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2025-11-16mm/huge_memory: update folio stat after successful splitWei Yang
The current implementation complicates this process: * It iterates over the resulting new folios. * It uses a flag (@stop_split) to conditionally skip updating the stat for the folio at @split_at during the loop. * It then attempts to update the skipped stat on a subsequent failure path. This logic is unnecessarily hard to follow. This commit refactors the code to update the folio statistics only after a successful split. This makes the logic much cleaner and sets the stage for further simplification of the stat-handling code. Link: https://lkml.kernel.org/r/20251021212142.25766-3-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: wang lian <lianux.mm@gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/huge_memory: avoid reinvoking folio_test_anon()Wei Yang
Patch series "mm/huge_memory: cleanup __split_unmapped_folio()", v3. This patch series cleans up and optimizes the internal logic of the __split_unmapped_folio() function. The goal is to improve clarity and efficiency by eliminating redundant checks, caching stable attribute values, and simplifying the iteration logic used for updating folio statistics. These changes make the code easier to follow and maintain. The split_huge_page_test selftest pass. This patch (of 4): During the execution of __split_unmapped_folio(), the folio's anon/!anon attribute is invariant (not expected to change). Therefore, it is safe and more efficient to retrieve this attribute once at the start and reuse it throughout the function. Link: https://lkml.kernel.org/r/20251021212142.25766-1-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20251016004613.514-1-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20251016004613.514-2-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20251021212142.25766-2-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: wang lian <lianux.mm@gmail.com> Reviewed-by: Barry Song <baohua@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Nico Pache <npache@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/debug_vm_pgtable: add [pte|pmd]_mkwrite_novma() testsAnshuman Khandual
Add some [pte|pmd]_mkwrite_novma() relevant tests. [anshuman.khandual@arm.com: add a new test combination per Huang Ying] Link: https://lkml.kernel.org/r/20251024013137.136926-1-anshuman.khandual@arm.com Link: https://lkml.kernel.org/r/20251022032951.3498553-1-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Huang Ying <ying.huang@linux.alibaba.com> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16iommu/sva: invalidate stale IOTLB entries for kernel address spaceLu Baolu
Introduce a new IOMMU interface to flush IOTLB paging cache entries for the CPU kernel address space. This interface is invoked from the x86 architecture code that manages combined user and kernel page tables, specifically before any kernel page table page is freed and reused. This addresses the main issue with vfree() which is a common occurrence and can be triggered by unprivileged users. While this resolves the primary problem, it doesn't address some extremely rare case related to memory unplug of memory that was present as reserved memory at boot, which cannot be triggered by unprivileged users. The discussion can be found at the link below. Enable SVA on x86 architecture since the IOMMU can now receive notification to flush the paging cache before freeing the CPU kernel page table pages. Link: https://lkml.kernel.org/r/20251022082635.2462433-9-baolu.lu@linux.intel.com Link: https://lore.kernel.org/linux-iommu/04983c62-3b1d-40d4-93ae-34ca04b827e5@intel.com/ Co-developed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Suggested-by: Jann Horn <jannh@google.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Vasant Hegde <vasant.hegde@amd.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yi Lai <yi1.lai@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: introduce deferred freeing for kernel page tablesDave Hansen
This introduces a conditional asynchronous mechanism, enabled by CONFIG_ASYNC_KERNEL_PGTABLE_FREE. When enabled, this mechanism defers the freeing of pages that are used as page tables for kernel address mappings. These pages are now queued to a work struct instead of being freed immediately. This deferred freeing allows for batch-freeing of page tables, providing a safe context for performing a single expensive operation (TLB flush) for a batch of kernel page tables instead of performing that expensive operation for each page table. Link: https://lkml.kernel.org/r/20251022082635.2462433-8-baolu.lu@linux.intel.com Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasant Hegde <vasant.hegde@amd.com> Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yi Lai <yi1.lai@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16x86/mm: use pagetable_free()Lu Baolu
The kernel's memory management subsystem provides a dedicated interface, pagetable_free(), for freeing page table pages. Updates two call sites to use pagetable_free() instead of the lower-level __free_page() or free_pages(). This improves code consistency and clarity, and ensures the correct freeing mechanism is used. Link: https://lkml.kernel.org/r/20251022082635.2462433-7-baolu.lu@linux.intel.com Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasant Hegde <vasant.hegde@amd.com> Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yi Lai <yi1.lai@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: introduce pure page table freeing functionDave Hansen
The pages used for ptdescs are currently freed back to the allocator in a single location. They will shortly be freed from a second location. Create a simple helper that just frees them back to the allocator. Link: https://lkml.kernel.org/r/20251022082635.2462433-6-baolu.lu@linux.intel.com Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasant Hegde <vasant.hegde@amd.com> Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yi Lai <yi1.lai@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16x86/mm: use 'ptdesc' when freeing PMD pagesDave Hansen
There are a billion ways to refer to a physical memory address. One of the x86 PMD freeing code location chooses to use a 'pte_t *' to point to a PMD page and then call a PTE-specific freeing function for it. That's a bit wonky. Just use a 'struct ptdesc *' instead. Its entire purpose is to refer to page table pages. It also means being able to remove an explicit cast. Right now, pte_free_kernel() is a one-liner that calls pagetable_dtor_free(). Effectively, all this patch does is remove one superfluous __pa(__va(paddr)) conversion and then call pagetable_dtor_free() directly instead of through a helper. Link: https://lkml.kernel.org/r/20251022082635.2462433-5-baolu.lu@linux.intel.com Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: David Hildenbrand <david@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasant Hegde <vasant.hegde@amd.com> Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yi Lai <yi1.lai@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: actually mark kernel page table pagesDave Hansen
Now that the API is in place, mark kernel page table pages just after they are allocated. Unmark them just before they are freed. Note: Unconditionally clearing the 'kernel' marking (via ptdesc_clear_kernel()) would be functionally identical to what is here. But having the if() makes it logically clear that this function can be used for kernel and non-kernel page tables. Link: https://lkml.kernel.org/r/20251022082635.2462433-4-baolu.lu@linux.intel.com Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasant Hegde <vasant.hegde@amd.com> Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yi Lai <yi1.lai@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: add a ptdesc flag to mark kernel page tablesDave Hansen
The page tables used to map the kernel and userspace often have very different handling rules. There are frequently *_kernel() variants of functions just for kernel page tables. That's not great and has lead to code duplication. Instead of having completely separate call paths, allow a 'ptdesc' to be marked as being for kernel mappings. Introduce helpers to set and clear this status. Note: this uses the PG_referenced bit. Page flags are a great fit for this since it is truly a single bit of information. Use PG_referenced itself because it's a fairly benign flag (as opposed to things like PG_lock). It's also (according to Willy) unlikely to go away any time soon. PG_referenced is not in PAGE_FLAGS_CHECK_AT_FREE. It does not need to be cleared before freeing the page, and pages coming out of the allocator should have it cleared. Regardless, introduce an API to clear it anyway. Having symmetry in the API makes it easier to change the underlying implementation later, like if there was a need to move to a PAGE_FLAGS_CHECK_AT_FREE bit. Link: https://lkml.kernel.org/r/20251022082635.2462433-3-baolu.lu@linux.intel.com Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Kevin Tian <kevin.tian@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasant Hegde <vasant.hegde@amd.com> Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yi Lai <yi1.lai@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16iommu: disable SVA when CONFIG_X86 is setLu Baolu
Patch series "Fix stale IOTLB entries for kernel address space", v7. This proposes a fix for a security vulnerability related to IOMMU Shared Virtual Addressing (SVA). In an SVA context, an IOMMU can cache kernel page table entries. When a kernel page table page is freed and reallocated for another purpose, the IOMMU might still hold stale, incorrect entries. This can be exploited to cause a use-after-free or write-after-free condition, potentially leading to privilege escalation or data corruption. This solution introduces a deferred freeing mechanism for kernel page table pages, which provides a safe window to notify the IOMMU to invalidate its caches before the page is reused. This patch (of 8): In the IOMMU Shared Virtual Addressing (SVA) context, the IOMMU hardware shares and walks the CPU's page tables. The x86 architecture maps the kernel's virtual address space into the upper portion of every process's page table. Consequently, in an SVA context, the IOMMU hardware can walk and cache kernel page table entries. The Linux kernel currently lacks a notification mechanism for kernel page table changes, specifically when page table pages are freed and reused. The IOMMU driver is only notified of changes to user virtual address mappings. This can cause the IOMMU's internal caches to retain stale entries for kernel VA. Use-After-Free (UAF) and Write-After-Free (WAF) conditions arise when kernel page table pages are freed and later reallocated. The IOMMU could misinterpret the new data as valid page table entries. The IOMMU might then walk into attacker-controlled memory, leading to arbitrary physical memory DMA access or privilege escalation. This is also a Write-After-Free issue, as the IOMMU will potentially continue to write Accessed and Dirty bits to the freed memory while attempting to walk the stale page tables. Currently, SVA contexts are unprivileged and cannot access kernel mappings. However, the IOMMU will still walk kernel-only page tables all the way down to the leaf entries, where it realizes the mapping is for the kernel and errors out. This means the IOMMU still caches these intermediate page table entries, making the described vulnerability a real concern. Disable SVA on x86 architecture until the IOMMU can receive notification to flush the paging cache before freeing the CPU kernel page table pages. Link: https://lkml.kernel.org/r/20251022082635.2462433-1-baolu.lu@linux.intel.com Link: https://lkml.kernel.org/r/20251022082635.2462433-2-baolu.lu@linux.intel.com Fixes: 26b25a2b98e4 ("iommu: Bind process address spaces to devices") Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasant Hegde <vasant.hegde@amd.com> Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yi Lai <yi1.lai@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16memcg: manually uninline __memcg_memory_eventShakeel Butt
__memcg_memory_event() has been unnecessarily marked inline even when it is not really performance critical. It is usually called to track extreme conditions. Over the time, it has evolved to include more functionality and inlining it is causing more harm. Before the patch: $ size mm/memcontrol.o net/ipv4/tcp_input.o net/ipv4/tcp_output.o text data bss dec hex filename 35645 10574 4192 50411 c4eb mm/memcontrol.o 54738 1658 0 56396 dc4c net/ipv4/tcp_input.o 34644 1065 0 35709 8b7d net/ipv4/tcp_output.o After the patch: $ size mm/memcontrol.o net/ipv4/tcp_input.o net/ipv4/tcp_output.o text data bss dec hex filename 35137 10446 4192 49775 c26f mm/memcontrol.o 54322 1562 0 55884 da4c net/ipv4/tcp_input.o 34492 1017 0 35509 8ab5 net/ipv4/tcp_output.o [akpm@linux-foundation.org: use EXPORT_SYMBOL_GPL for __memcg_memory_event, per Michal and Christoph] Link: https://lkml.kernel.org/r/20251021234425.1885471-1-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: SeongJae Park <sj@kernel.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/vmalloc: request large order pages from buddy allocatorVishal Moola (Oracle)
Sometimes, vm_area_alloc_pages() will want many pages from the buddy allocator. Rather than making requests to the buddy allocator for at most 100 pages at a time, we can eagerly request large order pages a smaller number of times. We still split the large order pages down to order-0 as the rest of the vmalloc code (and some callers) depend on it. We still defer to the bulk allocator and fallback path in case of order-0 pages or failure. Running 1000 iterations of allocations on a small 4GB system finds: 1000 2mb allocations: [Baseline] [This patch] real 46.310s real 0m34.582 user 0.001s user 0.006s sys 46.058s sys 0m34.365s 10000 200kb allocations: [Baseline] [This patch] real 56.104s real 0m43.696 user 0.001s user 0.003s sys 55.375s sys 0m42.995s Link: https://lkml.kernel.org/r/20251021194455.33351-2-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/vmstat: fix indentation in fold_diff functionJing Su
Adjust misaligned braces in fold_diff() to improve code readability and maintain consistent coding style. [akpm@linux-foundation.org: add braces, per Vlastimil & Liam] Link: https://lkml.kernel.org/r/aPc4I/8zXCGyiapN@pilot-ThinkCentre-M930t-N000 Signed-off-by: Jing Su <jingsusu@didiglobal.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Donet Tom <donettom@linux.ibm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Dev Jain <dev.jain@arm.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: remove reference to destructor in comment in calculate_sizes()William Kucharski
The commit that removed support for destructors from kmem_cache_alloc() never removed the comment regarding destructors in the explanation of the possible relocation of the free pointer in calculate_sizes(). Link: https://lkml.kernel.org/r/20251021110004.2209008-1-william.kucharski@oracle.com Fixes: 20c2df83d25c ("mm: Remove slab destructors from kmem_cache_create().") Signed-off-by: William Kucharski <william.kucharski@oracle.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Christoph Lameter (Ampere) <cl@gentwo.org> Acked-by: SeongJae Park <sj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Harry Yoo <harry.yoo@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/khugepaged: factor out common logic in [scan,alloc]_sleep_millisecs_store()Leon Hwang
Both scan_sleep_millisecs_store() and alloc_sleep_millisecs_store() perform the same operations: parse the input value, update their respective sleep interval, reset khugepaged_sleep_expire, and wake up the khugepaged thread. Factor out this duplicated logic into a helper function __sleep_millisecs_store(), and simplify both store functions. No functional change intended. Link: https://lkml.kernel.org/r/20251021134431.26488-1-leon.hwang@linux.dev Signed-off-by: Leon Hwang <leon.hwang@linux.dev> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Nico Pache <npache@redhat.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/damon/sysfs: remove misleading todo comment in nid_show()Swaraj Gaikwad
The TODO comment in nid_show() suggested returning an error if the goal was not using nid. However, this comment was found to be inaccurate and misleading.This patch removes the TODO comment without changing any existing behavior. This change follows feedback from SJ who pointed out [1] that wiring-order independence is expected and the function should simply show the last set value. and [2] checkpatch.pl complain about number of chars per line No functional code changes were made. Tested with KUnit: - Built kernel with KUnit and DAMON sysfs tests enabled. - Executed KUnit tests: ./tools/testing/kunit/kunit.py run --kunitconfig ./mm/damon/tests/ - All 25 tests passed, including damon_sysfs_test_add_targets. Link: https://lkml.kernel.org/r/20251021215323.29734-2-swarajgaikwad1925@gmail.com Link: https://lore.kernel.org/lkml/20251020151315.66260-1-sj@kernel.org/ [1] Link: https://lore.kernel.org/lkml/20251021010847.68473-1-sj@kernel.org/ [2] Signed-off-by: Swaraj Gaikwad <swarajgaikwad1925@gmail.com> Suggested-by: SeongJae Park <sj@kernel.org> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: David Hunter <david.hunter.linux@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/vmalloc: use kmalloc_array() instead of kmalloc()Mehdi Ben Hadj Khelifa
The number of NUMA nodes (nr_node_ids) is bounded, so overflow is not a practical concern here. However, using kmalloc_array() better reflects the intent to allocate an array of unsigned ints, and improves consistency with other NUMA-related allocations. No functional change intended. Link: https://lkml.kernel.org/r/20251018201207.27441-1-mehdi.benhadjkhelifa@gmail.com Signed-off-by: Mehdi Ben Hadj Khelifa <mehdi.benhadjkhelifa@gmail.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Khalid Aziz <khalid@kernel.org> Cc: David Hunter <david.hunter.linux@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16vmalloc: separate gfp_mask adjunctive parentheses in __vmalloc_node_noprof() ↵Bagas Sanjaya
kernel-doc comment Sphinx reports htmldocs warning on __vmalloc_node() comment: Documentation/core-api/mm-api:52: ./mm/vmalloc.c:4036: WARNING: Inline strong start-string without end-string. [docutils] Fix it by separating adjunctive parentheses from preceding gfp_mask formatting markup. Link: https://lkml.kernel.org/r/20251020044933.15222-1-bagasdotme@gmail.com Fixes: 32904ba6f5ef ("vmalloc: update __vmalloc_node_noprof() documentation") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Closes: https://lore.kernel.org/linux-next/20251020134902.3a11107e@canb.auug.org.au/ Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Stehen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: update resctl to use mmap_prepareLorenzo Stoakes
Make use of the ability to specify a remap action within mmap_prepare to update the resctl pseudo-lock to use mmap_prepare in favour of the deprecated mmap hook. Link: https://lkml.kernel.org/r/95b28b066f37ca25f56fa9460a9367f1a866f88b.1760959442.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: update mem char driver to use mmap_prepareLorenzo Stoakes
Update the mem char driver (backing /dev/mem and /dev/zero) to use f_op->mmap_prepare hook rather than the deprecated f_op->mmap. The /dev/zero implementation has a very unique and rather concerning characteristic in that it converts MAP_PRIVATE mmap() mappings anonymous when they are, in fact, not. The new f_op->mmap_prepare() can support this, but rather than introducing a helper function to perform this hack (and risk introducing other users), utilise the success hook to do so. We utilise the newly introduced shmem_zero_setup_desc() to allow for the shared mapping case via an f_op->mmap_prepare() hook. We also use the desc->action_error_hook to filter the remap error to -EAGAIN to keep behaviour consistent. Link: https://lkml.kernel.org/r/48f60764d7a6901819d1af778fa33b775d2e8c77.1760959442.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: add shmem_zero_setup_desc()Lorenzo Stoakes
Add the ability to set up a shared anonymous mapping based on a VMA descriptor rather than a VMA. This is a prerequisite for converting to the char mm driver to use the mmap_prepare hook. Link: https://lkml.kernel.org/r/d9181517a7e3d6b014a5697c6990d3722c2c9fcd.1760959442.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/hugetlbfs: update hugetlbfs to use mmap_prepareLorenzo Stoakes
Since we can now perform actions after the VMA is established via mmap_prepare, use desc->action_success_hook to set up the hugetlb lock once the VMA is setup. We also make changes throughout hugetlbfs to make this possible. Note that we must hide newly established hugetlb VMAs from the rmap until the operation is entirely complete as we establish a hugetlb lock during VMA setup that can be raced by rmap users. Link: https://lkml.kernel.org/r/b1afa16d3cfa585a03df9ae215ae9f905b3f0ed7.1760959442.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16doc: update porting, vfs documentation for mmap_prepare actionsLorenzo Stoakes
Now we have introduced the ability to specify that actions should be taken after a VMA is established via the vm_area_desc->action field as specified in mmap_prepare, update both the VFS documentation and the porting guide to describe this. Link: https://lkml.kernel.org/r/472ce3da7662ed1065cc299d14bffb70b1a845e7.1760959442.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: add ability to take further action in vm_area_descLorenzo Stoakes
Some drivers/filesystems need to perform additional tasks after the VMA is set up. This is typically in the form of pre-population. The forms of pre-population most likely to be performed are a PFN remap or the insertion of normal folios and PFNs into a mixed map. We start by implementing the PFN remap functionality, ensuring that we perform the appropriate actions at the appropriate time - that is setting flags at the point of .mmap_prepare, and performing the actual remap at the point at which the VMA is fully established. This prevents the driver from doing anything too crazy with a VMA at any stage, and we retain complete control over how the mm functionality is applied. Unfortunately callers still do often require some kind of custom action, so we add an optional success/error _hook to allow the caller to do something after the action has succeeded or failed. This is done at the point when the VMA has already been established, so the harm that can be done is limited. The error hook can be used to filter errors if necessary. There may be cases in which the caller absolutely must hold the file rmap lock until the operation is entirely complete. It is an edge case, but certainly the hugetlbfs mmap hook requires it. To accommodate this, we add the hide_from_rmap_until_complete flag to the mmap_action type. In this case, if a new VMA is allocated, we will hold the file rmap lock until the operation is entirely completed (including any success/error hooks). Note that we do not need to update __compat_vma_mmap() to accommodate this flag, as this function will be invoked from an .mmap handler whose VMA is not yet visible, so we implicitly hide it from the rmap. If any error arises on these final actions, we simply unmap the VMA altogether. Also update the stacked filesystem compatibility layer to utilise the action behaviour, and update the VMA tests accordingly. While we're here, rename __compat_vma_mmap_prepare() to __compat_vma_mmap() as we are now performing actions invoked by the mmap_prepare in addition to just the mmap_prepare hook. Link: https://lkml.kernel.org/r/2601199a7b2eaeadfcd8ab6e199c6d1706650c94.1760959442.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: introduce io_remap_pfn_range_[prepare, complete]()Lorenzo Stoakes
We introduce the io_remap*() equivalents of remap_pfn_range_prepare() and remap_pfn_range_complete() to allow for I/O remapping via mmap_prepare. Make these internal to mm, as they should only be used by internal helpers. Link: https://lkml.kernel.org/r/4065134f13a24a3e14691b7443bcee7490b18a5c.1760959442.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: abstract io_remap_pfn_range() based on PFNLorenzo Stoakes
The only instances in which we customise this function are ones in which we customise the PFN used. Instances where architectures were not passing the pgprot value through pgprot_decrypted() are ones where pgprot_decrypted() was a no-op anyway, so we can simply always pass pgprot through this function. Use this fact to simplify the use of io_remap_pfn_range(), by abstracting the PFN via io_remap_pfn_range_pfn() and using this instead of providing a general io_remap_pfn_range() function per-architecture. Link: https://lkml.kernel.org/r/d086191bf431b58ce3b231b4f4f555d080f60327.1760959442.git.lorenzo.stoakes@oracle.com Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: add remap_pfn_range_prepare(), remap_pfn_range_complete()Lorenzo Stoakes
We need the ability to split PFN remap between updating the VMA and performing the actual remap, in order to do away with the legacy f_op->mmap hook. To do so, update the PFN remap code to provide shared logic, and also make remap_pfn_range_notrack() static, as its one user, io_mapping_map_user() was removed in commit 9a4f90e24661 ("mm: remove mm/io-mapping.c"). Then, introduce remap_pfn_range_prepare(), which accepts VMA descriptor and PFN parameters, and remap_pfn_range_complete() which accepts the same parameters as remap_pfn_rangte(). remap_pfn_range_prepare() will set the cow vma->vm_pgoff if necessary, so it must be supplied with a correct PFN to do so. While we're here, also clean up the duplicated #ifdef __HAVE_PFNMAP_TRACKING check and put into a single #ifdef/#else block. We keep these internal to mm as they should only be used by internal helpers. Link: https://lkml.kernel.org/r/75b55de63249b3aa0fd5b3b08ed1d3ff19255d0d.1760959442.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Pedro Falcato <pfalcato@suse.de> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/vma: rename __mmap_prepare() function to avoid confusionLorenzo Stoakes
Now we have the f_op->mmap_prepare() hook, having a static function called __mmap_prepare() that has nothing to do with it is confusing, so rename the function to __mmap_setup(). Link: https://lkml.kernel.org/r/d25a22c60ca0f04091697ef9cda0d72ce0cf8af3.1760959442.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16relay: update relay to use mmap_prepareLorenzo Stoakes
It is relatively trivial to update this code to use the f_op->mmap_prepare hook in favour of the deprecated f_op->mmap hook, so do so. Link: https://lkml.kernel.org/r/7c9e82cdddf8b573ea3edb8cdb697363e3ccb5d7.1760959442.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: add vma_desc_size(), vma_desc_pages() helpersLorenzo Stoakes
It's useful to be able to determine the size of a VMA descriptor range used on f_op->mmap_prepare, expressed both in bytes and pages, so add helpers for both and update code that could make use of it to do so. Link: https://lkml.kernel.org/r/74ef338203c9ff08a9ace73a8f1f6116a79112a0.1760959442.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/vma: remove unused function, make internal functions staticLorenzo Stoakes
unlink_file_vma() is not used by anything, so remove it. vma_link() and vma_link_file() are only used within mm/vma.c, so make them static. Link: https://lkml.kernel.org/r/f2ab9ea051225a02e6d1d45a7608f4e149220117.1760959442.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16device/dax: update devdax to use mmap_prepareLorenzo Stoakes
The devdax driver does nothing special in its f_op->mmap hook, so straightforwardly update it to use the mmap_prepare hook instead. Link: https://lkml.kernel.org/r/1e8665d052ac8cf2f7ff92b6c7862614f7fd306c.1760959442.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: Pedro Falcato <pfalcato@suse.de> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/shmem: update shmem to use mmap_prepareLorenzo Stoakes
Patch series "expand mmap_prepare functionality, port more users", v5. Since commit c84bf6dd2b83 ("mm: introduce new .mmap_prepare() file callback"), The f_op->mmap hook has been deprecated in favour of f_op->mmap_prepare. This was introduced in order to make it possible for us to eventually eliminate the f_op->mmap hook which is highly problematic as it allows drivers and filesystems raw access to a VMA which is not yet correctly initialised. This hook also introduced complexity for the memory mapping operation, as we must correctly unwind what we do should an error arises. Overall this interface being so open has caused significant problems for us, including security issues, it is important for us to simply eliminate this as a source of problems. Therefore this series continues what was established by extending the functionality further to permit more drivers and filesystems to use mmap_prepare. We start by udpating some existing users who can use the mmap_prepare functionality as-is. We then introduce the concept of an mmap 'action', which a user, on mmap_prepare, can request to be performed upon the VMA: * Nothing - default, we're done * Remap PFN - perform PFN remap with specified parameters * I/O remap PFN - perform I/O PFN remap with specified parameters By setting the action in mmap_prepare, this allows us to dynamically decide what to do next, so if a driver/filesystem needs to determine whether to e.g. remap or use a mixed map, it can do so then change which is done. This significantly expands the capabilities of the mmap_prepare hook, while maintaining as much control as possible in the mm logic. We split [io_]remap_pfn_range*() functions which allow for PFN remap (a typical mapping prepopulation operation) split between a prepare/complete step, as well as io_mremap_pfn_range_prepare, complete for a similar purpose. From there we update various mm-adjacent logic to use this functionality as a first set of changes. We also add success and error hooks for post-action processing for e.g. output debug log on success and filtering error codes. This patch (of 15): This simply assigns the vm_ops so is easily updated - do so. Link: https://lkml.kernel.org/r/cover.1760959441.git.lorenzo.stoakes@oracle.com Link: https://lkml.kernel.org/r/7b93b1e89028e39507dac5ca01991e1374d5bbe8.1760959442.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baoquan He <bhe@redhat.com> Cc: Chatre, Reinette <reinette.chatre@intel.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Dave Young <dyoung@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Morse <james.morse@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicolas Pitre <nico@fluxnic.net> Cc: Oscar Salvador <osalvador@suse.de> Cc: Robin Murohy <robin.murphy@arm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/damon/reclaim: use min_sz_region for core address alignment when setting ↵Quanmin Yan
regions When setting regions in DAMON_RECLAIM, DAMON_MIN_REGION will be applied as the core address alignment, and the monitoring target address ranges would be aligned on DAMON_MIN_REGION * addr_unit. When users 1) set addr_unit to a value larger than 1, and 2) set the monitoring target address range as not aligned on DAMON_MIN_REGION * addr_unit, it will cause DAMON_RECLAIM to operate on unexpectedly large physical address ranges. For example, if the user sets the monitoring target address range to [4, 8) and addr_unit as 1024, the aimed monitoring target address range is [4 KiB, 8 KiB). Assuming DAMON_MIN_REGION is 4096, so resulting target address range will be [0, 4096) in the DAMON core layer address system, and [0, 4 MiB) in the physical address space, which is an unexpected range. To fix the issue, use min_sz_region for core address alignment when setting regions. Link: https://lkml.kernel.org/r/20251020130125.2875164-3-yanquanmin1@huawei.com Fixes: 7db551fcfb2a ("mm/damon/reclaim: support addr_unit for DAMON_RECLAIM") Signed-off-by: Quanmin Yan <yanquanmin1@huawei.com> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: ze zuo <zuoze1@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/damon: add a min_sz_region parameter to ↵Quanmin Yan
damon_set_region_biggest_system_ram_default() Patch series "mm/damon: fixes for address alignment issues in DAMON_LRU_SORT and DAMON_RECLAIM", v2. In DAMON_LRU_SORT and DAMON_RECLAIM, damon_set_regions() will apply DAMON_MIN_REGION as the core address alignment, and the monitoring target address ranges would be aligned on DAMON_MIN_REGION * addr_unit. When users 1) set addr_unit to a value larger than 1, and 2) set the monitoring target address range as not aligned on DAMON_MIN_REGION * addr_unit, it will cause DAMON_LRU_SORT and DAMON_RECLAIM to operate on unexpectedly large physical address ranges. For example, if the user sets the monitoring target address range to [4, 8) and addr_unit as 1024, the aimed monitoring target address range is [4 KiB, 8 KiB). Assuming DAMON_MIN_REGION is 4096, so resulting target address range will be [0, 4096) in the DAMON core layer address system, and [0, 4 MiB) in the physical address space, which is an unexpected range. To fix the issue, add a min_sz_region parameter to damon_set_region_biggest_system_ram_default() and use it when calling damon_set_regions(), replacing the direct use of DAMON_MIN_REGION. This patch (of 2): In DAMON_LRU_SORT, damon_set_regions() will apply DAMON_MIN_REGION as the core address alignment, and the monitoring target address ranges would be aligned on DAMON_MIN_REGION * addr_unit. When users 1) set addr_unit to a value larger than 1, and 2) set the monitoring target address range as not aligned on DAMON_MIN_REGION * addr_unit, it will cause DAMON_LRU_SORT to operate on unexpectedly large physical address ranges. For example, if the user sets the monitoring target address range to [4, 8) and addr_unit as 1024, the aimed monitoring target address range is [4 KiB, 8 KiB). Assuming DAMON_MIN_REGION is 4096, so resulting target address range will be [0, 4096) in the DAMON core layer address system, and [0, 4 MiB) in the physical address space, which is an unexpected range. To fix the issue, add a min_sz_region parameter to damon_set_region_biggest_system_ram_default() and use it when calling damon_set_regions(), replacing the direct use of DAMON_MIN_REGION. Link: https://lkml.kernel.org/r/20251020130125.2875164-1-yanquanmin1@huawei.com Link: https://lkml.kernel.org/r/20251020130125.2875164-2-yanquanmin1@huawei.com Fixes: 2e0fe9245d6b ("mm/damon/lru_sort: support addr_unit for DAMON_LRU_SORT") Signed-off-by: Quanmin Yan <yanquanmin1@huawei.com> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: ze zuo <zuoze1@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/khugepaged: guard is_zero_pfn() calls with pte_present()Lance Yang
A non-present entry, like a swap PTE, contains completely different data (swap type and offset). pte_pfn() doesn't know this, so if we feed it a non-present entry, it will spit out a junk PFN. What if that junk PFN happens to match the zeropage's PFN by sheer chance? While really unlikely, this would be really bad if it did. So, let's fix this potential bug by ensuring all calls to is_zero_pfn() in khugepaged.c are properly guarded by a pte_present() check. Link: https://lkml.kernel.org/r/20251020151111.53561-1-lance.yang@linux.dev Signed-off-by: Lance Yang <lance.yang@linux.dev> Suggested-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Nico Pache <npache@redhat.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16Docs/ABI/damon: document DAMOS quota goal path fileSeongJae Park
A DAMON sysfs interface file for DAMOS quota goal's optional path argument has been added. Document it on the ABI doc. Link: https://lkml.kernel.org/r/20251017212706.183502-11-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16Docs/admin-guide/mm/damon/usage: document DAMOS quota goal path fileSeongJae Park
A new DAMON sysfs interface file, namely 'path' has been added under DAMOS quota goal directory, for specifying the cgroup for DAMOS_QUOTA_NODE_MEMCG_{USED,FREE}_BP metrics. Document it on the usage document. Link: https://lkml.kernel.org/r/20251017212706.183502-10-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16Docs/mm/damon/design: document DAMOS_QUOTA_NODE_MEMCG_{USED,FREE}_BPSeongJae Park
Update design doc for the newly added two DAMOS quota auto-tuning target goal metrics, DAMOS_QUOTA_NODE_MEMCG_{USED,FREE}_BP. Link: https://lkml.kernel.org/r/20251017212706.183502-9-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/damon/sysfs-schemes: support DAMOS_QUOTA_NODE_MEMCG_FREE_BPSeongJae Park
Extend DAMON sysfs to support DAMOS_QUOTA_NODE_MEMCG_FREE_BP. Link: https://lkml.kernel.org/r/20251017212706.183502-8-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/damon/core: add DAMOS quota gaol metric for per-memcg per-numa free memorySeongJae Park
Add a variant of DAMOS_QUOTA_NODE_MEMCG_USED_BP, for the free memory portion. The value of the metric is implemented as the entire memory of the given NUMA node subtracted by the given cgroup's usage. So from a perspective, "unused" could be a better term than "free". But arguably it is not very clear what is better, so use the term "free". Link: https://lkml.kernel.org/r/20251017212706.183502-7-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/damon/sysfs-schemes: support DAMOS_QUOTA_NODE_MEMCG_USED_BPSeongJae Park
Add support of DAMOS_QUOTA_NODE_MEMCG_USED_BP. For this, extend quota goal metric inputs for the new metric, and update DAMOS core layer request construction logic to set the target cgroup, which is specified by the user, via the 'path' file. Link: https://lkml.kernel.org/r/20251017212706.183502-6-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/damon/sysfs-schemes: implement path file under quota goal directorySeongJae Park
Add a DAMOS sysfs file for specifying the cgroup of the interest for DAMOS_QUOTA_NODE_MEMCG_USED_BP. Link: https://lkml.kernel.org/r/20251017212706.183502-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/damon/core: implement DAMOS_QUOTA_NODE_MEMCG_USED_BPSeongJae Park
Implement the handling of the new DAMOS quota goal metric for per-memcg per-node memory usage, namely DAMOS_QUOTA_NODE_MEMCG_USED_BP. The metric value is calculated as the sum of active/inactive anon/file pages of the given cgroup for a given NUMA node. Link: https://lkml.kernel.org/r/20251017212706.183502-4-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/damon: add DAMOS quota goal type for per-memcg per-node memory usageSeongJae Park
Define a new DAMOS quota auto-tuning target metric for per-cgroup per-node memory usage. For specifying the cgroup of the interest, add a field, namely memcg_id, to damos_quota_goal struct. Note that this commit is only implementing the interface. The handling of the interface (the metric value calculation) will be implemented in the following commit. Link: https://lkml.kernel.org/r/20251017212706.183502-3-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/damon: document damos_quota_goal->nid use caseSeongJae Park
Patch series "mm/damon: allow DAMOS auto-tuned for per-memcg per-node memory usage". Introduce two new DAMOS quota auto-tuning target metrics for per-cgroup per-NUMA node memory utilization. Expected use cases are cgroup level access-aware NUMA memory managements, such as memory tiering or proactive reclamation on cgroup-based multi-tenant NUMA systems. Background ========== The aim-oriented aggressiveness auto-tuning feature of DAMOS is a highly recommended way for modern DAMOS use cases. Using it, users can specify what system status they want to achieve with what access-aware system operations. For example, reclaim cold memory aiming for 0.5 percent of memory pressure (proactive reclaim), or migrate hot and cold memory between NUMA nodes having different speed (memory tiering). Then DAMOS automatically adjusts the aggressiveness of the system operation (e.g., increase/decrease reclaim target coldness threshold) based on current status of the system. The use case is limited by the supported system status metrics for specifying the target system status. Two new system metrics for per-node memory usage ratio, namely DAMOS_QUOTA_NODE_MEM_{USED,FREE}_BP, were recently added to extend the use cases for access-aware NUMA nodes management, such as memory tiering. Those are expected to be useful for not only memory tiering but also general access-aware inter-NUMA node page migration, though. Limitation ---------- The per-node memory usage based auto-tuning can be applied only system-wide. For cgroups-based multi-tenant systems, it could arguably harm the fairness. For example, a cgroup may use faster NUMA node memory more than other cgroup, depending on their access pattern. If the user of each cgroup are promised to get the same quality and amount of the system resource, this can arguably be an unfair situation. DAMOS supports cgroup level system operations via DAMOS filter. But the quota auto-tuning system is not aware of cgroups. New DAMOS Quota Tuning Metrics for Per-Cgroup Per-NUMA Memory Usage =================================================================== To overcome the limitation, introduce two new DAMOS quota auto-tuning goal metrics, namely DAMOS_QUOTA_NODE_MEMCG_{USED,FREE}_BP. Those can be thought of as a variant of DAMOS_QUOTA_NODE_MEM_{USED,FREE}_BP that extended for cgroups. The two metrics specifies per-cgroup, per-node amount of used and unused memory in ratio to the total memory of the node. For example, let's assume a system has two NUMA nodes of size 100 GiB and 50 GiB. And two cgroups are using 40 GiB and 60 GiB of node 0, 20 GiB and 10 GiB of node 1, respectively, as illustrated by the below table. node-0 node-1 Total memory 100 GiB 50 GiB Cgroup A usage 40 GiB 20 GiB Cgroup B usage 60 GiB 10 GiB Then, DAMOS_QUOTA_NODE_MEMCG_USED_BP for the cgroups for the first node are, 40 GiB / 100 GiB = 4,000 bp (40 percent) and 60 GiB / 100 GiB = 6,000 bp (60 percent), respectively. Those for the second node are, 20 GiB / 50 GiB = 4000 bp (40 percent) and 10 GiB / 50 GiB = 2000 bp (20 percent), respectively. DAMOS_QUOTA_NODE_MEMCG_FREE_BP for the four cases are, 60 GiB /100 GiB = 6000 bp, 40 GiB / 100 GiB = 4000 bp, 30 GiB / 50 GiB = 6000 bp, and 40 GiB / 50 GiB = 8000 bp, respectively. DAMOS_QUOTA_NODE_MEMCG_USED_BP for cgroup A node-0: 4000 bp DAMOS_QUOTA_NODE_MEMCG_USED_BP for cgroup B node-0: 6000 bp DAMOS_QUOTA_NODE_MEMCG_USED_BP for cgroup A node-1: 4000 bp DAMOS_QUOTA_NODE_MEMCG_USED_BP for cgroup B node-1: 2000 bp DAMOS_QUOTA_NODE_MEMCG_FREE_BP for cgroup A node-0: 6000 bp DAMOS_QUOTA_NODE_MEMCG_FREE_BP for cgroup B node-0: 4000 bp DAMOS_QUOTA_NODE_MEMCG_FREE_BP for cgroup A node-1: 6000 bp DAMOS_QUOTA_NODE_MEMCG_FREE_BP for cgroup B node-1: 8000 bp Using these, users can specify how much [un]used amount of memory for per-cgroup and per-node DAMOS should make as a result of the auto-tuning. Example Usecase: Cgroup Level Memory Tiering ============================================ Let's suppose a typical and simple tiered memory system. The system equips two NUMA nodes. The first node (node 0) is CPU-attached and fast. The second node (node 1) is CPU-unattached and slow. It runs two cgroups that desire to use about 30 percent and 70 percent of the faster node as much as possible for their hot data, respectively. Then, the user can implement DAMOS-based memory tiering for the system using the DAMON user-space tool (damo), like below. # ./damo start \ `# kdamond for node 1 (slow)` \ --numa_node 1 --monitoring_intervals_goal 4% 3 5ms 10s \ `# promotion scheme for cgroup a` \ --damos_action migrate_hot 0 --damos_access_rate 5% max \ --damos_apply_interval 1s \ --damos_filter allow memcg /workloads/a \ --damos_filter allow young \ --damos_quota_interval 1s --damos_quota_space 200MB \ --damos_quota_goal node_memcg_used_bp 29.7% 0 /workloads/a \ \ `# promotion scheme for cgroup b` \ --damos_action migrate_hot 0 --damos_access_rate 5% max \ --damos_apply_interval 1s \ --damos_filter allow memcg /workloads/b \ --damos_filter allow young \ --damos_quota_interval 1s --damos_quota_space 200MB \ --damos_quota_goal node_memcg_used_bp 69.7% 0 workloads/b \ \ `# kdamond for node 0 (fast)` \ --numa_node 0 --monitoring_intervals_goal 4% 3 5ms 10s \ `# demotion scheme for cgroup a` \ --damos_action migrate_cold 1 --damos_access_rate 0% 0% \ --damos_apply_interval 1s \ --damos_filter allow memcg /workloads/a \ --damos_filter reject young \ --damos_quota_interval 1s --damos_quota_space 200MB \ --damos_quota_goal node_memcg_free_bp 70.5% 0 \ \ `# demotion scheme for cgroup b` \ --damos_action migrate_cold 1 --damos_access_rate 0% 0% \ --damos_apply_interval 1s \ --damos_filter allow memcg /workloads/a \ --damos_filter reject young \ --damos_quota_interval 1s --damos_quota_space 200MB \ --damos_quota_goal node_memcg_free_bp 30.5% 0 \ \ --damos_nr_quota_goals 1 1 1 1 --damos_nr_filters 1 1 1 1 \ --nr_targets 1 1 --nr_schemes 2 2 --nr_ctxs 1 1 With the command, the user-space tool will ask DAMON to spawn two kernel threads, each for monitoring accesses to node 1 (slow) and node 0 (fast), respectively. It installs two DAMOS schemes on each thread. Let's call them "promotion scheme for cgroup a/b", and "demotion scheme for cgroup a/b" in the order. The promotion schemes are installed on the DAMON thread for node 1 (slow), and demotion schemes are installed on the DAMON thread for node 0 (fast). Cgroup Level Hot Pages Migration (Promotion) -------------------------------------------- Promotion schemes will find memory regions on node 1 (slow), that some access was detected. The schemes will then migrate the found memory to node 0 (fast), hottest pages first. For accurate and effective migration, these schemes use two page level filters. First, the migration will be filtered for only cgroup A and cgroup B. That is, "promotion scheme for cgroup B" will not do the migration if the page is for cgroup A. Secondly, the schemes will ignore pages that having their page table's Accessed bits unset. The per-page Accessed bit check logic will also unset the bit if it was set, for the next check. For controlled amounts of system resource consumption and aiming on the target memory usage, the schemes use quotas setup. The migration is limited to be done only up to 200 MiB per second, to limit the peak system resource usage. And DAMOS_QUOTA_NODE_MEMCG_USED_BP target is set for 29.7% and 69.7% of node 0 (fast), respectively. The target value is lower than the high level goal (30% and 70% system memory), to give headroom on node 0 (fast). DAMOS will adjust the speed of the pages migration based on the target and current per-cgroup node 0 memory usage. For example, if cgroup A is utilizing only 10% of node 0, DAMOS will try to migrate more of cgroup A hot pages from node 1 to node 0, up to 200 MiB per second. If cgroup A utilizes more than 29.7% of node 0 memory, the cgroup A hot pages migration from node 1 to node 0 will be slowed and eventually stopped. Cgroup Level Cold Pages Migration (Demotion) -------------------------------------------- Demotion schemes are similar to promotion schemes, but differ in filtering setup and quota tuning setup. Those filter out pages having their page table Accessed bits set. And set 70.5% and 30.5% of node 0 memory free rate for the cgroup A and B, respectively. Hence, if promotion schemes or something made cgroup A and/or B uses more than 29.5% and 69.5% of node 0, demotion schemes will start migrating cold pages of appropriate cgroups in node 0 to node 1, under the 200 MiB per second speed cap, while adjusting the speed based on how much more than wanted memory is being used. The quota target values are set to overlap with promotion targets, to keep a minimum level of page exchanges between the nodes. This is to avoid a case that the target memory utilization is met, and then access pattern changes (pages in node 1 become hotter than pages in node 0) while the memory utilization is unchanged. Without the overlap, neither promotion of hotter pages in node 1, nor demotion of colder pages in node 0 will happen since both goals are met. As a result, the faster and slower node will unexpectedly serve cold and hot data. Test: Per-cgroup Memory Tiering =============================== I ran a simplified cgroup level memory tiering using the feature, and confirmed it works as intended. Setup ----- I configured a QEMU virtual machine representing a simplified version of the system that described on the above cgroup level memory tiering example use case. The system equips 40 CPU cores and two NUMA nodes each having 30 GiB physical memory. The first node (node 0) represents the faster NUMA node, and the second node (node 1) represents the slower NUMA node. In specific, below qemu command line options are used. [...] -object memory-backend-ram,size=30G,id=m0 \ -object memory-backend-ram,size=30G,id=m1 \ -numa node,cpus=0-39,memdev=m0 \ -numa node,memdev=m1 \ [...] I booted the virtual machine with a kernel that this patch series is applied. On the virtual machine, I created two cgroups, namely workload_a and workload_b. And ran a test program in each cgroup, resulting in one process per cgroup. The test program allocates 10 GiB memory and evenly split it into 10 regions. After the allocation, it repeatedly access the first region for one minute, than the second one for one minute, and so on. After the one minute repeated access for the 10-th region is done, it repeats the access from the first region. So the process has 10 GiB of data in total, but only 1 GiB of it is hot at a given moment, and the hot data is gradually changed. While the processes are running, run DAMON for a simple access-aware memory tiering using below script. It migrates hot and cold data of the cgroups into node 0 and node 1, aiming the first and the second cgroups (workload_a and workload_b, respectively) utilizing about 9.7 percent and 19.7 percent of node 0, respectively. Note that this setup is a simplified version of the above example use case, for ease of test. Also note that we assigned 30 GiB physical memory to node 0, but DAMON in this setup works for only 27 GiB of the memory. It is due to an internal implementation detail of DAMON user-space tool that not really important for this test. #!/bin/bash damo start \ --numa_node 1 \ --damos_action migrate_hot 0 --damos_access_rate 5% max \ --damos_apply_interval 1s \ --damos_filter allow memcg /workload_a \ --damos_filter allow young \ --damos_quota_interval 1s \ --damos_quota_goal node_memcg_used_bp 9.7% 0 /workload_a \ --damos_action migrate_hot 0 --damos_access_rate 5% max \ --damos_apply_interval 1s \ --damos_filter allow memcg /workload_b \ --damos_filter allow young \ --damos_quota_interval 1s \ --damos_quota_goal node_memcg_used_bp 19.7% 0 /workload_b \ --numa_node 0 \ --damos_action migrate_cold 1 --damos_access_rate 0% 0% \ --damos_apply_interval 1s \ --damos_filter allow memcg /workload_a \ --damos_filter reject young \ --damos_quota_interval 1s \ --damos_quota_goal node_memcg_free_bp 90.5% 0 /workload_a \ --damos_action migrate_cold 1 --damos_access_rate 0% 0% \ --damos_apply_interval 1s \ --damos_filter allow memcg /workload_b \ --damos_filter reject young \ --damos_quota_interval 1s \ --damos_quota_goal node_memcg_free_bp 80.5% 0 /workload_b \ --damos_nr_quota_goals 1 1 1 1 --damos_nr_filters 2 2 2 2 \ --nr_targets 1 1 --nr_schemes 2 2 --nr_ctxs 1 1 After starting DAMON, the pages continuously be migrated across nodes. A few minutes later, the memory usage of the cgroups converges into the aimed amounts, and keeps the level, as expected. To confirm the status is kept in the target level as expected, I collected the memory usage stat of the cgroups using memory.numa_stat file, after the stats are converged. I repeat the stat collection 42 times with 5 seconds delay between each of the collections. The results are as below: node0_memory_usage average stdev workload_a 2.79GiB 522.06MiB workload_b 5.15GiB 739.10MiB The average values are quite close to the targeted values: 27 GiB * 9.7% = 2.619 GiB for workload_a, and 27 GiB * 19.7% = 5.319 GiB. A level of variances are expected, given the overlap of the promotion/demotion targets, and dynamic data access pattern of the workloads. Give that, the measured variances are at a reasonable level. Patches Sequence ================ The first patch (patch 1) updates the kernel-doc comment of damos_quota_goal struct to clarify usage of optional fields of the struct, since later patches will add such optional fields. Following four patches (patches 2-5) implement a new DAMOS quota goal metric for per-cgroup per-node memory usage. Those extends the core layer interface for the new metric (patch 2), implement the metric value calculation on the core layer (patch 3), add DAMON sysfs interface file for the target cgroup specification (patch 4), and implement support of the new metric on DAMON sysfs interface (patch 5). Next two patches implment the second new DAMOS quota goal metric for per-cgroup per-node free (or, unused) memory. Those implement it in the core layer (patch 6) and DAMON sysfs interface (patch 7), extending the existing implementation for memory usage metric. Final three patches update the design (patch 8), the usage (patch 9), and the ABI (patch 10) documents for the changes that are introduced by this patch series. This patch (of 10): damos_quota_goal kerneldoc comment is not explaining when @metric is used. Update the comment for that. Link: https://lkml.kernel.org/r/20251017212706.183502-1-sj@kernel.org Link: https://lkml.kernel.org/r/20251017212706.183502-2-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: vmscan: simplify the logic for activating dirty file foliosBaolin Wang
After commit 6b0dfabb3555 ("fs: Remove aops->writepage"), we no longer attempt to write back filesystem folios through reclaim. However, in the shrink_folio_list() function, there still remains some logic related to writeback control of dirty file folios. The original logic was that, for direct reclaim, or when folio_test_reclaim() is false, or the PGDAT_DIRTY flag is not set, the dirty file folios would be directly activated to avoid being scanned again; otherwise, it will try to writeback the dirty file folios. However, since we can no longer perform writeback on dirty folios, the dirty file folios will still be activated. Additionally, under the original logic, if we continue to try writeback dirty file folios, we will also check the references flag, sc->may_writepage, and may_enter_fs(), which may result in dirty file folios being left in the inactive list. This is unreasonable. Even if these dirty folios are scanned again, we still cannot clean them. Therefore, the checks on these dirty file folios appear to be redundant and can be removed. Dirty file folios should be directly moved to the active list to avoid being scanned again. Since we set the PG_reclaim flag for the dirty folios, once the writeback is completed, they will be moved back to the tail of the inactive list to be retried for quick reclaim. Link: https://lkml.kernel.org/r/ba5c49955fd93c6850bcc19abf0e02e1573768aa.1760687075.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: vmscan: filter out the dirty file folios for node_reclaim()Baolin Wang
Patch series "optimize the logic for handling dirty file folios during reclaim", v2. Since we no longer attempt to write back filesystem folios during reclaim, some logic for handling dirty file folios in the reclaim process also needs to be updated. Please check the details in each patch. This patch (of 2): After commit 6b0dfabb3555 ("fs: Remove aops->writepage"), we no longer attempt to write back filesystem folios in pageout(), and only tmpfs/shmem folios and anonymous swapcache folios can be written back. Therefore, we should also filter out the dirty filesystem folios for node_reclaim() to avoid unnecessary LRU scans. Link: https://lkml.kernel.org/r/cover.1760687075.git.baolin.wang@linux.alibaba.com Link: https://lkml.kernel.org/r/c91f5ecc5152b647904c7503618a01885d913928.1760687075.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16tools/mm/page_owner_sort: add help option supportYe Liu
Add -h/--help option to display usage information and improve code style. Link: https://lkml.kernel.org/r/20251016054927.138510-1-ye.liu@linux.dev Signed-off-by: Ye Liu <liuye@kylinos.cn> Cc: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>