Commit Graph

1398050 Commits

Author SHA1 Message Date
Lorenzo Stoakes
b734b9d973 mm/vma: small VMA lock cleanups
We declare vma_start_read() as a static function in mm/mmap_lock.c, so
there is no need to provide a stub for !CONFIG_PER_VMA_LOCK.

__is_vma_write_locked() is declared in a header and should therefore be
static inline.

Put parens around (refcnt & VMA_LOCK_OFFSET) in is_vma_writer_only() to
make precedence clear.

Link: https://lkml.kernel.org/r/20251024090902.1118174-1-lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Liam Howlett <liam.howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:26 -08:00
Harry Yoo
ad8b2e0961 treewide: include linux/pgalloc.h instead of asm/pgalloc.h
For now, including <asm/pgalloc.h> instead of <linux/pgalloc.h> is
technically fine unless the .c file calls p*d_populate_kernel() helper
functions.

But it is a better practice to always include <linux/pgalloc.h>.  Include
<linux/pgalloc.h> instead of <asm/pgalloc.h> outside arch/.

Link: https://lkml.kernel.org/r/20251024113047.119058-3-harry.yoo@oracle.com
Signed-off-by: Harry Yoo <harry.yoo@oracle.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:25 -08:00
Harry Yoo
5e0fa7ed98 MAINTAINERS: add include/linux/pgalloc.h to MM CORE section
Patch series "mm: MISC follow-up patches for linux/pgalloc.h", v2.

This is a follow-up patch series for the patch series named: "[PATCH V5
mm-hotfixes 0/3] mm, x86: fix crash due to missing page table sync and
make it harder to miss".


This patch (of 2):

Since include/linux/pgtable.h is already listed in the MM CORE section,
add it to the section as well to keep it maintained by the appropriate
maintainers.

Link: https://lkml.kernel.org/r/20251024113047.119058-1-harry.yoo@oracle.com
Link: https://lkml.kernel.org/r/20251024113047.119058-2-harry.yoo@oracle.com
Signed-off-by: Harry Yoo <harry.yoo@oracle.com>
Acked-by: SeongJae Park <sj@kernel.org>
Acked-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:25 -08:00
SeongJae Park
809ba69f9f selftests/damon/sysfs: add obsolete_target test
A new DAMON sysfs file for pin-point target removal, namely
obsolete_target, has been added.  Add a test for the functionality.  It
starts DAMON with three monitoring target processes, mark one in the
middle as obsolete, commit it, and confirm the internal DAMON status is
updated to remove the target in the middle.

Link: https://lkml.kernel.org/r/20251023012535.69625-10-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Bijan Tabatabai <bijan311@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:25 -08:00
SeongJae Park
65a9033db7 sysfs.py: extend assert_ctx_committed() for monitoring targets
assert_ctx_committed() is not asserting monitoring targets commitment,
since all existing callers of the function assume no target changes. 
Extend it for future usage.

Link: https://lkml.kernel.org/r/20251023012535.69625-9-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Bijan Tabatabai <bijan311@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:25 -08:00
SeongJae Park
a00f18abef drgn_dump_damon_status: dump damon_target->obsolete
A new field of damon_target for pin-point target removal, namely obsolete,
has newly been added.  Extend drgn_dump_damon_status.py to dump it, for
easily writing a future DAMON selftests of it.

Link: https://lkml.kernel.org/r/20251023012535.69625-8-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Bijan Tabatabai <bijan311@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:24 -08:00
SeongJae Park
badfa4361c selftests/damon/_damon_sysfs: support obsolete_target file
A DAMON sysfs file, namely obsolete_target, has been newly introduced. 
Add a support of that file to _damon_sysfs.py so that DAMON selftests for
the file can be easily written.

Link: https://lkml.kernel.org/r/20251023012535.69625-7-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Bijan Tabatabai <bijan311@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:24 -08:00
SeongJae Park
9abe8d0519 Docs/ABI/damon: document obsolete_target sysfs file
Update DAMON ABI document for the newly added obsolete_target DAMON sysfs
file.

Link: https://lkml.kernel.org/r/20251023012535.69625-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Bijan Tabatabai <bijan311@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:24 -08:00
SeongJae Park
e06469cdf1 Docs/admin-guide/mm/damon/usage: document obsolete_target file
Document the newly added obsolete_target DAMON sysfs file.

Link: https://lkml.kernel.org/r/20251023012535.69625-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Bijan Tabatabai <bijan311@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:24 -08:00
SeongJae Park
e35afdf228 mm/damon/sysfs: implement obsolete_target file
There is no good way to remove DAMON targets in the middle of the existing
targets list.  It restricts efficient and flexible DAMON use cases. 
Improve the usability by implementing a new DAMON sysfs interface file,
namely obsolete_target, under each target directory.  It is connected to
the obsolete field of parameters commit-source targets, so allows removing
arbitrary targets in the middle of existing targets list.

Note that the sysfs files are not automatically updated.  For example,
let's suppose there are three targets in the running context, and a user
removes the third target using this feature.  If the user writes 'commit'
to the kdamond 'state' file again, DAMON sysfs interface will again try to
remove the third target.  But because there is no matching target in the
running context, the commit will fail.  It is the user's responsibility to
understand resulting DAMON internal targets list change, and construct
sysfs files (using nr_targets and other sysfs files) to correctly
represent it.

Also note that this is arguably an improvement rather than a fix of broken
things.

Link: https://lkml.kernel.org/r/20251023012535.69625-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Reported-by: Bijan Tabatabai <bijan311@gmail.com>
Closes: https://github.com/damonitor/damo/issues/36
Reviewed-by: Bijan Tabatabai <bijan311@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:23 -08:00
SeongJae Park
60bd24f272 mm/damon/sysfs: test commit input against realistic destination
DAMON sysfs interface tests if given online parameters update request is
valid, by committing those using the DAMON kernel API, to a test-purpose
destination context.  The test-purpose destination context is constructed
using damon_new_ctx(), so it has no target, no scheme.

If a source target has the obsolete field set, the test-purpose commit
will fail because damon_commit_targets() fails when there is a source
obsolete target that cannot find its matching destination target.  DAMON
sysfs interface is not letting users set the field for now, so there is no
problem.  However, the following commit will support that.  Also there
could be similar future changes that making commit fails based on current
context structure.

Make the test purpose commit destination context similar to the current
running one, by committing the running one to the test purpose context,
before doing the real test-purpose commit.

Link: https://lkml.kernel.org/r/20251023012535.69625-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Bijan Tabatabai <bijan311@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:23 -08:00
SeongJae Park
adf7d6cdd7 mm/damon/core: add damon_target->obsolete for pin-point removal
Patch series "mm/damon: support pin-point targets removal".

DAMON maintains the targets in a list, and allows committing only an
entire list of targets having the new parameters.  Targets having same
index on the lists are treated as matching source and destination
targets.  If an existing target cannot find a matching one in the
sources list, the target is removed.  This means that there is no way to
remove only a specific monitoring target in the middle of the current
targets list.

Such pin-point target removal is really needed in some use cases,
though.  Monitoring access patterns on virtual address spaces of
processes that spawned from the same ancestor is one example.  If a
process of the group is terminated, the user may want to remove the
matching DAMON target as soon as possible, to save in-kernel memory
usage for the unnecessary target data.  The user may also want to do
that without turning DAMON off or removing unnecessary targets, to keep
the current monitoring results for other active processes.

Extend DAMON kernel API and sysfs ABI to support the pin-point removal
in the following way.  For API, add a new damon_target field, namely
'obsolete'.  If the field on parameters commit source target is set, it
means the matching destination target is obsolete.  Then the parameters
commit logic removes the destination target from the existing targets
list.  For sysfs ABI, add a new file under the target directory, namely
'obsolete_target'.  It is connected with the 'obsolete' field of the
commit source targets, so internally using the new API.

Also add a selftest for the new feature.  The related helper scripts for
manipulating the sysfs interface and dumping in-kernel DAMON status are
also extended for this.  Note that the selftest part was initially
posted as an individual RFC series [1], but now merged into this one.

Bijan Tabatabai has originally reported this issue, and participated in
this solution design on a GitHub issue [1] for DAMON user-space tool.


This patch (of 9):

DAMON's monitoring targets parameters update function,
damon_commit_targets(), is not providing a way to remove a target in the
middle of the existing targets list.  Extend the API by adding a field to
struct damon_target.  If the field of a damon_commit_targets() source
target is set, it indicates the matching target on the existing targets
list is obsolete.  damon_commit_targets() understands that and removes
those from the list, while respecting the index based matching for other
non-obsolete targets.

Link: https://lkml.kernel.org/r/20251023012535.69625-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20251023012535.69625-2-sj@kernel.org
Link: https://github.com/damonitor/damo/issues/36 [1]
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Bijan Tabatabai <bijan311@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:23 -08:00
Dmitry Ilvokhin
e97d7c5165 mm: shmem/tmpfs hugepage defaults config choice
Allow to override defaults for shemem and tmpfs at config time.  This is
consistent with how transparent hugepages can be configured.

Same results can be achieved with the existing
'transparent_hugepage_shmem' and 'transparent_hugepage_tmpfs' settings in
the kernel command line, but it is more convenient to define basic
settings at config time instead of changing kernel command line later.

Defaults for shmem and tmpfs were not changed.  They are remained the same
as before: 'never' for both cases.  Options 'deny' and 'force' are omitted
intentionally since these are special values and supposed to be used for
emergencies or testing and are not expected to be permanent ones.

Primary motivation for adding config option is to enable policy
enforcement at build time.  In large-scale production environments (Meta's
for example), the kernel configuration is often maintained centrally close
to the kernel code itself and owned by the kernel engineers, while boot
parameters are managed independently (e.g.  by provisioning systems).  In
such setups, the kernel build defines the supported and expected behavior
in a single place, but there is no reliable or uniform control over the
kernel command line options.

A build-time default allows kernel integrators to enforce a predictable
hugepage policy for shmem/tmpfs on a base layer, ensuring reproducible
behavior and avoiding configuration drift caused by possible boot-time
differences.

In short, primary benefit is mostly operational: it provides a way to
codify preferred policy in the kernel configuration, which is versioned,
reviewed, and tested as part of the kernel build process, rather than
depending on potentially variable boot parameters.

[d@ilvokhin.com: v2]
  Link: https://lkml.kernel.org/r/aQECPpjd-fU_TC79@shell.ilvokhin.com
Link: https://lkml.kernel.org/r/aPpv8sAa2sYgNu3L@shell.ilvokhin.com
Signed-off-by: Dmitry Ilvokhin <d@ilvokhin.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Kiryl Shutsemau <kas@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:23 -08:00
SeongJae Park
f46dbea0d9 Docs/admin-guide/mm/damon/stat: document negative idle time
Commit a983a26d52 ("mm/damon/stat: expose negative idle time")
introduced the negative idle time feature for DAMON_STAT.  But it is not
documented.  Document it on the usage document.

Link: https://lkml.kernel.org/r/20251026182216.118200-9-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:22 -08:00
SeongJae Park
da8644a476 Docs/admin-guide/mm/damon/stat: document aggr_interval_us parameter
Commit cc7ceb1d14 ("mm/damon/stat: expose the current tuned aggregation
interval"), has introduced 'aggr_interval_us' parameter for DAMON_STAT. 
But the new parameter is not yet documented.  Document it on the usage
document for the module.

Link: https://lkml.kernel.org/r/20251026182216.118200-8-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:22 -08:00
SeongJae Park
448666e418 Docs/admin-guide/mm/damon/lru_sort: document addr_unit parameter
Commit 2e0fe9245d ("mm/damon/lru_sort: support addr_unit for
DAMON_LRU_SORT") introduced the 'addr_unit' parameter for DAMON_LRU_SORT. 
But the usage document is not updated for that.  Update the document.

Link: https://lkml.kernel.org/r/20251026182216.118200-7-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:22 -08:00
SeongJae Park
bb01656e00 Docs/admin-guide/mm/damon/reclaim: document addr_unit parameter
Commit 7db551fcfb ("mm/damon/reclaim: support addr_unit for
DAMON_RECLAIM") introduced the 'addr_unit' parameter for DAMON_RECLAIM. 
But the usage document is not updated for that.  Update the document.

Link: https://lkml.kernel.org/r/20251026182216.118200-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:22 -08:00
SeongJae Park
29221406f0 Docs/admin-guide/mm/damon/usage: document empty target regions commit behavior
Committing a monitoring target with empty target regions is for keeping
the current monitoring results.  This behavior was introduced by commit
9732336006 ("mm/damon/sysfs: update monitoring target regions for online
input commit").  The behavior is not documented, though.  Update the usage
document for clarifying this behavior.

Link: https://lkml.kernel.org/r/20251026182216.118200-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:21 -08:00
SeongJae Park
a01386c16d Docs/admin-guide/mm/damon/stat: fix a typo: s/sampling events/sampling interval/
It is a contextual typo.  Fix it.

Link: https://lkml.kernel.org/r/20251026182216.118200-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:21 -08:00
SeongJae Park
d7484f6edd Docs/mm/damon/design: fix wrong link to intervals goal section
Commit b243d666d1 ("Docs/admin-guide/mm/damon/usage: add intervals_goal
directory on the hierarchy") mistakenly added a wrong reference for
intervals goal usage documentation on the design document.  Fix it.

Link: https://lkml.kernel.org/r/20251026182216.118200-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:21 -08:00
SeongJae Park
50ca642364 mm/damon/core: fix wrong comment of damon_call() return timing
Patch series "mm/damon: misc documentation fixups".

First three patches fix up issues in the documents, including wrong
explanation of a behavior, wrong link, and a contextual typo.  Following
five patches update documents for not yet documented features and
behaviors.


This patch (of 8):

damon_call() works asynchronously and synchronously for repeat and
non-repeat mode requests, respectively.  The comment about the behavior is
wrong, though.  Fix it.

The wrong comment was introduced together with the repeat mode, by commit
43df7676e5 ("mm/damon/core: introduce repeat mode damon_call()").

Link: https://lkml.kernel.org/r/20251026182216.118200-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20251026182216.118200-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:21 -08:00
Kairui Song
4fd58b51ef mm, swap: remove redundant argument for isolating a cluster
The order argument was introduced by an intermediate commit and was then
never used, just remove it.

Link: https://lkml.kernel.org/r/20251024-swap-clean-after-swap-table-p1-v2-5-a709469052e7@tencent.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:20 -08:00
Kairui Song
ab61de9b78 mm/migrate, swap: drop usage of folio_index
This helper was used when swap cache was mixed with page cache.  Now they
are completely separate from each other, access to the swap cache is all
wrapped by the swap_cache_* helpers, which expect the folio's swap entry
as a parameter.

This helper is no longer used, remove the last redundant user and drop it.

Link: https://lkml.kernel.org/r/20251024-swap-clean-after-swap-table-p1-v2-4-a709469052e7@tencent.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Acked-by: Chris Li <chrisl@kernel.org>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:20 -08:00
Kairui Song
a983471cfc mm, swap: cleanup swap entry allocation parameter
We no longer need this GFP parameter after commit 8578e0c00d ("mm, swap:
use the swap table for the swap cache and switch API").  Before that
commit the GFP parameter is already almost identical for all callers, so
nothing changed by that commit.  Swap table just moved the GFP to lower
layer and make it more defined and changes depend on atomic or sleep
allocation.

Now this parameter is no longer used, just remove it.  No behavior change.

Link: https://lkml.kernel.org/r/20251024-swap-clean-after-swap-table-p1-v2-3-a709469052e7@tencent.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Acked-by: Chris Li <chrisl@kernel.org>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:20 -08:00
Kairui Song
e4adea27b9 mm, swap: rename helper for setup bad slots
The name inc_cluster_info_page is very confusing, as this helper is only
used during swapon to mark bad slots.  Rename it properly and turn the
VM_BUG_ON in it into WARN_ON to expose more potential issues.  Swapon is a
cold path, so adding more checks should be a good idea.

No feature change except new WARN_ON.

Link: https://lkml.kernel.org/r/20251024-swap-clean-after-swap-table-p1-v2-2-a709469052e7@tencent.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Acked-by: Chris Li <chrisl@kernel.org>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:20 -08:00
Kairui Song
9fb749cd15 mm, swap: do not perform synchronous discard during allocation
Patch series "mm, swap: misc cleanup and bugfix", v2.

A few cleanups and a bugfix that are either suitable after the swap table
phase I or found during code review.

Patch 1 is a bugfix and needs to be included in the stable branch, the
rest have no behavioral change.


This patch (of 5):

Since commit 1b7e90020e ("mm, swap: use percpu cluster as allocation
fast path"), swap allocation is protected by a local lock, which means we
can't do any sleeping calls during allocation.

However, the discard routine is not taken well care of.  When the swap
allocator failed to find any usable cluster, it would look at the pending
discard cluster and try to issue some blocking discards.  It may not
necessarily sleep, but the cond_resched at the bio layer indicates this is
wrong when combined with a local lock.  And the bio GFP flag used for
discard bio is also wrong (not atomic).

It's arguable whether this synchronous discard is helpful at all.  In most
cases, the async discard is good enough.  And the swap allocator is doing
very differently at organizing the clusters since the recent change, so it
is very rare to see discard clusters piling up.

So far, no issues have been observed or reported with typical SSD setups
under months of high pressure.  This issue was found during my code
review.  But by hacking the kernel a bit: adding a mdelay(500) in the
async discard path, this issue will be observable with WARNING triggered
by the wrong GFP and cond_resched in the bio layer for debug builds.

So now let's apply a hotfix for this issue: remove the synchronous discard
in the swap allocation path.  And when order 0 is failing with all cluster
list drained on all swap devices, try to do a discard following the swap
device priority list.  If any discards released some cluster, try the
allocation again.  This way, we can still avoid OOM due to swap failure if
the hardware is very slow and memory pressure is extremely high.

This may cause more fragmentation issues if the discarding hardware is
really slow.  Ideally, we want to discard pending clusters before
continuing to iterate the fragment cluster lists.  This can be implemented
in a cleaner way if we clean up the device list iteration part first.

Link: https://lkml.kernel.org/r/20251024-swap-clean-after-swap-table-p1-v2-0-a709469052e7@tencent.com
Link: https://lkml.kernel.org/r/20251024-swap-clean-after-swap-table-p1-v2-1-c5b0e1092927@tencent.com
Fixes: 1b7e90020e ("mm, swap: use percpu cluster as allocation fast path")
Signed-off-by: Kairui Song <kasong@tencent.com>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Chris Li <chrisl@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:19 -08:00
Wei Yang
f0b1602871 mm/huge_memory: optimize old_order derivation during folio splitting
Folio splitting requires both the folio's original order (@old_order) and
the new target order (@split_order).

In the current implementation, @old_order is repeatedly retrieved using
folio_order().

However, for every iteration after the first, the folio being split is the
result of the previous split, meaning its order is already known to be
equal to the previous iteration's @split_order.

This commit optimizes the logic:

  * Instead of calling folio_order(), we now set @old_order directly to
    the value of @split_order from the previous iteration.

This change avoids unnecessary function calls and simplifies the loop
setup.

Also it removes a check for non-existent case, since for uniform splitting
we only do split when @split_order == @new_order.

Link: https://lkml.kernel.org/r/20251021212142.25766-5-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: wang lian <lianux.mm@gmail.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:19 -08:00
Wei Yang
fc4f15ee0b mm/huge_memory: optimize and simplify folio stat update after split
The loop executed after a successful folio split currently has two
combined responsibilities:

  * updating statistics for the new folios
  * determining the folio for the next split iteration.

This commit refactors the logic to directly calculate and update folio
statistics, eliminating the need for the iteration step.

We can do this because all necessary information is already available:

  * All resulting new folios have the same order, which is @split_order.
  * The exact number of new folios can be calculated directly using
    @old_order and @split_order.
  * The folio for the subsequent split is simply the one containing
    @split_at.

By leveraging this knowledge, we can achieve the stat update more cleanly
and efficiently without the looping logic.

Link: https://lkml.kernel.org/r/20251021212142.25766-4-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: wang lian <lianux.mm@gmail.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:19 -08:00
Wei Yang
092ef38997 mm/huge_memory: update folio stat after successful split
The current implementation complicates this process:

  * It iterates over the resulting new folios.
  * It uses a flag (@stop_split) to conditionally skip updating the stat
    for the folio at @split_at during the loop.
  * It then attempts to update the skipped stat on a subsequent failure
    path.

This logic is unnecessarily hard to follow.

This commit refactors the code to update the folio statistics only after a
successful split.  This makes the logic much cleaner and sets the stage
for further simplification of the stat-handling code.

Link: https://lkml.kernel.org/r/20251021212142.25766-3-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: wang lian <lianux.mm@gmail.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:19 -08:00
Wei Yang
ef0258857d mm/huge_memory: avoid reinvoking folio_test_anon()
Patch series "mm/huge_memory: cleanup __split_unmapped_folio()", v3.

This patch series cleans up and optimizes the internal logic of the
__split_unmapped_folio() function.

The goal is to improve clarity and efficiency by eliminating redundant
checks, caching stable attribute values, and simplifying the iteration
logic used for updating folio statistics.

These changes make the code easier to follow and maintain.

The split_huge_page_test selftest pass.


This patch (of 4):

During the execution of __split_unmapped_folio(), the folio's anon/!anon
attribute is invariant (not expected to change).

Therefore, it is safe and more efficient to retrieve this attribute once
at the start and reuse it throughout the function.

Link: https://lkml.kernel.org/r/20251021212142.25766-1-richard.weiyang@gmail.com
Link: https://lkml.kernel.org/r/20251016004613.514-1-richard.weiyang@gmail.com
Link: https://lkml.kernel.org/r/20251016004613.514-2-richard.weiyang@gmail.com
Link: https://lkml.kernel.org/r/20251021212142.25766-2-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: wang lian <lianux.mm@gmail.com>
Reviewed-by: Barry Song <baohua@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Nico Pache <npache@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:18 -08:00
Anshuman Khandual
eca1fba233 mm/debug_vm_pgtable: add [pte|pmd]_mkwrite_novma() tests
Add some [pte|pmd]_mkwrite_novma() relevant tests.

[anshuman.khandual@arm.com: add a new test combination per Huang Ying]
  Link: https://lkml.kernel.org/r/20251024013137.136926-1-anshuman.khandual@arm.com
Link: https://lkml.kernel.org/r/20251022032951.3498553-1-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Huang Ying <ying.huang@linux.alibaba.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:18 -08:00
Lu Baolu
e37d5a2d60 iommu/sva: invalidate stale IOTLB entries for kernel address space
Introduce a new IOMMU interface to flush IOTLB paging cache entries for
the CPU kernel address space.  This interface is invoked from the x86
architecture code that manages combined user and kernel page tables,
specifically before any kernel page table page is freed and reused.

This addresses the main issue with vfree() which is a common occurrence
and can be triggered by unprivileged users.  While this resolves the
primary problem, it doesn't address some extremely rare case related to
memory unplug of memory that was present as reserved memory at boot, which
cannot be triggered by unprivileged users.  The discussion can be found at
the link below.

Enable SVA on x86 architecture since the IOMMU can now receive
notification to flush the paging cache before freeing the CPU kernel page
table pages.

Link: https://lkml.kernel.org/r/20251022082635.2462433-9-baolu.lu@linux.intel.com
Link: https://lore.kernel.org/linux-iommu/04983c62-3b1d-40d4-93ae-34ca04b827e5@intel.com/
Co-developed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Suggested-by: Jann Horn <jannh@google.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robin Murohy <robin.murphy@arm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Yi Lai <yi1.lai@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:18 -08:00
Dave Hansen
5ba2f0a155 mm: introduce deferred freeing for kernel page tables
This introduces a conditional asynchronous mechanism, enabled by
CONFIG_ASYNC_KERNEL_PGTABLE_FREE.  When enabled, this mechanism defers the
freeing of pages that are used as page tables for kernel address mappings.
These pages are now queued to a work struct instead of being freed
immediately.

This deferred freeing allows for batch-freeing of page tables, providing a
safe context for performing a single expensive operation (TLB flush) for a
batch of kernel page tables instead of performing that expensive operation
for each page table.

Link: https://lkml.kernel.org/r/20251022082635.2462433-8-baolu.lu@linux.intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robin Murohy <robin.murphy@arm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: Vasant Hegde <vasant.hegde@amd.com>
Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Yi Lai <yi1.lai@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:18 -08:00
Lu Baolu
bf9e4e30f3 x86/mm: use pagetable_free()
The kernel's memory management subsystem provides a dedicated interface,
pagetable_free(), for freeing page table pages.  Updates two call sites to
use pagetable_free() instead of the lower-level __free_page() or
free_pages().  This improves code consistency and clarity, and ensures the
correct freeing mechanism is used.

Link: https://lkml.kernel.org/r/20251022082635.2462433-7-baolu.lu@linux.intel.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robin Murohy <robin.murphy@arm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: Vasant Hegde <vasant.hegde@amd.com>
Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Yi Lai <yi1.lai@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:17 -08:00
Dave Hansen
0189429567 mm: introduce pure page table freeing function
The pages used for ptdescs are currently freed back to the allocator in a
single location.  They will shortly be freed from a second location.

Create a simple helper that just frees them back to the allocator.

Link: https://lkml.kernel.org/r/20251022082635.2462433-6-baolu.lu@linux.intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robin Murohy <robin.murphy@arm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: Vasant Hegde <vasant.hegde@amd.com>
Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Yi Lai <yi1.lai@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:17 -08:00
Dave Hansen
412d000346 x86/mm: use 'ptdesc' when freeing PMD pages
There are a billion ways to refer to a physical memory address.  One of
the x86 PMD freeing code location chooses to use a 'pte_t *' to point to a
PMD page and then call a PTE-specific freeing function for it.  That's a
bit wonky.

Just use a 'struct ptdesc *' instead.  Its entire purpose is to refer to
page table pages.  It also means being able to remove an explicit cast.

Right now, pte_free_kernel() is a one-liner that calls
pagetable_dtor_free().  Effectively, all this patch does is remove one
superfluous __pa(__va(paddr)) conversion and then call
pagetable_dtor_free() directly instead of through a helper.

Link: https://lkml.kernel.org/r/20251022082635.2462433-5-baolu.lu@linux.intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robin Murohy <robin.murphy@arm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: Vasant Hegde <vasant.hegde@amd.com>
Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Yi Lai <yi1.lai@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:17 -08:00
Dave Hansen
977870522a mm: actually mark kernel page table pages
Now that the API is in place, mark kernel page table pages just after they
are allocated.  Unmark them just before they are freed.

Note: Unconditionally clearing the 'kernel' marking (via
ptdesc_clear_kernel()) would be functionally identical to what is here. 
But having the if() makes it logically clear that this function can be
used for kernel and non-kernel page tables.

Link: https://lkml.kernel.org/r/20251022082635.2462433-4-baolu.lu@linux.intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robin Murohy <robin.murphy@arm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: Vasant Hegde <vasant.hegde@amd.com>
Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Yi Lai <yi1.lai@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:17 -08:00
Dave Hansen
27bfafac65 mm: add a ptdesc flag to mark kernel page tables
The page tables used to map the kernel and userspace often have very
different handling rules.  There are frequently *_kernel() variants of
functions just for kernel page tables.  That's not great and has lead to
code duplication.

Instead of having completely separate call paths, allow a 'ptdesc' to be
marked as being for kernel mappings.  Introduce helpers to set and clear
this status.

Note: this uses the PG_referenced bit.  Page flags are a great fit for
this since it is truly a single bit of information.  Use PG_referenced
itself because it's a fairly benign flag (as opposed to things like
PG_lock).  It's also (according to Willy) unlikely to go away any time
soon.

PG_referenced is not in PAGE_FLAGS_CHECK_AT_FREE.  It does not need to be
cleared before freeing the page, and pages coming out of the allocator
should have it cleared.  Regardless, introduce an API to clear it anyway. 
Having symmetry in the API makes it easier to change the underlying
implementation later, like if there was a need to move to a
PAGE_FLAGS_CHECK_AT_FREE bit.

Link: https://lkml.kernel.org/r/20251022082635.2462433-3-baolu.lu@linux.intel.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robin Murohy <robin.murphy@arm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: Vasant Hegde <vasant.hegde@amd.com>
Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Yi Lai <yi1.lai@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:16 -08:00
Lu Baolu
72f98ef9a4 iommu: disable SVA when CONFIG_X86 is set
Patch series "Fix stale IOTLB entries for kernel address space", v7.

This proposes a fix for a security vulnerability related to IOMMU Shared
Virtual Addressing (SVA).  In an SVA context, an IOMMU can cache kernel
page table entries.  When a kernel page table page is freed and
reallocated for another purpose, the IOMMU might still hold stale,
incorrect entries.  This can be exploited to cause a use-after-free or
write-after-free condition, potentially leading to privilege escalation or
data corruption.

This solution introduces a deferred freeing mechanism for kernel page
table pages, which provides a safe window to notify the IOMMU to
invalidate its caches before the page is reused.


This patch (of 8):

In the IOMMU Shared Virtual Addressing (SVA) context, the IOMMU hardware
shares and walks the CPU's page tables.  The x86 architecture maps the
kernel's virtual address space into the upper portion of every process's
page table.  Consequently, in an SVA context, the IOMMU hardware can walk
and cache kernel page table entries.

The Linux kernel currently lacks a notification mechanism for kernel page
table changes, specifically when page table pages are freed and reused. 
The IOMMU driver is only notified of changes to user virtual address
mappings.  This can cause the IOMMU's internal caches to retain stale
entries for kernel VA.

Use-After-Free (UAF) and Write-After-Free (WAF) conditions arise when
kernel page table pages are freed and later reallocated.  The IOMMU could
misinterpret the new data as valid page table entries.  The IOMMU might
then walk into attacker-controlled memory, leading to arbitrary physical
memory DMA access or privilege escalation.  This is also a
Write-After-Free issue, as the IOMMU will potentially continue to write
Accessed and Dirty bits to the freed memory while attempting to walk the
stale page tables.

Currently, SVA contexts are unprivileged and cannot access kernel
mappings.  However, the IOMMU will still walk kernel-only page tables all
the way down to the leaf entries, where it realizes the mapping is for the
kernel and errors out.  This means the IOMMU still caches these
intermediate page table entries, making the described vulnerability a real
concern.

Disable SVA on x86 architecture until the IOMMU can receive notification
to flush the paging cache before freeing the CPU kernel page table pages.

Link: https://lkml.kernel.org/r/20251022082635.2462433-1-baolu.lu@linux.intel.com
Link: https://lkml.kernel.org/r/20251022082635.2462433-2-baolu.lu@linux.intel.com
Fixes: 26b25a2b98 ("iommu: Bind process address spaces to devices")
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robin Murohy <robin.murphy@arm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: Vasant Hegde <vasant.hegde@amd.com>
Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Cc: Yi Lai <yi1.lai@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:16 -08:00
Shakeel Butt
5ff592bec7 memcg: manually uninline __memcg_memory_event
__memcg_memory_event() has been unnecessarily marked inline even when it
is not really performance critical.  It is usually called to track extreme
conditions.  Over the time, it has evolved to include more functionality
and inlining it is causing more harm.

Before the patch:
$ size mm/memcontrol.o net/ipv4/tcp_input.o net/ipv4/tcp_output.o
   text    data     bss     dec     hex filename
  35645   10574    4192   50411    c4eb mm/memcontrol.o
  54738    1658       0   56396    dc4c net/ipv4/tcp_input.o
  34644    1065       0   35709    8b7d net/ipv4/tcp_output.o

After the patch:
$ size mm/memcontrol.o net/ipv4/tcp_input.o net/ipv4/tcp_output.o
   text    data     bss     dec     hex filename
  35137   10446    4192   49775    c26f mm/memcontrol.o
  54322    1562       0   55884    da4c net/ipv4/tcp_input.o
  34492    1017       0   35509    8ab5 net/ipv4/tcp_output.o

[akpm@linux-foundation.org: use EXPORT_SYMBOL_GPL for __memcg_memory_event, per Michal and Christoph]
Link: https://lkml.kernel.org/r/20251021234425.1885471-1-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: SeongJae Park <sj@kernel.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:16 -08:00
Vishal Moola (Oracle)
a061578043 mm/vmalloc: request large order pages from buddy allocator
Sometimes, vm_area_alloc_pages() will want many pages from the buddy
allocator.  Rather than making requests to the buddy allocator for at most
100 pages at a time, we can eagerly request large order pages a smaller
number of times.

We still split the large order pages down to order-0 as the rest of the
vmalloc code (and some callers) depend on it.  We still defer to the bulk
allocator and fallback path in case of order-0 pages or failure.

Running 1000 iterations of allocations on a small 4GB system finds:

1000 2mb allocations:
	[Baseline]			[This patch]
	real    46.310s			real    0m34.582
	user    0.001s			user    0.006s
	sys     46.058s			sys     0m34.365s

10000 200kb allocations:
	[Baseline]			[This patch]
	real    56.104s			real    0m43.696
	user    0.001s			user    0.003s
	sys     55.375s			sys     0m42.995s

Link: https://lkml.kernel.org/r/20251021194455.33351-2-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:15 -08:00
Jing Su
645a3c4243 mm/vmstat: fix indentation in fold_diff function
Adjust misaligned braces in fold_diff() to improve code readability and
maintain consistent coding style.

[akpm@linux-foundation.org: add braces, per Vlastimil & Liam]
Link: https://lkml.kernel.org/r/aPc4I/8zXCGyiapN@pilot-ThinkCentre-M930t-N000
Signed-off-by: Jing Su <jingsusu@didiglobal.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Donet Tom <donettom@linux.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:15 -08:00
William Kucharski
fe62415c9b mm: remove reference to destructor in comment in calculate_sizes()
The commit that removed support for destructors from kmem_cache_alloc()
never removed the comment regarding destructors in the explanation of the
possible relocation of the free pointer in calculate_sizes().

Link: https://lkml.kernel.org/r/20251021110004.2209008-1-william.kucharski@oracle.com
Fixes: 20c2df83d2 ("mm: Remove slab destructors from kmem_cache_create().")
Signed-off-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Christoph Lameter (Ampere) <cl@gentwo.org>
Acked-by: SeongJae Park <sj@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:15 -08:00
Leon Hwang
2da6fe91c2 mm/khugepaged: factor out common logic in [scan,alloc]_sleep_millisecs_store()
Both scan_sleep_millisecs_store() and alloc_sleep_millisecs_store()
perform the same operations: parse the input value, update their
respective sleep interval, reset khugepaged_sleep_expire, and wake up the
khugepaged thread.

Factor out this duplicated logic into a helper function
__sleep_millisecs_store(), and simplify both store functions.

No functional change intended.

Link: https://lkml.kernel.org/r/20251021134431.26488-1-leon.hwang@linux.dev
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Nico Pache <npache@redhat.com>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:15 -08:00
Swaraj Gaikwad
fae4e86024 mm/damon/sysfs: remove misleading todo comment in nid_show()
The TODO comment in nid_show() suggested returning an error if the goal
was not using nid.  However, this comment was found to be inaccurate and
misleading.This patch removes the TODO comment without changing any
existing behavior.

This change follows feedback from SJ who pointed out [1] that wiring-order
independence is expected and the function should simply show the last set
value.  and [2] checkpatch.pl complain about number of chars per line

No functional code changes were made.

Tested with KUnit:
- Built kernel with KUnit and DAMON sysfs tests enabled.
- Executed KUnit tests:
  ./tools/testing/kunit/kunit.py run --kunitconfig ./mm/damon/tests/
- All 25 tests passed, including damon_sysfs_test_add_targets.

Link: https://lkml.kernel.org/r/20251021215323.29734-2-swarajgaikwad1925@gmail.com
Link: https://lore.kernel.org/lkml/20251020151315.66260-1-sj@kernel.org/ [1]
Link: https://lore.kernel.org/lkml/20251021010847.68473-1-sj@kernel.org/ [2]
Signed-off-by: Swaraj Gaikwad <swarajgaikwad1925@gmail.com>
Suggested-by: SeongJae Park <sj@kernel.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: David Hunter <david.hunter.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:14 -08:00
Mehdi Ben Hadj Khelifa
f0c74b6cb9 mm/vmalloc: use kmalloc_array() instead of kmalloc()
The number of NUMA nodes (nr_node_ids) is bounded, so overflow is not a
practical concern here.  However, using kmalloc_array() better reflects
the intent to allocate an array of unsigned ints, and improves consistency
with other NUMA-related allocations.

No functional change intended.

Link: https://lkml.kernel.org/r/20251018201207.27441-1-mehdi.benhadjkhelifa@gmail.com
Signed-off-by: Mehdi Ben Hadj Khelifa <mehdi.benhadjkhelifa@gmail.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Khalid Aziz <khalid@kernel.org>
Cc: David Hunter <david.hunter.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:14 -08:00
Bagas Sanjaya
184c753342 vmalloc: separate gfp_mask adjunctive parentheses in __vmalloc_node_noprof() kernel-doc comment
Sphinx reports htmldocs warning on __vmalloc_node() comment:

Documentation/core-api/mm-api:52: ./mm/vmalloc.c:4036: WARNING: Inline strong start-string without end-string. [docutils]

Fix it by separating adjunctive parentheses from preceding gfp_mask
formatting markup.

Link: https://lkml.kernel.org/r/20251020044933.15222-1-bagasdotme@gmail.com
Fixes: 32904ba6f5ef ("vmalloc: update __vmalloc_node_noprof() documentation")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/linux-next/20251020134902.3a11107e@canb.auug.org.au/
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Stehen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:14 -08:00
Lorenzo Stoakes
8247e2600e mm: update resctl to use mmap_prepare
Make use of the ability to specify a remap action within mmap_prepare to
update the resctl pseudo-lock to use mmap_prepare in favour of the
deprecated mmap hook.

Link: https://lkml.kernel.org/r/95b28b066f37ca25f56fa9460a9367f1a866f88b.1760959442.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Dave Martin <dave.martin@arm.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Morse <james.morse@arm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Robin Murohy <robin.murphy@arm.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:14 -08:00
Lorenzo Stoakes
ab04945f91 mm: update mem char driver to use mmap_prepare
Update the mem char driver (backing /dev/mem and /dev/zero) to use
f_op->mmap_prepare hook rather than the deprecated f_op->mmap.

The /dev/zero implementation has a very unique and rather concerning
characteristic in that it converts MAP_PRIVATE mmap() mappings anonymous
when they are, in fact, not.

The new f_op->mmap_prepare() can support this, but rather than introducing
a helper function to perform this hack (and risk introducing other users),
utilise the success hook to do so.

We utilise the newly introduced shmem_zero_setup_desc() to allow for the
shared mapping case via an f_op->mmap_prepare() hook.

We also use the desc->action_error_hook to filter the remap error to
-EAGAIN to keep behaviour consistent.

Link: https://lkml.kernel.org/r/48f60764d7a6901819d1af778fa33b775d2e8c77.1760959442.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Chatre, Reinette <reinette.chatre@intel.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Dave Martin <dave.martin@arm.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Morse <james.morse@arm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Robin Murohy <robin.murphy@arm.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:13 -08:00
Lorenzo Stoakes
89646d9c74 mm: add shmem_zero_setup_desc()
Add the ability to set up a shared anonymous mapping based on a VMA
descriptor rather than a VMA.

This is a prerequisite for converting to the char mm driver to use the
mmap_prepare hook.

Link: https://lkml.kernel.org/r/d9181517a7e3d6b014a5697c6990d3722c2c9fcd.1760959442.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Chatre, Reinette <reinette.chatre@intel.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Dave Martin <dave.martin@arm.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Morse <james.morse@arm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Robin Murohy <robin.murphy@arm.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16 17:28:13 -08:00