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2025-07-13mm/balloon_compaction: make PageOffline sticky until the page is freedDavid Hildenbrand
Let the page freeing code handle clearing the page type. Being able to identify balloon pages until actually freed is a requirement for upcoming movable_ops migration changes. Link: https://lkml.kernel.org/r/20250704102524.326966-6-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: Harry Yoo <harry.yoo@oracle.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Eugenio Pé rez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm/balloon_compaction: convert balloon_page_delete() to balloon_page_finalize()David Hildenbrand
Let's move the removal of the page from the balloon list into the single caller, to remove the dependency on the PG_isolated flag and clarify locking requirements. Note that for now, balloon_page_delete() was used on two paths: (1) Removing a page from the balloon for deflation through balloon_page_list_dequeue() (2) Removing an isolated page from the balloon for migration in the per-driver migration handlers. Isolated pages were already removed from the balloon list during isolation. So instead of relying on the flag, we can just distinguish both cases directly and handle it accordingly in the caller. We'll shuffle the operations a bit such that they logically make more sense (e.g., remove from the list before clearing flags). In balloon migration functions we can now move the balloon_page_finalize() out of the balloon lock and perform the finalization just before dropping the balloon reference. Document that the page lock is currently required when modifying the movability aspects of a page; hopefully we can soon decouple this from the page lock. Link: https://lkml.kernel.org/r/20250704102524.326966-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Eugenio Pé rez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price <gourry@gourry.net> Cc: Harry Yoo <harry.yoo@oracle.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13maple tree: add some commentsDev Jain
Add comments explaining the fields for maple_metadata, since "end" is ambiguous and "gap" can be confused as the largest gap, whereas it is actually the offset of the largest gap. Add comment for mas_ascend() to explain, whose min and max we are trying to find. Explain that, for example, if we are already on offset zero, then the parent min is mas->min, otherwise we need to walk up to find the implied pivot min. Link: https://lkml.kernel.org/r/20250703063338.51509-1-dev.jain@arm.com Signed-off-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm: fix spelling issue in swap.hXuanye Liu
recliam -> reclaim Link: https://lkml.kernel.org/r/20250702071235.212794-1-liuqiye2025@163.com Signed-off-by: Xuanye Liu <liuqiye2025@163.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm/hugetlb: remove prepare_hugepage_range()Peter Xu
Only mips and loongarch implemented this API, however what it does was checking against stack overflow for either len or addr. That's already done in arch's arch_get_unmapped_area*() functions, even though it may not be 100% identical checks. For example, for both of the architectures, there will be a trivial difference on how stack top was defined. The old code uses STACK_TOP which may be slightly smaller than TASK_SIZE on either of them, but the hope is that shouldn't be a problem. It means the whole API is pretty much obsolete at least now, remove it completely. Link: https://lkml.kernel.org/r/20250627160707.2124580-1-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Muchun Song <muchun.song@linux.dev> Cc: Jann Horn <jannh@google.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm/page_isolation: remove migratetype parameter from more functionsZi Yan
migratetype is no longer overwritten during pageblock isolation, start_isolate_page_range(), has_unmovable_pages(), and set_migratetype_isolate() no longer need which migratetype to restore during isolation failure. For has_unmoable_pages(), it needs to know if the isolation is for CMA allocation, so adding PB_ISOLATE_MODE_CMA_ALLOC provide the information. At the same time change isolation flags to enum pb_isolate_mode (PB_ISOLATE_MODE_MEM_OFFLINE, PB_ISOLATE_MODE_CMA_ALLOC, PB_ISOLATE_MODE_OTHER). Remove REPORT_FAILURE and check PB_ISOLATE_MODE_MEM_OFFLINE, since only PB_ISOLATE_MODE_MEM_OFFLINE reports isolation failures. alloc_contig_range() no longer needs migratetype. Replace it with a newly defined acr_flags_t to tell if an allocation is for CMA. So does __alloc_contig_migrate_range(). Add ACR_FLAGS_NONE (set to 0) to indicate ordinary allocations. Link: https://lkml.kernel.org/r/20250617021115.2331563-7-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Richard Chang <richardycc@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm/page_isolation: remove migratetype from undo_isolate_page_range()Zi Yan
Since migratetype is no longer overwritten during pageblock isolation, undoing pageblock isolation no longer needs which migratetype to restore. Link: https://lkml.kernel.org/r/20250617021115.2331563-6-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Richard Chang <richardycc@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm/page_isolation: remove migratetype from move_freepages_block_isolate()Zi Yan
Since migratetype is no longer overwritten during pageblock isolation, moving a pageblock out of MIGRATE_ISOLATE no longer needs a new migratetype. Add pageblock_isolate_and_move_free_pages() and pageblock_unisolate_and_move_free_pages() to be explicit about the page isolation operations. Both share the common code in __move_freepages_block_isolate(), which is renamed from move_freepages_block_isolate(). Add toggle_pageblock_isolate() to flip pageblock isolation bit in __move_freepages_block_isolate(). Make set_pageblock_migratetype() only accept non MIGRATE_ISOLATE types, so that one should use set_pageblock_isolate() to isolate pageblocks. As a result, move pageblock migratetype code out of __move_freepages_block(). Link: https://lkml.kernel.org/r/20250617021115.2331563-5-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Richard Chang <richardycc@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm/page_alloc: add support for initializing pageblock as isolatedZi Yan
MIGRATE_ISOLATE is a standalone bit, so a pageblock cannot be initialized to just MIGRATE_ISOLATE. Add init_pageblock_migratetype() to enable initialize a pageblock with a migratetype and isolated. Link: https://lkml.kernel.org/r/20250617021115.2331563-4-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Richard Chang <richardycc@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm/page_isolation: make page isolation a standalone bitZi Yan
During page isolation, the original migratetype is overwritten, since MIGRATE_* are enums and stored in pageblock bitmaps. Change MIGRATE_ISOLATE to be stored a standalone bit, PB_migrate_isolate, like PB_compact_skip, so that migratetype is not lost during pageblock isolation. Link: https://lkml.kernel.org/r/20250617021115.2331563-3-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Richard Chang <richardycc@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm/page_alloc: pageblock flags functions clean upZi Yan
Patch series "Make MIGRATE_ISOLATE a standalone bit", v10. This patchset moves MIGRATE_ISOLATE to a standalone bit to avoid being overwritten during pageblock isolation process. Currently, MIGRATE_ISOLATE is part of enum migratetype (in include/linux/mmzone.h), thus, setting a pageblock to MIGRATE_ISOLATE overwrites its original migratetype. This causes pageblock migratetype loss during alloc_contig_range() and memory offline, especially when the process fails due to a failed pageblock isolation and the code tries to undo the finished pageblock isolations. In terms of performance for changing pageblock types, no performance change is observed: 1. I used perf to collect stats of offlining and onlining all memory of a 40GB VM 10 times and see that get_pfnblock_flags_mask() and set_pfnblock_flags_mask() take about 0.12% and 0.02% of the whole process respectively with and without this patchset across 3 runs. 2. I used perf to collect stats of dd from /dev/random to a 40GB tmpfs file and find get_pfnblock_flags_mask() takes about 0.05% of the process with and without this patchset across 3 runs. This patch (of 6): No functional change is intended. 1. Add __NR_PAGEBLOCK_BITS for the number of pageblock flag bits and use roundup_pow_of_two(__NR_PAGEBLOCK_BITS) as NR_PAGEBLOCK_BITS to take right amount of bits for pageblock flags. 2. Rename PB_migrate_skip to PB_compact_skip. 3. Add {get,set,clear}_pfnblock_bit() to operate one a standalone bit, like PB_compact_skip. 3. Make {get,set}_pfnblock_flags_mask() internal functions and use {get,set}_pfnblock_migratetype() for pageblock migratetype operations. 4. Move pageblock flags common code to get_pfnblock_bitmap_bitidx(). 3. Use MIGRATETYPE_MASK to get the migratetype of a pageblock from its flags. 4. Use PB_migrate_end in the definition of MIGRATETYPE_MASK instead of PB_migrate_bits. 5. Add a comment on is_migrate_cma_folio() to prevent one from changing it to use get_pageblock_migratetype() and causing issues. Link: https://lkml.kernel.org/r/20250617021115.2331563-1-ziy@nvidia.com Link: https://lkml.kernel.org/r/20250617021115.2331563-2-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Richard Chang <richardycc@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm,memory_hotplug: drop status_change_nid parameter from memory_notifyOscar Salvador
There no users left of status_change_nid, so drop it from memory_notify struct. Link: https://lkml.kernel.org/r/20250616135158.450136-12-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Harry Yoo <harry.yoo@oracle.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Rakie Kim <rakie.kim@sk.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm,memory_hotplug: implement numa node notifierOscar Salvador
There are at least six consumers of hotplug_memory_notifier that what they really are interested in is whether any numa node changed its state, e.g: going from having memory to not having memory and vice versa. Implement a specific notifier for numa nodes when their state gets changed, which will later be used by those consumers that are only interested in numa node state changes. Add documentation as well. [dan.carpenter@linaro.org: set failure reason in offline_pages()] Link: https://lkml.kernel.org/r/be4fd31b-7d09-46b0-8329-6d0464ffa7a5@sabinyo.mountain Link: https://lkml.kernel.org/r/20250616135158.450136-4-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Hildenbrand <david@redhat.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm,memory_hotplug: remove status_change_nid_normal and update documentationOscar Salvador
Now that the last user of status_change_nid_normal is gone, we can remove it. Update documentation accordingly. Link: https://lkml.kernel.org/r/20250616135158.450136-3-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Hildenbrand <david@redhat.com> Cc: Harry Yoo <harry.yoo@oracle.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Joanthan Cameron <Jonathan.Cameron@huawei.com> Cc: Rakie Kim <rakie.kim@sk.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm, madvise: extract mm code from prctl_set_vma() to mm/madvise.cVlastimil Babka
Setting anon_name is done via madvise_set_anon_name() and behaves a lot of like other madvise operations. However, apparently because madvise() has lacked the 4th argument and prctl() not, the userspace entry point has been implemented via prctl(PR_SET_VMA, ...) and handled first by prctl_set_vma(). Currently prctl_set_vma() lives in kernel/sys.c but setting the vma->anon_name is mm-specific code so extract it to a new set_anon_vma_name() function under mm. mm/madvise.c seems to be the most straightforward place as that's where madvise_set_anon_name() lives. Stop declaring the latter in mm.h and instead declare set_anon_vma_name(). Link: https://lkml.kernel.org/r/20250624-anon_name_cleanup-v2-2-600075462a11@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Hildenbrand <david@redhat.com> Tested-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Colin Cross <ccross@google.com> Cc: Jann Horn <jannh@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm/madvise: eliminate very confusing manipulation of prev VMALorenzo Stoakes
The madvise code has for the longest time had very confusing code around the 'prev' VMA pointer passed around various functions which, in all cases except madvise_update_vma(), is unused and instead simply updated as soon as the function is invoked. To compound the confusion, the prev pointer is also used to indicate to the caller that the mmap lock has been dropped and that we can therefore not safely access the end of the current VMA (which might have been updated by madvise_update_vma()). Clear up this confusion by not setting prev = vma anywhere except in madvise_walk_vmas(), update all references to prev which will always be equal to vma after madvise_vma_behavior() is invoked, and adding a flag to indicate that the lock has been dropped to make this explicit. Additionally, drop a redundant BUG_ON() from madvise_collapse(), which is simply reiterating the BUG_ON(mmap_locked) above it (note that BUG_ON() is not appropriate here, but we leave existing code as-is). We finally adjust the madvise_walk_vmas() logic to be a little clearer - delaying the assignment of the end of the range to the start of the new range until the last moment and handling the lock being dropped scenario immediately. Additionally add some explanatory comments. [lorenzo.stoakes@oracle.com: fix very subtle bug] Link: https://lkml.kernel.org/r/dca94cde-8afb-4eab-8e57-3f508624d670@lucifer.local Link: https://lkml.kernel.org/r/63d281c5df2e64225ab5b4bda398b45e22818701.1750433500.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-12Merge branch 'mm-hotfixes-stable' into mm-stable to pick up changes whichAndrew Morton
are required for a merge of the series "mm: folio_pte_batch() improvements".
2025-07-09mm: remove callers of pfn_t functionalityAlistair Popple
All PFN_* pfn_t flags have been removed. Therefore there is no longer a need for the pfn_t type and all uses can be replaced with normal pfns. Link: https://lkml.kernel.org/r/bbedfa576c9822f8032494efbe43544628698b1f.1750323463.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Balbir Singh <balbirs@nvidia.com> Cc: Björn Töpel <bjorn@kernel.org> Cc: Björn Töpel <bjorn@rivosinc.com> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Deepak Gupta <debug@rivosinc.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Inki Dae <m.szyprowski@samsung.com> Cc: John Groves <john@groves.net> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm: remove PFN_DEV, PFN_MAP, PFN_SPECIAL, PFN_SG_CHAIN and PFN_SG_LASTAlistair Popple
The PFN_MAP flag is no longer used for anything, so remove it. The PFN_SG_CHAIN and PFN_SG_LAST flags never appear to have been used so also remove them. The last user of PFN_SPECIAL was removed by 653d7825c149 ("dcssblk: mark DAX broken, remove FS_DAX_LIMITED support"). Users of PFN_DEV were removed earlier in this series by "mm: Remove remaining uses of PFN_DEV". Link: https://lkml.kernel.org/r/670b3950d70b4d97b905bb597dadfd3633de4314.1750323463.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Cc: Balbir Singh <balbirs@nvidia.com> Cc: Björn Töpel <bjorn@kernel.org> Cc: Björn Töpel <bjorn@rivosinc.com> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: Deepak Gupta <debug@rivosinc.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Inki Dae <m.szyprowski@samsung.com> Cc: John Groves <john@groves.net> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm: remove devmap related functions and page table bitsAlistair Popple
Now that DAX and all other reference counts to ZONE_DEVICE pages are managed normally there is no need for the special devmap PTE/PMD/PUD page table bits. So drop all references to these, freeing up a software defined page table bit on architectures supporting it. Link: https://lkml.kernel.org/r/6389398c32cc9daa3dfcaa9f79c7972525d310ce.1750323463.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Acked-by: Will Deacon <will@kernel.org> # arm64 Acked-by: David Hildenbrand <david@redhat.com> Suggested-by: Chunyan Zhang <zhang.lyra@gmail.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Balbir Singh <balbirs@nvidia.com> Cc: Björn Töpel <bjorn@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Deepak Gupta <debug@rivosinc.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Inki Dae <m.szyprowski@samsung.com> Cc: John Groves <john@groves.net> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm: remove redundant pXd_devmap callsAlistair Popple
DAX was the only thing that created pmd_devmap and pud_devmap entries however it no longer does as DAX pages are now refcounted normally and pXd_trans_huge() returns true for those. Therefore checking both pXd_devmap and pXd_trans_huge() is redundant and the former can be removed without changing behaviour as it will always be false. Link: https://lkml.kernel.org/r/d58f089dc16b7feb7c6728164f37dea65d64a0d3.1750323463.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Cc: Balbir Singh <balbirs@nvidia.com> Cc: Björn Töpel <bjorn@kernel.org> Cc: Björn Töpel <bjorn@rivosinc.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Deepak Gupta <debug@rivosinc.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Inki Dae <m.szyprowski@samsung.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: John Groves <john@groves.net> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm/gup: remove pXX_devmap usage from get_user_pages()Alistair Popple
GUP uses pXX_devmap() calls to see if it needs to a get a reference on the associated pgmap data structure to ensure the pages won't go away. However it's a driver responsibility to ensure that if pages are mapped (ie. discoverable by GUP) that they are not offlined or removed from the memmap so there is no need to hold a reference on the pgmap data structure to ensure this. Furthermore mappings with PFN_DEV are no longer created, hence this effectively dead code anyway so can be removed. Link: https://lkml.kernel.org/r/708b2be76876659ec5261fe5d059b07268b98b36.1750323463.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Cc: Balbir Singh <balbirs@nvidia.com> Cc: Björn Töpel <bjorn@kernel.org> Cc: Björn Töpel <bjorn@rivosinc.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: Deepak Gupta <debug@rivosinc.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Inki Dae <m.szyprowski@samsung.com> Cc: John Groves <john@groves.net> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm/percpu: conditionally define _shared_alloc_tag via ↵Hao Ge
CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU Recently discovered this entry while checking kallsyms on ARM64: ffff800083e509c0 D _shared_alloc_tag If ARCH_NEEDS_WEAK_PER_CPU is not defined(it is only defined for s390 and alpha architectures), there's no need to statically define the percpu variable _shared_alloc_tag. Therefore, we need to implement isolation for this purpose. When building the core kernel code for s390 or alpha architectures, ARCH_NEEDS_WEAK_PER_CPU remains undefined (as it is gated by #if defined(MODULE)). However, when building modules for these architectures, the macro is explicitly defined. Therefore, we remove all instances of ARCH_NEEDS_WEAK_PER_CPU from the code and introduced CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU to replace the relevant logic. We can now conditionally define the perpcu variable _shared_alloc_tag based on CONFIG_ARCH_MODULE_NEEDS_WEAK_PER_CPU. This allows architectures (such as s390/alpha) that require weak definitions for percpu variables in modules to include the definition, while others can omit it via compile-time exclusion. Link: https://lkml.kernel.org/r/20250618015809.1235761-1-hao.ge@linux.dev Signed-off-by: Hao Ge <gehao@kylinos.cn> Suggested-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> [s390] Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Chistoph Lameter <cl@linux.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Richard Henderson <richard.henderson@linaro.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm/memfd: reserve hugetlb folios before allocationVivek Kasireddy
When we try to allocate a folio via alloc_hugetlb_folio_reserve(), we need to ensure that there is an active reservation associated with the allocation. Otherwise, our allocation request would fail if there are no active reservations made at that moment against any other allocations. This is because alloc_hugetlb_folio_reserve() checks h->resv_huge_pages before proceeding with the allocation. Therefore, to address this issue, we just need to make a reservation (by calling hugetlb_reserve_pages()) before we try to allocate the folio. This will also ensure that proper region/subpool accounting is done associated with our allocation. Link: https://lkml.kernel.org/r/20250618053415.1036185-3-vivek.kasireddy@intel.com Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com> Cc: Steve Sistare <steven.sistare@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: David Hildenbrand <david@redhat.com> Cc: Gerd Hoffmann <kraxel@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm/hugetlb: make hugetlb_reserve_pages() return nr of entries updatedVivek Kasireddy
Patch series "mm/memfd: Reserve hugetlb folios before allocation", v4. There are cases when we try to pin a folio but discover that it has not been faulted-in. So, we try to allocate it in memfd_alloc_folio() but the allocation request may not succeed if there are no active reservations in the system at that instant. Therefore, making a reservation (by calling hugetlb_reserve_pages()) associated with the allocation will ensure that our request would not fail due to lack of reservations. This will also ensure that proper region/subpool accounting is done with our allocation. This patch (of 3): Currently, hugetlb_reserve_pages() returns a bool to indicate whether the reservation map update for the range [from, to] was successful or not. This is not sufficient for the case where the caller needs to determine how many entries were updated for the range. Therefore, have hugetlb_reserve_pages() return the number of entries updated in the reservation map associated with the range [from, to]. Also, update the callers of hugetlb_reserve_pages() to handle the new return value. Link: https://lkml.kernel.org/r/20250618053415.1036185-1-vivek.kasireddy@intel.com Link: https://lkml.kernel.org/r/20250618053415.1036185-2-vivek.kasireddy@intel.com Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com> Cc: Steve Sistare <steven.sistare@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: David Hildenbrand <david@redhat.com> Cc: Gerd Hoffmann <kraxel@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09codetag: avoid unused alloc_tags sections/symbolsPetr Pavlu
With CONFIG_MEM_ALLOC_PROFILING=n, vmlinux and all modules unnecessarily contain the symbols __start_alloc_tags and __stop_alloc_tags, which define an empty range. In the case of modules, the presence of these symbols also forces the linker to create an empty .codetag.alloc_tags section. Update codetag.lds.h to make the data conditional on CONFIG_MEM_ALLOC_PROFILING. Link: https://lkml.kernel.org/r/20250618125037.53182-1-petr.pavlu@suse.com Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Casey Chen <cachen@purestorage.com> Cc: Petr Pavlu <petr.pavlu@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm/damon: fix minor typos in damon headerNathan Gao
Fix typos in include/linux/damon.h. Link: https://lkml.kernel.org/r/20250618163331.54910-1-sj@kernel.org Signed-off-by: Nathan Gao <zcgao@amazon.com> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm: update core kernel code to use vm_flags_t consistentlyLorenzo Stoakes
The core kernel code is currently very inconsistent in its use of vm_flags_t vs. unsigned long. This prevents us from changing the type of vm_flags_t in the future and is simply not correct, so correct this. While this results in rather a lot of churn, it is a critical pre-requisite for a future planned change to VMA flag type. Additionally, update VMA userland tests to account for the changes. To make review easier and to break things into smaller parts, driver and architecture-specific changes is left for a subsequent commit. The code has been adjusted to cascade the changes across all calling code as far as is needed. We will adjust architecture-specific and driver code in a subsequent patch. Overall, this patch does not introduce any functional change. Link: https://lkml.kernel.org/r/d1588e7bb96d1ea3fe7b9df2c699d5b4592d901d.1750274467.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Kees Cook <kees@kernel.org> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Jan Kara <jack@suse.cz> Acked-by: Christian Brauner <brauner@kernel.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm: change vm_get_page_prot() to accept vm_flags_t argumentLorenzo Stoakes
Patch series "use vm_flags_t consistently". The VMA flags field vma->vm_flags is of type vm_flags_t. Right now this is exactly equivalent to unsigned long, but it should not be assumed to be. Much code that references vma->vm_flags already correctly uses vm_flags_t, but a fairly large chunk of code simply uses unsigned long and assumes that the two are equivalent. This series corrects that and has us use vm_flags_t consistently. This series is motivated by the desire to, in a future series, adjust vm_flags_t to be a u64 regardless of whether the kernel is 32-bit or 64-bit in order to deal with the VMA flag exhaustion issue and avoid all the various problems that arise from it (being unable to use certain features in 32-bit, being unable to add new flags except for 64-bit, etc.) This is therefore a critical first step towards that goal. At any rate, using the correct type is of value regardless. We additionally take the opportunity to refer to VMA flags as vm_flags where possible to make clear what we're referring to. Overall, this series does not introduce any functional change. This patch (of 3): We abstract the type of the VMA flags to vm_flags_t, however in may places it is simply assumed this is unsigned long, which is simply incorrect. At the moment this is simply an incongruity, however in future we plan to change this type and therefore this change is a critical requirement for doing so. Overall, this patch does not introduce any functional change. [lorenzo.stoakes@oracle.com: add missing vm_get_page_prot() instance, remove include] Link: https://lkml.kernel.org/r/552f88e1-2df8-4e95-92b8-812f7c8db829@lucifer.local Link: https://lkml.kernel.org/r/cover.1750274467.git.lorenzo.stoakes@oracle.com Link: https://lkml.kernel.org/r/a12769720a2743f235643b158c4f4f0a9911daf0.1750274467.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Christian Brauner <brauner@kernel.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64] Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Jann Horn <jannh@google.com> Cc: Kees Cook <kees@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09highmem: remove a use of folio->pageMatthew Wilcox (Oracle)
Call folio_address() instead of page_address(). Link: https://lkml.kernel.org/r/20250613194825.3175276-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm/huge_memory: don't mark refcounted folios special in vmf_insert_folio_pud()David Hildenbrand
Marking PUDs that map a "normal" refcounted folios as special is against our rules documented for vm_normal_page(). normal (refcounted) folios shall never have the page table mapping marked as special. Fortunately, there are not that many pud_special() check that can be mislead and are right now rather harmless: e.g., none so far bases decisions whether to grab a folio reference on that decision. Well, and GUP-fast will fallback to GUP-slow. All in all, so far no big implications as it seems. Getting this right will get more important as we introduce folio_normal_page_pud() and start using it in more place where we currently special-case based on other VMA flags. Fix it just like we fixed vmf_insert_folio_pmd(). Add folio_mk_pud() to mimic what we do with folio_mk_pmd(). Link: https://lkml.kernel.org/r/20250613092702.1943533-4-david@redhat.com Fixes: dbe54153296d ("mm/huge_memory: add vmf_insert_folio_pud()") Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Alistair Popple <apopple@nvidia.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm: remove zero_user()Matthew Wilcox (Oracle)
All users have now been converted to either memzero_page() or folio_zero_range(). Link: https://lkml.kernel.org/r/20250612143443.2848197-6-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Alex Markuze <amarkuze@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Xiubo Li <xiubli@redhat.com> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm: madvise: use per_vma lock for MADV_FREEBarry Song
MADV_FREE is another option, besides MADV_DONTNEED, for dynamic memory freeing in user-space native or Java heap memory management. For example, jemalloc can be configured to use MADV_FREE, and recent versions of the Android Java heap have also increasingly adopted MADV_FREE. Supporting per-VMA locking for MADV_FREE thus appears increasingly necessary. We have replaced walk_page_range() with walk_page_range_vma(). Along with the proposed madvise_lock_mode by Lorenzo, the necessary infrastructure is now in place to begin exploring per-VMA locking support for MADV_FREE and potentially other madvise using walk_page_range_vma(). This patch adds support for the PGWALK_VMA_RDLOCK walk_lock mode in walk_page_range_vma(), and leverages madvise_lock_mode from madv_behavior to select the appropriate walk_lock—either mmap_lock or per-VMA lock—based on the context. Because we now dynamically update the walk_ops->walk_lock field, we must ensure this is thread-safe. The madvise_free_walk_ops is now defined as a stack variable instead of a global constant. Link: https://lkml.kernel.org/r/20250611104745.57405-1-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: SeongJae Park <sj@kernel.org> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Tangquan Zheng <zhengtangquan@oppo.com> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm/memory-tier: fix abstract distance calculation overflowLi Zhijian
In mt_perf_to_adistance(), the calculation of abstract distance (adist) involves multiplying several int values including MEMTIER_ADISTANCE_DRAM. *adist = MEMTIER_ADISTANCE_DRAM * (perf->read_latency + perf->write_latency) / (default_dram_perf.read_latency + default_dram_perf.write_latency) * (default_dram_perf.read_bandwidth + default_dram_perf.write_bandwidth) / (perf->read_bandwidth + perf->write_bandwidth); Since these values can be large, the multiplication may exceed the maximum value of an int (INT_MAX) and overflow (Our platform did), leading to an incorrect adist. User-visible impact: The memory tiering subsystem will misinterpret slow memory (like CXL) as faster than DRAM, causing inappropriate demotion of pages from CXL (slow memory) to DRAM (fast memory). For example, we will see the following demotion chains from the dmesg, where Node0,1 are DRAM, and Node2,3 are CXL node: Demotion targets for Node 0: null Demotion targets for Node 1: null Demotion targets for Node 2: preferred: 0-1, fallback: 0-1 Demotion targets for Node 3: preferred: 0-1, fallback: 0-1 Change MEMTIER_ADISTANCE_DRAM to be a long constant by writing it with the 'L' suffix. This prevents the overflow because the multiplication will then be done in the long type which has a larger range. Link: https://lkml.kernel.org/r/20250611023439.2845785-1-lizhijian@fujitsu.com Link: https://lkml.kernel.org/r/20250610062751.2365436-1-lizhijian@fujitsu.com Fixes: 3718c02dbd4c ("acpi, hmat: calculate abstract distance with HMAT") Signed-off-by: Li Zhijian <lizhijian@fujitsu.com> Reviewed-by: Huang Ying <ying.huang@linux.alibaba.com> Acked-by: Balbir Singh <balbirs@nvidia.com> Reviewed-by: Donet Tom <donettom@linux.ibm.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09alloc_tag: add sequence number for module and iteratorDavid Wang
Codetag iterator use <id,address> pair to guarantee the validness. But both id and address can be reused, there is theoretical possibility when module inserted right after another module removed, kmalloc returns an address same as the address kfree by previous module and IDR key reuses the key recently removed. Add a sequence number to codetag_module and code_iterator, the sequence number is strickly incremented whenever a module is loaded. An iterator is valid if and only if its sequence number match codetag_module's. Link: https://lkml.kernel.org/r/20250609064200.112639-1-00107082@163.com Signed-off-by: David Wang <00107082@163.com> Acked-by: Suren Baghdasaryan <surenb@google.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm/pagewalk: split walk_page_range_novma() into kernel/user partsLorenzo Stoakes
walk_page_range_novma() is rather confusing - it supports two modes, one used often, the other used only for debugging. The first mode is the common case of traversal of kernel page tables, which is what nearly all callers use this for. Secondly it provides an unusual debugging interface that allows for the traversal of page tables in a userland range of memory even for that memory which is not described by a VMA. It is far from certain that such page tables should even exist, but perhaps this is precisely why it is useful as a debugging mechanism. As a result, this is utilised by ptdump only. Historically, things were reversed - ptdump was the only user, and other parts of the kernel evolved to use the kernel page table walking here. Since we have some complicated and confusing locking rules for the novma case, it makes sense to separate the two usages into their own functions. Doing this also provide self-documentation as to the intent of the caller - are they doing something rather unusual or are they simply doing a standard kernel page table walk? We therefore establish two separate functions - walk_page_range_debug() for this single usage, and walk_kernel_page_table_range() for general kernel page table walking. The walk_page_range_debug() function is currently used to traverse both userland and kernel mappings, so we maintain this and in the case of kernel mappings being traversed, we have walk_page_range_debug() invoke walk_kernel_page_table_range() internally. We additionally make walk_page_range_debug() internal to mm. Link: https://lkml.kernel.org/r/20250605135104.90720-1-lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Hildenbrand <david@redhat.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Barry Song <baohua@kernel.org> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: WANG Xuerui <kernel@xen0n.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09alloc_tag: remove empty module tag sectionCasey Chen
The empty MOD_CODETAG_SECTIONS() macro added an incomplete .data section in module linker script, which caused symbol lookup tools like gdb to misinterpret symbol addresses e.g., __ib_process_cq incorrectly mapping to unrelated functions like below. (gdb) disas __ib_process_cq Dump of assembler code for function trace_event_fields_cq_schedule: Removing the empty section restores proper symbol resolution and layout, ensuring .data placement behaves as expected. Link: https://lkml.kernel.org/r/20250610162258.324645-1-cachen@purestorage.com Fixes: 0db6f8d7820a ("alloc_tag: load module tags into separate contiguous memory") 22d407b164ff ("lib: add allocation tagging support for memory allocation profiling") Signed-off-by: Casey Chen <cachen@purestorage.com> Reviewed-by: Yuanyuan Zhong <yzhong@purestorage.com> Acked-by: Suren Baghdasaryan <surenb@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Luis Chamberalin <mcgrof@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm/filemap: allow arch to request folio size for exec memoryRyan Roberts
Change the readahead config so that if it is being requested for an executable mapping, do a synchronous read into a set of folios with an arch-specified order and in a naturally aligned manner. We no longer center the read on the faulting page but simply align it down to the previous natural boundary. Additionally, we don't bother with an asynchronous part. On arm64 if memory is physically contiguous and naturally aligned to the "contpte" size, we can use contpte mappings, which improves utilization of the TLB. When paired with the "multi-size THP" feature, this works well to reduce dTLB pressure. However iTLB pressure is still high due to executable mappings having a low likelihood of being in the required folio size and mapping alignment, even when the filesystem supports readahead into large folios (e.g. XFS). The reason for the low likelihood is that the current readahead algorithm starts with an order-0 folio and increases the folio order by 2 every time the readahead mark is hit. But most executable memory tends to be accessed randomly and so the readahead mark is rarely hit and most executable folios remain order-0. So let's special-case the read(ahead) logic for executable mappings. The trade-off is performance improvement (due to more efficient storage of the translations in iTLB) vs potential for making reclaim more difficult (due to the folios being larger so if a part of the folio is hot the whole thing is considered hot). But executable memory is a small portion of the overall system memory so I doubt this will even register from a reclaim perspective. I've chosen 64K folio size for arm64 which benefits both the 4K and 16K base page size configs. Crucially the same amount of data is still read (usually 128K) so I'm not expecting any read amplification issues. I don't anticipate any write amplification because text is always RO. Note that the text region of an ELF file could be populated into the page cache for other reasons than taking a fault in a mmapped area. The most common case is due to the loader read()ing the header which can be shared with the beginning of text. So some text will still remain in small folios, but this simple, best effort change provides good performance improvements as is. Confine this special-case approach to the bounds of the VMA. This prevents wasting memory for any padding that might exist in the file between sections. Previously the padding would have been contained in order-0 folios and would be easy to reclaim. But now it would be part of a larger folio so more difficult to reclaim. Solve this by simply not reading it into memory in the first place. Benchmarking ============ The below shows pgbench and redis benchmarks on Graviton3 arm64 system. First, confirmation that this patch causes more text to be contained in 64K folios: +----------------------+---------------+---------------+---------------+ | File-backed folios by| system boot | pgbench | redis | | size as percentage of+-------+-------+-------+-------+-------+-------+ | all mapped text mem |before | after |before | after |before | after | +======================+=======+=======+=======+=======+=======+=======+ | base-page-4kB | 78% | 30% | 78% | 11% | 73% | 14% | | thp-aligned-8kB | 1% | 0% | 0% | 0% | 1% | 0% | | thp-aligned-16kB | 17% | 4% | 17% | 3% | 20% | 4% | | thp-aligned-32kB | 1% | 1% | 1% | 2% | 1% | 1% | | thp-aligned-64kB | 3% | 63% | 3% | 81% | 4% | 77% | | thp-aligned-128kB | 0% | 1% | 1% | 1% | 1% | 2% | | thp-unaligned-64kB | 0% | 0% | 0% | 1% | 0% | 1% | | thp-unaligned-128kB | 0% | 1% | 0% | 0% | 0% | 0% | | thp-partial | 0% | 0% | 0% | 1% | 0% | 1% | +----------------------+-------+-------+-------+-------+-------+-------+ | cont-aligned-64kB | 4% | 65% | 4% | 83% | 6% | 79% | +----------------------+-------+-------+-------+-------+-------+-------+ The above shows that for both workloads (each isolated with cgroups) as well as the general system state after boot, the amount of text backed by 4K and 16K folios reduces and the amount backed by 64K folios increases significantly. And the amount of text that is contpte-mapped significantly increases (see last row). And this is reflected in performance improvement. "(I)" indicates a statistically significant improvement. Note TPS and Reqs/sec are rates so bigger is better, ms is time so smaller is better: +-------------+-------------------------------------------+------------+ | Benchmark | Result Class | Improvemnt | +=============+===========================================+============+ | pts/pgbench | Scale: 1 Clients: 1 RO (TPS) | (I) 3.47% | | | Scale: 1 Clients: 1 RO - Latency (ms) | -2.88% | | | Scale: 1 Clients: 250 RO (TPS) | (I) 5.02% | | | Scale: 1 Clients: 250 RO - Latency (ms) | (I) -4.79% | | | Scale: 1 Clients: 1000 RO (TPS) | (I) 6.16% | | | Scale: 1 Clients: 1000 RO - Latency (ms) | (I) -5.82% | | | Scale: 100 Clients: 1 RO (TPS) | 2.51% | | | Scale: 100 Clients: 1 RO - Latency (ms) | -3.51% | | | Scale: 100 Clients: 250 RO (TPS) | (I) 4.75% | | | Scale: 100 Clients: 250 RO - Latency (ms) | (I) -4.44% | | | Scale: 100 Clients: 1000 RO (TPS) | (I) 6.34% | | | Scale: 100 Clients: 1000 RO - Latency (ms)| (I) -5.95% | +-------------+-------------------------------------------+------------+ | pts/redis | Test: GET Connections: 50 (Reqs/sec) | (I) 3.20% | | | Test: GET Connections: 1000 (Reqs/sec) | (I) 2.55% | | | Test: LPOP Connections: 50 (Reqs/sec) | (I) 4.59% | | | Test: LPOP Connections: 1000 (Reqs/sec) | (I) 4.81% | | | Test: LPUSH Connections: 50 (Reqs/sec) | (I) 5.31% | | | Test: LPUSH Connections: 1000 (Reqs/sec) | (I) 4.36% | | | Test: SADD Connections: 50 (Reqs/sec) | (I) 2.64% | | | Test: SADD Connections: 1000 (Reqs/sec) | (I) 4.15% | | | Test: SET Connections: 50 (Reqs/sec) | (I) 3.11% | | | Test: SET Connections: 1000 (Reqs/sec) | (I) 3.36% | +-------------+-------------------------------------------+------------+ [ryan.roberts@arm.com: fix use-after-free] Link: https://lkml.kernel.org/r/ea7f9da7-9a9f-4b85-9d0a-35b320f5ed25@arm.com [ryan.roberts@arm.com: use the vma_pages() helper instead of open-coding] Link: https://lkml.kernel.org/r/0e0f674b-3b7e-494f-ae7a-fc9dbb98dad4@arm.com Link: https://lkml.kernel.org/r/20250609092729.274960-6-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Will Deacon <will@kernel.org> Cc: Chaitanya S Prakash <chaitanyas.prakash@arm.com> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm/readahead: store folio order in struct file_ra_stateRyan Roberts
Previously the folio order of the previous readahead request was inferred from the folio who's readahead marker was hit. But due to the way we have to round to non-natural boundaries sometimes, this first folio in the readahead block is often smaller than the preferred order for that request. This means that for cases where the initial sync readahead is poorly aligned, the folio order will ramp up much more slowly. So instead, let's store the order in struct file_ra_state so we are not affected by any required alignment. We previously made enough room in the struct for a 16 order field. This should be plenty big enough since we are limited to MAX_PAGECACHE_ORDER anyway, which is certainly never larger than ~20. Since we now pass order in struct file_ra_state, page_cache_ra_order() no longer needs it's new_order parameter, so let's remove that. Worked example: Here we are touching pages 17-256 sequentially just as we did in the previous commit, but now that we are remembering the preferred order explicitly, we no longer have the slow ramp up problem. Note specifically that we no longer have 2 rounds (2x ~128K) of order-2 folios: TYPE STARTOFFS ENDOFFS SIZE STARTPG ENDPG NRPG ORDER RA ----- ---------- ---------- ---------- ------- ------- ----- ----- -- HOLE 0x00000000 0x00001000 4096 0 1 1 FOLIO 0x00001000 0x00002000 4096 1 2 1 0 FOLIO 0x00002000 0x00003000 4096 2 3 1 0 FOLIO 0x00003000 0x00004000 4096 3 4 1 0 FOLIO 0x00004000 0x00005000 4096 4 5 1 0 FOLIO 0x00005000 0x00006000 4096 5 6 1 0 FOLIO 0x00006000 0x00007000 4096 6 7 1 0 FOLIO 0x00007000 0x00008000 4096 7 8 1 0 FOLIO 0x00008000 0x00009000 4096 8 9 1 0 FOLIO 0x00009000 0x0000a000 4096 9 10 1 0 FOLIO 0x0000a000 0x0000b000 4096 10 11 1 0 FOLIO 0x0000b000 0x0000c000 4096 11 12 1 0 FOLIO 0x0000c000 0x0000d000 4096 12 13 1 0 FOLIO 0x0000d000 0x0000e000 4096 13 14 1 0 FOLIO 0x0000e000 0x0000f000 4096 14 15 1 0 FOLIO 0x0000f000 0x00010000 4096 15 16 1 0 FOLIO 0x00010000 0x00011000 4096 16 17 1 0 FOLIO 0x00011000 0x00012000 4096 17 18 1 0 FOLIO 0x00012000 0x00013000 4096 18 19 1 0 FOLIO 0x00013000 0x00014000 4096 19 20 1 0 FOLIO 0x00014000 0x00015000 4096 20 21 1 0 FOLIO 0x00015000 0x00016000 4096 21 22 1 0 FOLIO 0x00016000 0x00017000 4096 22 23 1 0 FOLIO 0x00017000 0x00018000 4096 23 24 1 0 FOLIO 0x00018000 0x00019000 4096 24 25 1 0 FOLIO 0x00019000 0x0001a000 4096 25 26 1 0 FOLIO 0x0001a000 0x0001b000 4096 26 27 1 0 FOLIO 0x0001b000 0x0001c000 4096 27 28 1 0 FOLIO 0x0001c000 0x0001d000 4096 28 29 1 0 FOLIO 0x0001d000 0x0001e000 4096 29 30 1 0 FOLIO 0x0001e000 0x0001f000 4096 30 31 1 0 FOLIO 0x0001f000 0x00020000 4096 31 32 1 0 FOLIO 0x00020000 0x00021000 4096 32 33 1 0 FOLIO 0x00021000 0x00022000 4096 33 34 1 0 FOLIO 0x00022000 0x00024000 8192 34 36 2 1 FOLIO 0x00024000 0x00028000 16384 36 40 4 2 FOLIO 0x00028000 0x0002c000 16384 40 44 4 2 FOLIO 0x0002c000 0x00030000 16384 44 48 4 2 FOLIO 0x00030000 0x00034000 16384 48 52 4 2 FOLIO 0x00034000 0x00038000 16384 52 56 4 2 FOLIO 0x00038000 0x0003c000 16384 56 60 4 2 FOLIO 0x0003c000 0x00040000 16384 60 64 4 2 FOLIO 0x00040000 0x00050000 65536 64 80 16 4 FOLIO 0x00050000 0x00060000 65536 80 96 16 4 FOLIO 0x00060000 0x00080000 131072 96 128 32 5 FOLIO 0x00080000 0x000a0000 131072 128 160 32 5 FOLIO 0x000a0000 0x000c0000 131072 160 192 32 5 FOLIO 0x000c0000 0x000e0000 131072 192 224 32 5 FOLIO 0x000e0000 0x00100000 131072 224 256 32 5 FOLIO 0x00100000 0x00120000 131072 256 288 32 5 FOLIO 0x00120000 0x00140000 131072 288 320 32 5 Y HOLE 0x00140000 0x00800000 7077888 320 2048 1728 Link: https://lkml.kernel.org/r/20250609092729.274960-5-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Chaitanya S Prakash <chaitanyas.prakash@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm/readahead: make space in struct file_ra_stateRyan Roberts
We need to be able to store the preferred folio order associated with a readahead request in the struct file_ra_state so that we can more accurately increase the order across subsequent readahead requests. But struct file_ra_state is per-struct file, so we don't really want to increase it's size. mmap_miss is currently 32 bits but it is only counted up to 10 * MMAP_LOTSAMISS, which is currently defined as 1000. So 16 bits should be plenty. Redefine it to unsigned short, making room for order as unsigned short in follow up commit. Link: https://lkml.kernel.org/r/20250609092729.274960-4-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Chaitanya S Prakash <chaitanyas.prakash@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09proc: use the same treatment to check proc_lseek as ones for proc_read_iter ↵wangzijie
et.al Check pde->proc_ops->proc_lseek directly may cause UAF in rmmod scenario. It's a gap in proc_reg_open() after commit 654b33ada4ab("proc: fix UAF in proc_get_inode()"). Followed by AI Viro's suggestion, fix it in same manner. Link: https://lkml.kernel.org/r/20250607021353.1127963-1-wangzijie1@honor.com Fixes: 3f61631d47f1 ("take care to handle NULL ->proc_lseek()") Signed-off-by: wangzijie <wangzijie1@honor.com> Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com> Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09userfaultfd: remove UFFD_CLOEXEC, UFFD_NONBLOCK, and UFFD_FLAGS_SETTal Zussman
UFFD_CLOEXEC, UFFD_NONBLOCK, and UFFD_FLAGS_SET have been unused since they were added in commit 932b18e0aec6 ("userfaultfd: linux/userfaultfd_k.h"). Remove them and the associated BUILD_BUG_ON() checks. Link: https://lkml.kernel.org/r/20250619-uffd-fixes-v3-4-a7274d3bd5e4@columbia.edu Signed-off-by: Tal Zussman <tz2294@columbia.edu> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Peter Xu <peterx@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09userfaultfd: correctly prevent registering VM_DROPPABLE regionsTal Zussman
Patch series "mm: userfaultfd: assorted fixes and cleanups", v3. Two fixes and two cleanups for userfaultfd. Note that the third patch yields a small change in the ABI, but we seem to have concluded that it is acceptable in this case. This patch (of 4): vma_can_userfault() masks off non-userfaultfd VM flags from vm_flags. The vm_flags & VM_DROPPABLE test will then always be false, incorrectly allowing VM_DROPPABLE regions to be registered with userfaultfd. Additionally, vm_flags is not guaranteed to correspond to the actual VMA's flags. Fix this test by checking the VMA's flags directly. Link: https://lkml.kernel.org/r/20250619-uffd-fixes-v3-0-a7274d3bd5e4@columbia.edu Link: https://lore.kernel.org/linux-mm/5a875a3a-2243-4eab-856f-bc53ccfec3ea@redhat.com/ Link: https://lkml.kernel.org/r/20250619-uffd-fixes-v3-1-a7274d3bd5e4@columbia.edu Fixes: 9651fcedf7b9 ("mm: add MAP_DROPPABLE for designating always lazily freeable mappings") Signed-off-by: Tal Zussman <tz2294@columbia.edu> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Peter Xu <peterx@redhat.com> Acked-by: Jason A. Donenfeld <Jason@zx2c4.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09drivers/base/node: rename __register_one_node() to register_one_node()Donet Tom
The register_one_node() function was a simple wrapper around __register_one_node(). To simplify the code, register_one_node() has been removed, and __register_one_node() has been renamed to register_one_node(). Link: https://lkml.kernel.org/r/8262cd0f44eeb048a1fcd3ac8382760d7f7dea60.1748452242.git.donettom@linux.ibm.com Signed-off-by: Donet Tom <donettom@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09drivers/base/node: rename register_memory_blocks_under_node() and remove ↵Donet Tom
context argument The function register_memory_blocks_under_node() is now only called from the memory hotplug path, as register_memory_blocks_under_node_early() handles registration during early boot. Therefore, the context argument used to differentiate between early boot and hotplug is no longer needed and was removed. Since the function is only called from the hotplug path, we renamed register_memory_blocks_under_node() to register_memory_blocks_under_node_hotplug() Link: https://lkml.kernel.org/r/907c22292b0ee4975107876efc875c75c11badd9.1748452242.git.donettom@linux.ibm.com Signed-off-by: Donet Tom <donettom@linux.ibm.com> Acked-by: Oscar Salvador <osalvador@suse.de> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09drivers/base/node: remove register_memory_blocks_under_node() function call ↵Donet Tom
from register_one_node register_one_node() is now only called via cpu_up() → __try_online_node() during CPU hotplug operations to online a node. At this stage, the node has not yet had any memory added. As a result, there are no memory blocks to walk or register, so calling register_memory_blocks_under_node() is unnecessary. Therefore, the call to register_memory_blocks_under_node() has been removed from register_one_node(). Link: https://lkml.kernel.org/r/ecf07075b1a41015fcf58823997d5c2ed7b8c18f.1748452242.git.donettom@linux.ibm.com Signed-off-by: Donet Tom <donettom@linux.ibm.com> Acked-by: Oscar Salvador <osalvador@suse.de> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09drivers/base/node: optimize memory block registration to reduce boot timeDonet Tom
Patch series "drivers/base/node.c: optimization and cleanups", v7. This patch (of 7) During node device initialization, `memory blocks` are registered under each NUMA node. The `memory blocks` to be registered are identified using the node's start and end PFNs, which are obtained from the node's pg_data However, not all PFNs within this range necessarily belong to the same node—some may belong to other nodes. Additionally, due to the discontiguous nature of physical memory, certain sections within a `memory block` may be absent. As a result, `memory blocks` that fall between a node's start and end PFNs may span across multiple nodes, and some sections within those blocks may be missing. `Memory blocks` have a fixed size, which is architecture dependent. Due to these considerations, the memory block registration is currently performed as follows: for_each_online_node(nid): start_pfn = pgdat->node_start_pfn; end_pfn = pgdat->node_start_pfn + node_spanned_pages; for_each_memory_block_between(PFN_PHYS(start_pfn), PFN_PHYS(end_pfn)) mem_blk = memory_block_id(pfn_to_section_nr(pfn)); pfn_mb_start=section_nr_to_pfn(mem_blk->start_section_nr) pfn_mb_end = pfn_start + memory_block_pfns - 1 for (pfn = pfn_mb_start; pfn < pfn_mb_end; pfn++): if (get_nid_for_pfn(pfn) != nid): continue; else do_register_memory_block_under_node(nid, mem_blk, MEMINIT_EARLY); Here, we derive the start and end PFNs from the node's pg_data, then determine the memory blocks that may belong to the node. For each `memory block` in this range, we inspect all PFNs it contains and check their associated NUMA node ID. If a PFN within the block matches the current node, the memory block is registered under that node. If CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, get_nid_for_pfn() performs a binary search in the `memblock regions` to determine the NUMA node ID for a given PFN. If it is not enabled, the node ID is retrieved directly from the struct page. On large systems, this process can become time-consuming, especially since we iterate over each `memory block` and all PFNs within it until a match is found. When CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, the additional overhead of the binary search increases the execution time significantly, potentially leading to soft lockups during boot. In this patch, we iterate over `memblock region` to identify the `memory blocks` that belong to the current NUMA node. `memblock regions` are contiguous memory ranges, each associated with a single NUMA node, and they do not span across multiple nodes. for_each_memory_region(r): // r => region if (!node_online(r->nid)): continue; else for_each_memory_block_between(r->base, r->base + r->size - 1): do_register_memory_block_under_node(r->nid, mem_blk, MEMINIT_EARLY); We iterate over all memblock regions, and if the node associated with the region is online, we calculate the start and end memory blocks based on the region's start and end PFNs. We then register all the memory blocks within that range under the region node. Test Results on My system with 32TB RAM ======================================= 1. Boot time with CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled. Without this patch ------------------ Startup finished in 1min 16.528s (kernel) With this patch --------------- Startup finished in 17.236s (kernel) - 78% Improvement 2. Boot time with CONFIG_DEFERRED_STRUCT_PAGE_INIT disabled. Without this patch ------------------ Startup finished in 28.320s (kernel) With this patch --------------- Startup finished in 15.621s (kernel) - 46% Improvement [donettom@linux.ibm.com: restore removed extra line] Link: https://lkml.kernel.org/r/20250609140354.467908-1-donettom@linux.ibm.com Link: https://lkml.kernel.org/r/2a0a05c2dffc62a742bf1dd030098be4ce99be28.1748452241.git.donettom@linux.ibm.com Link: https://lkml.kernel.org/r/2a0a05c2dffc62a742bf1dd030098be4ce99be28.1748452241.git.donettom@linux.ibm.com Signed-off-by: Donet Tom <donettom@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Oscar Salvador <osalvador@suse.de> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm: remove the for_reclaim field from struct writeback_controlChristoph Hellwig
This field is now only set to one in the i915 gem code that only calls writeback_iter on it, which ignores the flag. All other checks are thuse dead code and the field can be removed. Link: https://lkml.kernel.org/r/20250610054959.2057526-7-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nhat Pham <nphamcs@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm: stop passing a writeback_control structure to swap_writeoutChristoph Hellwig
swap_writeout only needs the swap_iocb cookie from the writeback_control structure, so pass it explicitly. Link: https://lkml.kernel.org/r/20250610054959.2057526-6-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nhat Pham <nphamcs@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09mm: stop passing a writeback_control structure to shmem_writeoutChristoph Hellwig
shmem_writeout only needs the swap_iocb cookie and the split folio list. Pass those explicitly and remove the now unused list member from struct writeback_control. Link: https://lkml.kernel.org/r/20250610054959.2057526-3-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nhat Pham <nphamcs@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>