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2025-11-16mm/damon/core: fix wrong comment of damon_call() return timingSeongJae Park
Patch series "mm/damon: misc documentation fixups". First three patches fix up issues in the documents, including wrong explanation of a behavior, wrong link, and a contextual typo. Following five patches update documents for not yet documented features and behaviors. This patch (of 8): damon_call() works asynchronously and synchronously for repeat and non-repeat mode requests, respectively. The comment about the behavior is wrong, though. Fix it. The wrong comment was introduced together with the repeat mode, by commit 43df7676e550 ("mm/damon/core: introduce repeat mode damon_call()"). Link: https://lkml.kernel.org/r/20251026182216.118200-1-sj@kernel.org Link: https://lkml.kernel.org/r/20251026182216.118200-2-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm, swap: remove redundant argument for isolating a clusterKairui Song
The order argument was introduced by an intermediate commit and was then never used, just remove it. Link: https://lkml.kernel.org/r/20251024-swap-clean-after-swap-table-p1-v2-5-a709469052e7@tencent.com Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Nhat Pham <nphamcs@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/migrate, swap: drop usage of folio_indexKairui Song
This helper was used when swap cache was mixed with page cache. Now they are completely separate from each other, access to the swap cache is all wrapped by the swap_cache_* helpers, which expect the folio's swap entry as a parameter. This helper is no longer used, remove the last redundant user and drop it. Link: https://lkml.kernel.org/r/20251024-swap-clean-after-swap-table-p1-v2-4-a709469052e7@tencent.com Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Chris Li <chrisl@kernel.org> Acked-by: Nhat Pham <nphamcs@gmail.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm, swap: cleanup swap entry allocation parameterKairui Song
We no longer need this GFP parameter after commit 8578e0c00dcf ("mm, swap: use the swap table for the swap cache and switch API"). Before that commit the GFP parameter is already almost identical for all callers, so nothing changed by that commit. Swap table just moved the GFP to lower layer and make it more defined and changes depend on atomic or sleep allocation. Now this parameter is no longer used, just remove it. No behavior change. Link: https://lkml.kernel.org/r/20251024-swap-clean-after-swap-table-p1-v2-3-a709469052e7@tencent.com Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Chris Li <chrisl@kernel.org> Acked-by: Nhat Pham <nphamcs@gmail.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm, swap: rename helper for setup bad slotsKairui Song
The name inc_cluster_info_page is very confusing, as this helper is only used during swapon to mark bad slots. Rename it properly and turn the VM_BUG_ON in it into WARN_ON to expose more potential issues. Swapon is a cold path, so adding more checks should be a good idea. No feature change except new WARN_ON. Link: https://lkml.kernel.org/r/20251024-swap-clean-after-swap-table-p1-v2-2-a709469052e7@tencent.com Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Chris Li <chrisl@kernel.org> Acked-by: Nhat Pham <nphamcs@gmail.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm, swap: do not perform synchronous discard during allocationKairui Song
Patch series "mm, swap: misc cleanup and bugfix", v2. A few cleanups and a bugfix that are either suitable after the swap table phase I or found during code review. Patch 1 is a bugfix and needs to be included in the stable branch, the rest have no behavioral change. This patch (of 5): Since commit 1b7e90020eb77 ("mm, swap: use percpu cluster as allocation fast path"), swap allocation is protected by a local lock, which means we can't do any sleeping calls during allocation. However, the discard routine is not taken well care of. When the swap allocator failed to find any usable cluster, it would look at the pending discard cluster and try to issue some blocking discards. It may not necessarily sleep, but the cond_resched at the bio layer indicates this is wrong when combined with a local lock. And the bio GFP flag used for discard bio is also wrong (not atomic). It's arguable whether this synchronous discard is helpful at all. In most cases, the async discard is good enough. And the swap allocator is doing very differently at organizing the clusters since the recent change, so it is very rare to see discard clusters piling up. So far, no issues have been observed or reported with typical SSD setups under months of high pressure. This issue was found during my code review. But by hacking the kernel a bit: adding a mdelay(500) in the async discard path, this issue will be observable with WARNING triggered by the wrong GFP and cond_resched in the bio layer for debug builds. So now let's apply a hotfix for this issue: remove the synchronous discard in the swap allocation path. And when order 0 is failing with all cluster list drained on all swap devices, try to do a discard following the swap device priority list. If any discards released some cluster, try the allocation again. This way, we can still avoid OOM due to swap failure if the hardware is very slow and memory pressure is extremely high. This may cause more fragmentation issues if the discarding hardware is really slow. Ideally, we want to discard pending clusters before continuing to iterate the fragment cluster lists. This can be implemented in a cleaner way if we clean up the device list iteration part first. Link: https://lkml.kernel.org/r/20251024-swap-clean-after-swap-table-p1-v2-0-a709469052e7@tencent.com Link: https://lkml.kernel.org/r/20251024-swap-clean-after-swap-table-p1-v2-1-c5b0e1092927@tencent.com Fixes: 1b7e90020eb7 ("mm, swap: use percpu cluster as allocation fast path") Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Nhat Pham <nphamcs@gmail.com> Acked-by: Chris Li <chrisl@kernel.org> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/huge_memory: optimize old_order derivation during folio splittingWei Yang
Folio splitting requires both the folio's original order (@old_order) and the new target order (@split_order). In the current implementation, @old_order is repeatedly retrieved using folio_order(). However, for every iteration after the first, the folio being split is the result of the previous split, meaning its order is already known to be equal to the previous iteration's @split_order. This commit optimizes the logic: * Instead of calling folio_order(), we now set @old_order directly to the value of @split_order from the previous iteration. This change avoids unnecessary function calls and simplifies the loop setup. Also it removes a check for non-existent case, since for uniform splitting we only do split when @split_order == @new_order. Link: https://lkml.kernel.org/r/20251021212142.25766-5-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: wang lian <lianux.mm@gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/huge_memory: optimize and simplify folio stat update after splitWei Yang
The loop executed after a successful folio split currently has two combined responsibilities: * updating statistics for the new folios * determining the folio for the next split iteration. This commit refactors the logic to directly calculate and update folio statistics, eliminating the need for the iteration step. We can do this because all necessary information is already available: * All resulting new folios have the same order, which is @split_order. * The exact number of new folios can be calculated directly using @old_order and @split_order. * The folio for the subsequent split is simply the one containing @split_at. By leveraging this knowledge, we can achieve the stat update more cleanly and efficiently without the looping logic. Link: https://lkml.kernel.org/r/20251021212142.25766-4-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: wang lian <lianux.mm@gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/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>
2025-11-16memcg: 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: 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>
2025-11-16mm: 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: 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>
2025-11-16mm: 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>
2025-11-16mm/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>
2025-11-16mm/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: 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>
2025-11-16memcg: net: track network throttling due to memcg memory pressureShakeel Butt
The kernel can throttle network sockets if the memory cgroup associated with the corresponding socket is under memory pressure. The throttling actions include clamping the transmit window, failing to expand receive or send buffers, aggressively prune out-of-order receive queue, FIN deferred to a retransmitted packet and more. Let's add memcg metric to track such throttling actions. At the moment memcg memory pressure is defined through vmpressure and in future it may be defined using PSI or we may add more flexible way for the users to define memory pressure, maybe through ebpf. However the potential throttling actions will remain the same, so this newly introduced metric will continue to track throttling actions irrespective of how memcg memory pressure is defined. Link: https://lkml.kernel.org/r/20251016161035.86161-1-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Daniel Sedlak <daniel.sedlak@cdn77.com> Cc: David S. Miller <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kacinski <kuba@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Neal Cardwell <ncardwell@google.com> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Simon Horman <horms@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/khugepaged: fix comment for default scan sleep durationwang lian
The comment for khugepaged_scan_sleep_millisecs incorrectly states the default scan period is 30 seconds. The actual default value in the code is 10000ms (10 seconds). This patch corrects the comment to match the code, preventing potential confusion. The incorrect comment has existed since the feature was first introduced. While at it, replace the magic value 512 by HPAGE_PMD_NR and use 'ptes'. Link: https://lkml.kernel.org/r/20251015092957.37432-1-lianux.mm@gmail.com Signed-off-by: wang lian <lianux.mm@gmail.com> Suggested-by: David Hildenbrand <david@redhat.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: SeongJae Park <sj@kernel.org> Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Acked-by: Nico Pache <npache@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/page_alloc: simplify and cleanup pcp lockingVlastimil Babka
The pcp locking relies on pcp_spin_trylock() which has to be used together with pcp_trylock_prepare()/pcp_trylock_finish() to work properly on !SMP !RT configs. This is tedious and error-prone. We can remove pcp_spin_lock() and underlying pcpu_spin_lock() because we don't use it. Afterwards pcp_spin_unlock() is only used together with pcp_spin_trylock(). Therefore we can add the UP_flags parameter to them both and handle pcp_trylock_prepare()/finish() within. Additionally for the configs where pcp_trylock_prepare()/finish() are no-op (SMP || RT) make them pass &UP_flags to a no-op inline function. This ensures typechecking and makes the local variable "used" so we can remove the __maybe_unused attributes. In my compile testing, bloat-o-meter reported no change on SMP config, so the compiler is capable of optimizing away the no-ops same as before, and we have simplified the code using pcp_spin_trylock(). Link: https://lkml.kernel.org/r/20251015-b4-pcp-lock-cleanup-v2-1-740d999595d5@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Joshua Hahn <joshua.hahnjy@gmail.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/page_alloc: batch page freeing in free_frozen_page_commitJoshua Hahn
Before returning, free_frozen_page_commit calls free_pcppages_bulk using nr_pcp_free to determine how many pages can appropritately be freed, based on the tunable parameters stored in pcp. While this number is an accurate representation of how many pages should be freed in total, it is not an appropriate number of pages to free at once using free_pcppages_bulk, since we have seen the value consistently go above 2000 in the Meta fleet on larger machines. As such, perform batched page freeing in free_pcppages_bulk by using pcp->batch. In order to ensure that other processes are not starved of the zone lock, free both the zone lock and pcp lock to yield to other threads. Note that because free_frozen_page_commit now performs a spinlock inside the function (and can fail), the function may now return with a freed pcp. To handle this, return true if the pcp is locked on exit and false otherwise. In addition, since free_frozen_page_commit must now be aware of what UP flags were stored at the time of the spin lock, and because we must be able to report new UP flags to the callers, add a new unsigned long* parameter UP_flags to keep track of this. The following are a few synthetic benchmarks, made on three machines. The first is a large machine with 754GiB memory and 316 processors. The second is a relatively smaller machine with 251GiB memory and 176 processors. The third and final is the smallest of the three, which has 62GiB memory and 36 processors. On all machines, I kick off a kernel build with -j$(nproc). Negative delta is better (faster compilation) Large machine (754GiB memory, 316 processors) make -j$(nproc) +------------+---------------+-----------+ | Metric (s) | Variation (%) | Delta(%) | +------------+---------------+-----------+ | real | 0.8070 | - 1.4865 | | user | 0.2823 | + 0.4081 | | sys | 5.0267 | -11.8737 | +------------+---------------+-----------+ Medium machine (251GiB memory, 176 processors) make -j$(nproc) +------------+---------------+----------+ | Metric (s) | Variation (%) | Delta(%) | +------------+---------------+----------+ | real | 0.2806 | +0.0351 | | user | 0.0994 | +0.3170 | | sys | 0.6229 | -0.6277 | +------------+---------------+----------+ Small machine (62GiB memory, 36 processors) make -j$(nproc) +------------+---------------+----------+ | Metric (s) | Variation (%) | Delta(%) | +------------+---------------+----------+ | real | 0.1503 | -2.6585 | | user | 0.0431 | -2.2984 | | sys | 0.1870 | -3.2013 | +------------+---------------+----------+ Here, variation is the coefficient of variation, i.e. standard deviation / mean. [joshua.hahnjy@gmail.com: simplify checks] Link: https://lkml.kernel.org/r/20251014192827.851389-1-joshua.hahnjy@gmail.com Link: https://lkml.kernel.org/r/20251014145011.3427205-4-joshua.hahnjy@gmail.com Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com> Suggested-by: Chris Mason <clm@fb.com> Co-developed-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Brendan Jackman <jackmanb@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Michal Hocko <mhocko@suse.com> Cc: SeongJae Park <sj@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/page_alloc: batch page freeing in decay_pcp_highJoshua Hahn
It is possible for pcp->count - pcp->high to exceed pcp->batch by a lot. When this happens, we should perform batching to ensure that free_pcppages_bulk isn't called with too many pages to free at once and starve out other threads that need the pcp or zone lock. Since we are still only freeing the difference between the initial pcp->count and pcp->high values, there should be no change to how many pages are freed. Link: https://lkml.kernel.org/r/20251014145011.3427205-3-joshua.hahnjy@gmail.com Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com> Suggested-by: Chris Mason <clm@fb.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Co-developed-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Brendan Jackman <jackmanb@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Michal Hocko <mhocko@suse.com> Cc: SeongJae Park <sj@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/page_alloc/vmstat: simplify refresh_cpu_vm_stats change detectionJoshua Hahn
Patch series "mm/page_alloc: Batch callers of free_pcppages_bulk", v5. Motivation & Approach ===================== While testing workloads with high sustained memory pressure on large machines in the Meta fleet (1Tb memory, 316 CPUs), we saw an unexpectedly high number of softlockups. Further investigation showed that the zone lock in free_pcppages_bulk was being held for a long time, and was called to free 2k+ pages over 100 times just during boot. This causes starvation in other processes for the zone lock, which can lead to the system stalling as multiple threads cannot make progress without the locks. We can see these issues manifesting as warnings: [ 4512.591979] rcu: INFO: rcu_sched self-detected stall on CPU [ 4512.604370] rcu: 20-....: (9312 ticks this GP) idle=a654/1/0x4000000000000000 softirq=309340/309344 fqs=5426 [ 4512.626401] rcu: hardirqs softirqs csw/system [ 4512.638793] rcu: number: 0 145 0 [ 4512.651177] rcu: cputime: 30 10410 174 ==> 10558(ms) [ 4512.666657] rcu: (t=21077 jiffies g=783665 q=1242213 ncpus=316) While these warnings don't indicate a crash or a kernel panic, they do point to the underlying issue of lock contention. To prevent starvation in both locks, batch the freeing of pages using pcp->batch. Because free_pcppages_bulk is called with the pcp lock and acquires the zone lock, relinquishing and reacquiring the locks are only effective when both of them are broken together (unless the system was built with queued spinlocks). Thus, instead of modifying free_pcppages_bulk to break both locks, batch the freeing from its callers instead. A similar fix has been implemented in the Meta fleet, and we have seen significantly less softlockups. Testing ======= The following are a few synthetic benchmarks, made on three machines. The first is a large machine with 754GiB memory and 316 processors. The second is a relatively smaller machine with 251GiB memory and 176 processors. The third and final is the smallest of the three, which has 62GiB memory and 36 processors. On all machines, I kick off a kernel build with -j$(nproc). Negative delta is better (faster compilation). Large machine (754GiB memory, 316 processors) make -j$(nproc) +------------+---------------+-----------+ | Metric (s) | Variation (%) | Delta(%) | +------------+---------------+-----------+ | real | 0.8070 | - 1.4865 | | user | 0.2823 | + 0.4081 | | sys | 5.0267 | -11.8737 | +------------+---------------+-----------+ Medium machine (251GiB memory, 176 processors) make -j$(nproc) +------------+---------------+----------+ | Metric (s) | Variation (%) | Delta(%) | +------------+---------------+----------+ | real | 0.2806 | +0.0351 | | user | 0.0994 | +0.3170 | | sys | 0.6229 | -0.6277 | +------------+---------------+----------+ Small machine (62GiB memory, 36 processors) make -j$(nproc) +------------+---------------+----------+ | Metric (s) | Variation (%) | Delta(%) | +------------+---------------+----------+ | real | 0.1503 | -2.6585 | | user | 0.0431 | -2.2984 | | sys | 0.1870 | -3.2013 | +------------+---------------+----------+ Here, variation is the coefficient of variation, i.e. standard deviation / mean. Based on these results, it seems like there are varying degrees to how much lock contention this reduces. For the largest and smallest machines that I ran the tests on, it seems like there is quite some significant reduction. There is also some performance increases visible from userspace. Interestingly, the performance gains don't scale with the size of the machine, but rather there seems to be a dip in the gain there is for the medium-sized machine. One possible theory is that because the high watermark depends on both memory and the number of local CPUs, what impacts zone contention the most is not these individual values, but rather the ratio of mem:processors. This patch (of 5): Currently, refresh_cpu_vm_stats returns an int, indicating how many changes were made during its updates. Using this information, callers like vmstat_update can heuristically determine if more work will be done in the future. However, all of refresh_cpu_vm_stats's callers either (a) ignore the result, only caring about performing the updates, or (b) only care about whether changes were made, but not *how many* changes were made. Simplify the code by returning a bool instead to indicate if updates were made. In addition, simplify fold_diff and decay_pcp_high to return a bool for the same reason. Link: https://lkml.kernel.org/r/20251014145011.3427205-1-joshua.hahnjy@gmail.com Link: https://lkml.kernel.org/r/20251014145011.3427205-2-joshua.hahnjy@gmail.com Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Brendan Jackman <jackmanb@google.com> Cc: Chris Mason <clm@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Michal Hocko <mhocko@suse.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: huge_memory: use folio_can_map_prot_numa() for pmd folioKefeng Wang
The folio_can_map_prot_numa() checks whether the folio can map prot numa, which skips unsuitable folio, i.e. zone device, shared folios (KSM, CoW), non-movable dma pinned, dirty file folio and folios that already have the expected node affinity. Although the ksm only applies to small folios, an extra test was added for large folios, but the other policies should be applied to pmd folio, which helps to avoid unnecessary pmd change and folio migration attempts. Link: https://lkml.kernel.org/r/20251023113737.3572790-5-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.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: Ryan Roberts <ryan.roberts@arm.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: mprotect: convert to folio_can_map_prot_numa()Kefeng Wang
The prot_numa_skip() naming is not good since it updates the folio access time except checking whether to skip prot NUMA, so rename it to folio_can_map_prot_numa(), and cleanup it a bit, remove ret by directly return value instead of goto style. Adding a new helper vma_is_single_threaded_private() to check whether it's a single threaded private VMA, and make folio_can_map_prot_numa() a non-static function so that they could be reused in change_huge_pmd(), since folio_can_map_prot_numa() will be shared in different paths, let's move it near change_prot_numa() in mempolicy.c. Link: https://lkml.kernel.org/r/20251023113737.3572790-4-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: David Hildenbrand <david@redhat.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: Ryan Roberts <ryan.roberts@arm.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm: mprotect: avoid unnecessary struct page accessing if pte_protnone()Kefeng Wang
If the pte_protnone() is true, we could avoid unnecessary struct page accessing and reduce cache footprint when scanning page tables for prot numa, there was a similar change before, see more commit a818f5363a0e ("autonuma: reduce cache footprint when scanning page tables"). Link: https://lkml.kernel.org/r/20251023113737.3572790-3-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Lance Yang <lance.yang@linux.dev> 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: mprotect: always skip dma pinned folio in prot_numa_skip()Kefeng Wang
Patch series "mm: some optimizations for prot numa", v5. This patch (of 4): If the folio (even not CoW folio) is dma pinned, it can't be migrated due to the elevated reference count. So always skip a pinned folio to avoid wasting cycles when folios are migrated. Link: https://lkml.kernel.org/r/20251023113737.3572790-1-wangkefeng.wang@huawei.com Link: https://lkml.kernel.org/r/20251023113737.3572790-2-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Barry Song <baohua@kernel.org> Reviewed-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>