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Hongfu Li c5efd0bded selftests/mm: fix clone cleartid race in pkey sighandler tests 
Passing a stack-local child_pid to clone() with CLONE_CHILD_CLEARTID is
unsafe: the kernel clears that address when the child exits, which may
happen after the test function has returned and the stack slot has been
reused.

Neither testcase uses the settid/cleartid pointers for synchronization.

Drop CLONE_PARENT_SETTID and CLONE_CHILD_CLEARTID and pass NULL for the
clone tid arguments.  Wait for the clone child to exit via tkill in
test_sigsegv_handler_with_different_pkey_for_stack(), matching
test_pkru_sigreturn(), so the detached thread cannot overlap with the next
testcase.

Link: https://lore.kernel.org/20260706081600.3570203-7-lihongfu@kylinos.cn
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
Cc: David Hildenbrand <david@kernel.org>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Keith Lucas <keith.lucas@oracle.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Liam R. Howlett (Oracle) <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Yury Khrustalev <yury.khrustalev@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:30 -07:00
Hongfu Li 5a8e068339 selftests/mm: add missing pthread_create() return checks in pkey tests 
Add missing pthread_create() return checks in pkey sighandler tests to
avoid hanging in pthread_cond_wait() when thread creation fails.

Link: https://lore.kernel.org/20260706081600.3570203-6-lihongfu@kylinos.cn
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Liam R. Howlett (Oracle) <liam@infradead.org>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Tested-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Keith Lucas <keith.lucas@oracle.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Yury Khrustalev <yury.khrustalev@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:30 -07:00
Hongfu Li 654b88fe7d selftests/mm: add missing mmap() return checks in pkey tests 
Add missing checks against mmap() return value, replace (void *)-1 with
MAP_FAILED for better readability and consistency.

Link: https://lore.kernel.org/20260706081600.3570203-5-lihongfu@kylinos.cn
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Liam R. Howlett (Oracle) <liam@infradead.org>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Tested-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Keith Lucas <keith.lucas@oracle.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Yury Khrustalev <yury.khrustalev@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:30 -07:00
Hongfu Li 4b87c918ad selftests/mm: use pkey_assert on clone_raw failure in pkey test 
Use pkey_assert(0) instead of perror("clone") when clone_raw() fails.  The
old path only printed an error and continued; the test now exits via
pkey_assert() on failure so it does not hang or proceed with an invalid
child.

Link: https://lore.kernel.org/20260706081600.3570203-4-lihongfu@kylinos.cn
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Liam R. Howlett (Oracle) <liam@infradead.org>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Tested-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Keith Lucas <keith.lucas@oracle.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Yury Khrustalev <yury.khrustalev@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:29 -07:00
Hongfu Li 9ee05ad72b selftests/mm: unify pkey sighandler selftest assertions and tracing 
Add per-test tracing to the pkey signal-handler selftest and use
pkey_assert() for error handling.  Each test enables tracing at start and
disables it at end; on failure, pkey_assert() calls abort_hooks() to turn
tracing off so ftrace is not left enabled.

Link: https://lore.kernel.org/20260706081600.3570203-3-lihongfu@kylinos.cn
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Liam R. Howlett (Oracle) <liam@infradead.org>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Tested-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Keith Lucas <keith.lucas@oracle.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Yury Khrustalev <yury.khrustalev@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:29 -07:00
Hongfu Li e453129b4c selftests/mm: move pkey selftest helpers to pkey_util.c 
Patch series "selftests/mm: refactor pkey helpers and fix mmap error
handling", v10.

The main changes in this series are to refactor shared tracing and
assertion helpers into a common file, unify both pkey selftests on
pkey_assert() and per-test tracing for consistent diagnostics, and add
missing mmap() return checks with MAP_FAILED used throughout for
readability and consistency.


This patch (of 10):

Move pkey selftest debugging helpers into shared code so both pkey
selftests can use the same tracing and abort-hook logic.  Also fix
cat_into_file() to print file, not str, in the open() failure message.

Link: https://lore.kernel.org/20260706081600.3570203-1-lihongfu@kylinos.cn
Link: https://lore.kernel.org/20260706081600.3570203-2-lihongfu@kylinos.cn
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Liam R. Howlett (Oracle) <liam@infradead.org>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Tested-by: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Keith Lucas <keith.lucas@oracle.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Yury Khrustalev <yury.khrustalev@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:29 -07:00
yahia ahmed 5af3f83dcf mm/shmem: fix data-race in shmem_fault 
shmem_fault and shmem_writeout access inode->i_private without holding a
lock, while shmem_fallocate is modifying it while holding a lock, thus a
data-race is created.

Fix this by using READ_ONCE and WRITE_ONCE, which provides an atomic,
lockless read and write of inode->i_private which prevents compiler
optimizations such as caching in registers and add writing to
inode->i_private with WRITE_ONCE to prevent the compiler from writing in
registers.

Link: https://lore.kernel.org/20260630120222.11562-1-yahia.a.abdrabou@gmail.com
Signed-off-by: yahia ahmed <yahia.a.abdrabou@gmail.com>
Reported-by: syzbot+76cc716982cf0254f302@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=76cc716982cf0254f302
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:29 -07:00
Usama Arif ea928e9e18 mm/vmpressure: move v1 userspace eventfd code into memcontrol-v1.c 
Clean up mm/vmpressure.c by separating the cgroup v1 userspace eventfd
interface from the shared and v2 in-kernel code.

Currently, almost half of mm/vmpressure.c exists to serve tree=true:
struct vmpressure_event, the events list and its mutex, the work_struct
and vmpressure_work_fn that drains tree_scanned/tree_reclaimed, the parent
walk, vmpressure_event(), vmpressure_register_event(),
vmpressure_unregister_event(), and vmpressure_prio() (which always calls
vmpressure() with tree=true).

Move it all into mm/memcontrol-v1.c (built only when CONFIG_MEMCG_V1=y) as
a single contiguous block, following the per-component layout already used
by that file.  Keeping the v1 vmpressure code with the rest of the
deprecated cgroup v1 memory controller makes the full footprint of the
CONFIG_MEMCG_V1 option easy to see in one place, which matters more than
component-level file separation for code that has no active development.

vmpressure.c keeps the shared bits (constants, vmpressure_calc_level, the
runtime hierarchy check, the tree=false body, init/cleanup plumbing) and
calls into three small v1 hooks for the tree=true accumulator and the v1
portions of init/cleanup.  The hooks have static-inline no-op stubs in
include/linux/vmpressure.h for the !MEMCG_V1 case, so callers don't need
ifdefs.  vmpressure_prio() gets the same treatment, which means vmscan.c's
call site disappears at compile time on v2-only kernels.

The only #ifdef CONFIG_MEMCG_V1 in source remains around the v1-only
fields inside struct vmpressure itself.

Memory savings on CONFIG_MEMCG_V1=n (measured with pahole):

  struct vmpressure :  112B ->   24B
  struct mem_cgroup : 1664B -> 1536B

This split is the first step toward eventually making vmpressure
CONFIG_MEMCG_V1 only.  The v2 in-kernel socket pressure path (tree=false)
cannot be removed today immediately: PSI is not an exact replacement for
vmpressure, and switching networking socket-buffer back-off to PSI may
regress networking performance or increase memory pressure in workloads
that today rely on vmpressure's hysteresis.  The medium-term plan is to
introduce a PSI-based socket-pressure path, keep vmpressure available for
v2 behind a defconfig as an opt-out for several releases, and only then
drop the tree=false path entirely, at which point everything that remains
of the vmpressure block in mm/memcontrol-v1.c is the whole subsystem.

Link: https://lore.kernel.org/20260630112617.1198623-3-usama.arif@linux.dev
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:28 -07:00
Usama Arif a33b5c9116 mm/vmpressure: skip tree=true accounting on cgroup v2 
Patch series "mm/vmpressure: reduce CPU, memory and code overhead on
cgroup v2", v3.

The vmpressure subsystem has two distinct consumers, gated by the @tree
argument:

  tree=false : in-kernel socket pressure, consumed by TCP/SCTP. This
               is cgroup v2 only; v1 sockets read memcg->tcpmem_pressure
               instead.
  tree=true  : cgroup v1 userspace eventfd notifications via the
               memory.pressure_level / cgroup.event_control interface.
               v2 has no equivalent (userspace gets reclaim signals
               through memory.pressure / PSI, which doesn't touch
               vmpressure).

So of the four (hierarchy, tree) combinations, only two carry data that
anyone reads.  The existing early return in vmpressure() covered v1 +
tree=false; the symmetric v2 + tree=true case was falling through and
doing the full lock / accumulate / schedule_work / parent-walk dance, even
though the events list it eventually iterates is empty on cgroup v2
(vmpressure_register_event() is wired up only through the v1 cftype
"memory.pressure_level" and can't be reached from a v2 memcg).

Patch 1 extends the existing early return to also skip v2 + tree=true.  On
a v2-only host this eliminates a contended path where reclaimers can
serialize on a single global sr_lock.  bpftrace on a 176-core production
host (cgroup v2, 285 memcgs, sustained reclaim) showed ~16,200 such calls
per minute with tree = true.

Patch 2 follows up with a cleanup: it splits the v1 userspace eventfd
interface (struct vmpressure_event, the events list and its mutex, the
work_struct and its handler, the parent walk, vmpressure_register_event /
unregister_event, and vmpressure_prio) into a new mm/memcontrol-v1.c built
only when CONFIG_MEMCG_V1=y, behind small no-op stubs in the header. 
mm/vmpressure.c keeps the shared bits and the tree=false socket-pressure
path.  The size of vmpressure.c goes down to half and the code is much
more simpler.  The only #ifdef CONFIG_MEMCG_V1 remaining in source is
around the v1-only fields inside struct vmpressure itself.  Memory savings
on CONFIG_MEMCG_V1=n:
struct vmpressure : 112B -> 24B
struct mem_cgroup : 1664B -> 1536B

This split is the first step toward eventually making vmpressure
CONFIG_MEMCG_V1 only.  The v2 in-kernel socket pressure path (tree=false)
cannot be removed today immediately: PSI is not an exact replacement for
vmpressure, and switching networking socket-buffer back-off to PSI may
regress networking performance or increase memory pressure in workloads
that today rely on vmpressure's hysteresis.  The medium-term plan is to
introduce a PSI-based socket-pressure path, keep vmpressure available for
v2 behind a defconfig as an opt-out for several releases, and only then
drop the tree=false path entirely, at which point everything that remains
in mm/memcontrol-v1.c is the whole subsystem.


This patch (of 2):

vmpressure() has two outputs gated by the @tree argument:

  @tree=false drives in-kernel socket pressure (mem_cgroup_set_
              socket_pressure), consumed by TCP/SCTP. This only
              applies on cgroup v2; on v1 socket memory is charged
              separately via tcpmem and the consumer reads
              memcg->tcpmem_pressure instead.

  @tree=true  drives userspace eventfd notifications via the v1
              memory.pressure_level / cgroup.event_control interface.
              v2 has no equivalent: userspace gets reclaim signals
              through memory.pressure (PSI), which does not touch
              vmpressure.

The existing early return covered v1 + @tree=false.  The symmetric v2 +
@tree=true case was falling through and doing the full lock / accumulate /
schedule_work / parent-walk dance for an events list that can never be
populated.  bpftrace on a 176-core production host (cgroup v2,
CONFIG_MEMCG_V1=n, 285 memcgs, sustained reclaim) showed ~16,200
@tree=true vmpressure() calls per minute.  Add an early return that skips
cgroup v2 + tree = true which avoids us doing all this work.  On a v2-only
host this also eliminates a lock contention path that can serialise
reclaimers on a single global sr_lock.

[usama.arif@linux.dev: simplify the guard]
  Link: https://lore.kernel.org/e8e1a409-48d8-4fa7-ae98-49485a1607f6@linux.dev
Link: https://lore.kernel.org/20260630112617.1198623-1-usama.arif@linux.dev
Link: https://lore.kernel.org/20260630112617.1198623-2-usama.arif@linux.dev
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.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: Michal Koutný <mkoutny@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:28 -07:00
Wentao Guan bd1e4c4aa4 mm/hugetlb: avoid unnecessary TLB flush for empty folio list in vmemmap optimize 
Since 79359d6d24 ("hugetlb: perform vmemmap optimization on a list of
pages") __hugetlb_vmemmap_optimize_folios() unconditionally issues a final
flush_tlb_all() in its out path.  However, a TLB flush must be paired with
an actual page table modification.

When the input folio list is empty, neither PMD splitting nor PTE
remapping takes place, so no page tables are modified and the flush is
pure overhead.  An empty list is reached in common paths such as
gather_bootmem_prealloc_node() on nodes without bootmem gigantic pages,
hugetlb_pages_alloc_boot_node() when no pages were allocated, and runtime
allocation failure paths in set_max_huge_pages().

Add an early return for empty lists.  This restores the basic invariant
that TLB flushes are only issued when page tables have been modified, and
it also makes the NULL hstate passed by gather_bootmem_prealloc_node() on
an empty list harmless.

Assisted-by: kimi-cli:kimi-k2.7 code
Assisted-by: Github Copilot:gpt-5.2 #Reported-by
Link: https://lore.kernel.org/20260701053422.3664813-1-guanwentao@uniontech.com
Link: https://lore.kernel.org/20260630113857.3319612-1-guanwentao@uniontech.com
Fixes: 79359d6d24 ("hugetlb: perform vmemmap optimization on a list of pages")
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Guan Wentao <guanwentao@uniontech.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:28 -07:00
JP Kobryn 9f2fd03c9b mm/page_alloc: use existing highatomic reserves on the buddy fastpath 
ALLOC_HIGHATOMIC currently provides both access to MIGRATE_HIGHATOMIC free
pages and permission to create new highatomic pageblock reserves.  This
makes it unsuitable for the fastpath.

However, the fastpath can reach rmqueue_buddy() while MIGRATE_HIGHATOMIC
reserves have free pages available.  In this situation, the allocation can
fall back to other migratetypes without trying those reserves first.

Allow high-priority non-blocking allocations to use existing
MIGRATE_HIGHATOMIC reserves on the buddy fastpath without growing them. 
First tighten the criteria for reserving pageblocks so that growth may
only occur in the slowpath.  Then allow fastpath usage by enabling
ALLOC_HIGHATOMIC when the GFP mask describes a non-blocking high-priority
allocation.  This logic has been factored out from gfp_to_alloc_flags() to
a new function gfp_to_alloc_flags_nonblocking().

A UDP receive workload was run with free MIGRATE_HIGHATOMIC pageblocks
available in the target zone.  Before this patch, the workload did not
consume these blocks.  With this patch, eligible order-1 allocations
reaching the buddy path consumed existing MIGRATE_HIGHATOMIC pageblocks,
with no highatomic misses observed.  The workload did not grow highatomic
reserves and NAPI page-frag allocations remained healthy with no failures
or order-0 fallbacks.

Link: https://lore.kernel.org/20260623004600.113347-1-jp.kobryn@linux.dev
Signed-off-by: JP Kobryn <jp.kobryn@linux.dev>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Frank van der Linden <fvdl@google.com>
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: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:28 -07:00
SJ Park 6028a90f33 mm/damon/sysfs: fix typos in probe_{add,rm}_dirs: s/attr/probe/ 
damon_sysfs_probe_{add,rm}_dirs names a variable for damon_sysf_probe as
'attr'.  Probably a trivial copy-pasta error, but it makes the code not
pleasant to read.  Fix those.

Link: https://lore.kernel.org/20260630141726.92246-12-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
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: 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>
 2026-07-30 19:40:27 -07:00
SJ Park ea0e5f5786 mm/damon/sysfs: split out filters setup function 
damon_sysfs_set_probe() is doing not only probe setup but also filters
setup.  Split out filters setup for readability.

Link: https://lore.kernel.org/20260630141726.92246-11-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
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: 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>
 2026-07-30 19:40:27 -07:00
SJ Park 8c02207a06 mm/damon/sysfs: split probe setup function out 
damon_sysfs_set_probes() function is relatively long.  It has two nested
loop for setting two nested entities, namely probe and filter.  Split out
the probe level setup for readability.

Link: https://lore.kernel.org/20260630141726.92246-10-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
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: 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>
 2026-07-30 19:40:27 -07:00
SJ Park 97ae89aa9f mm/damon/core: reduce range setup in damon_commit_target_regions() 
damon_commit_target_regions() calls damon_set_regions() for updating the
destination target's monitoring target region boundaries.  It sets the
boundaries same to source target's monitoring regions, even if they are
adjacent.  Meanwhile, damon_set_region() sets the destination target
regions exactly the same to the source, only when the target regions are
empty.  When there are existing target regions, only a few regions are
expanded or shrunk to fit on only the boundaries for disjoint regions in
the source.  Hence the adjacent source ranges mean nothing in common
cases.  When there are many regions, such adjacent range setup is only a
waste of time and space.  We recently found [1] it is actually causing
memory overhead.  Setup the ranges for only distinct ranges.

Link: https://lore.kernel.org/20260630141726.92246-9-sj@kernel.org
Link: https://lore.kernel.org/20260603112306.58490-1-akinobu.mita@gmail.com [1]
Signed-off-by: SJ Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
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: 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>
 2026-07-30 19:40:27 -07:00
SJ Park 8fa52376da selftests/damon/sysfs.sh: test all files in quota goal dir 
DAMON sysfs interface for DAMOS quota has quite extended since its initial
introduction.  The test case for that in DAMON sysfs interface essential
file operations test (sysfs.sh) has not accordingly extended, though. 
Extend the test case to test all existing files.

Link: https://lore.kernel.org/20260630141726.92246-8-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
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: 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>
 2026-07-30 19:40:26 -07:00
SJ Park 01ff35b160 selftests/damon/sysfs.sh: test dests dir 
DAMON selftest interface essential file operations test (sysfs.sh) is not
testing DAMOS dests/ directory.  Add the test.

Link: https://lore.kernel.org/20260630141726.92246-7-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
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: 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>
 2026-07-30 19:40:26 -07:00
SJ Park 7acb8fafc1 selftests/damon/sysfs.sh: test {core,ops}_filters/ directories 
DAMON sysfs interface essential file operations test (sysf.sh) is not
testing DAMOS {core,ops}_filters directories.  Add the tests.

Link: https://lore.kernel.org/20260630141726.92246-6-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
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: 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>
 2026-07-30 19:40:26 -07:00
SJ Park 1dfb454ea5 selftests/damon/sysfs.sh: test multiple probe dirs creation 
DAMON sysfs essential file operations test (sysfs.sh) was extended to test
DAMON probes sysfs directory, by commit 14885da09b
("selftests/damon/sysfs.sh: test probes dir").  Unlike other DAMON sysfs
files, it is testing only a single directory case.  Extend it for multiple
directories.

Link: https://lore.kernel.org/20260630141726.92246-5-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
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: 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>
 2026-07-30 19:40:26 -07:00
SJ Park 5b3c43405a mm/damon/tests/core-kunit: test damon_rand() 
Commit 9012c4e647 ("mm/damon: replace damon_rand() with a per-ctx
lockless PRNG") optimized DAMON for better performance.  Add a kunit test
for ensuring the bounds of the output.

Link: https://lore.kernel.org/20260630141726.92246-4-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
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: 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>
 2026-07-30 19:40:25 -07:00
SJ Park fb6e06631d Docs/ABI/damon: document probe files 
DAMON ABI document is not updated for the DAMON probe sysfs files. 
Update.

Link: https://lore.kernel.org/20260630141726.92246-3-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
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: 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>
 2026-07-30 19:40:25 -07:00
SJ Park 6eceb61256 Docs/mm/damon/design: update for DAMOS_QUOTA_NODE_ELIGIBLE_MEM_BP 
Patch series "mm/damon: update, optimize, and clean up doc, tests, and
code".

Patches 1 and 2 update the design and ABI documents for recently added
DAMON features.  Patches 3-7 add or update more unit and self tests for
DAMON to cover recently changed or added functions and sysfs files.  Patch
8 optimizes damon_commit_target_regions() to skip unnecessary adjacent
ranges setup.  Patches 9-11 clean and fix up recently added DAMON sysfs
interface code for readability.


This patch (of 11):

Commit 9138e27a3b ("mm/damon: add node_eligible_mem_bp goal metric")
introduced DAMOS_QUOTA_NODE_ELIGIBLE_MEM_BP but forgot updating the DAMON
design document for that.  Update.

Link: https://lore.kernel.org/20260630141726.92246-1-sj@kernel.org
Link: https://lore.kernel.org/20260630141726.92246-2-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
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: SeongJae Park <sj@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>
 2026-07-30 19:40:25 -07:00
Usama Arif d547b10017 mm: rename ARCH_ENABLE_THP_MIGRATION to ARCH_HAS_PMD_SOFTLEAVES 
CONFIG_ARCH_ENABLE_THP_MIGRATION gates PMD-level migration entries. 
PMD-level device-private entries use the same migration mechanism and
therefore require the same architecture support.

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

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

No functional change intended.

Link: https://lore.kernel.org/20260706114320.1643046-7-usama.arif@linux.dev
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Kiryl Shutsemau <kas@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:25 -07:00
Usama Arif 1f5a3d1afa mm/migrate_device: move softleaf_to_folio() inside device-private branch 
migrate_vma_collect_pmd() calls softleaf_to_folio() on a non-present PMD
before checking the entry's type.  softleaf_to_folio() converts the
entry's offset to a PFN, which is only meaningful for migration or
device-private entries.

A PMD swap entry's offset is a swap offset, not a PFN, so the lookup would
either return a bogus folio pointer or trip pfn_to_page validation on a
debug kernel.  In the non-device-private path the returned folio is then
unused (the OR short-circuits to migrate_vma_collect_skip()), but the
lookup itself is already unsafe.

Move the softleaf_to_folio() call inside the device-private branch where
the folio is actually needed, mirroring the equivalent
change_non_present_huge_pmd() fix.

Link: https://lore.kernel.org/20260706114320.1643046-6-usama.arif@linux.dev
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Kiryl Shutsemau <kas@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:24 -07:00
Usama Arif a6c30b073f mm/huge_memory: move softleaf_to_folio() inside migration branch 
change_non_present_huge_pmd() calls softleaf_to_folio() unconditionally at
the top of the function.  softleaf_to_folio() extracts a PFN from the
entry and converts it to a folio pointer, which is only meaningful for
migration and device_private entries that encode a real PFN.

A swap entry encodes a swap offset instead, so softleaf_to_folio() would
produce a bogus pointer and crash on mprotect() when a PMD swap entry is
present.

Move the call into the migration_write branch where the folio is actually
used, so the function is safe for any non-present PMD type.

Link: https://lore.kernel.org/20260706114320.1643046-5-usama.arif@linux.dev
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Kiryl Shutsemau <kas@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:24 -07:00
Usama Arif eecd06034b fs/proc: use softleaf_has_pfn() in pagemap PMD walker 
pagemap_pmd_range_thp() assumes that every non-present PMD is a migration
entry and unconditionally calls softleaf_to_page().  This will crash on
any non-present PMD type that does not encode a PFN, such as the upcoming
PMD-level swap entries.

Guard the page lookup with softleaf_has_pfn(), matching how
pte_to_pagemap_entry() already handles non-present PTEs.

Link: https://lore.kernel.org/20260706114320.1643046-4-usama.arif@linux.dev
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Kiryl Shutsemau <kas@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:24 -07:00
Usama Arif b707057443 mm: extract mm_prepare_for_swap_entries() helper 
When a swap entry is installed in a page table, the mm must be added to
init_mm.mmlist so that swapoff can find and unuse its swap entries.  This
double-checked locking pattern is currently open-coded in
try_to_unmap_one() and copy_nonpresent_pte().

Move it into mm_prepare_for_swap_entries() in mm/internal.h and convert
both callers so it can be reused by upcoming PMD-level swap entry code
paths that also need to register the mm with swapoff.

copy_nonpresent_pte() previously inserted into &src_mm->mmlist rather than
&init_mm.mmlist, but the insertion point is irrelevant, mmlist is a
circular list and swapoff walks it entirely from init_mm.mmlist, so only
membership matters, not position.

Link: https://lore.kernel.org/20260706114320.1643046-3-usama.arif@linux.dev
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Kiryl Shutsemau <kas@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:23 -07:00
Usama Arif 608c745597 mm: add softleaf_to_pmd() and convert existing callers 
Patch series "mm: preparatory patches for PMD level swap entries", v2.

This is the preparatory part of the PMD page table swapin work.  The full
PMD swap entry series has been split into two parts:

  1. this preparatory series, which contains the first 6 patches. Zi [1]
     and Lance [2] suggested to separate this out from the core series.
  2. the PMD swap entry core series, which depends on this one. I will
     send this once the preparatory series is merged in mm-new as v3
     as the combined is currently at v2 [1].
     I have not marked this prep series as v3, as its not really adding
     support for PMD swap entries.

This series does not introduce PMD swap entries and does not install any
new page-table entry type.  It only cleans up existing PMD softleaf
helpers and call sites so the follow-up PMD swap entry series can be
smaller and easier to review.

It should be safe to merge independently.  The patches are either helper
additions, refactors of existing open-coded logic, defensive checks that
preserve current migration/device-private behavior, or a mechanical rename
of the PMD softleaf Kconfig gate.  The follow-up series depends on these
helpers, but this series does not depend on the follow-up series.

Patch breakdown:

  1. mm: add softleaf_to_pmd() and convert existing callers
     Add the PMD counterpart to softleaf_to_pte() and convert existing
     swp_entry_to_pmd() users that are constructing PMD softleaf
     entries.

  2. mm: extract mm_prepare_for_swap_entries() helper
     Hoist the "register mm with swapoff" double-checked-locking
     pattern out of try_to_unmap_one() and copy_nonpresent_pte() so
     future PMD-level users do not need another open-coded copy.

  3. fs/proc: use softleaf_has_pfn() in pagemap PMD walker
     Avoid assuming every non-present PMD softleaf entry encodes a PFN.
     Existing migration/device-private behavior is preserved.

  4. mm/huge_memory: move softleaf_to_folio() inside migration branch
     Keep the folio lookup in change_non_present_huge_pmd() scoped to
     the migration-entry branch that actually needs it.

  5. mm/migrate_device: move softleaf_to_folio() inside device-private
     branch
     Apply the same ordering cleanup to migrate_vma_collect_pmd(): only
     derive a folio after confirming the PMD entry is device-private.

  6. mm: rename ARCH_ENABLE_THP_MIGRATION to ARCH_HAS_PMD_SOFTLEAVES
     Rename the architecture gate to describe what it actually enables:
     PMD softleaf entries.  Migration remains the only current user in
     this series; the follow-up series adds PMD swap entries.


This patch (of 6):

Add softleaf_to_pmd() as the PMD counterpart to softleaf_to_pte(),
completing the symmetry of the softleaf abstraction for page table leaf
entries.

The upcoming PMD swap entry support needs to construct PMD entries from
swap entries.  Converting existing swp_entry_to_pmd() callers to
softleaf_to_pmd() in a prep patch keeps the feature patches focused on new
functionality rather than mixing refactoring with new code.

Link: https://lore.kernel.org/20260706114320.1643046-1-usama.arif@linux.dev
Link: https://lore.kernel.org/20260706114320.1643046-2-usama.arif@linux.dev
Link: https://lore.kernel.org/all/6E99CC4E-A026-4DE3-8A5A-34216771F521@nvidia.com/ [1]
Link: https://lore.kernel.org/all/b08cafbb-a4b7-4609-84ae-dbb2cfcfc8be@linux.dev/#t [2]
Link: https://lore.kernel.org/all/20260602142537.198755-1-usama.arif@linux.dev/ [3]
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Kiryl Shutsemau <kas@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:23 -07:00
Baolin Wang afa433c327 mm: vmscan: remove the redundant FOLIOREF_RECLAIM_CLEAN logic 
folio_check_references() will return FOLIOREF_RECLAIM_CLEAN for referenced
file folios, indicating that we can proceed to reclaim clean file folios
or keep them if they are dirty file folios.  However, after commit
6b0dfabb35 ("fs: Remove aops->writepage"), we no longer attempt to write
back filesystem folios through reclaim.  Instead, we always activate dirty
file folios and wakeup the flush workers to write them back.  As a result,
the FOLIOREF_RECLAIM_CLEAN logic is now redundant: for dirty file folios,
we will no longer reach the 'references == FOLIOREF_RECLAIM_CLEAN' branch
in shrink_folio_list().

Additionally, lazyfree folios are also placed on the file LRU list, but if
a lazyfree folio becomes dirty, try_to_unmap() will fail and thus prevent
reclaim of the re-dirtied lazyfree folios.

Therefore, we can drop the FOLIOREF_RECLAIM_CLEAN-related logic.

Link: https://lore.kernel.org/def70a713e10bcbdf3b9fccc2139ecc07b64f2cb.1782715791.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:23 -07:00
Jiayuan Chen 6958d08e3a mm/damon/tests/core-kunit: test split above max_nr_regions/2 
Add a test that exercises kdamond_split_regions() when the total region
count is already above max_nr_regions / 2, asserting that the function
still splits a fraction of the regions (makes progress) and does not
overshoot max_nr_regions.

The region size and min_region_sz are picked so the split arithmetic does
not depend on the page size.

All tests pass:
  damon: pass:31 fail:0 skip:0 total:31
  Totals: pass:31 fail:0 skip:0 total:31

Link: https://lore.kernel.org/20260626085851.70754-3-jiayuan.chen@linux.dev
Link: https://lore.kernel.org/20260629145630.134891-3-sj@kernel.org
Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com>
Signed-off-by: SJ Park <sj@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: Shu Anzai <shu17az@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:23 -07:00
Jiayuan Chen 1a582e6e01 mm/damon/core: split a fraction of regions when nr_regions exceeds max/2 
Patch series "mm/damon/core: detect internal variation above
max_nr_regions/2", v3.

kdamond_split_regions() bails out early when nr_regions is already above
max_nr_regions / 2.  A large region that picks up new internal variation
after that point never gets split, so we lose visibility into its hot/cold
structure.

We hit this with damon-paddr on hugepage workloads and damon-vaddr on
processes that mmap a large anonymous range.

Example with max_nr_regions == 1500.  A target ends up with 799 small
hot/cold regions plus one big region (an earlier merge collapsed a
uniformly-accessed range into a single piece):

H:hot
C:cold

      r1     r2     r3                 r800
    HHHHHH|CCCCCC|HHHHHH|...|HHHHHH..........................|

    nr_regions = 800  >  max_nr_regions / 2 = 750

Now a cold subarea shows up inside r800:

      r1     r2     r3                 r800
    HHHHHH|CCCCCC|HHHHHH|...|HHHHHH........CCCCCC.............|

The small regions can't merge with each other (their access counts
differ), so budget never frees up.  r800 can't be split because nr_regions
> max_nr_regions / 2 returns early.  The cold subarea stays invisible.

Patch 1 keeps refining on this path: when nr_regions is above
max_nr_regions / 2 but still under the maximum, it splits a fraction of
the regions instead of returning.  The fraction shrinks as the remaining
budget shrinks, so the count approaches max_nr_regions smoothly.  A
useless split is undone by the next merge cycle.

Patch 2 adds a KUnit test for the case where nr_regions is already above
max_nr_regions / 2.

Thanks to SJ for the suggestion to drive the split fraction from the
remaining budget rather than an age-based filter.


This patch (of 2):

kdamond_split_regions() returns early when nr_regions is above
max_nr_regions / 2, leaving internal access variation inside a large
region undetected.

Such a layout is common with damon-paddr on hugepage workloads or
damon-vaddr on processes with a large anonymous mmap.

For example, with max_nr_regions == 1500, a target may end up with 799
small alternating-temperature regions plus one large region that absorbed
a uniformly-accessed range during an earlier merge:

H:hot
C:cold

      r1     r2     r3                 r800
    HHHHHH|CCCCCC|HHHHHH|...|HHHHHH..........................|

    nr_regions = 800  >  max_nr_regions / 2 = 750

If a cold subarea later emerges inside r800:

      r1     r2     r3                 r800
    HHHHHH|CCCCCC|HHHHHH|...|HHHHHH........CCCCCC.............|

The small regions cannot merge with each other (different access counts),
so the budget stays full.  r800 cannot be split because nr_regions >
max_nr_regions / 2 causes an early return.  The cold subarea is never
discovered.

When nr_regions is above max_nr_regions / 2 but still under the maximum,
split only a fraction of the regions instead of returning.  One region in
every 'max_nr_regions / budget' regions is split, where budget is the
remaining room (max_nr_regions - nr_regions), starting from a rotating
offset so different regions get picked over time.  The fraction shrinks as
the budget shrinks, so the region count keeps refining while approaching
max_nr_regions smoothly rather than overshooting it.  An unnecessary split
is reverted by the next kdamond_merge_regions().

Link: https://lore.kernel.org/20260629145630.134891-1-sj@kernel.org
Link: https://lore.kernel.org/20260626085851.70754-2-jiayuan.chen@linux.dev
Link: https://lore.kernel.org/20260629145630.134891-2-sj@kernel.org
Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com>
Signed-off-by: SJ Park <sj@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: Shu Anzai <shu17az@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:22 -07:00
Sailesh Nandanavanam bafe4dbbd5 mm/damon/tests/core-kunit: add KUnit test for walk_control_obsolete behavior 
Add a KUnit test to verify that damos_walk() rejects new requests when
walk_control_obsolete is set.

Commit 33c3f6c2b4 ("mm/damon/core: fix damos_walk() vs kdamond_fn() exit
race") introduced walk_control_obsolete to prevent a race condition where
new requests could be registered during kdamond shutdown and never
handled.

This test simulates the shutdown condition by setting
walk_control_obsolete and verifies that damos_walk() returns -ECANCELED
immediately.

This validates the invariant introduced by the fix and helps prevent
regressions.

Link: https://patch.msgid.link/20260612062337.2459-1-saileshnandanavanam@gmail.com
Link: https://lore.kernel.org/20260629145538.134832-6-sj@kernel.org
Suggested-by: SJ Park <sj@kernel.org>
Signed-off-by: Sailesh Nandanavanam <saileshnandanavanam@gmail.com>
Signed-off-by: SJ Park <sj@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Asier Gutierrez <gutierrez.asier@huawei-partners.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Doehyun Baek <doehyunbaek@gmail.com>
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: Philippe Laferriere <plafer@proton.me>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:22 -07:00
Asier Gutierrez 2ab5ed1c2b samples/damon: fix typos in Kconfig help text 
Fix a couple  of typos in samples/damon/Kconfig help text. Change "Thps"
to "This", and "tierign" to "tiering".

Link: https://lore.kernel.org/20260629145538.134832-5-sj@kernel.org
Signed-off-by: Asier Gutierrez <gutierrez.asier@huawei-partners.com>
Signed-off-by: SJ Park <sj@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Doehyun Baek <doehyunbaek@gmail.com>
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: Philippe Laferriere <plafer@proton.me>
Cc: Sailesh Nandanavanam <saileshnandanavanam@gmail.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:22 -07:00
Doehyun Baek 914a458277 Docs/{admin-guide,mm}/damon: fix DAMON documentation details 
Fix minor DAMON documentation issues.  Correct the sysfs scheme file name
apply_interval_us, the DAMON_STAT module count, a malformed reference, a
misplaced label indentation, and a few typos.

Link: https://lore.kernel.org/20260629145538.134832-4-sj@kernel.org
Signed-off-by: Doehyun Baek <doehyunbaek@gmail.com>
Signed-off-by: SJ Park <sj@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: "Liam R. Howlett" <liam@infradead.org>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Asier Gutierrez <gutierrez.asier@huawei-partners.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: Philippe Laferriere <plafer@proton.me>
Cc: Sailesh Nandanavanam <saileshnandanavanam@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:22 -07:00
Philippe Laferriere e214b3d81a mm/damon/stat: use secs_to_jiffies() instead of msecs_to_jiffies() 
The conversion of a duration expressed in seconds reads as
msecs_to_jiffies(5 * MSEC_PER_SEC), which obscures the intent and
needlessly goes through milliseconds.  Use the dedicated secs_to_jiffies()
helper, which expresses the 5-second refresh interval directly.  No
functional change.

Found using Coccinelle (scripts/coccinelle/misc/secs_to_jiffies.cocci).

Link: https://lore.kernel.org/20260629145538.134832-3-sj@kernel.org
Signed-off-by: Philippe Laferriere <plafer@proton.me>
Signed-off-by: SJ Park <sj@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Asier Gutierrez <gutierrez.asier@huawei-partners.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Doehyun Baek <doehyunbaek@gmail.com>
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: Sailesh Nandanavanam <saileshnandanavanam@gmail.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:21 -07:00
Akinobu Mita 2817eaec9c mm/damon/core: use kvmalloc for target regions array 
Patch series "mm/damon: five misc fixups"

Five patches for miscellaneous DAMON fixups.  Use better fit kernel
functions, cleanup/fixup documents, and add unit tests.

The five patches were initially sent and revisioned by different
individuals.  Each patch contains changelog on their commentary area.  The
patches are curated into this series by SJ, for the convenience in
reposting.


This patch (of 5):

damon_commit_target_regions() temporarily allocates a single contiguous
memory region using kmalloc to store copies of all damon_regions of the
damon_target.  However, if the damon_target has a large number of
damon_regions, the total size may exceed KMALLOC_MAX_SIZE.

This problem can be avoided by using kvmalloc instead of kmalloc.

Link: https://lore.kernel.org/20260629145538.134832-1-sj@kernel.org
Link: https://lore.kernel.org/20260629145538.134832-2-sj@kernel.org
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: SJ Park <sj@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
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>
Cc: Asier Gutierrez <gutierrez.asier@huawei-partners.com>
Cc: Doehyun Baek <doehyunbaek@gmail.com>
Cc: Philippe Laferriere <plafer@proton.me>
Cc: Sailesh Nandanavanam <saileshnandanavanam@gmail.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-30 19:40:21 -07:00
Ruslan Valiyev 99cea7eb52 selftests/damon/sysfs_refresh: test kdamond refresh_ms 
Writing a non-zero value to a kdamond's 'refresh_ms' sysfs file should
make DAMON periodically update the read-only sysfs files on its own,
without the user writing update keywords such as 'update_schemes_stats' to
the 'state' file.  This behavior has no test coverage.

Add a test that starts a kdamond with refresh_ms set and a 'stat' scheme
whose default access pattern matches every monitored region, then polls
the scheme's 'nr_tried' stats file directly, without requesting an update.
The value can become non-zero only via the periodic refresh, so the test
confirms refresh_ms works; with refresh_ms disabled the stat stays zero
and the test fails.

Link: https://lore.kernel.org/20260602131217.2210912-3-linuxoid@gmail.com
Link: https://lore.kernel.org/20260629144927.134237-3-sj@kernel.org
Signed-off-by: Ruslan Valiyev <linuxoid@gmail.com>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: SJ Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-28 21:12:11 -07:00
Ruslan Valiyev b1c254e60b selftests/damon/_damon_sysfs: support kdamond refresh_ms 
Patch series "selftests/damon: test kdamond refresh_ms", v2.

The kdamond 'refresh_ms' sysfs file makes DAMON periodically update its
read-only sysfs files (DAMOS stats, tuned monitoring intervals and the
kdamond pid) on its own, so users don't have to write update keywords such
as 'update_schemes_stats' to the 'state' file.  It has no selftest
coverage.

The first patch adds refresh_ms support to the _damon_sysfs.py test
control module.  The second adds a test that sets refresh_ms and confirms
a scheme's stats are updated under sysfs without an explicit update
request; the test skips on kernels that predate the refresh_ms file.

Tested on current mainline under a DAMON-enabled kernel: the new test
passes and the existing DAMON selftests show no new failures.


This patch (of 2):

The Kdamond class has no way to set the kdamond-level 'refresh_ms' sysfs
file, which makes DAMON periodically update the read-only sysfs files
(DAMOS stats, tuned monitoring intervals and the kdamond pid) on its own.

Add a 'refresh_ms' parameter to Kdamond.  When it is set (including to
zero, to disable the periodic update), write it before turning the kdamond
on, so tests can exercise the auto-update behavior.  Leaving it unset
keeps the previous behavior of not touching the file, so callers running
against kernels without the feature are unaffected.

Link: https://lore.kernel.org/20260602131217.2210912-2-linuxoid@gmail.com
Link: https://lore.kernel.org/20260629144927.134237-2-sj@kernel.org
Signed-off-by: Ruslan Valiyev <linuxoid@gmail.com>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: SJ Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-28 21:12:11 -07:00
Cheng Nie 9b413dff81 selftests/damon/sysfs.py: validate memcg_path staging readback 
Add a dedicated test at the end of main() that stages memcg_path via sysfs
and verifies its readback.  Configure the memcg filter before start(), do
not call commit(), and ignore start() failures so the test does not depend
on CONFIG_MEMCG or cgroup layout.  Call stop() for cleanup without
checking its return value.

Link: https://lore.kernel.org/D2B37130D38E09AC+20260601090634.241864-1-niecheng1@uniontech.com
Link: https://lore.kernel.org/20260629144812.134159-3-sj@kernel.org
Signed-off-by: Cheng Nie <niecheng1@uniontech.com>
Signed-off-by: SJ Park <sj@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-28 21:12:11 -07:00
Cheng Nie 477e99645f selftests/damon/_damon_sysfs.py: fix memcg_path assignment 
Patch series "selftests/damon: fix memcg_path staging handling", v5.

Fix a bug in _damon_sysfs.py for damos_filter memcg_path setup, and add
a test case of it in sysfs.py.


This patch (of 2):

DamosFilter stores memcg_path for sysfs staging, but the constructor
assigns it with a trailing comma and therefore turns it into a tuple.

Fix the assignment so memcg_path is stored as the intended string.  This
makes memcg filter staging and follow-up validation use the written path
correctly.

Link: https://lore.kernel.org/20260629144812.134159-1-sj@kernel.org
Link: https://lore.kernel.org/464AE12D4BC6B6F4+20260601090519.240482-1-niecheng1@uniontech.com
Link: https://lore.kernel.org/20260629144812.134159-2-sj@kernel.org
Signed-off-by: Cheng Nie <niecheng1@uniontech.com>
Signed-off-by: SJ Park <sj@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-28 21:12:11 -07:00
Kunwu Chan 0185159faf selftests/damon: fix dead code, skipped checks, and broken lookups 
'hugeapge_size' in drgn_dump_damon_status.py was a dead elif branch. 
$fail_reason in sysfs.sh was undefined, silently emptying the error
message.  'exit' instead of 'exist' in sysfs.sh skipped a file existence
check.  'nohugeapge' in sysfs.py broke an action dict lookup.

Fix other wrong strings in the same files.

Link: https://lore.kernel.org/20260601032314.424013-4-kunwu.chan@linux.dev
Link: https://lore.kernel.org/20260629144648.134092-4-sj@kernel.org
Co-developed-by: Wang Lian <lianux.mm@gmail.com>
Signed-off-by: Wang Lian <lianux.mm@gmail.com>
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: SJ Park <sj@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: Kunwu Chan <chentao@kylinos.cn>
Cc: Wang Lian <lianux.mm@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-28 21:12:10 -07:00
Kunwu Chan 9ad3a4dbbc selftests/damon/damos_tried_regions: fix expectation output and join TypeError 
The expectation print has wrong operator precedence: '%' binds before the
conditional expression, so the else branch prints 'not met' without the
prefix 'expectation (>= 14) is'.  Add parentheses to fix it.

Also, '\n'.join() on the list of ints raises TypeError; convert to str in
the list comprehension.

Link: https://lore.kernel.org/20260601032314.424013-3-kunwu.chan@linux.dev
Link: https://lore.kernel.org/20260629144648.134092-3-sj@kernel.org
Co-developed-by: Wang Lian <lianux.mm@gmail.com>
Signed-off-by: Wang Lian <lianux.mm@gmail.com>
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: SJ Park <sj@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: Kunwu Chan <chentao@kylinos.cn>
Cc: Wang Lian <lianux.mm@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-28 21:12:10 -07:00
Kunwu Chan 8319dadcbd selftests/damon: prevent cross-context state pollution in DamonCtx 
Patch series "selftests/damon: misc fixes for test bugs", v3.

This series fixes several bugs in the DAMON selftests.  Most are trivial
but makes test output wrong or even silently pass the one test case for
'avail_operation' file existence check.

Patch 1 fixes mutable default arguments in DamonCtx.__init__() that cause
state to leak between test instances.

Patch 2 fixes wrong operator precedence and join TypeError in
damos_tried_regions.py.

Patch 3 fixes several wrong strings that produce dead elif branches,
skipped file existence checks, and broken dict key lookups.


This patch (of 3):

DamonCtx.__init__() uses mutable default values for monitoring_attrs,
targets, and schemes.  In Python these are evaluated once at function
definition time, so multiple DamonCtx instances can unintentionally share
the same lists and DamonAttrs instance.

Replace the mutable defaults with None sentinels and initialize the
objects when needed.

Link: https://lore.kernel.org/20260629144648.134092-1-sj@kernel.org
Link: https://lore.kernel.org/20260601032314.424013-2-kunwu.chan@linux.dev
Link: https://lore.kernel.org/20260629144648.134092-2-sj@kernel.org
Co-developed-by: Wang Lian <lianux.mm@gmail.com>
Signed-off-by: Wang Lian <lianux.mm@gmail.com>
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: SJ Park <sj@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: Kunwu Chan <chentao@kylinos.cn>
Cc: Wang Lian <lianux.mm@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-28 21:12:10 -07:00
David Hildenbrand (Arm) d045e8a05d mm: cleanup clear_not_present_full_ptes() and rename to clear_non_present_ptes() 
Let's clean it up a bit:

(1) There is no need to pass "full" anymore.

(2) No architecture overwrites it, and there isn't really a good reason
    to do so when dealing with non-present PTEs.

(3) While at it, call it "non-present", similar to copy_nonpresent_pte()
    and zap_nonpresent_ptes().

It's a shame that we have clear_non_present_ptes() correspond to
pte_clear() and clear_ptes() correspond to ptep_get_and_clear*().

Link: https://lore.kernel.org/20260629-clear_not_present_full_ptes-v2-3-96089871a1e7@kernel.org
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Oscar Salvador (SUSE) <osalvador@kernel.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jann Horn <jannh@google.com>
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: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-28 21:12:10 -07:00
David Hildenbrand (Arm) ef68364cd7 mm: drop pte_clear_not_present_full() 
In general, there is no good reason to do anything special when clearing
non-present PTEs.

In theory, HW that does have to invalidate TLBs for non-present PTEs could
benefit from a "full" parameter, but fortunately
pte_clear_not_present_full() is not wired up anymore ...  and there would
have to be something very convincing for us to care about that to re-add
it.

So, let's just use pte_clear() directly now.  To prevent the compiler
complaining on some configs about "set but not used" addr parameter,
silence that here.

Link: https://lore.kernel.org/20260629-clear_not_present_full_ptes-v2-2-96089871a1e7@kernel.org
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Oscar Salvador (SUSE) <osalvador@kernel.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jann Horn <jannh@google.com>
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: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-28 21:12:09 -07:00
David Hildenbrand (Arm) a71638ecc6 sparc/mm: drop custom pte_clear_not_present_full() 
Patch series "mm: cleanup clear_not_present_full_ptes()", v2.

While doing some review, I stumbled over clear_not_present_full_ptes() and
concluded that it needs some love.

Let's remove pte_clear_not_present_full() and cleanup
clear_not_present_full_ptes(), renaming it to clear_non_present_ptes().


This patch (of 3):

On sparc64, pte_clear_not_present_full() nowadays does a simple
__set_pte_at().  In __set_pte_at() -> maybe_tlb_batch_add(), we check
pte_accessible() to see whether to call tlb_batch_add().

However, non-present PTEs are surely not accessible, so tlb_batch_add() is
never called and the "full" parameter is irrelevant.

Let's drop the helper and just let common code do a pte_clear().

pte_clear() on sparc64 maps to set_pte_at()->set_ptes()->__set_pte_at()
... so it ends up calling the same function, just with "full=0".

Given that "full" is irrelevant, there is no change.

We added pte_clear_not_present_full() for sparc64 in commit 90f08e399d
("sparc: mmu_gather rework"), and I suspect that it was already not
required back then.

Link: https://lore.kernel.org/20260629-clear_not_present_full_ptes-v2-0-96089871a1e7@kernel.org
Link: https://lore.kernel.org/20260629-clear_not_present_full_ptes-v2-1-96089871a1e7@kernel.org
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jann Horn <jannh@google.com>
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: Oscar Salvador (SUSE) <osalvador@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-28 21:12:09 -07:00
SJ Park 5f0ead7e66 mm/damon/sysfs-schemes: kobject_del() region for populate_region error 
On CONFIG_DEBUG_KOBJECT_RELEASE enabled kernel, lack of kobject_del()
could cause directories creation failures due to the name conflicts.  Fix
the issue for tried region directories in the error handling path of
damon_sysfs_populate_region_dir() by adding a kobject_del() call.

Link: https://lore.kernel.org/20260628220121.97360-12-sj@kernel.org
Fixes: b574a82d10 ("mm/damon/sysfs-schemes: implement tried_regions/<r>/probes/")
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-28 21:12:09 -07:00
SJ Park f5b4541b85 mm/damon/sysfs: kobject_del() probe dirs in probes_addd_dir error path 
On CONFIG_DEBUG_KOBJECT_RELEASE enabled kernel, lack of kobject_del()
could cause directories creation failures due to the name conflicts.  Fix
the issue for data attribute probe filter directories in the error
handling path of damon_sysfs_probes_add_dirs() by adding a kobject_del()
call.

Link: https://lore.kernel.org/20260628220121.97360-11-sj@kernel.org
Fixes: af7cb41af9 ("mm/damon/sysfs: implement filters directory")
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-28 21:12:09 -07:00
SJ Park 092a336674 mm/damon/sysfs: kobject_del() probe filter dirs 
On CONFIG_DEBUG_KOBJECT_RELEASE enabled kernel, lack of kobject_del()
could cause directories creation failures due to the name conflicts.  Fix
those issues for data attribute probe filter directories by adding
kobject_del() calls.

Link: https://lore.kernel.org/20260628220121.97360-10-sj@kernel.org
Fixes: 82e66aef7714 ("mm/damon/sysfs: implement filter dir")
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-28 21:12:08 -07:00
SJ Park c37dfd6982 mm/damon/sysfs: kobject_del() probe dirs 
On CONFIG_DEBUG_KOBJECT_RELEASE enabled kernel, lack of kobject_del()
could cause directories creation failures due to the name conflicts.  Fix
those issues for data attribute probe directories by adding kobject_del()
calls.

Link: https://lore.kernel.org/20260628220121.97360-9-sj@kernel.org
Fixes: bf3ea3d30880 ("mm/damon/sysfs: implement probe dir")
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
 2026-07-28 21:12:08 -07:00