Mike Rapoport (Microsoft) [Mon, 11 Aug 2025 08:25:08 +0000 (11:25 +0300)]
kho: allow scratch areas with zero size
Patch series "kho: fixes and cleanups", v3.
These are small KHO and KHO test fixes and cleanups.
This patch (of 3):
Parsing of kho_scratch parameter treats zero size as an invalid value,
although it should be fine for user to request zero sized scratch area for
some types if scratch memory, when for example there is no need to create
scratch area in the low memory.
Treat zero as a valid value for a scratch area size but reject kho_scratch
parameter that defines no scratch memory at all.
Link: https://lkml.kernel.org/r/20250811082510.4154080-1-rppt@kernel.org Link: https://lkml.kernel.org/r/20250811082510.4154080-2-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Pratyush Yadav <pratyush@kernel.org> Cc: Alexander Graf <graf@amazon.com> Cc: Baoquan He <bhe@redhat.com> Cc: Changyuan Lyu <changyuanl@google.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pankaj Raghav [Mon, 11 Aug 2025 08:41:13 +0000 (10:41 +0200)]
block: use largest_zero_folio in __blkdev_issue_zero_pages()
Use largest_zero_folio() in __blkdev_issue_zero_pages(). On systems with
CONFIG_PERSISTENT_HUGE_ZERO_FOLIO enabled, we will end up sending larger
bvecs instead of multiple small ones.
Noticed a 4% increase in performance on a commercial NVMe SSD which does
not support OP_WRITE_ZEROES. The device's MDTS was 128K. The performance
gains might be bigger if the device supports bigger MDTS.
Link: https://lkml.kernel.org/r/20250811084113.647267-6-kernel@pankajraghav.com Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Acked-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Kiryl Shutsemau <kirill@shutemov.name> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Luis Chamberalin <mcgrof@kernel.org> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pankaj Raghav [Mon, 11 Aug 2025 08:41:12 +0000 (10:41 +0200)]
mm: add largest_zero_folio() routine
The callers of mm_get_huge_zero_folio() have access to a mm struct and the
lifetime of the huge_zero_folio is tied to the lifetime of the mm struct.
largest_zero_folio() will give access to huge_zero_folio when
PERSISTENT_HUGE_ZERO_FOLIO config option is enabled for callers that do
not want to tie the lifetime to a mm struct. This is very useful for
filesystem and block layers where the request completions can be async and
there is no guarantee on the mm struct lifetime.
This function will return a ZERO_PAGE folio if PERSISTENT_HUGE_ZERO_FOLIO
is disabled or if we failed to allocate a huge_zero_folio during early
init.
Link: https://lkml.kernel.org/r/20250811084113.647267-5-kernel@pankajraghav.com Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Co-developed-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Luis Chamberalin <mcgrof@kernel.org> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Cc: Kiryl Shutsemau <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pankaj Raghav [Mon, 11 Aug 2025 08:41:11 +0000 (10:41 +0200)]
mm: add persistent huge zero folio
Many places in the kernel need to zero out larger chunks, but the maximum
segment that can be zeroed out at a time by ZERO_PAGE is limited by
PAGE_SIZE.
This is especially annoying in block devices and filesystems where
multiple ZERO_PAGEs are attached to the bio in different bvecs. With
multipage bvec support in block layer, it is much more efficient to send
out larger zero pages as a part of single bvec.
This concern was raised during the review of adding Large Block Size
support to XFS[1][2].
Usually huge_zero_folio is allocated on demand, and it will be deallocated
by the shrinker if there are no users of it left. At moment,
huge_zero_folio infrastructure refcount is tied to the process lifetime
that created it. This might not work for bio layer as the completions can
be async and the process that created the huge_zero_folio might no longer
be alive. And, one of the main points that came up during discussion is
to have something bigger than zero page as a drop-in replacement.
Add a config option PERSISTENT_HUGE_ZERO_FOLIO that will result in
allocating the huge zero folio during early init and never free the memory
by disabling the shrinker. This makes using the huge_zero_folio without
having to pass any mm struct and does not tie the lifetime of the zero
folio to anything, making it a drop-in replacement for ZERO_PAGE.
If PERSISTENT_HUGE_ZERO_FOLIO config option is enabled, then
mm_get_huge_zero_folio() will simply return the allocated page instead of
dynamically allocating a new PMD page.
Use this option carefully in resource constrained systems as it uses one
full PMD sized page for zeroing purposes.
Pankaj Raghav [Mon, 11 Aug 2025 08:41:09 +0000 (10:41 +0200)]
mm: rename huge_zero_page to huge_zero_folio
Patch series "add persistent huge zero folio support", v3.
Many places in the kernel need to zero out larger chunks, but the maximum
segment we can zero out at a time by ZERO_PAGE is limited by PAGE_SIZE.
This concern was raised during the review of adding Large Block Size
support to XFS[1][2].
This is especially annoying in block devices and filesystems where
multiple ZERO_PAGEs are attached to the bio in different bvecs. With
multipage bvec support in block layer, it is much more efficient to send
out larger zero pages as a part of single bvec.
Some examples of places in the kernel where this could be useful:
- blkdev_issue_zero_pages()
- iomap_dio_zero()
- vmalloc.c:zero_iter()
- rxperf_process_call()
- fscrypt_zeroout_range_inline_crypt()
- bch2_checksum_update()
...
Usually huge_zero_folio is allocated on demand, and it will be deallocated
by the shrinker if there are no users of it left. At the moment,
huge_zero_folio infrastructure refcount is tied to the process lifetime
that created it. This might not work for bio layer as the completions can
be async and the process that created the huge_zero_folio might no longer
be alive. And, one of the main point that came during discussion is to
have something bigger than zero page as a drop-in replacement.
Add a config option PERSISTENT_HUGE_ZERO_FOLIO that will always allocate
the huge_zero_folio, and disable the shrinker so that huge_zero_folio is
never freed. This makes using the huge_zero_folio without having to pass
any mm struct and does not tie the lifetime of the zero folio to anything,
making it a drop-in replacement for ZERO_PAGE.
I have converted blkdev_issue_zero_pages() as an example as a part of this
series. I also noticed close to 4% performance improvement just by
replacing ZERO_PAGE with persistent huge_zero_folio.
I will send patches to individual subsystems using the huge_zero_folio
once this gets upstreamed.
As the transition already happened from exposing huge_zero_page to
huge_zero_folio, change the name of the shrinker and the other helper
function to reflect that.
No functional changes.
Link: https://lkml.kernel.org/r/20250811084113.647267-1-kernel@pankajraghav.com Link: https://lkml.kernel.org/r/20250811084113.647267-2-kernel@pankajraghav.com Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Luis Chamberalin <mcgrof@kernel.org> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Kiryl Shutsemau <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Mon, 11 Aug 2025 11:26:31 +0000 (13:26 +0200)]
mm: rename vm_ops->find_special_page() to vm_ops->find_normal_page()
... and hide it behind a kconfig option. There is really no need for any
!xen code to perform this check.
The naming is a bit off: we want to find the "normal" page when a PTE was
marked "special". So it's really not "finding a special" page.
Improve the documentation, and add a comment in the code where XEN ends up
performing the pte_mkspecial() through a hypercall. More details can be
found in commit 923b2919e2c3 ("xen/gntdev: mark userspace PTEs as special
on x86 PV guests").
Link: https://lkml.kernel.org/r/20250811112631.759341-12-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Mon, 11 Aug 2025 11:26:30 +0000 (13:26 +0200)]
mm: introduce and use vm_normal_page_pud()
Let's introduce vm_normal_page_pud(), which ends up being fairly simple
because of our new common helpers and there not being a PUD-sized zero
folio.
Use vm_normal_page_pud() in folio_walk_start() to resolve a TODO,
structuring the code like the other (pmd/pte) cases. Defer introducing
vm_normal_folio_pud() until really used.
Note that we can so far get PUDs with hugetlb, daxfs and PFNMAP entries.
Link: https://lkml.kernel.org/r/20250811112631.759341-11-david@redhat.com Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Mon, 11 Aug 2025 11:26:29 +0000 (13:26 +0200)]
mm/memory: factor out common code from vm_normal_page_*()
Let's reduce the code duplication and factor out the non-pte/pmd related
magic into __vm_normal_page().
To keep it simpler, check the pfn against both zero folios, which
shouldn't really make a difference.
It's a good question if we can even hit the !CONFIG_ARCH_HAS_PTE_SPECIAL
scenario in the PMD case in practice: but doesn't really matter, as it's
now all unified in vm_normal_page_pfn().
Add kerneldoc for all involved functions.
Note that, as a side product, we now:
* Support the find_special_page special thingy also for PMD
* Don't check for is_huge_zero_pfn() anymore if we have
CONFIG_ARCH_HAS_PTE_SPECIAL and the PMD is not special. The
VM_WARN_ON_ONCE would catch any abuse
No functional change intended.
Link: https://lkml.kernel.org/r/20250811112631.759341-10-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Mon, 11 Aug 2025 11:26:28 +0000 (13:26 +0200)]
mm/memory: convert print_bad_pte() to print_bad_page_map()
print_bad_pte() looks like something that should actually be a WARN or
similar, but historically it apparently has proven to be useful to detect
corruption of page tables even on production systems -- report the issue
and keep the system running to make it easier to actually detect what is
going wrong (e.g., multiple such messages might shed a light).
As we want to unify vm_normal_page_*() handling for PTE/PMD/PUD, we'll
have to take care of print_bad_pte() as well.
Let's prepare for using print_bad_pte() also for non-PTEs by adjusting the
implementation and renaming the function to print_bad_page_map(). Provide
print_bad_pte() as a simple wrapper.
Document the implicit locking requirements for the page table re-walk.
To make the function a bit more readable, factor out the ratelimit check
into is_bad_page_map_ratelimited() and place the printing of page table
content into __print_bad_page_map_pgtable(). We'll now dump information
from each level in a single line, and just stop the table walk once we hit
something that is not a present page table.
The report will now look something like (dumping pgd to pmd values):
Not using pgdp_get(), because that does not work properly on some arm
configs where pgd_t is an array. Note that we are dumping all levels even
when levels are folded for simplicity.
Link: https://lkml.kernel.org/r/20250811112631.759341-9-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Commit 5e901e249ad1 ("mm/rmap: convert "enum rmap_level" to "enum
pgtable_level"") changed VM_WARN_ON_ONCE, a run time warning, into
BUILD_BUG, a compile time error. After this adjustment, certain builds
with older versions of clang (such as arm64 allmodconfig) started
failing to build with:
In file included from mm/rmap.c:63:
In file included from include/linux/ksm.h:14:
include/linux/rmap.h:440:3: error: call to __compiletime_assert_890 declared with 'error' attribute: BUILD_BUG failed
BUILD_BUG();
^
...
<scratch space>:21:1: note: expanded from here
__compiletime_assert_890
^
While __folio_rmap_sanity_checks() is marked 'inline', the compiler may
not always honor it, such as when sanitizers or other instrumentation is
enabled. If __folio_rmap_sanity_checks() is not inlined, there is no
way the compiler can eliminate the default cause.
Mark __folio_rmap_sanity_checks() as __always_inline to allow the
BUILD_BUG() to work consistently, which clears up the error.
David Hildenbrand [Mon, 11 Aug 2025 11:26:27 +0000 (13:26 +0200)]
mm/rmap: convert "enum rmap_level" to "enum pgtable_level"
Let's factor it out, and convert all checks for unsupported levels to
BUILD_BUG(). The code is written in a way such that force-inlining will
optimize out the levels.
Link: https://lkml.kernel.org/r/20250811112631.759341-8-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Mon, 11 Aug 2025 11:26:26 +0000 (13:26 +0200)]
powerpc/ptdump: rename "struct pgtable_level" to "struct ptdump_pglevel"
We want to make use of "pgtable_level" for an enum in core-mm. Other
architectures seem to call "struct pgtable_level" either:
* "struct pg_level" when not exposed in a header (riscv, arm)
* "struct ptdump_pg_level" when expose in a header (arm64)
So let's follow what arm64 does.
Link: https://lkml.kernel.org/r/20250811112631.759341-7-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Mon, 11 Aug 2025 11:26:25 +0000 (13:26 +0200)]
mm/huge_memory: mark PMD mappings of the huge zero folio special
The huge zero folio is refcounted (+mapcounted -- is that a word?)
differently than "normal" folios, similarly (but different) to the
ordinary shared zeropage.
For this reason, we special-case these pages in
vm_normal_page*/vm_normal_folio*, and only allow selected callers to still
use them (e.g., GUP can still take a reference on them).
vm_normal_page_pmd() already filters out the huge zero folio, to indicate
it a special (return NULL). However, so far we are not making use of
pmd_special() on architectures that support it
(CONFIG_ARCH_HAS_PTE_SPECIAL), like we would with the ordinary shared
zeropage.
Let's mark PMD mappings of the huge zero folio similarly as special, so we
can avoid the manual check for the huge zero folio with
CONFIG_ARCH_HAS_PTE_SPECIAL next, and only perform the check on
!CONFIG_ARCH_HAS_PTE_SPECIAL.
In copy_huge_pmd(), where we have a manual pmd_special() check to handle
PFNMAP, we have to manually rule out the huge zero folio. That code needs
a serious cleanup, but that's something for another day.
While at it, update the doc regarding the shared zero folios.
No functional change intended: vm_normal_page_pmd() still returns NULL
when it encounters the huge zero folio.
Link: https://lkml.kernel.org/r/20250811112631.759341-6-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Mon, 11 Aug 2025 11:26:24 +0000 (13:26 +0200)]
fs/dax: use vmf_insert_folio_pmd() to insert the huge zero folio
Let's convert to vmf_insert_folio_pmd().
There is a theoretical change in behavior: in the unlikely case there is
already something mapped, we'll now still call trace_dax_pmd_load_hole()
and return VM_FAULT_NOPAGE.
Previously, we would have returned VM_FAULT_FALLBACK, and the caller would
have zapped the PMD to try a PTE fault.
However, that behavior was different to other PTE+PMD faults, when there
would already be something mapped, and it's not even clear if it could be
triggered.
Assuming the huge zero folio is already mapped, all good, no need to
fallback to PTEs.
Assuming there is already a leaf page table ... the behavior would be
just like when trying to insert a PMD mapping a folio through
dax_fault_iter()->vmf_insert_folio_pmd().
Assuming there is already something else mapped as PMD? It sounds like a
BUG, and the behavior would be just like when trying to insert a PMD
mapping a folio through dax_fault_iter()->vmf_insert_folio_pmd().
So, it sounds reasonable to not handle huge zero folios differently to
inserting PMDs mapping folios when there already is something mapped.
Link: https://lkml.kernel.org/r/20250811112631.759341-5-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Mon, 11 Aug 2025 11:26:23 +0000 (13:26 +0200)]
mm/huge_memory: support huge zero folio in vmf_insert_folio_pmd()
Just like we do for vmf_insert_page_mkwrite() -> ... ->
insert_page_into_pte_locked() with the shared zeropage, support the huge
zero folio in vmf_insert_folio_pmd().
When (un)mapping the huge zero folio in page tables, we neither adjust the
refcount nor the mapcount, just like for the shared zeropage.
For now, the huge zero folio is not marked as special yet, although
vm_normal_page_pmd() really wants to treat it as special. We'll change
that next.
Link: https://lkml.kernel.org/r/20250811112631.759341-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Mon, 11 Aug 2025 11:26:22 +0000 (13:26 +0200)]
mm/huge_memory: move more common code into insert_pud()
Let's clean it all further up.
No functional change intended.
Link: https://lkml.kernel.org/r/20250811112631.759341-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Mon, 11 Aug 2025 11:26:21 +0000 (13:26 +0200)]
mm/huge_memory: move more common code into insert_pmd()
Patch series "mm: vm_normal_page*() improvements", v3.
Cleanup and unify vm_normal_page_*() handling, also marking the huge
zerofolio as special in the PMD. Add+use vm_normal_page_pud() and cleanup
that XEN vm_ops->find_special_page thingy.
There are plans of using vm_normal_page_*() more widely soon.
This patch (of 11):
Let's clean it all further up.
No functional change intended.
Link: https://lkml.kernel.org/r/20250811112631.759341-1-david@redhat.com Link: https://lkml.kernel.org/r/20250811112631.759341-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Juegren Gross <jgross@suse.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mariano Pache <npache@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Cc: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Mon, 11 Aug 2025 14:39:48 +0000 (16:39 +0200)]
treewide: remove MIGRATEPAGE_SUCCESS
At this point MIGRATEPAGE_SUCCESS is misnamed for all folio users,
and now that we remove MIGRATEPAGE_UNMAP, it's really the only "success"
return value that the code uses and expects.
Let's just get rid of MIGRATEPAGE_SUCCESS completely and just use "0"
for success.
Link: https://lkml.kernel.org/r/20250811143949.1117439-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> [mm] Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com> [jfs] Acked-by: David Sterba <dsterba@suse.com> [btrfs] Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Byungchul Park <byungchul@sk.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Eugenio Pé rez <eperezma@redhat.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Lance Yang <lance.yang@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
David Hildenbrand [Mon, 11 Aug 2025 14:39:47 +0000 (16:39 +0200)]
mm/migrate: remove MIGRATEPAGE_UNMAP
migrate_folio_unmap() is the only user of MIGRATEPAGE_UNMAP. We want to
remove MIGRATEPAGE_* completely.
It's rather weird to have a generic MIGRATEPAGE_UNMAP, documented to be
returned from address-space callbacks, when it's only used for an internal
helper.
Let's start by having only a single "success" return value for
migrate_folio_unmap() -- 0 -- by moving the "folio was already freed"
check into the single caller.
There is a remaining comment for PG_isolated, which we renamed to
PG_movable_ops_isolated recently and forgot to update.
While we might still run into that case with zsmalloc, it's something we
want to get rid of soon. So let's just focus that optimization on real
folios only for now by excluding movable_ops pages. Note that concurrent
freeing can happen at any time and this "already freed" check is not
relevant for correctness.
Link: https://lkml.kernel.org/r/20250811143949.1117439-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Byungchul Park <byungchul@sk.com> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Eugenio Pé rez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Dave Kleikamp <dave.kleikamp@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kairui Song [Mon, 11 Aug 2025 17:20:18 +0000 (01:20 +0800)]
mm/mincore: use a helper for checking the swap cache
Introduce a mincore_swap helper for checking swap entries. Move all swap
related logic and sanity debug check into it, and separate them from page
cache checking.
The performance is better after this commit. mincore_page is never called
on a swap cache space now, so the logic can be simpler. The sanity check
also covers more potential cases now, previously the WARN_ON only catches
potentially corrupted page table, now if shmem contains a swap entry with
!CONFIG_SWAP, a WARN will be triggered. This changes the mincore value
when the WARN is triggered, but this shouldn't matter. The WARN_ON means
the data is already corrupted or something is very wrong, so it really
should not happen.
Before this series:
mincore on a swaped out 16G anon mmap range:
Took 488220 us
mincore on 16G shmem mmap range:
Took 530272 us.
After this commit:
mincore on a swaped out 16G anon mmap range:
Took 446763 us
mincore on 16G shmem mmap range:
Took 460496 us.
About ~10% faster.
Link: https://lkml.kernel.org/r/20250811172018.48901-3-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.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: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kairui Song [Mon, 11 Aug 2025 17:20:17 +0000 (01:20 +0800)]
mm/mincore, swap: consolidate swap cache checking for mincore
Patch series "mm/mincore: minor clean up for swap cache checking".
This series cleans up a swap cache helper only used by mincore, move it
back into mincore code. Also separate the swap cache related logics out
of shmem / page cache logics in mincore.
With this series we have less lines of code and better performance.
Before this series:
mincore on a swaped out 16G anon mmap range:
Took 488220 us
mincore on 16G shmem mmap range:
Took 530272 us.
After this series:
mincore on a swaped out 16G anon mmap range:
Took 446763 us
mincore on 16G shmem mmap range:
Took 460496 us.
About ~10% faster.
This patch (of 2):
The filemap_get_incore_folio (previously find_get_incore_page) helper was
introduced by commit 61ef18655704 ("mm: factor find_get_incore_page out of
mincore_page") to be used by later commit f5df8635c5a3 ("mm: use
find_get_incore_page in memcontrol"), so memory cgroup charge move code
can be simplified.
But commit 6b611388b626 ("memcg-v1: remove charge move code") removed that
user completely, it's only used by mincore now.
So this commit basically reverts commit 61ef18655704 ("mm: factor
find_get_incore_page out of mincore_page"). Move it back to mincore side
to simplify the code.
Link: https://lkml.kernel.org/r/20250811172018.48901-1-ryncsn@gmail.com Link: https://lkml.kernel.org/r/20250811172018.48901-2-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Nhat Pham <nphamcs@gmail.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: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Sang-Heon Jeon [Tue, 5 Aug 2025 12:39:40 +0000 (21:39 +0900)]
mm/damon: update expired description of damos_action
Nowadays, damos operation actions support a greater operation set. But
comments (also, generated documentation) weren't updated. So fix the
comments with current support status.
Suren Baghdasaryan [Fri, 8 Aug 2025 15:28:49 +0000 (08:28 -0700)]
fs/proc/task_mmu: execute PROCMAP_QUERY ioctl under per-vma locks
Utilize per-vma locks to stabilize vma after lookup without taking
mmap_lock during PROCMAP_QUERY ioctl execution. If vma lock is
contended, we fall back to mmap_lock but take it only momentarily
to lock the vma and release the mmap_lock. In a very unlikely case
of vm_refcnt overflow, this fall back path will fail and ioctl is
done under mmap_lock protection.
This change is designed to reduce mmap_lock contention and prevent
PROCMAP_QUERY ioctl calls from blocking address space updates.
Link: https://lkml.kernel.org/r/20250808152850.2580887-4-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Acked-by: SeongJae Park <sj@kernel.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand <david@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: T.J. Mercier <tjmercier@google.com> Cc: Ye Bin <yebin10@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Suren Baghdasaryan [Fri, 8 Aug 2025 15:28:48 +0000 (08:28 -0700)]
fs/proc/task_mmu: factor out proc_maps_private fields used by PROCMAP_QUERY
Refactor struct proc_maps_private so that the fields used by PROCMAP_QUERY
ioctl are moved into a separate structure. In the next patch this allows
ioctl to reuse some of the functions used for reading /proc/pid/maps
without using file->private_data. This prevents concurrent modification
of file->private_data members by ioctl and /proc/pid/maps readers.
The change is pure code refactoring and has no functional changes.
Link: https://lkml.kernel.org/r/20250808152850.2580887-3-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: SeongJae Park <sj@kernel.org> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand <david@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: T.J. Mercier <tjmercier@google.com> Cc: Ye Bin <yebin10@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Suren Baghdasaryan [Fri, 8 Aug 2025 15:28:47 +0000 (08:28 -0700)]
selftests/proc: test PROCMAP_QUERY ioctl while vma is concurrently modified
Patch series " execute PROCMAP_QUERY ioctl under per-vma lock", v4.
With /proc/pid/maps now being read under per-vma lock protection we can
reuse parts of that code to execute PROCMAP_QUERY ioctl also without
taking mmap_lock. The change is designed to reduce mmap_lock contention
and prevent PROCMAP_QUERY ioctl calls from blocking address space updates.
This patchset was split out of the original patchset [1] that introduced
per-vma lock usage for /proc/pid/maps reading. It contains PROCMAP_QUERY
tests, code refactoring patch to simplify the main change and the actual
transition to per-vma lock.
This patch (of 3):
Extend /proc/pid/maps tearing tests to verify PROCMAP_QUERY ioctl operation
correctness while the vma is being concurrently modified.
Link: https://lkml.kernel.org/r/20250808152850.2580887-1-surenb@google.com Link: https://lkml.kernel.org/r/20250808152850.2580887-2-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Tested-by: SeongJae Park <sj@kernel.org> Acked-by: SeongJae Park <sj@kernel.org> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand <david@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Thomas Weißschuh <linux@weissschuh.net> Cc: T.J. Mercier <tjmercier@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Ye Bin <yebin10@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
selftests/mm: fix unused parameter warnings for different architectures
There are functions which have unused arguments for different
architectures. Separate the code for each architecture and move #ifdef
arch outside these functions.
Link: https://lkml.kernel.org/r/20250731160132.1795351-9-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
selftests/mm: mark more unused arguments with __unused
Mark the arguments which cannot be removed with __unused attribute.
Link: https://lkml.kernel.org/r/20250731160132.1795351-8-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Mark the arguments which cannot be removed with __unused attribute.
Link: https://lkml.kernel.org/r/20250731160132.1795351-7-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20250731160132.1795351-6-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add -Wunused family of flags and fix all the warnings coming because of
argc and argv. Remove them if they aren't being used entirely. Use
__unused compiler attribute with argc where argv is being used.
Link: https://lkml.kernel.org/r/20250731160132.1795351-5-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Add __unused macro instead of using the complete verbose unused compiler
attribute. The raw __attribute__((__unused__)) is quite long and makes
code too much verbose to the kernel developer's taste.
Link: https://lkml.kernel.org/r/20250731160132.1795351-4-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The while loop doesn't execute and following warning gets generated:
protection_keys.c:561:15: warning: code will never be executed
[-Wunreachable-code]
int rpkey = alloc_random_pkey();
Let's enable the while loop such that it gets executed nr_iterations
times. Simplify the code a bit as well.
Link: https://lkml.kernel.org/r/20250731160132.1795351-3-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
selftests/mm: add -Wunreachable-code and fix warnings
Patch series "selftests/mm: Add compiler flags and fix found warnings", v2.
Recently, I reviewed a patch on the mm/kselftest mailing list about a test
which had obvious type mismatch fix in it. It was strange why that wasn't
caught during development and when patch was accepted. This led me to
discover that those extra compiler options to catch these warnings aren't
being used. When I added them, I found tens of warnings in just mm suite.
In this series, I'm adding these flags and fixing those warnings. In the
last try several months ago [1], I'd patches for individual tests. I've
made patches better by grouping the same type of fixes together. Hence
there is no changelog for individual patches.
This patch (of 8):
Enable -Wunreachable-code flag to catch dead code and fix them.
1. Remove the dead code and write a comment instead:
hmm-tests.c:2033:3: warning: code will never be executed
[-Wunreachable-code]
perror("Should not reach this\n");
^~~~~~
2. ksft_exit_fail_msg() calls exit(). Remove the dead code.
split_huge_page_test.c:301:3: warning: code will never be executed
[-Wunreachable-code]
goto cleanup;
^~~~~~~~~~~~
Link: https://lkml.kernel.org/r/20250731160132.1795351-1-usama.anjum@collabora.com Link: https://lkml.kernel.org/r/20250731160132.1795351-2-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Yueyang Pan [Sat, 2 Aug 2025 11:52:46 +0000 (11:52 +0000)]
mm/damon/vaddr: support stat-purpose DAMOS filters
This patch extends DAMOS_STAT handling of the DAMON operations sets for
virtual address spaces for ops-level DAMOS filters. It leverages the
walk_page_range to walk the page table and gets the folio from page table.
The last folio scanned is stored in damos->last_applied to prevent double
counting.
Yueyang Pan [Sat, 2 Aug 2025 11:52:45 +0000 (11:52 +0000)]
mm/damon/paddr: move filters existence check function to ops-common
Patch series "mm/damon/vaddr: support stat-purpose DAMOS filters", v4.
Extend DAMOS_STAT handling of the DAMON operations sets for virtual
address spaces for ops-level DAMOS filters.
Functionality Test
==================
I wrote a small test program which allocates 10GB of DRAM, use
madvise(MADV_HUGEPAGE) to convert the base pages to 2MB huge pages Then my
program does the following things in order:
1. Write sequentially to the whole 10GB region
2. Read the first 5GB region sequentially for 10 times
3. Sleep 5s
4. Read the second 5GB region sequentially for 10 times
With a proper damon setting, we are expected to see df-passed to be 10GB
and hot region move around with the read
As you can see the total df-passed region is 10GiB and the hot region
moves as the seq read keeps going
This patch (of 2):
This patch moves damon_pa_scheme_has_filter to ops-common. renaming to
damos_ops_has_filter. Doing so allows us to reuse its logic in the vaddr
version of DAMOS_STAT.
Bijan Tabatabai [Wed, 6 Aug 2025 23:42:54 +0000 (18:42 -0500)]
mm/damon/core: skip needless update of damon_attrs in damon_commit_ctx()
Currently, damon_commit_ctx() always calls damon_set_attrs() even if the
attributes have not been changed. This can be problematic when the DAMON
state is committed relatively frequently because damon_set_attrs() resets
ctx->next_{aggregation,ops_update}_sis, causing aggregation and ops update
operations to be needlessly delayed.
This patch avoids this by only calling damon_set_attrs() in
damon_commit_ctx when the attributes have been changed.
Link: https://lkml.kernel.org/r/20250806234254.10572-1-bijan311@gmail.com Signed-off-by: Bijan Tabatabai <bijantabatab@micron.com> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Bijan Tabatabai <bijan311@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Wei Yang [Mon, 4 Aug 2025 06:41:06 +0000 (06:41 +0000)]
mm/rmap: do __folio_mod_stat() in __folio_add_rmap()
It is required to modify folio statistic after rmap changes, so it looks
reasonable to do it in __folio_add_rmap(), which is the current behavior
of __folio_remove_rmap() and folio_add_new_anon_rmap().
Call __folio_mod_stat() in __folio_add_rmap(), so that rmap adjustment
family shares the same pattern.
Link: https://lkml.kernel.org/r/20250804064106.21269-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Rik van Riel <riel@surriel.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Harry Yoo <harry.yoo@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Qianfeng Rong [Mon, 4 Aug 2025 12:56:57 +0000 (20:56 +0800)]
maple_tree: remove redundant __GFP_NOWARN
Commit 16f5dfbc851b ("gfp: include __GFP_NOWARN in GFP_NOWAIT") made
GFP_NOWAIT implicitly include __GFP_NOWARN.
Therefore, explicit __GFP_NOWARN combined with GFP_NOWAIT (e.g.,
`GFP_NOWAIT | __GFP_NOWARN`) is now redundant. Let's clean up these
redundant flags across subsystems.
No functional changes.
Link: https://lkml.kernel.org/r/20250804125657.482109-1-rongqianfeng@vivo.com Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Qianfeng Rong [Mon, 4 Aug 2025 13:00:17 +0000 (21:00 +0800)]
xarray: remove redundant __GFP_NOWARN
Commit 16f5dfbc851b ("gfp: include __GFP_NOWARN in GFP_NOWAIT") made
GFP_NOWAIT implicitly include __GFP_NOWARN.
Therefore, explicit __GFP_NOWARN combined with GFP_NOWAIT (e.g.,
`GFP_NOWAIT | __GFP_NOWARN`) is now redundant. Let's clean up these
redundant flags across subsystems.
Vitaly Wool [Wed, 6 Aug 2025 12:55:52 +0000 (14:55 +0200)]
rust: support large alignments in allocations
Add support for large (> PAGE_SIZE) alignments in Rust allocators. All
the preparations on the C side are already done, we just need to add
bindings for <alloc>_node_align() functions and start using those.
Link: https://lkml.kernel.org/r/20250806125552.1727073-1-vitaly.wool@konsulko.se Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.se> Acked-by: Danilo Krummrich <dakr@kernel.org> Acked-by: Alice Ryhl <aliceryhl@google.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Jann Horn <jannh@google.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Miguel Ojeda [Sat, 16 Aug 2025 21:02:14 +0000 (23:02 +0200)]
rust: alloc: fix missing import needed for `rusttest`
There is a missing import of `NumaNode` that is used in the `rusttest`
target:
error[E0412]: cannot find type `NumaNode` in this scope
--> rust/kernel/alloc/allocator_test.rs:43:15
|
43 | _nid: NumaNode,
| ^^^^^^^^ not found in this scope
|
help: consider importing this struct
|
12 + use crate::alloc::NumaNode;
|
Thus fix it by adding it.
Link: https://lkml.kernel.org/r/20250816210214.2729269-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Jann Horn <jannh@google.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vitaly Wool <vitaly.wool@konsulko.se> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Vitaly Wool [Wed, 6 Aug 2025 12:55:22 +0000 (14:55 +0200)]
rust: add support for NUMA ids in allocations
Add a new type to support specifying NUMA identifiers in Rust allocators
and extend the allocators to have NUMA id as a parameter. Thus, modify
ReallocFunc to use the new extended realloc primitives from the C side of
the kernel (i.e. k[v]realloc_node_align/vrealloc_node_align) and add the
new function alloc_node to the Allocator trait while keeping the existing
one (alloc) for backward compatibility.
This will allow to specify node to use for allocation of e. g. {KV}Box,
as well as for future NUMA aware users of the API.
Link: https://lkml.kernel.org/r/20250806125522.1726992-1-vitaly.wool@konsulko.se Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.se> Acked-by: Danilo Krummrich <dakr@kernel.org> Acked-by: Alice Ryhl <aliceryhl@google.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Jann Horn <jannh@google.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Vitaly Wool [Wed, 6 Aug 2025 12:41:47 +0000 (14:41 +0200)]
mm/slub: allow to set node and align in k[v]realloc
Reimplement k[v]realloc_node() to be able to set node and alignment should
a user need to do so. In order to do that while retaining the maximal
backward compatibility, add k[v]realloc_node_align() functions and
redefine the rest of API using these new ones.
While doing that, we also keep the number of _noprof variants to a
minimum, which implies some changes to the existing users of older _noprof
functions, that basically being bcachefs.
With that change we also provide the ability for the Rust part of the
kernel to set node and alignment in its K[v]xxx [re]allocations.
Link: https://lkml.kernel.org/r/20250806124147.1724658-1-vitaly.wool@konsulko.se Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.se> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Jann Horn <jannh@google.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Vitaly Wool [Wed, 6 Aug 2025 12:41:08 +0000 (14:41 +0200)]
mm/vmalloc: allow to set node and align in vrealloc
Patch series "support large align and nid in Rust allocators", v15.
The series provides the ability for Rust allocators to set NUMA node and
large alignment.
This patch (of 4):
Reimplement vrealloc() to be able to set node and alignment should a user
need to do so. Rename the function to vrealloc_node_align() to better
match what it actually does now and introduce macros for vrealloc() and
friends for backward compatibility.
With that change we also provide the ability for the Rust part of the
kernel to set node and alignment in its allocations.
Link: https://lkml.kernel.org/r/20250806124034.1724515-1-vitaly.wool@konsulko.se Link: https://lkml.kernel.org/r/20250806124108.1724561-1-vitaly.wool@konsulko.se Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.se> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Jann Horn <jannh@google.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Adrian Huang (Lenovo) [Wed, 6 Aug 2025 14:59:06 +0000 (22:59 +0800)]
mm: correct misleading comment on mmap_lock field in mm_struct
The comment previously described the offset of mmap_lock as 0x120 (hex),
which is misleading. The correct offset is 56 bytes (decimal) from the
last cache line boundary. Using '0x120' could confuse readers trying to
understand why the count and owner fields reside in separate cachelines.
This change also removes an unnecessary space for improved formatting.
Link: https://lkml.kernel.org/r/20250806145906.24647-1-adrianhuang0701@gmail.com Signed-off-by: Adrian Huang (Lenovo) <adrianhuang0701@gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Replace typeof() with __auto_type in the swap() macro in uffd-stress.c.
__auto_type was introduced in GCC 4.9 and reduces the compile time for all
compilers. No functional changes intended.
Kairui Song [Wed, 6 Aug 2025 16:17:48 +0000 (00:17 +0800)]
mm, swap: prefer nonfull over free clusters
We prefer a free cluster over a nonfull cluster whenever a CPU local
cluster is drained to respect the SSD discard behavior [1]. It's not a
best practice for non-discarding devices. And this is causing a higher
fragmentation rate.
So for a non-discarding device, prefer nonfull over free clusters. This
reduces the fragmentation issue by a lot.
Testing with make -j96, defconfig, using 64k mTHP, 8G ZRAM:
Kairui Song [Wed, 6 Aug 2025 16:17:47 +0000 (00:17 +0800)]
mm, swap: remove fragment clusters counter
It was used for calculating the iteration number when the swap allocator
wants to scan the whole fragment list. Now the allocator only scans one
fragment cluster at a time, so no one uses this counter anymore.
Remove it as a cleanup; the performance change is marginal:
Build linux kernel using 10G ZRAM, make -j96, defconfig with 2G cgroup
memory limit, on top of tmpfs, 64kB mTHP enabled:
Link: https://lkml.kernel.org/r/20250806161748.76651-3-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Reviewed-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Chris Li <chrisl@kernel.org> 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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kairui Song [Wed, 6 Aug 2025 16:17:46 +0000 (00:17 +0800)]
mm, swap: only scan one cluster in fragment list
Patch series "mm, swap: improve cluster scan strategy", v2.
This series improves the large allocation performance and reduces the
failure rate. Some design of the cluster alloactor was later found to be
improvable after thorough testing.
The allocator spent too much effort scanning the fragment list, which is
not helpful in most setups, but causes serious contention of the list lock
(si->lock). Besides, the allocator prefers free clusters when searching
for a new cluster due to historical reasons, which causes fragmentation
issues.
So make the allocator only scan one cluster for high order allocation, and
prefer nonfull cluster. This both improves the performance and reduces
fragmentation.
For example, build kernel test with make -j96 and 10G ZRAM with 64kB mTHP
enabled shows better performance and a lower failure rate:
Fragment clusters were mostly failing high order allocation already. The
reason we scan it through now is that a swap slot may get freed without
releasing the swap cache, so a swap map entry will end up in HAS_CACHE
only status, and the cluster won't be moved back to non-full or free
cluster list. This may cause a higher allocation failure rate.
Usually only !SWP_SYNCHRONOUS_IO devices may have a large number of slots
stuck in HAS_CACHE only status. Because when a !SWP_SYNCHRONOUS_IO
device's usage is low (!vm_swap_full()), it will try to lazy free the swap
cache.
But this fragment list scan out is a bit overkill. Fragmentation is
only an issue for the allocator when the device is getting full, and by
that time, swap will be releasing the swap cache aggressively already.
Only scanning one fragment cluster at a time is good enough to reclaim
already pinned slots, and move the cluster back to nonfull.
And besides, only high order allocation requires iterating over the list,
order 0 allocation will succeed on the first attempt. And high order
allocation failure isn't a serious problem.
So the iteration of fragment clusters is trivial, but it will slow down
large allocation by a lot when the fragment cluster list is long. So it's
better to drop this fragment cluster iteration design.
Test on a 48c96t system, build linux kernel using 10G ZRAM, make -j48,
defconfig with 768M cgroup memory limit, on top of tmpfs, 4K folio only:
The performance is a lot better for large folios, and the large order
allocation failure rate is only very slightly higher or unchanged even
for !SWP_SYNCHRONOUS_IO devices high pressure.
Link: https://lkml.kernel.org/r/20250806161748.76651-1-ryncsn@gmail.com Link: https://lkml.kernel.org/r/20250806161748.76651-2-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Chris Li <chrisl@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Suren Baghdasaryan [Mon, 4 Aug 2025 23:33:49 +0000 (16:33 -0700)]
mm: change vma_start_read() to drop RCU lock on failure
vma_start_read() can drop and reacquire RCU lock in certain failure cases.
It's not apparent that the RCU session started by the caller of this
function might be interrupted when vma_start_read() fails to lock the vma.
This might become a source of subtle bugs and to prevent that we change
the locking rules for vma_start_read() to drop RCU read lock upon failure.
This way it's more obvious that RCU-protected objects are unsafe after
vma locking fails.
Suren Baghdasaryan [Mon, 4 Aug 2025 23:33:48 +0000 (16:33 -0700)]
mm: limit the scope of vma_start_read()
Limit the scope of vma_start_read() as it is used only as a helper for
higher-level locking functions implemented inside mmap_lock.c and we are
about to introduce more complex RCU rules for this function. The change
is pure code refactoring and has no functional changes.
Sudarsan Mahendran [Tue, 5 Aug 2025 01:36:29 +0000 (18:36 -0700)]
selftests/mm: pass filename as input param to VM_PFNMAP tests
Enable these tests to be run on other pfnmap'ed memory like NVIDIA's EGM.
Add '--' as a separator to pass in file path. This allows passing of cmd
line arguments to kselftest_harness. Use '/dev/mem' as default filename.
Existing test passes:
pfnmap
TAP version 13
1..6
# Starting 6 tests from 1 test cases.
# PASSED: 6 / 6 tests passed.
# Totals: pass:6 fail:0 xfail:0 xpass:0 skip:0 error:0
Pass params to kselftest_harness:
pfnmap -r pfnmap:mremap_fixed
TAP version 13
1..1
# Starting 1 tests from 1 test cases.
# RUN pfnmap.mremap_fixed ...
# OK pfnmap.mremap_fixed
ok 1 pfnmap.mremap_fixed
# PASSED: 1 / 1 tests passed.
# Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0
Pass non-existent file name as input:
pfnmap -- /dev/blah
TAP version 13
1..6
# Starting 6 tests from 1 test cases.
# RUN pfnmap.madvise_disallowed ...
# SKIP Cannot open '/dev/blah'
Pass non pfnmap'ed file as input:
pfnmap -r pfnmap.madvise_disallowed -- randfile.txt
TAP version 13
1..1
# Starting 1 tests from 1 test cases.
# RUN pfnmap.madvise_disallowed ...
# SKIP Invalid file: 'randfile.txt'. Not pfnmap'ed
Link: https://lkml.kernel.org/r/20250805013629.47629-1-sudarsanm@google.com Signed-off-by: Sudarsan Mahendran <sudarsanm@google.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Sergey Senozhatsky [Tue, 5 Aug 2025 10:19:29 +0000 (19:19 +0900)]
zram: protect recomp_algorithm_show() with ->init_lock
sysfs handlers should be called under ->init_lock and are not supposed to
unlock it until return, otherwise e.g. a concurrent reset() can occur.
There is one handler that breaks that rule: recomp_algorithm_show().
Move ->init_lock handling outside of __comp_algorithm_show() (also drop it
and call zcomp_available_show() directly) so that the entire
recomp_algorithm_show() loop is protected by the lock, as opposed to
protecting individual iterations.
The patch does not need to go to -stable, as it does not fix any
runtime errors (at least I can't think of any). It makes
recomp_algorithm_show() "atomic" w.r.t. zram reset() (just like the
rest of zram sysfs show() handlers), that's a pretty minor change.
/dev/zero: try to align PMD_SIZE for private mapping
Attempt to map aligned to huge page size for private mapping which could
achieve performance gains, the mprot_tw4m in libMicro average execution
time on arm64:
- Test case: mprot_tw4m
- Before the patch: 22 us
- After the patch: 17 us
If THP config is not set, we fall back to system page size mappings.
Link: https://lkml.kernel.org/r/20250731122305.2669090-1-zhangqilong3@huawei.com Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Tested-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Goto-san reported confusing pgpromote statistics where the
pgpromote_success count significantly exceeded pgpromote_candidate.
On a system with three nodes (nodes 0-1: DRAM 4GB, node 2: NVDIMM 4GB):
# Enable demotion only
echo 1 > /sys/kernel/mm/numa/demotion_enabled
numactl -m 0-1 memhog -r200 3500M >/dev/null &
pid=$!
sleep 2
numactl memhog -r100 2500M >/dev/null &
sleep 10
kill -9 $pid # terminate the 1st memhog
# Enable promotion
echo 2 > /proc/sys/kernel/numa_balancing
After a few seconds, we observeed `pgpromote_candidate < pgpromote_success`
$ grep -e pgpromote /proc/vmstat
pgpromote_success 2579
pgpromote_candidate 0
In this scenario, after terminating the first memhog, the conditions for
pgdat_free_space_enough() are quickly met, and triggers promotion.
However, these migrated pages are only counted for in PGPROMOTE_SUCCESS,
not in PGPROMOTE_CANDIDATE.
To solve these confusing statistics, introduce PGPROMOTE_CANDIDATE_NRL to
count the missed promotion pages. And also, not counting these pages into
PGPROMOTE_CANDIDATE is to avoid changing the existing algorithm or
performance of the promotion rate limit.
Link: https://lkml.kernel.org/r/20250729035101.1601407-1-ruansy.fnst@fujitsu.com Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> Signed-off-by: Ruan Shiyang <ruansy.fnst@fujitsu.com> Reported-by: Yasunori Gotou (Fujitsu) <y-goto@fujitsu.com> Suggested-by: Huang Ying <ying.huang@linux.alibaba.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Valentin Schneider <vschneid@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/mglru: update MG-LRU proactive reclaim statistics only to memcg
Users can use /sys/kernel/debug/lru_gen to trigger proactive memory
reclaim of a specified memcg. Currently, statistics such as pgrefill,
pgscan and pgsteal will be updated to the /proc/vmstat system memory
statistics.
This will confuse some system memory pressure monitoring tools, making it
difficult to determine whether pgscan and pgsteal are caused by
system-level pressure or by proactive memory reclaim of some specific
memory cgroup.
Therefore, make this interface behave similarly to memory.reclaim. Update
proactive memory reclaim statistics only to its memory cgroup.
Link: https://lkml.kernel.org/r/20250717082845.34673-1-jiahao.kernel@gmail.com Signed-off-by: Hao Jia <jiahao1@lixiang.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kinsey Ho <kinseyho@google.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Yuanchu Xie <yuanchu@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Joshua Hahn [Tue, 5 Aug 2025 20:50:47 +0000 (13:50 -0700)]
mempolicy: clarify what zone reclaim means
The zone_reclaim_mode API controls the reclaim behavior when a node runs
out of memory. Contrary to its user-facing name, it is internally
referred to as "node_reclaim_mode".
This can be confusing. But because we cannot change the name of the API
since it has been in place since at least 2.6, let's try to be more
explicit about what the behavior of this API is.
Change the description to clarify what zone reclaim entails, and be
explicit about the RECLAIM_ZONE bit, whose purpose has led to some
confusion in the past already [1] [2].
While at it, also soften the warning about changing these bits.
mm/userfaultfd: fix kmap_local LIFO ordering for CONFIG_HIGHPTE
With CONFIG_HIGHPTE on 32-bit ARM, move_pages_pte() maps PTE pages using
kmap_local_page(), which requires unmapping in Last-In-First-Out order.
The current code maps dst_pte first, then src_pte, but unmaps them in the
same order (dst_pte, src_pte), violating the LIFO requirement. This
causes the warning in kunmap_local_indexed():
Fix this by reversing the unmap order to respect LIFO ordering.
This issue follows the same pattern as similar fixes:
- commit eca6828403b8 ("crypto: skcipher - fix mismatch between mapping and unmapping order")
- commit 8cf57c6df818 ("nilfs2: eliminate staggered calls to kunmap in nilfs_rename")
Both of which addressed the same fundamental requirement that kmap_local
operations must follow LIFO ordering.
Link: https://lkml.kernel.org/r/20250731144431.773923-1-sashal@kernel.org Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI") Signed-off-by: Sasha Levin <sashal@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Also, do_migrate_range() may be called between memory_failure() setting
the hwposion flag and isolation of the folio from the lru, so remove
WARN_ON().
Also, in other places unmap_poisoned_folio() is called when the folio is
isolated, so obey that in do_migrate_range().
Link: https://lkml.kernel.org/r/20250627125747.3094074-3-tujinjiang@huawei.com Fixes: b15c87263a69 ("hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined") Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Sumanth Korikkar [Thu, 7 Aug 2025 18:35:45 +0000 (20:35 +0200)]
mm: fix accounting of memmap pages
For !CONFIG_SPARSEMEM_VMEMMAP, memmap page accounting is currently done
upfront in sparse_buffer_init(). However, sparse_buffer_alloc() may
return NULL in failure scenario.
Also, memmap pages may be allocated either from the memblock allocator
during early boot or from the buddy allocator. When removed via
arch_remove_memory(), accounting of memmap pages must reflect the original
allocation source.
To ensure correctness:
* Account memmap pages after successful allocation in sparse_init_nid()
and section_activate().
* Account memmap pages in section_deactivate() based on allocation
source.
Brian Mak [Tue, 5 Aug 2025 21:15:26 +0000 (14:15 -0700)]
kexec: add KEXEC_FILE_NO_CMA as a legal flag
Commit 07d24902977e ("kexec: enable CMA based contiguous allocation")
introduces logic to use CMA-based allocation in kexec by default. As part
of the changes, it introduces a kexec_file_load flag to disable the use of
CMA allocations from userspace. However, this flag is broken since it is
missing from the list of legal flags for kexec_file_load. kexec_file_load
returns EINVAL when attempting to use the flag.
Fix this by adding the KEXEC_FILE_NO_CMA flag to the list of legal flags
for kexec_file_load.
Link: https://lkml.kernel.org/r/20250805211527.122367-2-makb@juniper.net Fixes: 07d24902977e ("kexec: enable CMA based contiguous allocation") Signed-off-by: Brian Mak <makb@juniper.net> Cc: Alexander Graf <graf@amazon.com> Cc: Baoquan He <bhe@redhat.com> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Young <dyoung@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Rob Herring <robh@kernel.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Zi Yan [Tue, 5 Aug 2025 17:51:40 +0000 (13:51 -0400)]
selftests/mm: fix FORCE_READ to read input value correctly
FORCE_READ() converts input value x to its pointer type then reads from
address x. This is wrong. If x is a non-pointer, it would be caught it
easily. But all FORCE_READ() callers are trying to read from a pointer
and FORCE_READ() basically reads a pointer to a pointer instead of the
original typed pointer. Almost no access violation was found, except the
one from split_huge_page_test.
Fix it by implementing a simplified READ_ONCE() instead.
Link: https://lkml.kernel.org/r/20250805175140.241656-1-ziy@nvidia.com Fixes: 3f6bfd4789a0 ("selftests/mm: reuse FORCE_READ to replace "asm volatile("" : "+r" (XXX));"") Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by:wang lian <lianux.mm@gmail.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Kairui Song <ryncsn@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mark Brown <broonie@kernel.org> Cc: SeongJae Park <sj@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Li RongQing [Thu, 14 Aug 2025 10:23:33 +0000 (18:23 +0800)]
mm/hugetlb: early exit from hugetlb_pages_alloc_boot() when max_huge_pages=0
Optimize hugetlb_pages_alloc_boot() to return immediately when
max_huge_pages is 0, avoiding unnecessary CPU cycles and the below log
message when hugepages aren't configured in the kernel command line.
[ 3.702280] HugeTLB: allocation took 0ms with hugepage_allocation_threads=32
Link: https://lkml.kernel.org/r/20250814102333.4428-1-lirongqing@baidu.com Signed-off-by: Li RongQing <lirongqing@baidu.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Tested-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Jane Chu <jane.chu@oracle.com> Cc: David Hildenbrand <david@redhat.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
SeongJae Park [Sat, 16 Aug 2025 16:55:59 +0000 (09:55 -0700)]
mm/damon/sysfs-schemes: put damos dests dir after removing its files
damon_sysfs_scheme_rm_dirs() puts dests directory kobject before removing
its internal files. Sincee putting the kobject frees its container
struct, and the internal files removal accesses the container,
use-after-free happens. Fix it by putting the reference _after_ removing
the files.
The reason is that defined(CONFIG_ZSMALLOC) evaluates to 1 only when
CONFIG_ZSMALLOC=y, we should use IS_ENABLED(CONFIG_ZSMALLOC) instead. But
when I use IS_ENABLED(CONFIG_ZSMALLOC), page_movable_ops() cannot access
zsmalloc_mops because zsmalloc_mops is in a module.
To solve this problem, we define a set_movable_ops() interface to register
and unregister offline_movable_ops / zsmalloc_movable_ops in mm/migrate.c,
and call them at mm/balloon_compaction.c & mm/zsmalloc.c. Since
offline_movable_ops / zsmalloc_movable_ops are always accessible, all
#ifdef / #endif are removed in page_movable_ops().
Link: https://lkml.kernel.org/r/20250817151759.2525174-1-chenhuacai@loongson.cn Fixes: 84caf98838a3 ("mm: stop storing migration_ops in page->mapping") Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Huacai Chen <chenhuacai@loongson.cn> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Sang-Heon Jeon [Sat, 16 Aug 2025 01:51:16 +0000 (10:51 +0900)]
mm/damon/core: fix damos_commit_filter not changing allow
Current damos_commit_filter() does not persist the `allow' value of the
filter. As a result, changing the `allow' value of a filter and
committing doesn't change the `allow' value.
Add the missing `allow' value update, so committing the filter
persistently changes the `allow' value well.
Jinjiang Tu [Fri, 15 Aug 2025 07:32:09 +0000 (15:32 +0800)]
mm/memory-failure: fix infinite UCE for VM_PFNMAP pfn
When memory_failure() is called for a already hwpoisoned pfn,
kill_accessing_process() will be called to kill current task. However, if
the vma of the accessing vaddr is VM_PFNMAP, walk_page_range() will skip
the vma in walk_page_test() and return 0.
Before commit aaf99ac2ceb7 ("mm/hwpoison: do not send SIGBUS to processes
with recovered clean pages"), kill_accessing_process() will return EFAULT.
For x86, the current task will be killed in kill_me_maybe().
However, after this commit, kill_accessing_process() simplies return 0,
that means UCE is handled properly, but it doesn't actually. In such
case, the user task will trigger UCE infinitely.
To fix it, add .test_walk callback for hwpoison_walk_ops to scan all vmas.
Link: https://lkml.kernel.org/r/20250815073209.1984582-1-tujinjiang@huawei.com Fixes: aaf99ac2ceb7 ("mm/hwpoison: do not send SIGBUS to processes with recovered clean pages") Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Jane Chu <jane.chu@oracle.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Shuai Xue <xueshuai@linux.alibaba.com> Cc: Zi Yan <ziy@nvidia.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Axel Rasmussen [Fri, 15 Aug 2025 21:59:14 +0000 (14:59 -0700)]
MAINTAINERS: mark MGLRU as maintained
The three folks being added here are actively working on MGLRU within
Google, so we can review patches for this feature and plan to contribute
some improvements / extensions to it on an ongoing basis.
With three of us we may have some hope filling Yu Zhao's shoes, since he
has moved on to other projects these days.
Link: https://lkml.kernel.org/r/20250815215914.3671925-1-axelrasmussen@google.com Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Alice Ryhl [Thu, 14 Aug 2025 07:54:54 +0000 (07:54 +0000)]
mm: rust: add page.rs to MEMORY MANAGEMENT - RUST
The page.rs file currently isn't included anywhere, and I think it's a
good fit for the MEMORY MANAGEMENT - RUST entry. The file was originally
added for use by Rust Binder, but I believe there is also work to use it
in the upcoming scatterlist abstractions.
This should have been fine because we're only in the 2nd slot and there's
another one after this, but iterate_folioq should not try to map a folio
that skips the whole size, and more importantly part here does not end up
zero (because 'PAGE_SIZE - skip % PAGE_SIZE' ends up PAGE_SIZE and not
zero..), so skip forward to the "advance to next folio" code
Sang-Heon Jeon [Tue, 12 Aug 2025 14:00:46 +0000 (23:00 +0900)]
selftests/damon: fix selftests by installing drgn related script
drgn_dump_damon_status is not installed during kselftest setup. It can
break other tests which depend on drgn_dump_damon_status. Install
drgn_dump_damon_status files to fix broken test.
Link: https://lkml.kernel.org/r/20250812140046.660486-1-ekffu200098@gmail.com Fixes: f3e8e1e51362 ("selftests/damon: add drgn script for extracting damon status") Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Honggyu Kim <honggyu.kim@sk.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Easwar Hariharan [Tue, 12 Aug 2025 18:02:14 +0000 (18:02 +0000)]
.mailmap: add entry for Easwar Hariharan
Map my old, obsolete work email address to my current one.
Link: https://lkml.kernel.org/r/20250812180218.92755-1-easwar.hariharan@linux.microsoft.com Signed-off-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com> Cc: Carlos Bilbao <carlos.bilbao@kernel.org> Cc: Jarkko Sakkinen <jarkko@kernel.org> Cc: Shannon Nelson <sln@onemain.com> Cc: Dmitry Baryshkov <lumag@kernel.org> Cc: Hans Verkuil <hverkuil@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lorenzo Stoakes [Sun, 3 Aug 2025 11:11:23 +0000 (12:11 +0100)]
selftests/mm: add test for invalid multi VMA operations
We can use UFFD to easily assert invalid multi VMA moves, so do so,
asserting expected behaviour when VMAs invalid for a multi VMA operation
are encountered.
We assert both that such operations are not permitted, and that we do not
even attempt to move the first VMA under these circumstances.
We also assert that we can still move a single VMA regardless.
We then assert that a partial failure can occur if the invalid VMA appears
later in the range of multiple VMAs, both at the very next VMA, and also at
the end of the range.
As part of this change, we are using the is_range_valid() helper more
aggressively. Therefore, fix a bug where stale buffered data would hang
around on success, causing subsequent calls to is_range_valid() to
potentially give invalid results.
We simply have to fflush() the stream on success to resolve this issue.
Link: https://lkml.kernel.org/r/c4fb86dd5ba37610583ad5fc0e0c2306ddf318b9.1754218667.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lorenzo Stoakes [Sun, 3 Aug 2025 11:11:22 +0000 (12:11 +0100)]
mm/mremap: catch invalid multi VMA moves earlier
Previously, any attempt to solely move a VMA would require that the
span specified reside within the span of that single VMA, with no gaps
before or afterwards.
After commit d23cb648e365 ("mm/mremap: permit mremap() move of multiple
VMAs"), the multi VMA move permitted a gap to exist only after VMAs.
This was done to provide maximum flexibility.
However, We have consequently permitted this behaviour for the move of
a single VMA including those not eligible for multi VMA move.
The change introduced here means that we no longer permit non-eligible
VMAs from being moved in this way.
This is consistent, as it means all eligible VMA moves are treated the
same, and all non-eligible moves are treated as they were before.
This change does not break previous behaviour, which equally would have
disallowed such a move (only in all cases).
Link: https://lkml.kernel.org/r/2b5aad5681573be85b5b8fac61399af6fb6b68b6.1754218667.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Hildenbrand <david@redhat.com> Cc: Jann Horn <jannh@google.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>
Lorenzo Stoakes [Sun, 3 Aug 2025 11:11:21 +0000 (12:11 +0100)]
mm/mremap: allow multi-VMA move when filesystem uses thp_get_unmapped_area
The multi-VMA move functionality introduced in commit d23cb648e365
("mm/mremap: permit mremap() move of multiple VMA") doesn't allow moves of
file-backed mappings which specify a custom f_op->get_unmapped_area
handler excepting hugetlb and shmem.
We expand this to include thp_get_unmapped_area to support file-backed
mappings for filesystems which use large folios.
Additionally, when the first VMA in a range is not compatible with a
multi-VMA move, instead of moving the first VMA and returning an error,
this series results in us not moving anything and returning an error
immediately.
Examining this second change in detail:
The semantics of multi-VMA moves in mremap() very clearly indicate that a
failure can result in a partial move of VMAs.
This is in line with other aggregate operations within the kernel, which
share these semantics.
There are two classes of failures we're concerned with - eligiblity for
mutli-VMA move, and transient failures that would occur even if the user
individually moved each VMA.
The latter is due to out-of-memory conditions (which, given the
allocations involved are small, would likely be fatal in any case), or
hitting the mapping limit.
Regardless of the cause, transient issues would be fatal anyway, so it
isn't really material which VMAs succeeded at being moved or not.
However with when it comes to multi-VMA move eligiblity, we face another
issue - we must allow a single VMA to succeed regardless of this
eligiblity (as, of course, it is not a multi-VMA move) - but we must then
fail multi-VMA operations.
The two means by which VMAs may fail the eligbility test are - the VMAs
being UFFD-armed, or the VMA being file-backed and providing its own
f_op->get_unmapped_area() helper (because this may result in MREMAP_FIXED
being disregarded), excepting those known to correctly handle
MREMAP_FIXED.
It is therefore conceivable that a user could erroneously try to use this
functionality in these instances, and would prefer to not perform any move
at all should that occur.
This series therefore avoids any move of subsequent VMAs should the first
be multi-VMA move ineligble and the input span exceeds that of the first
VMA.
We also add detailed test logic to assert that multi VMA move with
ineligible VMAs functions as expected.
This patch (of 3):
We currently restrict multi-VMA move to avoid filesystems or drivers which
provide a custom f_op->get_unmapped_area handler unless it is known to
correctly handle MREMAP_FIXED.
We do this so we do not get unexpected result when moving from one area to
another (for instance, if the handler would align things resulting in the
moved VMAs having different gaps than the original mapping).
More and more filesystems are moving to using large folios, and typically
do so (in part) by setting f_op->get_unmapped_area to
thp_get_unmapped_area.
When mremap() invokes the file system's get_unmapped MREMAP_FIXED, it does
so via get_unmapped_area(), called in vrm_set_new_addr(). In order to do
so, it converts the MREMAP_FIXED flag to a MAP_FIXED flag and passes this
to the unmapped area handler.
The __get_unmapped_area() function (called by get_unmapped_area()) in turn
invokes the filesystem or driver's f_op->get_unmapped_area() handler.
Therefore this is a point at which thp_get_unmapped_area() may be called
(also, this is the case for anonymous mappings where the size is huge page
aligned).
thp_get_unmapped_area() calls thp_get_unmapped_area_vmflags() and
__thp_get_unmapped_area() in turn (falling back to
mm_get_unmapped_area_vm_flags() which is known to handle MAP_FIXED
correctly).
The __thp_get_unmapped_area() function in turn does nothing to change the
address hint, nor the MAP_FIXED flag, only adjusting alignment parameters.
It hten calls mm_get_unmapped_area_vmflags(), and in turn arch-specific
unmapped area functions, all of which honour MAP_FIXED correctly.
Therefore, we can safely add thp_get_unmapped_area to the known-good
handlers.
Sang-Heon Jeon [Sun, 10 Aug 2025 12:42:01 +0000 (21:42 +0900)]
mm/damon/core: fix commit_ops_filters by using correct nth function
damos_commit_ops_filters() incorrectly uses damos_nth_filter() which
iterates core_filters. As a result, performing a commit unintentionally
corrupts ops_filters.
Add damos_nth_ops_filter() which iterates ops_filters. Use this function
to fix issues caused by wrong iteration.
Link: https://lkml.kernel.org/r/20250810124201.15743-1-ekffu200098@gmail.com Fixes: 3607cc590f18 ("mm/damon/core: support committing ops_filters") # 6.15.x Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Lorenzo Stoakes [Mon, 11 Aug 2025 05:26:54 +0000 (06:26 +0100)]
tools/testing: add linux/args.h header and fix radix, VMA tests
Commit 857d18f23ab1 ("cleanup: Introduce ACQUIRE() and ACQUIRE_ERR() for
conditional locks") accidentally broke the radix tree, VMA userland tests
by including linux/args.h which is not present in the tools/include
directory.
This patch copies this over and adds an #ifdef block to avoid duplicate
__CONCAT declaration in conflict with system headers when we ultimately
include this.
Link: https://lkml.kernel.org/r/20250811052654.33286-1-lorenzo.stoakes@oracle.com Fixes: 857d18f23ab1 ("cleanup: Introduce ACQUIRE() and ACQUIRE_ERR() for conditional locks") Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Cc: Jann Horn <jannh@google.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
mm/debug_vm_pgtable: clear page table entries at destroy_args()
The mm/debug_vm_pagetable test allocates manually page table entries for
the tests it runs, using also its manually allocated mm_struct. That in
itself is ok, but when it exits, at destroy_args() it fails to clear those
entries with the *_clear functions.
The problem is that leaves stale entries. If another process allocates an
mm_struct with a pgd at the same address, it may end up running into the
stale entry. This is happening in practice on a debug kernel with
CONFIG_DEBUG_VM_PGTABLE=y, for example this is the output with some extra
debugging I added (it prints a warning trace if pgtables_bytes goes
negative, in addition to the warning at check_mm() function):
Here the modprobe process ended up with an allocated mm_struct from the
mm_struct slab that was used before by the debug_vm_pgtable test. That is
not a problem, since the mm_struct is initialized again etc., however, if
it ends up using the same pgd table, it bumps into the old stale entry
when clearing/freeing the page table entries, so it tries to free an entry
already gone (that one which was allocated by the debug_vm_pgtable test),
which also explains the negative pgtables_bytes since it's accounting for
not allocated entries in the current process.
As far as I looked pgd_{alloc,free} etc. does not clear entries, and
clearing of the entries is explicitly done in the free_pgtables->
free_pgd_range->free_p4d_range->free_pud_range->free_pmd_range->
free_pte_range path. However, the debug_vm_pgtable test does not call
free_pgtables, since it allocates mm_struct and entries manually for its
test and eg. not goes through page faults. So it also should clear
manually the entries before exit at destroy_args().
This problem was noticed on a reboot X number of times test being done on
a powerpc host, with a debug kernel with CONFIG_DEBUG_VM_PGTABLE enabled.
Depends on the system, but on a 100 times reboot loop the problem could
manifest once or twice, if a process ends up getting the right mm->pgd
entry with the stale entries used by mm/debug_vm_pagetable. After using
this patch, I couldn't reproduce/experience the problems anymore. I was
able to reproduce the problem as well on latest upstream kernel (6.16).
I also modified destroy_args() to use mmput() instead of mmdrop(), there
is no reason to hold mm_users reference and not release the mm_struct
entirely, and in the output above with my debugging prints I already had
patched it to use mmput, it did not fix the problem, but helped in the
debugging as well.
Pasha Tatashin [Fri, 8 Aug 2025 20:18:04 +0000 (20:18 +0000)]
kho: warn if KHO is disabled due to an error
During boot scratch area is allocated based on command line parameters or
auto calculated. However, scratch area may fail to allocate, and in that
case KHO is disabled. Currently, no warning is printed that KHO is
disabled, which makes it confusing for the end user to figure out why KHO
is not available. Add the missing warning message.
Link: https://lkml.kernel.org/r/20250808201804.772010-4-pasha.tatashin@soleen.com Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Pratyush Yadav <pratyush@kernel.org> Cc: Alexander Graf <graf@amazon.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baoquan He <bhe@redhat.com> Cc: Changyuan Lyu <changyuanl@google.com> Cc: Coiby Xu <coxu@redhat.com> Cc: Dave Vasilevsky <dave@vasilevsky.ca> Cc: Eric Biggers <ebiggers@google.com> Cc: Kees Cook <kees@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pasha Tatashin [Fri, 8 Aug 2025 20:18:03 +0000 (20:18 +0000)]
kho: mm: don't allow deferred struct page with KHO
KHO uses struct pages for the preserved memory early in boot, however,
with deferred struct page initialization, only a small portion of memory
has properly initialized struct pages.
This problem was detected where vmemmap is poisoned, and illegal flag
combinations are detected.
Don't allow them to be enabled together, and later we will have to teach
KHO to work properly with deferred struct page init kernel feature.
Link: https://lkml.kernel.org/r/20250808201804.772010-3-pasha.tatashin@soleen.com Fixes: 4e1d010e3bda ("kexec: add config option for KHO") Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Pratyush Yadav <pratyush@kernel.org> Cc: Alexander Graf <graf@amazon.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baoquan He <bhe@redhat.com> Cc: Changyuan Lyu <changyuanl@google.com> Cc: Coiby Xu <coxu@redhat.com> Cc: Dave Vasilevsky <dave@vasilevsky.ca> Cc: Eric Biggers <ebiggers@google.com> Cc: Kees Cook <kees@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pasha Tatashin [Fri, 8 Aug 2025 20:18:02 +0000 (20:18 +0000)]
kho: init new_physxa->phys_bits to fix lockdep
Patch series "Several KHO Hotfixes".
Three unrelated fixes for Kexec Handover.
This patch (of 3):
Lockdep shows the following warning:
INFO: trying to register non-static key. The code is fine but needs
lockdep annotation, or maybe you didn't initialize this object before use?
turning off the locking correctness validator.
Linus Torvalds [Wed, 13 Aug 2025 18:29:27 +0000 (11:29 -0700)]
Merge tag 'erofs-for-6.17-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs
Pull erofs fixes from Gao Xiang:
- Align FSDAX enablement among multiple devices
- Fix EROFS_FS_ZIP_ACCEL build dependency again to prevent forcing
CRYPTO{,_DEFLATE}=y even if EROFS=m
- Fix atomic context detection to properly launch kworkers on demand
- Fix block count statistics for 48-bit addressing support
* tag 'erofs-for-6.17-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
erofs: fix block count report when 48-bit layout is on
erofs: fix atomic context detection when !CONFIG_DEBUG_LOCK_ALLOC
erofs: Do not select tristate symbols from bool symbols
erofs: Fallback to normal access if DAX is not supported on extra device
Linus Torvalds [Wed, 13 Aug 2025 17:23:28 +0000 (10:23 -0700)]
Merge tag 'rcu.fixes.6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux
Pull RCU fix from Neeraj Upadhyay:
"Fix a regression introduced by commit b41642c87716 ("rcu: Fix
rcu_read_unlock() deadloop due to IRQ work") which results in boot
hang as reported by kernel test bot at [1].
This issue happens because RCU re-initializes the deferred QS IRQ work
everytime it is queued. With commit b41642c87716, the IRQ work
re-initialization can happen while it is already queued. This results
in IRQ work being requeued to itself. When IRQ work finally fires, as
it is requeued to itself, it is repeatedly executed and results in
hang.
Fix this with initializing the IRQ work only once before the CPU
boots"
Linus Torvalds [Wed, 13 Aug 2025 15:28:33 +0000 (08:28 -0700)]
Merge tag 'mm-hotfixes-stable-2025-08-12-20-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"12 hotfixes. 5 are cc:stable and the remainder address post-6.16
issues or aren't considered necessary for -stable kernels.
10 of these fixes are for MM"
* tag 'mm-hotfixes-stable-2025-08-12-20-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
proc: proc_maps_open allow proc_mem_open to return NULL
mm/mremap: avoid expensive folio lookup on mremap folio pte batch
userfaultfd: fix a crash in UFFDIO_MOVE when PMD is a migration entry
mm: pass page directly instead of using folio_page
selftests/proc: fix string literal warning in proc-maps-race.c
fs/proc/task_mmu: hold PTL in pagemap_hugetlb_range and gather_hugetlb_stats
mm/smaps: fix race between smaps_hugetlb_range and migration
mm: fix the race between collapse and PT_RECLAIM under per-vma lock
mm/kmemleak: avoid soft lockup in __kmemleak_do_cleanup()
MAINTAINERS: add Masami as a reviewer of hung task detector
mm/kmemleak: avoid deadlock by moving pr_warn() outside kmemleak_lock
kasan/test: fix protection against compiler elision
Linus Torvalds [Tue, 12 Aug 2025 15:52:05 +0000 (08:52 -0700)]
Merge tag 'for-6.17-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- fix bug in qgroups reporting incorrect usage for higher level qgroups
- in zoned mode, do not select metadata group as finish target
- convert xarray lock to RCU when trying to release extent buffer to
avoid a deadlock
- do not allow relocation on partially dropped subvolumes, which is
normally not possible but has been reported on old filesystems
- in tree-log, report errors on missing block group when unaccounting
log tree extent buffers
- with large folios, fix range length when processing ordered extents
* tag 'for-6.17-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix iteration bug in __qgroup_excl_accounting()
btrfs: zoned: do not select metadata BG as finish target
btrfs: do not allow relocation of partially dropped subvolumes
btrfs: error on missing block group when unaccounting log tree extent buffers
btrfs: fix wrong length parameter for btrfs_cleanup_ordered_extents()
btrfs: make btrfs_cleanup_ordered_extents() support large folios
btrfs: fix subpage deadlock in try_release_subpage_extent_buffer()
Linus Torvalds [Tue, 12 Aug 2025 15:19:23 +0000 (08:19 -0700)]
Merge tag 'snp_cache_coherency' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
- Add a mitigation for a cache coherency vulnerability when running an
SNP guest which makes sure all cache lines belonging to a 4K page are
evicted after latter has been converted to a guest-private page
[ SNP: Secure Nested Paging - not to be confused with Single Nucleotide
Polymorphism, which is the more common use of that TLA. I am on a
mission to write out the more obscure TLAs in order to keep track of
them.
Because while math tells us that there are only about 17k different
combinations of three-letter acronyms using English letters (26^3), I
am convinced that somehow Intel, AMD and ARM have together figured out
new mathematics, and have at least a million different TLAs that they
use. - Linus ]
* tag 'snp_cache_coherency' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sev: Evict cache lines during SNP memory validation
projects / users / jedix / linux-maple.git / log