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Author SHA1 Message Date
SJ Park 4e061ef21a mm/damon/core: hide private damos_quota_goal fields 
'last_psi_total' and 'list' of damos_quota_goal are intended to be used by
only the DAMON core layer.  Those are mistakenly not marked as private,
though.  Mark as private.

Link: https://lore.kernel.org/20260714143544.101305-4-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:05 -07:00
SJ Park 300cb8592d mm/damon/core: hide private damon_target fields 
'nr_regions', 'regions_list' and 'list' fields of damon_target are
intended to be used by only the DAMON core layer.  Those are mistakenly
not marked as private.  Mark as private.

Link: https://lore.kernel.org/20260714143544.101305-3-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:05 -07:00
SJ Park e0ea9467db mm/damon/core: hide private damon_region fields 
Patch series "mm/damon/core: hide core-private struct fields".

DAMON core structs hide core-private fields using 'private:' comment tags.
It is incomplete and inconsistent.  The linked list heads in a few
structs, for example, are intended to be hidden, and always be used using
the wrapper macros like damon_for_each_region().  But those were
mistakenly marked as non-private.  A few core layer-only fields were also
mistakenly added as non-private.

This only encourages callers to directly use the private fields.  It is
easy to make mistakes, and difficult to control.  Mark all such DAMON core
struct fields as private.

Patches 1-8 mark the private fields for damon_region, damon_target,
damos_quota_goal, damos_quota, damos_filter, damos, damon_filter and
damon_probe, respectively.  Patch 9 removes DAMON_SYSFS's direct access to
core-private field, damon_ctx->ops.  Finally patch 10 mark the private
fields for damon_ctx.


This patch (of 10):

damon_region->list is intended to be used by only the DAMON core layer. 
But it is mistakenly not marked as private.  Hide it from the callers by
marking it private.

Link: https://lore.kernel.org/20260714143544.101305-1-sj@kernel.org
Link: https://lore.kernel.org/20260714143544.101305-2-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:05 -07:00
xu xin 5c3746a0fe mm/mm_slot.h: add comments for mm_slot_lookup/insert 
mm_slot_lookup() and mm_slot_insert() are the only helpers in this header
that are implemented as macros rather than static inline functions.  This
may look inconsistent without explanation.

Explain they must be macros because hash_for_each_possible() needs the
table as an array (for sizeof), not a pointer.

Link: https://lore.kernel.org/20260714092815120Wv-CFDlLKtsTmda--97Qw@zte.com.cn
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Reviewed-by: Barry Song <baohua@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Qi Zheng <qi.zheng@linux.dev>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Wang Yaxin <wang.yaxin@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:04 -07:00
xu xin eed8da1ff6 mm/mm_slot.h: add a helper function mm_slot_remove 
Patch series "Two small patches to clean up mm/mm_slot.h", v3.

mm_slot.h is mainly used by THP and KSM.

Patch 1 introduces mm_slot_remove() to abstract the common
hash_del() + list_del() sequence used in both khugepaged and KSM.

Patch 2 adds a comment explaining why mm_slot_lookup/insert cannot
be converted to static inline functions.


This patch (of 2):

Both THP and KSM manage per-mm scanning slots using the mm_slot structure.
The slot is kept in a hash table and a list, and removal from both
containers requires the same two operations: hash_del() and list_del().

Introduce mm_slot_remove() to abstract the common hash_del() + list_del()
sequence used in both khugepaged and KSM.

No functional change is intended.

Link: https://lore.kernel.org/202607140924549782dUh3YBPmy8g1NDMK2zIW@zte.com.cn
Link: https://lore.kernel.org/20260714092622583ayzGzGYSjAareKKHt_T91@zte.com.cn
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Reviewed-by: Nico Pache <npache@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Barry Song <baohua@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Wang Yaxin <wang.yaxin@zte.com.cn>
Cc: Qi Zheng <qi.zheng@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:04 -07:00
Lorenzo Stoakes f4a31afd96 mm/mremap: convert mremap code to use vma_flags_t 
Replace use of the legacy vm_flags_t flags with vma_flags_t values
throughout the mremap logic.

Note that, in replacing vm_flags_clear() (which takes the VMA write lock)
with vma_clear_flags() and vma_clear_flags_mask() (which do not)
respectively in unmap_source_vma() and dontunmap_complete(), we do not add
a VMA write lock to account for htis.

This is because, in both cases, move_vma() is their calling function and
this has already acquired the VMA write lock on vrm->vma whose VMA flags
are being cleared.

In the case of vma_set_flags() in unmap_source_vma() we do need to do this
- as prev and next were not necessarily write locked at this point.

Additionally update comments to reflect the changes to be consistent.

No functional change intended.

Link: https://lore.kernel.org/20260711-b4-vma-flags-mm-v2-13-0fa2357d5431@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:04 -07:00
Lorenzo Stoakes 31b50515a7 mm/mprotect: convert mprotect code to use vma_flags_t 
Replace use of the legacy vm_flags_t flags with vma_flags_t values
throughout the mprotect logic.

Note that we retain the legacy vm_flags_t bit shifting code in
do_mprotect_pkey(), deferring a vma_flags_t approach to this for the time
being.

Additionally update comments to reflect the changes to be consistent.

No functional change intended.

Link: https://lore.kernel.org/20260711-b4-vma-flags-mm-v2-12-0fa2357d5431@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:04 -07:00
Lorenzo Stoakes 2fa484226b mm/mlock: convert mlock code to use vma_flags_t 
Replace use of the legacy vm_flags_t flags with vma_flags_t values
throughout the mlock logic.

Additionally update comments to reflect the changes to be consistent.

No functional change intended.

Link: https://lore.kernel.org/20260711-b4-vma-flags-mm-v2-11-0fa2357d5431@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:03 -07:00
Lorenzo Stoakes df751fe672 mm/vma: convert miscellaneous uses of VMA flags in core mm 
Update various uses of legacy flags in vma.c and mmap.c to the new
vma_flags_t type, updating comments alongside them to be consistent.

No functional change intended.

Link: https://lore.kernel.org/20260711-b4-vma-flags-mm-v2-10-0fa2357d5431@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:03 -07:00
Lorenzo Stoakes 8e7501a361 mm/vma: update create_init_stack_vma() to use vma_flags_t 
Replace use of the legacy vm_flags_t flags with vma_flags_t values in
create_init_stack_vma().

As part of this change we add VMA_STACK_EARLY and VMA_STACK_INCOMPLETE
vma_flags_t defines, and slightly rework create_init_stack_vma() for
clarity.

No functional change intended.

Link: https://lore.kernel.org/20260711-b4-vma-flags-mm-v2-9-0fa2357d5431@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:03 -07:00
Lorenzo Stoakes a2fdfd0080 mm: introduce vma_get_page_prot() and use it 
There's a large number of vm_get_page_prot(vma->vm_flags) invocations. 
Make life easier by introducing vma_get_page_prot() parameterised by the
VMA.

This also makes converting vm_get_page_prot() to vma_flags_t easier.

Also update the userland VMA tests to reflect the change.

No functional change intended.

Link: https://lore.kernel.org/20260711-b4-vma-flags-mm-v2-8-0fa2357d5431@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: Jani Nikula <jani.nikula@intel.com> # for i915
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>	[DRM]
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:03 -07:00
Lorenzo Stoakes e28266b033 mm/vma: rename vma_get_page_prot to vma_flags_to_page_prot 
Having vma_get_page_prot() refer to VMA flags and vma_set_page_prot()
refer to a VMA is confusing.

Rename vma_get_page_prot() to vma_flags_to_page_prot() to resolve this
confusion.

No functional change intended.

Link: https://lore.kernel.org/20260711-b4-vma-flags-mm-v2-7-0fa2357d5431@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:02 -07:00
Lorenzo Stoakes cc593403b1 mm/vma: convert vm_pgprot_modify() to use vma_flags_t and rename 
Update vm_pgprot_modify() to use the new VMA flags type vma_flags_t
and rename to vma_pgprot_modify() accordingly.

This is part of the ongoing work to convert vm_flags_t to vma_flags_t, in
order to eliminate the arbitrary limit of the number of bits in a system
word on available VMA flags.

Update VMA userland tests accordingly, updating vma_set_page_prot() to no
longer inline vma_pgprot_modify(), rather we can simply define
vma_pgprot_modify() as a static inline function and the tests will pick it
up from vma.h.

No functional change intended.

Link: https://lore.kernel.org/20260711-b4-vma-flags-mm-v2-6-0fa2357d5431@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:02 -07:00
Lorenzo Stoakes 96c09ae60b mm: prefer mm->def_vma_flags in mm logic 
Currently mm->def_flags (of type vm_flags_t) is union'd with
mm->def_vma_flags (of type vma_flags_t).

As part of the effort to convert vm_flags_t usage to vma_flags_t (in order
to no longer be arbitrarily limited to a system word size for VMA flags),
prefer mm->def_vma_flags to mm->def_flags throughout the mm logic.

We update dump_mm() to use the %*pb format which means we make no
assumption about the number of VMA flag bits on output when outputting
default VMA flags.

No functional change intended.

Link: https://lore.kernel.org/20260711-b4-vma-flags-mm-v2-5-0fa2357d5431@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:02 -07:00
Lorenzo Stoakes 8d80043131 mm: update generic_get_unmapped_area[_topdown]() to use vma_flags_t 
As part of the changes converting VMA flags from a system word size to a
bitmap, extend this change to generic_get_unmapped_area() and
generic_get_unmapped_area_topdown(), which also allows us to convert
stack_guard_placement() as well.

We retain arch_get_unmapped_area() and arch_get_unmapped_area_topdown()
as-is for now, using legacy_to_vma_flags() as necessary to do so.

No functional change intended.

Link: https://lore.kernel.org/20260711-b4-vma-flags-mm-v2-4-0fa2357d5431@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:01 -07:00
Lorenzo Stoakes 2ec748152d mm: convert __get_unmapped_area() to use vma_flags_t 
Update __get_unmapped_area() to be parameterised by vma_flags_t rather
than vm_flags_t as part of the effort to move VMA flags from a system word
to a bitmap.

We cascade the changes up to arch_get_unmapped_area_topdown() and
arch_get_unmapped_area(), where, for now, we use vma_flags_to_legacy() in
order to propagate the VMA flags.

No functional change intended.

Link: https://lore.kernel.org/20260711-b4-vma-flags-mm-v2-3-0fa2357d5431@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:01 -07:00
Lorenzo Stoakes 1944a0183c mm/vma: update do_mmap() to use vma_flags_t 
The core do_mmap() function accepts a vm_flags_t parameter which it then
manipulates before passing to mmap_region() to do the heavy lifting of the
memory mapping.

Update do_mmap() to instead accept a vma_flags_t parameter, and adjust all
the logic within do_mmap() to manipulate this instead.

This is as part of the ongoing effort to convert VMA flags from a system
word size to a bitmap type which allows us to unrestrict the number of VMA
flags, as well as gain control over how VMA flag manipulation occurs.

We do not cascade these changes to all functions which accept vm_flags_t,
but rather use vma_flags_to_legacy() where necessary, specifically
deferring converting calc_vm_prot_bits(), calc_vm_flag_bits() and
__get_unmapped_area() to vma_flags_t.

Also utilise the new vma_flags_can_grow() predicate which correctly
handles the case of architectures without upward growing stacks.

As part of this change, introduce VMA_SHADOW_STACK so we can correctly
handle the case of the shadow stack not being defined.

No functional change intended.

Link: https://lore.kernel.org/20260711-b4-vma-flags-mm-v2-2-0fa2357d5431@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:01 -07:00
Lorenzo Stoakes 3a50308b39 mm: introduce vma_flags_can_grow() and vma_can_grow() 
Patch series "mm: convert more vm_flags_t users to vma_flags_t", v2.

This series makes further progress in converting usage of the deprecated
vm_flags_t type to its replacement, vma_flags_t.

It focuses on mm, though updates some users of mm APIs also.

It updates:

* The core do_mmap() code path for VMA mapping.
* Unmapped area logic.
* The usage of mm->def_vma_flags.
* VMA page protection bit logic.
* General usage of VMA flags in core mm code, mlock, mprotect, mremap.


This patch (of 13):

These test whether the VMA has stack semantics, i.e.  is able to grow
upwards or downwards depending on the architecture.

In order to account for arches which do not support upward-growing stacks,
introduce VMA_GROWSUP whose definition depends on the architecture
supporting it, and use vma_flags_test_single_mask() in
vma_flags_can_grow() to account for this.

No functional change intended.

Link: https://lore.kernel.org/20260711-b4-vma-flags-mm-v2-0-0fa2357d5431@kernel.org
Link: https://lore.kernel.org/20260711-b4-vma-flags-mm-v2-1-0fa2357d5431@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:01 -07:00
Gregory Price 249c5ee21a selftests/dax: add dax/kmem hotplug sysfs regression test 
Add a kselftest for the dax/kmem whole-device "state" sysfs attribute
(/sys/bus/dax/devices/daxX.Y/state), which transitions a kmem-backed
dax device between "unplugged", "online" and "online_movable".

The kselftest also includes a test to demonstrate the force-unbind
does not deadlock - but this is destructive (the dax device can never
be rebound), so it only runs when DAX_KMEM_TEST_UNBIND=1 is set.

Provisioning a devdax device and binding it to kmem needs daxctl/ndctl
out of scope for an in-tree selftest.  As the test mutates a device's
memory, the operator opts in by naming it in DAX_KMEM_TEST_DEV (or
"auto" to pick the first kmem-bound device); it SKIPs when unset, when
no device is present, or when the memory cannot be freed to a baseline.

When a device is available it validates the interface contract:
  - online / online_movable actually add memory (MemTotal grows),
  - online is idempotent,
  - switching between online types without unplug is rejected,
  - unplug removes memory and the reported state is "unplugged"
  - invalid input is rejected,
  - unplug and unbind tolerate blocks toggled out-of-band through the
    per-block memoryX/state interface.

One specific regression test:
    online -> unplug -> online_movable -> unplug

Re-online must re-reserve per-range resources so subsequent unplug
actually offlines and removes instead of silently reporting success
while the memory stays online.

Link: https://lore.kernel.org/20260712154505.3564379-11-gourry@gourry.net
Signed-off-by: Gregory Price <gourry@gourry.net>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: David Hildenbrand (Arm) <david@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pankaj Gupta <pankaj.gupta@amd.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:00 -07:00
Gregory Price 2a6f2aef11 dax/kmem: add sysfs interface for atomic whole-device hotplug 
There is no atomic mechanism to offline and remove an entire
multi-block DAX kmem device.  This is presently done in two steps:
    1. offline all
    2. remove all

This creates a race condition where another entity operates directly on
the memory blocks and can cause hot-unplug to fail / unbind to deadlock.

Add a new 'state' sysfs attribute that enables an atomic whole-device
hotplug operation across its entire memory region.

daxX.Y/state mirrors the per-block memoryX/state ABI:
  - [offline, online, online_kernel, online_movable]
  - "unplugged" - is added specifically for dax0.0/state

The valid writable states include:
  - "unplugged":      memory blocks are not present
  - "online":         memory is online, zone chosen by the kernel
  - "online_kernel":  memory is online in ZONE_NORMAL
  - "online_movable": memory is online in ZONE_MOVABLE

Valid transitions:
  - unplugged                -> online[_kernel|_movable]
  - online[_kernel|_movable] -> unplugged
  - offline                  -> unplugged

A device can only be onlined from "unplugged", so it must be returned
there before being onlined into a different state.

For backwards compatibility the memory blocks are always created at probe
- existing tools expect them to be present after kmem binds.

"offline" is therefore a reportable state but is not writable: it only
arises from the legacy auto_online_blocks=offline policy.  Onlining such a
device through this attribute requires unplugging it first in an effort to
get drivers creating DAX devices to set a default.

Unplug is atomic across the whole device: dax_kmem_do_hotremove() collects
every added range and offlines/removes them in one operation.  Either the
operation succeeds or is entirely rolled back.

Unbind Note:
  An offline dax device memory is removed on unbind as before.

  If online at unbind, the resources are leaked (as before), but now
  we prevent deadlock if a memory region is impossible to hotremove.

Link: https://lore.kernel.org/20260712154505.3564379-10-gourry@gourry.net
Signed-off-by: Gregory Price <gourry@gourry.net>
Suggested-by: Hannes Reinecke <hare@suse.de>
Suggested-by: David Hildenbrand <david@kernel.org>
Reviewed-by: Dan Williams <djbw@kernel.org>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pankaj Gupta <pankaj.gupta@amd.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:00 -07:00
Gregory Price bb76d369b6 dax/kmem: extract hotplug/hotremove helper functions 
Refactor kmem _probe() _remove() by extracting init, cleanup, hotplug, and
hot-remove logic into separate helper functions:

  - dax_kmem_init_resources: inits IO_RESOURCE w/ request_mem_region
  - dax_kmem_cleanup_resources: cleans up initialized IO_RESOURCE
  - dax_kmem_do_hotplug: handles memory region reservation and adding
  - dax_kmem_do_hotremove: handles memory removal and resource cleanup

This is a pure refactoring with no functional change.  The helpers will
enable future extensions to support more granular control over memory
hotplug operations.

We need to split hotplug/hotunplug and init/cleanup in order to have the
resources available for hot-add.  Otherwise, when probe occurs, the dax
devices are never added to sysfs because the resources are never
registered.

Detaching hotunplug/cleanup allows us to re-use the hotunplug code without
destroying the underlying resources.

Link: https://lore.kernel.org/20260712154505.3564379-9-gourry@gourry.net
Signed-off-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: David Hildenbrand (Arm) <david@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pankaj Gupta <pankaj.gupta@amd.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:00 -07:00
Gregory Price 496a4cd658 dax/kmem: resolve default online type at probe time 
Resolve the default online type in kmem at probe time explicitly instead
of implicitly inheriting the system default by calling
add_memory_driver_managed().

No behavioral change at this point (still system default).

Link: https://lore.kernel.org/20260712154505.3564379-8-gourry@gourry.net
Signed-off-by: Gregory Price <gourry@gourry.net>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: David Hildenbrand (Arm) <david@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pankaj Gupta <pankaj.gupta@amd.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:57:00 -07:00
Gregory Price c17ba40c37 mm/memory_hotplug: add offline_and_remove_memory_ranges() 
offline_and_remove_memory() handles a single contiguous range.

Callers that manage a device composed of several ranges (dax/kmem)
currently have to call it in a loop, which gives up atomicity.

In addition to pushing rollback logic into the driver, the lack of
atomicity creates a race condition between system daemons trying to manage
the same resource:

   - Manager 1:  Offlines memory blocks.    Removes device.
                                        ^^^^
   - Manager 2:  Detects offline memory blocks, re-onlines them.

Add offline_and_remove_memory_ranges(), which takes an array of ranges and
processes them as one operation under a single lock_device_hotplug():

  - Phase 1 offlines every block of every range.
  - Phase 2 removes the ranges only if all ranges are offline.
  - If any offline fails, the whole operation is reverted.

This gives callers all-or-nothing semantics for the offline step, so a
failed or interrupted unplug leaves the device in a consistent state.

This also resolves the battling managers race - the second manager's
operation simply fails when the block is destroyed / cannot be onlined.

offline_and_remove_memory() becomes a thin wrapper that passes its single
range to the new helper, so the offline/rollback logic lives in one place.

Link: https://lore.kernel.org/20260712154505.3564379-7-gourry@gourry.net
Signed-off-by: Gregory Price <gourry@gourry.net>
Suggested-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Dan Williams <djbw@kernel.org>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pankaj Gupta <pankaj.gupta@amd.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:59 -07:00
Gregory Price 2b047c8a8c mm/memory_hotplug: add __add_memory_driver_managed() with online_type arg 
Existing callers of add_memory_driver_managed cannot select the preferred
online type (ZONE_NORMAL vs ZONE_MOVABLE), requiring it to hot-add memory
as offline blocks, and then follow up by onlining each memory block
individually.

Most drivers prefer the system default, but the CXL driver wants to plumb
a preferred policy through the dax kmem driver.

Refactor APIs to add a new interface which allows the dax kmem module to
select a preferred policy.

Overriding the configured auto-online policy is only safe for known
in-tree modules, where we know the override reflects a different,
user-requested policy.  We do not want arbitrary out-of-tree drivers
silently overriding the system-wide onlining policy, so restrict the new
interface to the kmem module using EXPORT_SYMBOL_FOR_MODULES() rather than
a plain EXPORT_SYMBOL_GPL().  Other in-tree modules (e.g.  cxl_core) can
be added to the allowed list as the need arises.

Refactor add_memory_driver_managed, extract __add_memory_driver_managed
- Add proper kernel-doc for add_memory_driver_managed while refactoring
- New helper accepts an explicit online_type.
- New helper validates online_type is between OFFLINE and ONLINE_MOVABLE

Refactor: add_memory_resource, extract __add_memory_resource
- new helper accepts an explicit online_type

Original APIs now explicitly pass the system-default to new helpers.

No functional change for existing users.

Link: https://lore.kernel.org/20260712154505.3564379-6-gourry@gourry.net
Signed-off-by: Gregory Price <gourry@gourry.net>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Dan Williams <djbw@kernel.org>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:59 -07:00
Gregory Price 7e00a85f78 mm/memory_hotplug: export mhp_get_default_online_type 
Drivers which may pass hotplug policy down to DAX need MMOP_ symbols and
the mhp_get_default_online_type function for hotplug use cases.

Some drivers (cxl) co-mingle their hotplug and devdax use-cases into the
same driver code, and chose the dax_kmem path as the default driver path -
making it difficult to require hotplug as a predicate to building the
overall driver (it may break other non-hotplug use-cases).

Export mhp_get_default_online_type function to allow these drivers to
build when hotplug is disabled and still use the DAX use case.

In the built-out case we simply return MMOP_OFFLINE as it's
non-destructive.  The internal function can never return -1 either, so we
choose this to allow for defining the function with 'enum mmop'.

Link: https://lore.kernel.org/20260712154505.3564379-5-gourry@gourry.net
Signed-off-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Dan Williams <djbw@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pankaj Gupta <pankaj.gupta@amd.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:59 -07:00
Gregory Price 65c1a93e43 mm/memory_hotplug: pass online_type to online_memory_block() via arg 
Modify online_memory_block() to accept the online type through its arg
parameter rather than calling mhp_get_default_online_type() internally.

This prepares for allowing callers to specify explicit online types.

Update the caller in add_memory_resource() to pass the default online
type via a local variable.

No functional change.

Link: https://lore.kernel.org/20260712154505.3564379-4-gourry@gourry.net
Signed-off-by: Gregory Price <gourry@gourry.net>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Dan Williams <djbw@kernel.org>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:58 -07:00
Gregory Price 5459c5be28 mm/memory_hotplug: add mhp_online_type_to_str() and export string helpers 
Add mhp_online_type_to_str() as the inverse of mhp_online_type_from_str(),
and export both so a driver can render and parse the memory online type
through its own sysfs interface.

Link: https://lore.kernel.org/20260712154505.3564379-3-gourry@gourry.net
Signed-off-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Dan Williams <djbw@kernel.org>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pankaj Gupta <pankaj.gupta@amd.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:58 -07:00
Gregory Price 463bd5b83b mm/memory: add memory_block_aligned_range() helper 
Patch series "dax/kmem: atomic whole-device hotplug via sysfs", v7.

The dax kmem driver onlines memory during probe using the system default
policy, with no atomic control for the state of an entire region at
runtime - only by toggling individual memory blocks.

Offlining and removing a whole region therefore races with other userland
controllers that interfere between the two steps.

This series adds a sysfs "state" attribute for atomic whole-device hotplug
control, plus the mm and dax plumbing to support it.

Transitions are atomic across every range of the device.  The state names
mirror the per-block memoryX/state ABI with one modification:

  - "unplugged":      memory blocks are not present
  - "online":         online as system RAM, zone chosen by the kernel
  - "online_kernel":  online in ZONE_NORMAL
  - "online_movable": online in ZONE_MOVABLE

"offline" (blocks present but offline) is reportable for backward
compatibility but is not writable because it entices the race condition we
are trying to solve (separate atomic steps for offline and unplug).

'unplugged' (atomic offline+remove of the whole device) is the new
capability provided by the new kmem sysfs attribute.

dax/kmem probe still creates the memory blocks by default when the default
policy is "offline", to preserve backwards compatibility.


This patch (of 10):

Memory hotplug operations require ranges aligned to memory block
boundaries.  This is a generic operation for hotplug.

Add memory_block_aligned_range() as a common helper in <linux/memory.h>
that aligns the start address up and end address down to memory block
boundaries.  Guard against end underflow when the range falls below the
first memory block boundary, returning an empty range instead.

Update dax/kmem to use this helper.

Link: https://lore.kernel.org/20260712154505.3564379-1-gourry@gourry.net
Link: https://lore.kernel.org/20260712154505.3564379-2-gourry@gourry.net
Signed-off-by: Gregory Price <gourry@gourry.net>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Dan Williams <djbw@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Pankaj Gupta <pankaj.gupta@amd.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:58 -07:00
Song Hu aace7a1f5f Docs/ABI/damon: document tried_regions probe hits 
The 'tried_regions/<R>/probes/<P>/hits' file, added in commit 5b0de1bc33
("mm/damon/sysfs-schemes: implement probe/hits file"), is described in
usage.rst but missing from the canonical ABI document.

Document the 'probes/' directory and the 'probes/<P>/hits' file.

Link: https://lore.kernel.org/20260714140117.94147-5-sj@kernel.org
Signed-off-by: Song Hu <husong@kylinos.cn>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: SJ Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:58 -07:00
Song Hu 66a0dae14a Docs/ABI/damon: document update_tuned_intervals state command 
The 'update_tuned_intervals' command of the 'state' file, added in commit
1077605396 ("mm/damon/sysfs: implement a command to update auto-tuned
monitoring intervals"), is described in usage.rst but missing from the
canonical ABI document.  Add it.

Link: https://lore.kernel.org/20260714140117.94147-4-sj@kernel.org
Signed-off-by: Song Hu <husong@kylinos.cn>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: SJ Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:57 -07:00
Song Hu 732c07c4d3 Docs/ABI/damon: fix typos 
Fix two typos in the DAMON sysfs ABI document:

  - "WDate:" -> "Date:" on the nr_regions/min entry
  - "manimum" -> "minimum" in the nr_accesses/min description

Link: https://lore.kernel.org/20260714140117.94147-3-sj@kernel.org
Signed-off-by: Song Hu <husong@kylinos.cn>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: SJ Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:57 -07:00
Song Hu 1b492fc823 Docs/ABI/damon: fix typo in intervals_goal sysfs path 
Patch series "Docs/ABI/damon: sysfs ABI document fixes and additions", v2.

This series fixes typos and fills in missing entries in the DAMON sysfs
ABI document (Documentation/ABI/testing/sysfs-kernel-mm-damon).

Patch 1 fixes a path typo, "intrvals_goal" -> "intervals_goal", in four
What: entries; the documented path points to a non-existent directory, so
it is Cc'ed to stable.

Patch 2 fixes two further typos ("WDate:", "manimum").

Patches 3 and 4 add ABI entries that exist in the kernel and are already
described in usage.rst but are missing from the canonical ABI document:
the 'update_tuned_intervals' state command (patch 3) and the
'tried_regions/<R>/probes/<P>/hits' file (patch 4).


This patch (of 4):

The ABI document spells the DAMON sysfs directory as "intrvals_goal"
(missing 'e') in four What: entries, but the kernel creates it as
"intervals_goal" (mm/damon/sysfs.c).  Following the documented path
therefore yields a non-existent directory.

Link: https://lore.kernel.org/20260714140117.94147-1-sj@kernel.org
Link: https://lore.kernel.org/20260714140117.94147-2-sj@kernel.org
Fixes: e2b23dc623 ("Docs/ABI/damon: document intervals auto-tuning ABI")
Signed-off-by: Song Hu <husong@kylinos.cn>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: SJ Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:57 -07:00
SJ Park 0250dbe08c mm/damon/core: skip aging from repeated aggressive merging 
The number of DAMON regions could temporarily exceed the user-defined
maximum number of regions limit for corner cases.  For example, users
could lower the limit via runtime parameters update.  For such a case,
kdamond_merge_regions() repeats merging regions in the case doubling the
merge threshold.  The repeated merge operation could update the age of
regions multiple times.  This corrupts the monitoring results.  Fix the
issue by asking the merge operation to skip aging for the corner case.

The user impact is degradation of the monitoring quality.  The impact
should be mild, since the degradation is only temporal, and it is not
common to happen in realistic setups.

The issue was discovered [1,2] by Sashiko.

Link: https://lore.kernel.org/20260712165432.87609-1-sj@kernel.org
Link: https://lore.kernel.org/20260621203548.10718-1-sj@kernel.org [1]
Link: https://lore.kernel.org/20260709145425.96247-1-sj@kernel.org [2]
Fixes: 310d6c15e9 ("mm/damon/core: merge regions aggressively when max_nr_regions is unmet")
Signed-off-by: SJ Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> # 6.10
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:57 -07:00
Hongfu Li 824d80962c selftests/mm: factor out hmm_buffer_alloc() to consolidate buffer setup 
Each HMM test open-codes the same buffer initialization sequence: allocate
main buffer, assign file descriptor and size, allocate mirror buffer, then
perform mmap mapping.  Factor out this repeated logic into a standalone
hmm_buffer_alloc() helper to eliminate ~35 open-coded copies.

The new helper supports distinct mmap_size and mirror_size parameters to
fit scenarios with THP alignment padding or per-page snapshot flags.  It
also exposes prot, flags and fd arguments, enabling support for
MAP_SHARED, MAP_HUGETLB and file-backed mappings.

Eliminates ~360 lines of redundant boilerplate code.  Fixes a missing NULL
pointer check bug in the hmm_buffer_alloc() previously used only by the
migration benchmark, now subsumed by this new unified helper.

Link: https://lore.kernel.org/20260713033209.280435-1-lihongfu@kylinos.cn
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:56 -07:00
Youngjun Park 4f93f0956f mm/swap: clarify unreachable cond_resched() in swap_reclaim_full_clusters 
Commit 66366d291f ("mm/swap: add cond_resched() in
swap_reclaim_full_clusters to prevent softlockup") added cond_resched() to
prevent soft lockups during heavy swap reclaim.

Currently, there are two call sites for this function:
1. swap_reclaim_work(): called with force=true in a workqueue context.
2. cluster_alloc_swap_entry(): called with force=false, holding a
   local_lock and potentially a global cluster spinlock (atomic context).

In the second case, calling cond_resched() would normally cause a
"scheduling while atomic" bug.  However, it is currently safe because when
force=false, 'to_scan' is initialized to 1.  The loop decrements it to 0
and breaks before ever reaching cond_resched().

This implicit dependency is hard to notice and recently triggered a false
positive in AI Sashiko review.

Add a comment to explicitly clarify that cond_resched() is unreachable in
atomic contexts.  This improves readability and prevents future misuse if
the loop logic or 'to_scan' initialization is modified.

Link: https://sashiko.dev/#/patchset/20260713025644.170839-1-youngjun.park@lge.com?part=4
Link: https://lore.kernel.org/20260713045014.219653-1-youngjun.park@lge.com
Signed-off-by: Youngjun Park <youngjun.park@lge.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:56 -07:00
Hongling Zeng 20dab9d72a mm: huge_memory: fix kobject cleanup in thpsize_create error 
When kobject_init_and_add() fails, the kobject API requires calling
kobject_put() to properly clean up the memory, not direct kfree().

According to the kobject API documentation, kobject_init_and_add() calls
kobject_init() internally.  If the subsequent kobject_add() fails, the
kobject has still been initialized and must be cleaned up via the
reference count mechanism (kobject_put), not direct kfree().

Direct kfree() leaves the kobject's internal state (including the
reference count and kset membership) uncleaned, which can cause:
 - Memory leaks of kobject internal structures
 - Potential use-after-free if there are pending references
 - Inconsistent state with the rest of the error handling code

This fix matches the pattern used elsewhere in the kernel and in the same
function (err_put label) which correctly uses kobject_put().

Link: https://lore.kernel.org/20260713054154.120915-1-zenghongling@kylinos.cn
Fixes: 3485b88390 ("mm: thp: introduce multi-size THP sysfs interface")
Signed-off-by: Hongling Zeng <zenghongling@kylinos.cn>
Suggested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Hongling Zeng <zenghongling@kylinos.cn>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:56 -07:00
Injae Ryou 98df164036 selftests/mm: fix on-fault-limit false failure under sudo-rs 
run_vmtests.sh runs on-fault-limit as the nobody user via "sudo -u nobody
./on-fault-limit", guarded by a check that nobody can access the binary
("sudo -u nobody ls ./on-fault-limit").

The guard resolves the relative path from the inherited working directory,
which only requires search permission on the test directory itself. 
Classic sudo passes the relative path through to execve() the same way, so
the two agree.  However, sudo-rs (the default sudo implementation since
Ubuntu 25.10) canonicalizes the command to an absolute path before
executing it, which requires search permission on every ancestor
directory.  When the kernel tree lives under a private home directory
(mode 0750, the Ubuntu default for new users since 21.04), the guard
passes but the execution fails with "command not found", and the test is
reported as a false FAIL:

  # running sudo -u nobody ./on-fault-limit
  sudo: './on-fault-limit': command not found
  # [FAIL]

Wrap the command in "sh -c" so that sudo only resolves the shell binary,
and the relative path is resolved by nobody's shell from the inherited
working directory, matching what the guard checks.  This is the only "sudo
-u nobody" invocation in the script; uid, cwd, rlimits (including
RLIMIT_MEMLOCK, which this test exercises) and the exit status are
unchanged through sh.

Verified on Ubuntu 26.04 (sudo-rs 0.2.13): the test now runs and passes
instead of failing.  Verified on Ubuntu 24.04 (sudo 1.9.15p5): behavior is
unchanged.

Link: https://lore.kernel.org/20260713092700.464376-1-injaeryou@gmail.com
Fixes: 5d2146a335 ("selftests/mm: skip mlock tests if nobody user can't read it")
Signed-off-by: Injae Ryou <injaeryou@gmail.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:56 -07:00
Yijia Wang 51f4bd13c3 selftests: mincore: count file-mmap readahead on both sides 
check_file_mmap() faults a page in the middle of a file mapping and
expects the mmap read-around path to make neighbouring pages resident. 
The test currently counts only pages after the faulted page.

That misses valid read-around on systems with large base page sizes.  On
arm64 with 64K pages and the default 128K readahead setting, the
read-around window is two pages wide and centred on the faulting page. 
Faulting page 32 makes pages 31 and 32 resident, so the forward-only scan
from page 33 reports ra_pages == 0 even though a neighbouring page was
brought in.

Keep the existing readahead assertion, but count resident neighbouring
pages on both sides of the faulted page.  This fixes the 64K-page false
failure without teaching the selftest to compute the expected readahead
window from sysfs or other implementation details.

Link: https://lore.kernel.org/20260713094319.771550-1-wangyijia.yeah@bytedance.com
Signed-off-by: Yijia Wang <wangyijia.yeah@bytedance.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:55 -07:00
Song Hu 169c0a1ec4 mm/damon/tests/core-kunit: test damon_nr_accesses_mvsum() 
damon_nr_accesses_mvsum() wraps damon_mvsum() with the monitoring
intervals of the context to compute the pseudo moving sum of a region's
access frequency, with a special case for when the whole aggregation
window remains.  damon_mvsum() itself is already covered by
damon_test_mvsum(), but the wrapper is not.

Add a table-driven KUnit test that exercises the full-window-remaining
boundary (with both reset and not-yet-reset nr_accesses), partially
elapsed windows, and the no-window-remaining case.

Link: https://lore.kernel.org/20260713094648.897239-1-husong@kylinos.cn
Signed-off-by: Song Hu <husong@kylinos.cn>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:55 -07:00
Guopeng Zhang 08d36b191f mm: memcg-v1: make mem_cgroup_oom_notify_cb() return void 
Commit 7d74b06f24 ("memcg: use for_each_mem_cgroup") replaced the
mem_cgroup_walk_tree() call in mem_cgroup_oom_notify() with
for_each_mem_cgroup_tree(), but left mem_cgroup_oom_notify_cb() with the
int return type required by the old callback interface.

The function now has a single direct caller and no failure path.  Make it
return void.

Link: https://lore.kernel.org/20260713093737.3299646-1-guopeng.zhang@linux.dev
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Reviewed-by: SJ Park <sj@kernel.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:55 -07:00
Guopeng Zhang afe9ae3fda mm: memcontrol: factor out memcg kmem uncharge sequence 
The kmem-uncharge sequence (mod_memcg_state(MEMCG_KMEM) +
memcg1_account_kmem + conditional memcg_uncharge) is duplicated verbatim
in obj_cgroup_release() and drain_obj_stock_slot().  Factor it into a
small memcg_uncharge_kmem() helper.  The reference get/put stays at the
call sites, as they differ.

No functional change.

Link: https://lore.kernel.org/20260713090304.3015329-1-guopeng.zhang@linux.dev
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Acked-by: Tao Cui <cuitao@kylinos.cn>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:55 -07:00
Guopeng Zhang 219a53f6c8 mm: memcontrol: drop unused cpu argument from flush_nmi_stats 
flush_nmi_stats() does not use its cpu argument.  Remove it from the
function and its !CONFIG_MEMCG_NMI_SAFETY_REQUIRES_ATOMIC stub.  The
caller still uses cpu for the subsequent per-CPU rstat flush.

No functional change.

Link: https://lore.kernel.org/20260713090010.2991906-1-guopeng.zhang@linux.dev
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:54 -07:00
Guopeng Zhang 45b1ec4887 mm: memcg-v1: fix wrong linux-mm list address in deprecation warnings 
The deprecation warnings for memory.oom_control and memory.pressure_level
use linux-mm-@kvack.org instead of the linux-mm mailing list address. 
Remove the extra hyphen.

Link: https://lore.kernel.org/20260713085756.2973549-1-guopeng.zhang@linux.dev
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:54 -07:00
Guopeng Zhang 466dd08cdc mm: memcg-v1: account vmpressure event allocations 
Commit 72797d218b ("mm/memcg: v1: account event registrations and drop
world-writable cgroup.event_control") accounted cgroup v1 event
registration allocations with GFP_KERNEL_ACCOUNT, but missed struct
vmpressure_event.

Use GFP_KERNEL_ACCOUNT for this allocation as well.

Link: https://lore.kernel.org/20260713085520.2953121-1-guopeng.zhang@linux.dev
Fixes: 72797d218b ("mm/memcg: v1: account event registrations and drop world-writable cgroup.event_control")
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Acked-by: Tao Cui <cuitao@kylinos.cn>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-06 18:56:54 -07:00
Guopeng Zhang 72f522bbf4 mm: memcontrol: update state_local when flushing NMI stats 
flush_nmi_stats() updates state[] for kmem and slab counters but leaves
the corresponding state_local[] counters unchanged.  Local kmem and slab
statistics therefore miss updates collected through the NMI-safe atomic
path.

Update state_local[] together with state[].

Link: https://lore.kernel.org/20260713085053.2916813-1-guopeng.zhang@linux.dev
Fixes: 940b01fc8d ("memcg: nmi safe memcg stats for specific archs")
Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn>
Acked-by: Tao Cui <cuitao@kylinos.cn>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-04 19:19:07 -07:00
Dev Jain 04b09ca57d mm/rmap: add anon folio unmap dispatcher 
Add ttu_anon_folio() as the common entry point for anonymous folio
unmapping.  It dispatches to the lazyfree or swapbacked helper as
appropriate.

Keep restoration of cleared PTEs in the caller, where the PTEs were
removed.

No functional change intended.

Link: https://lore.kernel.org/20260730094559.418003-6-dev.jain@arm.com
Signed-off-by: Dev Jain <dev.jain@arm.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Harry Yoo <harry@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-04 19:19:07 -07:00
Dev Jain 0caf74274d mm/rmap: refactor anon folio unmap in try_to_unmap_one 
Refactor anonymous swapbacked folio unmap to ttu_anon_swapbacked_folio(). 
While at it, rename the remaining subpage variables to page; folios have
pages, not subpages.

No functional change intended.

Link: https://lore.kernel.org/20260730094559.418003-5-dev.jain@arm.com
Signed-off-by: Dev Jain <dev.jain@arm.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Harry Yoo <harry@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-04 19:19:06 -07:00
Dev Jain 0955037b98 mm/rmap: refactor some code around lazyfree folio unmapping 
For lazyfree folio unmapping, after clearing the ptes we must abort the
operation if the folio got dirtied or it has unexpected references.

Refactor this logic into a function which will return whether we need
to abort or not.

If we abort, we restore the ptes and bail out of try_to_unmap_one.
Otherwise adjust the rss stats of the mm and jump to a label.

Also rename that label from "discard" to "finish_unmap"; the former
is appropriate in the lazyfree context, but the code following the label
is executed for other successful unmap code paths too, so 'discard' does
not sound correct for them.

No functional change intended.

Link: https://lore.kernel.org/20260730094559.418003-4-dev.jain@arm.com
Signed-off-by: Dev Jain <dev.jain@arm.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Harry Yoo <harry@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-04 19:19:06 -07:00
Dev Jain d4ec557282 mm/rmap: add try_to_unmap_poisoned_hugetlb_one 
Simplify try_to_unmap_one() by separating the hugetlb parts into
try_to_unmap_poisoned_hugetlb_one().

To understand the correctness of the refactoring, the following points
are noted:

1. try_to_unmap() is called for hugetlb folios only when they are
   hwpoisoned.

2. A hugetlb VMA cannot be mlocked.

3. page_vma_mapped_walk() returns at most one hugetlb mapping in a VMA,
   and that mapping points at the head PFN.

4. We won't ever process a softleaf entry that encodes a hugetlb folio;
   hugetlb folios are never swapped out, migration entries will be
   skipped (PVMW_MIGRATION not passed), and device-exclusive does not
   work for hugetlb.

5. The hwpoison entry is constructed from the poisoned folio, just as in
   the pre-refactor code. Any previous uffd-wp state is deliberately not
   preserved for the hwpoison entry.

6. TTU_HWPOISON is always present; for it to not be present, either the
   folio has to be in swapcache, or mapping_can_writeback() is true (see
   unmap_poisoned_folio), none of which is true for hugetlb folios.

7. Hugetlb uses separate counters from normal rss counters, therefore
   update_highwater_rss() need not be called.

While at it:

 - Change VM_BUG_* to VM_WARN_*.

 - Do not declare variables which are only used once.

 - Constify some variables.

 - Add some more VM_WARN_* to assert some invariants.

Except the above 4 points, no functional change intended.

Link: https://lore.kernel.org/20260730094559.418003-3-dev.jain@arm.com
Signed-off-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Suggested-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Harry Yoo <harry@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-04 19:19:06 -07:00
Dev Jain af56d6acf4 mm/rmap: convert page -> folio for hwpoison checks 
Patch series "mm/rmap: Refactor try_to_unmap_one", v4.

In preparation for batching anonymous large folio unmapping to optimize
it, refactor try_to_unmap_one.  This series refactors hugetlb,
anon-lazyfree and anon-swapbacked logic into their own functions,
significantly reducing the length of the huge try_to_unmap_one.


This patch (of 5):

try_to_unmap() receives hugetlb folios only from the hwpoison path. 
hugetlb_update_hwpoison() sets the hugetlb folio's head-page hwpoison bit,
and page_vma_mapped_walk() reports the hugetlb mapping at the head PFN, so
the previous PageHWPoison(subpage) check happened to work for hugetlb.

For non-hugetlb folios, unmap_poisoned_folio() currently rejects large
folios before calling try_to_unmap().  Hence it is always the case that if
try_to_unmap_one() handles an hwpoisoned folio, then the head page is
marked with the poison bit.

Therefore, convert the poisoned subpage checks to folio_test_hwpoison().

No functional change intended, except that, while at it,
convert VM_BUG_* to VM_WARN_*.

Link: https://lore.kernel.org/20260730094559.418003-1-dev.jain@arm.com
Link: https://lore.kernel.org/20260730094559.418003-2-dev.jain@arm.com
Signed-off-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Harry Yoo <harry@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-08-04 19:19:06 -07:00