 Oct 2025 17:27:52 +0000 (10:27 -0700)]
Merge tag 'mm-nonmm-stable-2025-10-10-15-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more updates from Andrew Morton:
"Just one series here - Mike Rappoport has taught KEXEC handover to
preserve vmalloc allocations across handover"
* tag 'mm-nonmm-stable-2025-10-10-15-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
lib/test_kho: use kho_preserve_vmalloc instead of storing addresses in fdt
kho: add support for preserving vmalloc allocations
kho: replace kho_preserve_phys() with kho_preserve_pages()
kho: check if kho is finalized in __kho_preserve_order()
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