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2026-08-24mm/rmap: track whether the page VMA mapped pgoff is anonymousLorenzo Stoakes (ARM)1-0/+2
Update the page_vma_mapped_walk structure to track whether the pgoff being tracked is an anonymous pgoff or not and update the comments to reflect this. This is necessary in order to determine the correct VMA page offset in vma_address_end() when pvmw->nr_pages > 1. Also document that pvmw->pgoff is meaningless for pvmw->nr_pages == 1 and for KSM. Do not set this field where pgoff is not specified. This is laying the groundwork for eventually using anonymous page offsets as the index for all anonymous folios. No functional change intended. Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-10-c21581c0c3c8@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Deucher <alexander.deucher@amd.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Barry Song <baohua@kernel.org> Cc: Boris Brezillon <boris.brezillon@collabora.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chris Li <chrisl@kernel.org> Cc: Christan König <christian.koenig@amd.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Dave Airlie <airlied@gmail.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price (Meta) <gourry@gourry.net> Cc: Harry Yoo <harry@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huang Ray <Ray.Huang@amd.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kees Cook <kees@kernel.org> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Matthew Auld <matthew.auld@intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Maxime Ripard <mripard@kernel.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Namhyung kim <namhyung@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Thomas Zimemrmann <tzimmermann@suse.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24mm: propagate VMA anonymous page offset on map, remap, split + mergeLorenzo Stoakes (ARM)4-49/+84
We must correctly update VMA anonymous page offset state on all VMA operations that would result in it changing, with special attention given to remapping. We cover most cases by simply updating vma_set_range() to do so (with a new anonymous page offset parameter), but also notably must update the merging and mapping logic to propagate this parameter correctly. The remap logic remains the same - we may update the anonymous page offset if the VMA is unfaulted, but now this applies to MAP_PRIVATE file-backed mappings too, so we update the code to reflect this. Note that we use __linear_anon_page_index() upon remap as the VMA may be shared, in order that we update the field consistently regardless of VMA type. Similarly, pass through anon page offset to the merge logic, updating the vma_merge_struct struct to propagate it, and also use __linear_anon_page_index() to obtain the anonymous page index so it can be safely used for both shared and MAP_PRIVATE file-backed mappings. In copy_vma(), the anonymous page offset is updated regardless of whether the mapping is a CoW mapping or not. This is both to keep the anonymous page offset consistent even for non-CoW mappings (it is set so should at least remain correct) and makes the logic cleaner. A self-merge however remains permitted only for mappings which can have a populated vma->anon_vma and do not require alignment on a separate file offset - that is pure anonymous VMAs, so only set can_self_merge if vma_is_anonymous(). Finally, we update insert_vm_struct() to correctly set the anonymous page offset on insertion of a VMA. We simply ensure state is correctly propagated here, so no functional changes are intended. Also update VMA userland tests to reflect this change. Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-9-c21581c0c3c8@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Deucher <alexander.deucher@amd.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Barry Song <baohua@kernel.org> Cc: Boris Brezillon <boris.brezillon@collabora.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chris Li <chrisl@kernel.org> Cc: Christan König <christian.koenig@amd.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Dave Airlie <airlied@gmail.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price (Meta) <gourry@gourry.net> Cc: Harry Yoo <harry@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huang Ray <Ray.Huang@amd.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kees Cook <kees@kernel.org> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Matthew Auld <matthew.auld@intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Maxime Ripard <mripard@kernel.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Namhyung kim <namhyung@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Thomas Zimemrmann <tzimmermann@suse.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24mm/vma: fix self-merge check in copy_vma()Lorenzo Stoakes (ARM)1-19/+16
The existing logic is very confusing so improve things. Firstly rename the confusing faulted_in_anon_vma variable to can_self_merge and update this when the page offset is updated. What is being checked for is a 'self-merge' - that is between the VMA being remapped and its prior VMA (remember that this is copy_vma() - if a non-MREMAP_DONTUNMAP remap the original VMA is only removed afterwards). This can happen if the VMA is moved immediately adjacent to itself, either before or after it: |----------------|----------------| | | | v | v |...............||---------------||...............| | new || old || new | |...............||---------------||---------------| In these cases the old VMA is simply expanded to cover the new range. It is also possible for the move to both self-merge and merge with a prior VMA if it is placed between a preceding VMA and its old self: |---------------| | | v | |---------------||...............||---------------| | prev || new || old | |---------------||...............||---------------| In this case, the old VMA is removed and 'prev' is expanded and replaces it. Since copy_vma_and_data() which calls copy_vma() intends to reference the old VMA after the merge, it must have this pointer updated. This kind of self-merge is not possible with a succeeding merge, as the merge always prefers to expand the preceding VMA if possible. copy_vma() accounts for this by explicitly checking to see if a self-merge occurred and updating the vmap pointer if so. However it incorrect did so even for a subsequent merge (this is simply a noop so it had no impact). So change this to only check for the case which matters - a backwards merge - and rearrange the parameters to make it clearer we're doing that - i.e. check new_vma->vm_start < old_vma_start (having already renamed vma_start to old_vma_start to make it clear this is the previous VMA). Also update the existing wall-of-text comment to be a lot clearer. While we're here, replace the VM_BUG_ON_VMA() with a VM_WARN_ON_ONCE_VMA() and update the VMA userland tests accordingly. No functional change intended. Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-7-c21581c0c3c8@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Deucher <alexander.deucher@amd.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Barry Song <baohua@kernel.org> Cc: Boris Brezillon <boris.brezillon@collabora.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chris Li <chrisl@kernel.org> Cc: Christan König <christian.koenig@amd.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Dave Airlie <airlied@gmail.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price (Meta) <gourry@gourry.net> Cc: Harry Yoo <harry@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huang Ray <Ray.Huang@amd.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kees Cook <kees@kernel.org> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Matthew Auld <matthew.auld@intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Maxime Ripard <mripard@kernel.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Namhyung kim <namhyung@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Thomas Zimemrmann <tzimmermann@suse.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24mm: introduce and use vma_filebacked_address()Lorenzo Stoakes (ARM)4-7/+31
In cases where we know that the VMA is file-backed, use vma_filebacked_address() rather than vma_address(). This lays the foundation for using the anonymous page offset via vma_anon_address(). Also add an assert to ensure that the VMA whose address is required is not anonymous. No functional change intended. Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-6-c21581c0c3c8@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Tested-by: syzbot@syzkaller.appspotmail.com Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Deucher <alexander.deucher@amd.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Barry Song <baohua@kernel.org> Cc: Boris Brezillon <boris.brezillon@collabora.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chris Li <chrisl@kernel.org> Cc: Christan König <christian.koenig@amd.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Dave Airlie <airlied@gmail.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price (Meta) <gourry@gourry.net> Cc: Harry Yoo <harry@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huang Ray <Ray.Huang@amd.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kees Cook <kees@kernel.org> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Matthew Auld <matthew.auld@intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Maxime Ripard <mripard@kernel.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Namhyung kim <namhyung@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Thomas Zimemrmann <tzimmermann@suse.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24mm: update print_bad_page_map() to show anon index if appropriateLorenzo Stoakes (ARM)1-3/+10
If the VMA is a CoW mapping page offset may differ from anon page offset, indicating different positions in the relevant rmap trees. Update print_bad_page_map() to reflect that - if the mapping is non-CoW or the indexes match, then output only one index as before, otherwise output both with (file) or (anon) suffixes to reflect which is which. It's not possible to give only one index as there is no folio available to perform folio_test_anon() upon (the page table entry is bad so this is unavailable). This is potentially useful debugging information and matches the existing page offset provided. Use the raw __linear_anon_page_index() function so as to always output this value regardless of whether the mapping is file-backed or not and to avoid asserts that shouldn't apply here. Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-5-c21581c0c3c8@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Gregory Price (Meta) <gourry@gourry.net> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Deucher <alexander.deucher@amd.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Barry Song <baohua@kernel.org> Cc: Boris Brezillon <boris.brezillon@collabora.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chris Li <chrisl@kernel.org> Cc: Christan König <christian.koenig@amd.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Dave Airlie <airlied@gmail.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Harry Yoo <harry@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huang Ray <Ray.Huang@amd.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kees Cook <kees@kernel.org> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Matthew Auld <matthew.auld@intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Maxime Ripard <mripard@kernel.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Namhyung kim <namhyung@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Thomas Zimemrmann <tzimmermann@suse.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24mm: abstract vma_address() and introduce vma_anon_address()Lorenzo Stoakes (ARM)1-12/+37
Introduce __vma_address() which abstracts the VMA start page offset field as pgoff_start, then update vma_address() to use it. Then introduce vma_anon_address() which does the equivalent of vma_address(), only using the anonymous page offset of the VMA rather than the file-backed one. Also add an assert to ensure that the function is not called for mappings which are file-backed but not MAP_PRIVATE to ensure it is only used in the correct places. This will be necessary for determining the address of a folio's index within a VMA when the folio belongs to a MAP_PRIVATE file-backed VMA but has been CoW'd, and thus is anonymous, once the anonymous VMA page offset field is used for the reverse mapping. No callers are updated, so no functional change intended. Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-4-c21581c0c3c8@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Deucher <alexander.deucher@amd.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Barry Song <baohua@kernel.org> Cc: Boris Brezillon <boris.brezillon@collabora.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chris Li <chrisl@kernel.org> Cc: Christan König <christian.koenig@amd.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Dave Airlie <airlied@gmail.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price (Meta) <gourry@gourry.net> Cc: Harry Yoo <harry@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huang Ray <Ray.Huang@amd.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kees Cook <kees@kernel.org> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Matthew Auld <matthew.auld@intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Maxime Ripard <mripard@kernel.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Namhyung kim <namhyung@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Thomas Zimemrmann <tzimmermann@suse.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24mm: provide vma_[flags_]is_cow_mapping() and remove is_cow_mapping()Lorenzo Stoakes (ARM)6-21/+20
All remaining callers of is_cow_mapping() are invoking it in the form of is_cow_mapping(vma->vm_flags) or an indirected version of this. Therefore, provide a helper - vma_is_cow_mapping() to directly test the VMA. Additionally provide a new helper vma_flags_is_cow_mapping() which performs the check using the new vma_flags_t type, and share this logic between vma_is_cow_mapping() and vma_desc_is_cow_mapping(). With these changes, no callers of is_cow_mapping() remain, so remove it. Also update the userland VMA tests to reflect the change. No functional change intended. [akpm@linux-foundation.org: fix kerneldoc comment typo, per Lorenzo] Link: https://lore.kernel.org/aob1goSSPH6sTN9y@gremlin Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-2-c21581c0c3c8@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Deucher <alexander.deucher@amd.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Barry Song <baohua@kernel.org> Cc: Boris Brezillon <boris.brezillon@collabora.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chris Li <chrisl@kernel.org> Cc: Christan König <christian.koenig@amd.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Dave Airlie <airlied@gmail.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price (Meta) <gourry@gourry.net> Cc: Harry Yoo <harry@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huang Ray <Ray.Huang@amd.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kees Cook <kees@kernel.org> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Matthew Auld <matthew.auld@intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Maxime Ripard <mripard@kernel.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Namhyung kim <namhyung@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Thomas Zimemrmann <tzimmermann@suse.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24mm/vma: introduce VMA anon page offset field and add helpersLorenzo Stoakes (ARM)2-0/+15
Patch series "mm/rmap: index MAP_PRIVATE file-backed folios by anonymous pgoff", v5. In memory management we've managed to manufacture a great deal of confusion around the concept of anonymous memory. We have: 1. 'Pure anon' memory - anonymous VMAs whose folios are anonymous and swap-backed (thus for reclaim purposes, treated as anonymous). These are simple enough. 2. shmem - file-backed VMAs, file-backed folios (from rmap perspective) so present in the page cache and mapped by an address_space object, but whose folios are also swap-backed (thus treated as anonymous for reclaim purposes). 3. MAP_PRIVATE-mapped /dev/zero - a strange beast whose VMAs have vma->vm_file set, but which clears vma->vm_ops to satisfy vma_is_anonymous(), resulting in VMAs that were mmap()'d referencing a file, but are in every other sense anonymous, including the folios. 4. Other MAP_PRIVATE-file backed mappings - These possess file-backed VMAs and have file-backed folios until CoW'd, at which point those CoW'd folios are anonymous. This series fixes issue 3. In order for us to traverse VMAs using the reverse mapping, we require two fields - folio->mapping and folio->index. The first tells the rmap code where to look for VMAs, and the second tells it at which offset the folio starts within the referenced object. For anonymous folios, folio->mapping points at an anon_vma object. For file-backed folios, it points at an address_space. And: * For file-backed folios folio->index is simply the page offset of the start of the folio within the file. * For anonymous folios belonging to pure anon mappings, folio->index is equal to the anonymous page offset of the folio. * For anonymous folios belonging to file-backed mappings (i.e. CoW'd folios of a MAP_PRIVATE file-backed mapping), folio->index is equal to the file page offset. This series establishes a new anonymous page offset property of VMAs to allow us to map anonymous folios at their anonymous page offset, consistent with pure anon. The purpose of doing so is to lay the foundations for the scalable CoW work. This is necessary because scalable CoW looks in the maple tree for the VMA located at folio->index << PAGE_SHIFT, before falling back to looking up tracked remaps if necessary. The MAP_PRIVATE file-backed case means that folio indices will very often conflict with one another and this remap tracking becomes substantially more contended, and of course the fast path can never be used. This also makes it possible, in future, to unshare anonymously mapped folios with deep fork hierarchies on remap, eliminating the need for remap tracking in the vast majority of cases. Similar to page offset of pure anonymous VMAs, we update the anonymous page offset of unfaulted file-backed VMAs on remap, but do not once CoW'd (i.e. vma->anon_vma is non-NULL). Overall, there is little impact on mergeability, which remains exactly the same for pure anonymous and shared file-backed mappings, with the only impact being on MAP_PRIVATE-mapped file-backed mappings, which must now match on anonymous page offset as well as file page offset to be merged. To fail to merge like this would require CoW'ing the mapping, then finding another VMA with identical file and compatible page offset to remap next to. This is therefore very much an edge case that should have very little impact (and which scalable CoW may very well address in any case). This patch (of 16): Establish fields in vm_area_struct to store the anonymous page offset of VMAs. Initially, the anonymous page offset of a VMA is vma->vm_start >> PAGE_SHIFT. When a VMA is remapped to new_address its anonymous page offset is either updated to new_address >> PAGE_SHIFT if unfaulted or, if faulted, remains equal to the anonymous page offset it had when first faulted. Currently, anonymous folios belonging to CoW'd MAP_PRIVATE-mapped file-backed VMAs are tracked by their file offsets. By adding anonymous offset as a property of VMAs, we can now track them by their anonymous page offset instead. By tracking this, we provide the means by which to eliminate this inconsistency, and more importantly lay the foundations for future work for the scalable CoW anonymous rmap rework. This patch simply adds the fields and some simple helpers. Subsequent patches will update mm code to make use of these fields correctly. The fields chosen are packed in the VMA such that, for 64-bit kernel builds, no additional space is taken up. The first field is present on cacheline 0 containing key VMA fields, and the second on cacheline 3, which contains file-backed reverse mapping fields. Given the relative time spent accessing reverse mapping fields as well as updating them, there shouldn't be any performance impact here from false sharing. Update the VMA userland tests to account for this change. No callsites are updated yet, so no functional change intended. Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-0-c21581c0c3c8@kernel.org Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-1-c21581c0c3c8@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Gregory Price (Meta) <gourry@gourry.net> Reviewed-by: Xu Xin <xu.xin16@zte.com.cn> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Deucher <alexander.deucher@amd.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Barry Song <baohua@kernel.org> Cc: Boris Brezillon <boris.brezillon@collabora.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chris Li <chrisl@kernel.org> Cc: Christan König <christian.koenig@amd.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Dave Airlie <airlied@gmail.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Harry Yoo <harry@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huang Ray <Ray.Huang@amd.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kees Cook <kees@kernel.org> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Matthew Auld <matthew.auld@intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Maxime Ripard <mripard@kernel.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Namhyung kim <namhyung@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Thomas Zimemrmann <tzimmermann@suse.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24mm/kconfig: drop redundant dependency wrappersKaitao Cheng1-9/+1
Some mm Kconfig entries repeat dependencies that are already expressed by their surrounding blocks or menus. The zsmalloc allocator options menu already depends on ZSMALLOC, so the outer if ZSMALLOC block does not add any extra constraint. MEMORY_HOTREMOVE and MHP_MEMMAP_ON_MEMORY are both inside the if MEMORY_HOTPLUG block, so their local depends on MEMORY_HOTPLUG entries are redundant. PTE_MARKER_UFFD_WP is the only entry under if USERFAULTFD. Move the USERFAULTFD dependency into the symbol itself and combine it with the architecture support dependency. This keeps the same visibility and defaults while avoiding duplicate dependency expressions. Link: https://lore.kernel.org/20260712093326.8313-1-kaitao.cheng@linux.dev Signed-off-by: Kaitao Cheng <chengkaitao@kylinos.cn> Suggested-by: Julian Braha <julianbraha@gmail.com> Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Liam R. Howlett <liam@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24mm: standardize printing for pgtable entriesDavid Hildenbrand (Arm)1-23/+79
Bad page map reporting currently stores page table entry values in an unsigned long long and prints them with fixed 64-bit-oriented format strings. This is inconsistent across call sites and does not work well for architectures where page table entry values are not naturally represented as 64-bit values, such as 32-bit or 128-bit entries. Introduce a common helper to convert raw page table entry values into a fixed-width hexadecimal string based on the actual entry size. Use it for bad page map reporting and for dumping the page table walk in __print_bad_page_map_pgtable(). Pass page table entry values to the reporting path as raw bytes together with their size, instead of forcing them through an unsigned long long. It keeps the printed output consistent and avoids truncation or misleading formatting for non-64-bit page table entries. Link: https://lore.kernel.org/20260709044334.1741263-1-anshuman.khandual@arm.com Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Co-developed-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: David Hildenbrand <david@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24mm/kconfig: drop redundant memory hotplug dependenciesKaitao Cheng1-3/+1
MHP_MEMMAP_ON_MEMORY is defined inside the MEMORY_HOTPLUG block, and MEMORY_HOTPLUG already depends on SPARSEMEM_VMEMMAP. Keep the explicit MEMORY_HOTPLUG dependency for local readability, but drop the redundant SPARSEMEM_VMEMMAP dependency. ZONE_DEVICE depends on MEMORY_HOTREMOVE, which depends on MEMORY_HOTPLUG. MEMORY_HOTPLUG in turn depends on SPARSEMEM_VMEMMAP. Drop the direct MEMORY_HOTPLUG and SPARSEMEM_VMEMMAP dependencies from ZONE_DEVICE. This does not change the set of valid configurations. Link: https://lore.kernel.org/20260707090331.52971-1-kaitao.cheng@linux.dev Signed-off-by: Kaitao Cheng <chengkaitao@kylinos.cn> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Muchun Song <muchun.song@linux.dev> Reviewed-by: Lorenzo Stoakes <ljs@kernel.org> Cc: Liam R. Howlett <liam@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24mm: nommu: point to the write iterator upon split_vmaHajime Tazaki1-0/+4
When a user invokes munmap(2) on a partial region allocated by mmap(), the kernel may split the original region if necessary and shrink it to the correct size. At the beginning of vmi_shrink_vma(), the unused part is cleared; however, an assertion is triggered if the shrink occurs after split_vma(). This commit fixes the issue by correctly configuring the pointer to the iterator at the end of split_vma(). This bug was detected using the Linux Test Project (LTP) test linked below, running on a nommu UML (User-Mode Linux) environment (via an out-of-tree extension to UML). Here is a minimal reproducible chunk of code for this issue: void *addr; size_t pagesize = getpagesize(); addr = mmap(NULL, pagesize * 4, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); munmap(addr + pagesize * 1, pagesize); This is the console output with CONFIG_DEBUG_MAPLE_TREE=y. nommu: WARN at __mas_set_range:791 (1) MAS: tree=0000000091c23b08 enode=0000000065057663 (ma_active) Store Type: node_store [9/9] index=70af8000 last=ffffffffffffffff min=0 max=ffffffffffffffff sheaf=0000000000000000, request 0 depth=0, flags=0 maple_tree(0000000091c23b08) flags 307, height 1 root 0000000083394c06 0-ffffffffffffffff: node 0000000010c90bd6 depth 0 type 1 parent 0000000050e1ddf8 contents: 0000000000000000 707A 7FFF 00000000eb0ac2b5 707AFFFF 0000000000000000 7093FFFF 0000000045ead616 7095FFFF 0000000000000000 7096CFFF 000 00000681c7151 7096FFFF 0000000000000000 70AF3FFF 000000006c78b9e9 70AF4FFF 000000001914ab0b 70AF7FFF 00000000000 00000 FFFFFFFFFFFFFFFF 0000000000000000 0 0000000000000000 0 0000000000000000 0 0000000000000000 0 0000000000000 000 0 00000000bca8be4f 0-707a7fff: 0000000000000000 707a8000-707affff: 00000000eb0ac2b5 707b0000-7093ffff: 0000000000000000 70940000-7095ffff: 0000000045ead616 70960000-7096cfff: 0000000000000000 7096d000-7096ffff: 00000000681c7151 70970000-70af3fff: 0000000000000000 70af4000-70af4fff: 000000006c78b9e9 70af5000-70af7fff: 000000001914ab0b 70af8000-ffffffffffffffff: 0000000000000000 nommu: Pass: 796 Run:797 Link: https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/syscalls/mseal/mseal02.c Link: https://lore.kernel.org/20260702012546.665383-1-thehajime@gmail.com Signed-off-by: Hajime Tazaki <thehajime@gmail.com> Cc: Jann Horn <jannh@google.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24mm: mempolicy: fix automatic numa balancing for shmemJohannes Weiner1-15/+6
Neha reports that mapped shmem aren't considered for NUMA balancing, noting convergence problems and bandwidth bottlenecking for cachelib based workloads on tiered memory systems. Looking at the code and going through the git history, this doesn't actually seem intentional: Commit fc3147245d19 ("mm: numa: Limit NUMA scanning to migrate-on-fault VMAs") added a vma_policy_mof() gate to task_numa_work() so VMAs whose policy lacks MPOL_F_MOF are skipped from NUMA balancing scans. The motivation was a real usecase: Oracle was pinning shared segments with mbind(MPOL_BIND) so trapping faults was both expensive and pointless. The handling of NULL from vm_ops->get_policy, however, treated "user explicitly opted out" the same as "user never specified anything." For VMAs whose shared policy is absent - the common case for shmem - the scan was disabled too. This issue is old. It probably hurts less in conventional NUMA. But it's very noticeable on tiered systems, where entire tmpfs workingsets can get stuck on lower-bandwidth memory. Fix this by having vma_policy_mof() use __get_vma_policy() directly, and thereby handle the fallback to task policy (-> preferred_node_policy() has MPOL_F_MOF per default). Every other consumer of vm_ops->get_policy already handles it this way, the scan-eligibility check was the outlier. This preserves Mel's intended fix: don't scan stuff the user explicitly pinned. But allow default policy vmas to participate in balancing. Link: https://lore.kernel.org/20260629163337.1264881-1-hannes@cmpxchg.org Fixes: fc3147245d19 ("mm: numa: Limit NUMA scanning to migrate-on-fault VMAs") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Neha Gholkar <nehagholkar@gmail.com> Tested-by: Neha Gholkar <nehagholkar@gmail.com> Reviewed-by: Gregory Price <gourry@gourry.net> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Balbir Singh <balbirs@nvidia.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Byungchul Park <byungchul@sk.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Zi Yan <ziy@nvidia.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24Merge branch 'mm-hotfixes-stable' into mm-stable to pick upAndrew Morton14-137/+326
already-upstream changes to memcontrol.c, needed by "memcg: move mem_cgroup_swappiness and vm_swappiness to mm/swap.h".
2026-08-24Merge tag 'slab-for-7.3' of ↵Linus Torvalds8-372/+731
git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab updates from Vlastimil Babka: - Add kfree_rcu_nolock() that can be used from contexts where spinning on a lock might be unsafe, such as a BPF program attached to an arbitrary function, or in NMI context. This complements the existing kfree_nolock() support (Harry Yoo) - Runtime instead of compile-time slabobj_ext sizing. Avoid wasting memory when memory allocation profiling is compiled but not enabled, with initial partial support to also avoid wasting memory for objcg pointers when those are not needed, while profiling is enabled (Vlastimil Babka) - Various non-urgent fixes, cleanups and optimizations (Hao Li, Hongling Zeng, Li RongQing, Li Xiasong, Seongjun Hong, Shengming Hu) * tag 'slab-for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: (31 commits) mm/slab, kfence, memcg: completely remove obj_ext for kfence objects mm/slab: stop allocating objcg pointers when unnecessary mm/slab: add cache_ and slab_needs_objcg() helpers mm/slab: stop exporting kvfree_rcu_barrier[_on_cache]() slub_kunit: extend the test for kfree_rcu_nolock() mm/slab: introduce kfree_rcu_nolock() mm/slab: introduce struct kvfree_rcu_head for kvfree_rcu batching mm/slab: reduce slabobj_ext memory with allocation profiling disabled mm/slab: introduce slab_obj_ext_has_codetag() mm/slab: allow kfree_rcu_sheaf() on PREEMPT_RT mm/slab: extend deferred free mechanism to handle rcu sheaves mm/slab: use call_rcu() in unknown context if irqs are enabled mm/slab: handle the !allow_spin case in kfree_rcu_sheaf() mm/slab: change struct slabobj_ext to a union mm/slab: replace slab.stride with obj_exts_in_object mm/slab: abstract slabobj_ext.ref access mm/slab: abstract slabobj_ext.objcg access mm/slab: make slab_obj_ext() determine object index mm: move struct slabobj_ext to mm/slab.h mm/slab: remove objs_per_slab() ...
2026-08-24Merge branch 'slab/for-7.3/kfree_rcu_nolock' into slab/for-nextVlastimil Babka (SUSE)3-103/+254
Merge series "mm/slab: introduce kfree_rcu_nolock() and improve slub_kunit coverage" from Harry Yoo. From the cover letter [1]: This series improves kmalloc_nolock() and kfree_nolock() coverage in slub_kunit and introduces kfree_rcu_nolock() for unknown context as suggested by Alexei Starovoitov. Unknown context means the caller does not know whether spinning on a lock is safe (e.g., a BPF program attached to an arbitrary kernel function or in NMI context). The slab allocator already supports unknown context via kmalloc_nolock() and kfree_nolock(), but te slab allocator does not support freeing objects by RCU in unknown context. It is not ideal to have completely separate batching for unknown context because the worst scenario where spinning on a lock would lead to deadlock is very rare, and in most cases, it is safe to use the existing mechanism (kfree_rcu_sheaf()). Since most part of the slab allocator already supports unknown context and sheaves support batching kvfree_rcu() calls for slab objects, implement kfree_rcu_nolock() with minimal changes by teaching kfree_rcu_sheaf() how to support unknown context and making it a little bit harder to allocate an empty sheaf, instead of making intrusive changes to the existing kvfree_rcu batching logic. kfree_rcu_nolock() tries to free the object to the rcu sheaf if trylock succeeds. Once the rcu sheaf becomes full, it is submitted to RCU via call_rcu() if spinning is allowed or IRQs are enabled (to avoid calling call_rcu() in the middle of call_rcu()). Otherwise, call_rcu() is deferred via irq work. When there is no sheaf available, kfree_rcu_sheaf() falls back to defer_kfree_rcu(). It submits the object to kvfree_rcu batching via irq work. To do this, patch 6 converts kvfree_rcu to use kvfree_rcu_head without visible changes to the API for now. Unlike kfree_rcu(), only the 2-argument variant is supported. This is because the last resort of the 1-arg variant is synchronize_rcu(), which cannot be used in an unknown context. As suggested by Alexei Starovoitov, kfree_rcu_nolock() can be used with struct kvfree_rcu_head (8 bytes), which is smaller than struct rcu_head (16 bytes). Link: https://lore.kernel.org/all/20260729-kfree_rcu_nolock-v5-0-a28cdcda9673@kernel.org/ [1]
2026-08-24Merge branch 'slab/for-7.3/objext_split' into slab/for-nextVlastimil Babka (SUSE)7-208/+414
Merge series "mm/slab, alloc_tag: reduce obj_ext memory waste" from myself. From the cover letter [1]: It's been bothering me that the memory usage of struct slabobj_ext depend only on config options and not whether the fields are actually used. So with both CONFIG_MEMCG=y and CONFIG_MEM_ALLOC_PROFILING=y there is always objcg field and codetag_ref field. And thus: 1) Having memory allocation profiling config-enabled but not boot-enabled means wasted memory on unused codetag_refs. This makes it less suitable for a general distro config and the page allocator side doesn't suffer from this, only slab and percpu. 2) Complementary, with memory allocation profiling enabled, there are caches/slabs that don't need the objcg field, so memory is wasted on those. This series should solve the point 1) fully for slab; pcpuobj_ext handling can be perhaps improved similarly, haven't looked into that. For 2) it avoids allocating objcg fields for KMALLOC_NORMAL and KMALLOC_NO_OBJ_EXT caches where we know they are not necessary because kmalloc() with __GFP_ACCOUNT will pick a KMALLOC_CGROUP type (except with SLUB_TINY). The named kmem_caches are tricky. They can be created with SLAB_ACCOUNT and then we know objcg fields are always needed. But also they can be created without SLAB_ACCOUNT and then some allocations have __GFP_ACCOUNT and some not and we don't know that in advance. This series introduces a SLAB_MAY_ACCOUNT flag that's currently internal only and is applied to all caches (unless kmem accounting is disabled) except KMALLOC_NORMAL (unless that aliases KMALLOC_RECLAIM) and KMALLOC_NO_OBJ_EXT. As a followup we can make SLAB_MAY_ACCOUNT explicit and add it to to caches where we know __GFP_ACCOUNT is used. Then we could only honour __GFP_ACCOUNT for those, while warning for an unexpected usage elsewhere. To check for regressions, I forward-ported a microbenchmark hacked into slub_kunit that was used to evaluate sheaves. Tried 3 scenarios, MEMCG and KFENCE were always enabled: - CONFIG_MEM_ALLOC_PROFILING=n - CONFIG_MEM_ALLOC_PROFILING=y but _ENABLED_BY_DEFAULT=n - same but booted with sysctl.vm.mem_profiling=1 The results are quite noisy, but no regression was apparent, except perhaps few percents for the last case. I don't expect it will be visible in any real workloads. Link: https://lore.kernel.org/all/20260727-b4-objext_split-v3-0-c29ef0f1f257@kernel.org/ [1]
2026-08-23Merge tag 'rcu.2026.08.18a' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux Pull RCU updates from Paul McKenney: "Make expedited grace periods expedite normal RCU callbacks Miscellaneous fixes: - Improve diagnostic output with character task states - Mark accesses to inform KCSAN of concurrency design - Move from kmalloc() to kmalloc_obj() - Documentation updates - Improve handling of RCU deferred quiescent states - Clean up unused function arguments and structure fields - Reduce show_rcu_gp_kthreads() stack space Tasks RCU updates: - Clean up after SRCU re-implementation of Tasks Trace RCU - Mark accesses to inform KCSAN of concurrency design - Add ->lazy_timer status to diagnostic output - Remove an unnecessary memory barrier - Fix a data race, courtesy of KCSAN - Documentation updates - Convert cond_resched_tasks_rcu_qs() from macro to static inline function SRCU updates: - Add Rust helpers for SRCU - Avoid losing queued work at cleanup_srcu_struct() time Torture-test updates: - Preparation work for immediate RCU priority deboosting - Test RCU readers from real interrupt handlers (as opposed to softirq) - Simplify code through use of cpumask_next_wrap() - Improve diagnostic output with character task states - Add rcutorture.nwriters parameter to allow lightweight stall testing, and rcutorture.stall_only to make doing so easier - Test an RCU Tasks Trace grace period implying an RCU grace period - Make RCU Tasks Trace torturing track reader batches - Fix a data race, courtesy of KCSAN - Plug a shuffle_tmp_mask memory leak on kthread spawn failure" * tag 'rcu.2026.08.18a' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux: (59 commits) rcu: Add closing parenthesis in comment in rcu_read_unlock_strict() rcutorture: Make {,s}rcu_read_delay() better handle forward-progress testing rcutorture: Announce declining to forward-progress test torture: Don't leak shuffle_tmp_mask when shuffler kthread fails to start rcutorture: Use this_cpu_inc() for rcu_torture_count[] and rcu_torture_batch[] rcutorture: Make RCU Tasks Trace track Reader Batches rcutorture: Test RCU Tasks Trace GP implying RCU GP rcutorture: Add a stall_only module parameter rcutorture: Add nwriters module parameter rcutorture: Use task_state_to_char() for task-state reporting rcutorture: Use cpumask_next_wrap() in rcu_torture_preempt() rcutorture: Test RCU readers from hardware interrupt handlers rcutorture: Check for immediate deboosting at reader end srcu: Queue sdp->work when the delay timer is successfully deleted rcu-tasks: Convert cond_resched_tasks_rcu_qs() to static inline rcu-tasks: Fix some comments for call_rcu_tasks() and call_rcu_tasks_rude() rcu-tasks: Rename tasks_rcu_exit_srcu_stall_timer to tasks_rcu_exit_stall_timer rcu: Mark interrupts-enabled accesses to rdp->cpu_no_qs.s rcu: Reduce stack usage in show_rcu_gp_kthreads() rcu: Mark accesses to ->rcu_urgent_qs and ->rcu_need_heavy_qs ...
2026-08-23Merge tag 'liveupdate-v7.3-rc1-20260823' of ↵Linus Torvalds3-56/+136
git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux Pull more liveupdate updates from Mike Rapoport: "Make boot time huge page allocation work nicely with kexec handover. Today allocation of gigantic pages in HugeTLB cannot work reliably with kexec handover (KHO): - HugeTLB allocates gigantic pages using memblock and autoscaling of KHO scratch accounts for these allocations. When gigantic pages occupy half of the memory of more, KHO fails to allocate its scratch memory. - After kexec handover, memblock allocations exclusively use KHO scratch that is not supposed to contain preserved memory. This essentially blocks preservation of HugeTLB with gigantic pages. Extend early memory pools available for KHO kernel with areas that are guaranteed not to contain preserved memory" * tag 'liveupdate-v7.3-rc1-20260823' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux: (21 commits) kho: exclude hugetlb memory from scratch size calculation memblock: add memblock_reserved_hugetlb_size() memblock: make HugeTLB bootmem allocation work with KHO memblock: always include KHO headers kho: extend scratch mm/mm_init: don't rely on memblock to get KHO scratch migratetype kho: initialize preserved memory map radix tree earlier kho: initialize kho_scratch pointer earlier in boot kho: expose kho_scratch_overlap() to kexec_handover.h kho: add kho_radix_init_tree() kho: allow destroying KHO radix tree kho: allow early-boot usage of the KHO radix tree kho: add data argument to radix walk callback kho: add callback for table pages kho: add a struct for radix callbacks kho: move all memory retrieval logic to kho_mem_retrieve() kho: store incoming radix tree in kho_in kho: disallow wide keys in radix tree kho: make radix max key width more obvious kho: generalize radix tree APIs ...
2026-08-20Merge tag 'mm-hotfixes-stable-2026-08-19-21-33' of ↵Linus Torvalds4-23/+96
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull hotfixes from Andrew Morton: "8 hotfixes. 5 are cc:stable. 5 are for MM. All are singletons, please see their changelogs for details" * tag 'mm-hotfixes-stable-2026-08-19-21-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm/pagewalk: fix stale walk->action escaping walk_pmd_range() mm, swap: don't free a hibernation slot that is in the swap cache mm: memcg-v1: fix memsw and TCP failcnt accounting mm/vmscan: report RCU-tasks quiescent states in shrink_lruvec() mailmap: add entries for Guodong Xu MAINTAINERS, mailmap: update email address for JP Kobryn MAINTAINERS: remove git URL for Squashfs memcg: keep folio's objcg same as its node
2026-08-20Merge tag 'mm-stable-2026-08-18-18-39' of ↵Linus Torvalds106-3730/+7139
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - "mm: drop "sub" prefix from various places" (Dev Jain) page->folio conversion and a naming cleanup - "mm/kasan: remove redundant initialization for kasan_flag_write_only" (Igor Putko) KASAN cleanup work - "mm/filemap: reduce unnecessary xarray lookups" (Chi Zhiling) Small speedup in the pagecaache read code - "mm/percpu: Fix possible NOFS/NOIO reclaim recursion" (Kaitao Cheng) Improve the vmalloc code - mainly the avoidance of GFP_KERNEL allocations when the caller asked for GFP_NOFS or GFP_NOIO - "mm/kmemleak: avoid soft lockup when scanning task stacks" (Breno Leitao) Avoid a soft lockup watchdog trigger from the kmemleak scanning code in extreme situations - "mm/page_owner: misc cleanups" (Ye Liu) Cleanups to the page_owner code. For some reason lots of people have been working on the page_owner code this cycle. - "mm: convert to walk_page_range_vma() to eliminate find_vma()" (Kefeng Wang) Simplify and accelerate the page walking library function - "mm/migrate: preparatory cleanups for batch copy and offload" (Shivank Garg) Cleanups in the migration code - "mm/page_owner: add per-fd filter infrastructure for print_mode and NUMA filtering" (Zhen Ni) Per-fd filtering to page_owner in order to reduce the sometimes vast amount of output it can produce - "mm: Refactor bootmem gigantic hugepage allocation" (Muchun Song) Fixes and preparatory cleanups around bootmem HugeTLB handling, sparse initialization ordering, and related vmemmap setup - "mm/zsmalloc: reduce lock contention in zs_free()" (Wenchao Hao) Reduce lock contention in zs_free(), which dominates the unmap path under memory pressure on Android (LMK kills) and on x86 servers running zswap-heavy workloads. Up to 1.83x improvement in microbenchmarking. - "move alloc_tag.c file under mm/" (Suren Baghdasaryan) - "samples/damon: handle damon_{start,stop}() failures" (SJ Park) Fix improper handling of damon_start(), damon_stop(), and damon_call() failures across DAMON sample modules to prevent potential memory leaks, operation disruptions and use-after-free bugs - "mm/damon/sysfs: kobject_del() directories that users can create/remove" (SJ Park) Fix delayed sysfs directory removal under DEBUG_KOBJECT_RELEASE causeing creation failures due to duplicate directory names by adding missing kobject_del() calls before creating new directories - "mm: cleanup clear_not_present_full_ptes()" (David Hildenbrand) Clean up the core pte handling code - "selftests/damon: misc fixes for test bugs" (Kunwu Chan) Fix several bugs in the DAMON selftests - "selftests/damon: fix memcg_path staging handling" (Cheng Nie) Fix a bug in _damon_sysfs.py for damos_filter memcg_path setup, and add a test case for it in sysfs.py. - "selftests/damon: test kdamond refresh_ms" (Ruslan Valiyev) Selftest coverage for DAMON's refresh_ms sysfs feature by updating the test control module and verifying that scheme stats update automatically without manual intervention - "mm/damon: five misc fixups" (Akinobu Mita) Miscellaneous DAMON fixups. - "mm/damon/core: detect internal variation above max_nr_regions/2" (Jiayuan Chen) Fix DAMON's region splitting behavior when region counts exceed half the maximum budget by dynamically scaling down the split fraction as the limit approaches, preventing large regions from staying un-split, and add corresponding KUnit test coverage - "mm: preparatory patches for PMD level swap entries" (Usama Arif) Refactor and clean up PMD softleaf helpers, call sites, and architecture flags to lay the groundwork for a follow-up series that introduces PMD page table swap entries - "mm/damon: update, optimize, and clean up doc, tests, and code" (SJ Park) Update DAMON design and ABI documentation, expands unit and selftest coverage, optimize damon_commit_target_regions(), and clean up recently added sysfs interface code for better readability - "mm/vmpressure: reduce CPU, memory and code overhead on cgroup v2" (Usama Arif) Optimize vmpressure() by skipping unnecessary work on cgroup v2 for userspace event notifications and refactor v1-only eventfd handling into mm/memcontrol-v1.c to reduce memory overhead and code complexity - "selftests/mm: refactor pkey helpers and fix mmap error handling" (Hongfu Li) Refactor pkeys shared tracing and assertion helpers into a common file, unify protection key selftests to use consistent diagnostic logging and assertions, and enforce standardized MAP_FAILED return checks for mmap() calls across the tests - "mm/damon: optimize out nr_accesses_bp" (SJ Park) Replace the error-prone, continuously updated nr_accesses_bp field in damon_region with an on-demand moving sum function, reducing structure memory overhead and avoiding state corruption bugs - "Open HugeTLB allocation routine for more generic use" (Ackerley Tng) Decouple HugeTLB folio allocation from VMA dependencies by introducing hugetlb_alloc_folio(), enabling subsystems like guest_memfd to allocate HugeTLB folios without standard VMA reservations or pseudo-VMAs - "mm/damon: provide pseudo moving sum probe_hits" (SJ Park) Integrate DAMON's probe_hits attribute counter into the pseudo moving sum infrastructure, enabling real-time, online monitoring without waiting for full aggregation intervals - "mm: Some cleanups for page allocator APIs" (Brendan Jackman) Simplify and refactor the page allocator entry points and flags by unifying allocation paths, adding internal alloc_flags arguments, and eliminating redundant __ prefixed alloc_pages variants. - "Fix incorrect access of hugetlb pte entries" (Dev Jain) Enforce the consistent use of huge_ptep_get() instead of ptep_get() for HugeTLB entries and fixes an unaligned address issue in arm64's huge_ptep_get() implementation - "mm/damon: validate all parameters in the core" (SJ Park) Consolidate parameter validation into the DAMON core specifically within damon_start() and damon_commit_ctx() to centralize error checking, eliminate caller-side redundant checks and to improve maintenance efficiency - "tools/mm/page_owner_sort: fix filtering and cleanup issues" (Yichong Chen) Rename is_need() to filter_record() for clearer return semantics, fix per-record allocation memory leaks and bound output copies in search_pattern() to address an existing buffer issue - "memcg: bail out reclaim when memcg is dying" (Jiayuan Chen) Mitigate a system-wide stall which occurs when a cgroup is removed while one of its memory control files is doing synchronous reclaim - "mm/memory-failure: add panic option for unrecoverable pages" (Breno Leitao) Introduce an opt-in vm.panic_on_unrecoverable_memory_failure sysctl that immediately panics the kernel on unrecoverable memory errors in kernel-owned pages to preserve error context and prevent delayed, silent data corruption - "mm/damon: refactor damon_{start,stop,commit}() for simple error handling" (SJ Park) Refactor the DAMON core API functions to guarantee that all contexts are fully stopped when damon_start(), damon_stop(), or damon_commit() fail, eliminating the need for complex and error-prone caller-side cleanup code - "Keep tail page private zero at free and folio split" (Zi Yan) Add checks to ensure tail_page->private is zero when freeing compound or high-order pages and when promoting tail pages during large folio splits. By validating these fields at free and split time, it allows the removal of redundant private field clearing inside prep_compound_tail() - "mm: drop redundant lru_add_drain in anon folio reuse paths" (Barry Song) Eliminate redundant lru_add_drain() calls in wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock contention and system overhead By validating folio refcounts against the LRU cache before draining and removing unnecessary drains in the swap path, it achieves up to a 30.5% reduction in drain calls during heavy swap workloads - "mm: clean up folio LRU and swap declarations" (Jianyue Wu) Reorganize folio LRU and swap code by relocating page-cluster state to mm/swap_state.c, renaming mm/swap.c to mm/folio.c, and moving MM-internal reclaim declarations into mm/internal.h. - "userfaultfd: working set tracking for VM guest memory" (Kiryl Shutsemau) Add userfaultfd support for tracking the working set of VM guest memory, so a VMM can identify hot pages and reclaim cold ones to tiered or remote storage - "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 2)" (David Hildenbrand) Remove the remaining pieces of CONFIG_HAVE_BOOTMEM_INFO_NODE, performing some smaller cleanups around freeing of reserved vmemmap pages on the way. - "mm/damon: update probe hits for runtime parameter commits" (SJ Park) Ensure that DAMON's probe_hits attribute counter is properly updated when monitoring intervals are changed at runtime, matching the behavior of nr_accesses. To achieve this, it refactors and renames existing helper functions for shared use, applies the updates to probe_hits, and handles edge cases in damon_probe_hits_mvsum() to maintain measurement accuracy. - "KSM: performance optimizations for rmap_walk_ksm" (xu xin) Resolve a severe KSM reverse-mapping performance bottleneck where thousands of split VMAs sharing a single anon_vma cause extended lock contention. By adding an interval-filtering check during the rmap walk, it reduces worst-case anon_vma lock hold times from over 500ms down to under 2ms, preventing application freezes and latency spikes under memory pressure. - "mm: split a couple of headers from internal.h" (Mike Rapoport) Split declarations related to mm_init, memblock, vmalloc and sparse into new headers - "KSM: use linear_page_index in collect_procs_ksm()" (xu xin) Apply the interval tree optimization from rmap_walk_ksm() to collect_procs_ksm() to avoid iterating over non-matching VMAs during KSM memory error handling. It hoists loop-invariant address initialization and restricts the anon_vma_interval_tree_foreach walk to a targeted page offset range, reducing redundant checks and improving lookup efficiency. - "selftests/mm: avoid false failures in hugetlb and KSM tests" (Sayali Patil) Fix issues in the hugetlb and KSM MM selftest categories that can report failures when the prerequisites for the tests are not satisfied - "mm/damon: introduce data attributes only monitoring" (SJ Park) Introduce attribute-weighted region management in DAMON, allowing users to prioritize specific data attributes (such as page sizes or cgroups) over or instead of access monitoring. By assigning weights to attribute probes, DAMON can completely disable access tracking and adjust monitoring regions based on weighted probe-hit counters to optimize monitoring quality for attribute-focused workloads. - "mm/hmm: Add mmap lock-drop support for userfaultfd-backed mappings" (Stanislav Kinsburskii) Extend hmm_range_fault() to support userfaultfd-backed regions by allowing the mmap lock to be dropped during fault handling via a new hmm_range_fault_locked() helper. By accepting a locked pointer and signaling retry status when lock release occurs, it enables page fault resolution in userfaultfd regions while preserving backward compatibility for existing callers. - "mm: make VMA page offset handling more consistent" (Lorenzo Stoakes) Clean up and standardize how vma->vm_pgoff is accessed and manipulated across file-backed and anonymous mappings in the kernel It introduces dedicated helper functions such as vma_start_pgoff(), vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while renaming rmap interval tree helpers to better reflect their functionality. These changes establish a cleaner foundation for future work that will unify virtual page offset indexing for all anonymous and CoW'd folios. - "mm: handle device-private PMDs in walk callbacks" (Usama Arif) Address kernel panics and state corruption caused by MM walk callbacks reaching non-present device-private PMD swap entries created during HMM migrations It ensures that functions which acquire pmd_trans_huge_lock() properly recognize device-private PMDs instead of assuming a present THP or a standard migration entry. - "mm/rmap: Refactor try_to_unmap_one" (Dev Jain) Refactor try_to_unmap_one by modularizing Hugetlb, anonymous-lazyfree, and anonymous-swapbacked logic into dedicated functions, laying the structural groundwork for batched anonymous large folio unmapping. - "Docs/ABI/damon: sysfs ABI document fixes and additions" (Song Hu) Fix typos and fills in missing entries in the DAMON sysfs ABI document - "dax/kmem: atomic whole-device hotplug via sysfs" (Gregory Price) Introduce an atomic sysfs state attribute and supporting DAX/MM infrastructure to prevent userland races when offlining and removing entire memory regions By adding an unplugged state alongside standard online modes, it enables whole-device atomic hotplug control while preserving backward compatibility. - "mm: convert more vm_flags_t users to vma_flags_t" (Lorenzo Stoakes) Continue transitioning the kernel from the deprecated vm_flags_t type to vma_flags_t across core memory management infrastructure. It replaces legacy type usage in core functions such as do_mmap(), unmapped area allocation, mm->def_vma_flags, and VMA operations like mlock, mprotect, and mremap. - "Two small patches to clean up mm/mm_slot.h" (xu xin) Refactor mm_slot.h by introducing mm_slot_remove() to unify duplicate slot deletion sequences in khugepaged and KSM. It also adds code documentation explaining why mm_slot_lookup and mm_slot_insert must remain as preprocessor macros rather than static inline functions. - "mm/damon/core: hide core-private struct fields" (SJ Park) Clean up DAMON core structures by consistently marking internal-only fields with private: comment tags to prevent improper direct access from outer layers. It enforces encapsulation across core structures including damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to interact through approved access APIs instead of exposing raw struct members. - "mm/damon: unurgent fixes for infinite loop, NULL de-ref and races" (SJ Park) Address potential infinite loops, NULL dereferences, and race conditions identified in DAMON It fixes an infinite loop triggered by extreme user configurations, a NULL pointer dereference within unit tests and minor monitoring accuracy degradation caused by subtle runtime races. - "mm/page_alloc: fixes for free_pages_nolock() on RT/UP" (Brendan Jackman) Fix an NMI safety flaw in __free_frozen_pages() where freeing pages on non-SMP or PREEMPT_RT kernels can bypass can_spin_trylock() checks via non-PCP or isolated migration paths. It also resolves potential kernel crashes and privilege escalation risks triggered when BPF tracing runs in NMI context alongside memory hotplug or large allocation frees. - "mm/page_alloc: couple of followups for recent cleanups" (Brendan Jackman) Clean up and update page allocator nomenclature, documentation, and debug assertions. It aligns internal FPI_ flags with the public "nolock" naming convention, removes outdated internal implementation details from high-level page allocator comments, and eliminates obsolete VM_BUG_ON() assertions in allocation paths. - "mm/mseal: further cleanups" (Lorenzo Stoakes) Refactor and simplify the mseal implementation by clarifying API boundaries and removing unnecessary code complexity. It replaces generic do_mseal() usage outside the syscall with a dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO, eliminates mm_struct parameters to enforce that sealing applies only to current->mm, and streamlines overall logic and comments with no functional changes intended. - "mm/vmscan: fix swappiness=max and clean up per-node proactive reclaim" (Ridong Chen) Resolve reclaim behavior bugs and clean up function parameters across memory reclaim paths It fixes swappiness=max in both standard reclaim and MGLRU so unswappable anonymous memory no longer falls back to evicting page cache, ensures reclaim_store() returns accurate error codes instead of collapsing all failures into -EAGAIN, and removes the obsolete gfp_mask parameter from __node_reclaim(). - "mm: mincore: misc cleanups" (Kefeng Wang) Clean up and simplifies the mincore code. Most importantly, it removes the historical special behavior that always reports VM_PFNMAP pages as non-resident. - "mm/huge_memory: drop dead split helper variants" (Kiryl Shutsemau) Two trivial cleanups in the folio split API - "mm/damon: fix uninitialized DAMOS field and kunit exec expectation bugs" (SJ Park) Resolve minor operational and testing bugs in DAMON identified by Sashiko. It initializes the damos->last_applied field to prevent occasional efficiency degradation and fixes invalid memory accesses in DAMON KUnit tests during test failure handling. - "cleanup for stable_page_flags()" (Jinjiang Tu) Clean up and refactor stable_page_flags() used by /proc/kpageflags without altering functionality. It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag bits, converts folio-specific flag checks to standard folio_test_*() helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling. - "Batch unmap of uffd-wp file folios" (Dev Jain) Extend batched folio unmapping support to file folios within userfaultfd write-protect (uffd-wp) VMAs by adding batching capabilities to pte_install_uffd_wp_if_needed(). This removes special-case restrictions on uffd-wp VMAs in try_to_unmap_one(), significantly simplifying the function's control flow and complexity. - "mm/early_ioremap: clarify and clean up early_ioremap_reset()" (Sang-Heon Jeon) Clarify and clean up the architecture-specific usage of __late_set_fixmap() and __late_clear_fixmap() after early_ioremap_reset() It adds explicit documentation regarding when early_ioremap_reset() must be called and removes redundant macro definitions and reset calls in the RISC-V and ARM64 architectures. - "mm: fix reclaim storms in defrag_mode" (Johannes Weiner) Address severe performance regressions, swap storms, and spurious OOMs caused by vm.defrag_mode=1 under high memory pressure in Meta production It updates the page allocator slowpath so non-movable allocation requests actively trigger direct reclaim and direct compaction at pageblock_order scale, allowing them to claim whole pageblocks rather than spinning unproductively. - "zram: lockmap tweaks" (Sebastian Siewior) Optimize and fix lockdep tracking for zram devices by consolidating per-entry lockmaps and isolate lock classes across multiple instances This reduces memory overhead by replacing per-entry lockdep_map instances with a single map per struct zram, and assigns a dynamic lock_class_key to each instance to prevent false deadlock reports when different zram devices are backed by distinct filesystems. * tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (501 commits) selftests/mm: thuge-gen: fix test_shmget() for PAGE_SIZE check selftests/mm: unpoison pages in memory-failure teardown mm/shmem: downgrade final i_blocks check in shmem_evict_inode() to pr_warn() mm/khugepaged: replace mutex_lock/mutex_unlock usage with guard macro mm/zsmalloc: fix release order of locks in zs_page_migrate() Documentation: zram: remove sections numbering ksm: stop iterating VMAs when ksm_test_exit returns true mm: fold userfaultfd_rwp() to false without CONFIG_ARCH_HAS_PTE_PROTNONE mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch() zram: use a custom key for each zram object zram: move lockmap to be per-zram instead per table selftests/mm: fix gup_longterm EINVAL error message mm: page_alloc: fix non-movable reclaim storm in defrag_mode mm: page_alloc: move capture_control to the page allocator mm: compaction: support non-movable compaction for pageblock requests mm: page_alloc: __GFP_FS lockdep annotation for direct compaction hugetlb: evaluate subpool free state while locked mm/damon: remove trailing semicolons after function definitions mm/damon/ops-common: prevent migration fallback to non-target nodes mm/damon: update outdated comment about DAMOS filter handling ...
2026-08-20Merge tag 'for-7.3/block-20260819' of ↵Linus Torvalds5-5/+4
git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux Pull block updates from Jens Axboe: - NVMe updates via Keith: - Enable Clang context analysis for the nvme host driver, adding context annotations across core, fabrics, rdma, tcp and pci - nvmet reservation state exposed through a new namespace-level debugfs directory, plus ABI documentation for the host sysfs and target configfs interfaces - nvme-tcp host memory disclosure fixes on the read path: reject a read that transferred too few bytes, don't accept C2HData based on blk_rq_payload_bytes() alone, and fix the R2T case for a read command - Parallelize nvme-rdma I/O queue allocation and startup (Surabhi) - Apple nvme fixes and quirks: page aligned admin queue buffers, destroy the admin queue on removal, and various DMA/NVMMU correctness fixes - A large pile of nvmet and host fixes for out-of-bounds reads, refcount/resource leaks, and NULL derefs across auth, zns, passthru, pci-epf, rdma and configfs - Various other fixes and cleanups - MD updates via Yu Kuai: - llbitmap reshape support, the large series wiring exact bitmap mapping and reshape lifecycle through raid5 and raid10, growing the page cache in place, and remapping checkpointed bits as reshape progresses - raid5 fixes for lockless max_nr_stripes and recovery_offset accesses, a reshape deadlock with more failed devices than max degraded, and bitmap batch counter consistency - Atomic write handling for raid1/raid10, and removal of the REQ_NOWAIT support from raid1/10/456 - raid5-ppl use-after-free fix in ppl_do_flush() - A batch of smaller fixes across md core and the bitmap code - s390/dasd ESE full-track write support and the surrounding infrastructure, plus enabling CONTEXT_ANALYSIS for s390/block - RWF_DONTCACHE support for block devices, built on new task-context bio completion infrastructure, and wiring it up for the iomap and buffer dropbehind writeback paths - Async io_uring zone reset all, plus zone management command cleanups allowing REQ_NOWAIT and tightening conventional zone rejection - Block integrity refactoring: lift BIP_CHECK_FLAGS to the shared header, handle nogenerate/noverify properly in fs-integrity, and drop the blk-integrity.h include from bdev.c - Split out a new blk_plug.h header - ublk improvements: add UBLK_F_IO_DESC_SIZE, split request validation from io_desc init, reject non-power-of-2 zone sizes in SET_PARAMS, and a series of hardening fixes around map/unmap and auto buf reg - null_blk cleanups and configfs serialization fixes - nbd queue freeze removal on the setup paths, and a new pre_defined_connections module parameter for pre-created devices - blk-cgroup fixes for the race between policy activation and blkg destruction, and accounting per-cpu stats over possible CPUs across blk-stat, iolatency, iocost and kyber - Various dio fixes: leak on metadata mapping error, validate user space vectors during extraction, and set dma_alignment from the backing file for loop and zloop direct I/O - bio cleanups - Various other fixes and cleanups all over * tag 'for-7.3/block-20260819' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (241 commits) nbd: add pre_defined_connections module parameter for pre-created devices nbd: remove queue freeze for newly created nbd from netlink path nbd: factor out a nbd_genl_foreach_sock nbd: skip queue freeze when setting size at device startup nbd: remove queue freeze in nbd_add_socket nbd: clear queue limits on disconnect nbd: disallow NBD_SET_SOCK on an active device nbd: simplify find_fallback() by removing redundant logic blk-mq: add missing call to srcu_barrier() in blk_mq_free_tag_set() block: mtip32xx: synchronize ioctls with device removal ublk: avoid teardown retry loop on xarray allocation failure null_blk: fix UBSAN shift-out-of-bounds when zone_size is 0 or overflows block: don't include blk-integrity.h in bdev.c xfs: avoid double deferrals for RWF_DONTCACHE writes loop: Fix recently introduced lock inversion block: set QUEUE_FLAG_DYING unconditionally in blk_mark_disk_dead() swim3: Add missing MODULE_DESCRIPTION selftests: ublk: add SET_PARAMS validation test selftests: ublk: add helper for SET_PARAMS ublk: reject non-power-of-2 zone sizes in SET_PARAMS ...
2026-08-18Merge tag 'memblock-v7.3-rc1' of ↵Linus Torvalds5-101/+47
git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock Pull memblock updates from Mike Rapoport: "Non-urgent fixes: - Fix calculation of node_spanned_pages when running with 'kernelcore=mirror' - Properly handle failure to allocate per_cpu_nodestats in free_area_init_core_hotplug() - Fix deferred initialization of the memory map for configurations where node's RAM end is not aligned on PAGES_PER_SECTION Cleanups: - Remove redundant pageblock_align() call in free_unused_memmap() - Remove unnecessary invalid range checks in users of memblock iterators. Some users of for_each_mem_range() and for_each_mem_pfn_range() verify that start < end for each range. This is redundant because memblock iterators guarantee to never return an invalid range - Stop overlapping zones with 'kernelcore=mirror' and align behaviour of 'kernelcore=mirror' with other variants of kernelcore and movablecore - Remove redundant updates of numa_nodes_parsed mask in the callers of numa_add_memblk(), the latter always updates the mask anyway - Remove unnecessary initialization of pgdat->per_cpu_nodestats to NULL, the variable is reset to the actual value a few lines below" * tag 'memblock-v7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock: (25 commits) mm/mm_init: deferred_grow_zone(): fix out-of-range first_deferred_pfn mm/mm_init: remove unnecessary initialization of pgdat->per_cpu_nodestats mm/mm_init: remove redundant memset in free_area_init() mm: numa_memblks: use numa_add_reserved_memblk() in numa_cleanup_meminfo() arch_numa: remove redundant node_possible_map assignment mm: numa_memblks: remove redundant numa_nodemask_from_meminfo() LoongArch: remove redundant numa_nodes_parsed node_set() arch_numa: remove redundant numa_nodes_parsed node_set() x86/numa: remove redundant numa_nodes_parsed node_set() of/numa: remove redundant numa_nodes_parsed node_set() ACPI: NUMA: remove redundant numa_nodes_parsed node_set() mm: numa_memblks: set numa_nodes_parsed in numa_add_memblk() mm/mm_init: handle alloc_percpu failure in free_area_init_core_hotplug mm/mm_init: drop overlap_memmap_init() mm/mm_init: don't overlap NORMAL and MOVABLE zones with kernelcore=mirror mm/hugetlb: remove unnecessary empty range check in hugetlb_bootmem_set_nodes() mm: remove unnecessary empty range check in early_calculate_totalpages() powerpc64/kasan: Remove unreachable invalid range check in kasan_init_phys_region() ARM: remove unreachable invalid range check in kasan_init() riscv: remove unreachable invalid range check in kasan_init() ...
2026-08-17Merge tag 'vfs-7.3-rc1.lookup' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs lookup updates from Christian Brauner: "This refactors lookup_open() and adds vfs_lookup_open() for nfsd. mnt_want_write() and parent locking are moved into lookup_open() itself. audit_inode_child() is also now called in lookup_open() on failure. That is the calling convention in vfs_create() and vfs_mkdir(), but lookup_open() made no such call when atomic_open() should have created a file and did not. And neither did the regular ->create() path fwiw. This also contains work to remove the unneeded excl argument from the ->create() inode op" * tag 'vfs-7.3-rc1.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fs/namei.c: fix coding style in atomic_open() and lookup_open() fs/namei.c: fix kerneldoc of atomic_open() and vfs_lookup_open() fs/namei.c: update stale comments in lookup_open() Remove excl arg to ->create inode_operation fs/namei.c: update kerneldoc of atomic_open() vfs: call audit_inode_child() in lookup_open() on failure vfs: move create error && negative dentry case in lookup_open() up VFS: add vfs_lookup_open() for nfsd VFS: move delegated_inode retry loop into lookup_open() VFS: move mnt_want_write() and locking into lookup_open()
2026-08-13mm/pagewalk: fix stale walk->action escaping walk_pmd_range()Hyunwoo Kim1-4/+2
If ->pmd_entry() sets walk->action = ACTION_AGAIN, the pmd_none() check is retried. The PMD entry may be cleared at the point of retry. In this case, if walk->ops->install_pte is not specified, the code continues to the next PMD entry in the range without resetting walk->action to ACTION_SUBTREE. This leaves walk->action erroneously set to ACTION_AGAIN, which is incorrect. This was incorrect but not problematic up until commit 3b89863c3fa4 ("mm/pagewalk: fix race between concurrent split and refault") which updated walk_pud_range() to check for walk->action == ACTION_AGAIN upon walk_pmd_range()'s return, causing the PUD walk to be retried. In this case this results in duplicate walk callbacks being invoked, which is erroneous and will break any caller that is not idempotent with respect to this (and waste time for those which are). The result is an out-of-bounds write, triggered by a local fuzzer: [ 2.272695] ================================================================== [ 2.273471] BUG: KASAN: slab-out-of-bounds in __mincore_unmapped_range+0x14f/0x190 [ 2.274302] Write of size 1 at addr ffff888008d9b000 by task poc/106 [ 2.274966] [ 2.275154] CPU: 0 UID: 1000 PID: 106 Comm: poc Not tainted 7.2.0-rc6-00429-ga7c7074b58d2 #55 PREEMPT(lazy) [ 2.275159] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 2.275164] Call Trace: [ 2.275170] <TASK> [ 2.275172] dump_stack_lvl+0x53/0x70 [ 2.275200] print_report+0xd0/0x630 [ 2.275210] ? __pfx__raw_spin_lock_irqsave+0x10/0x10 [ 2.275219] ? irqentry_exit+0xd2/0x670 [ 2.275224] ? irqentry_exit+0xd2/0x670 [ 2.275226] ? __virt_addr_valid+0xef/0x1a0 [ 2.275239] ? __mincore_unmapped_range+0x14f/0x190 [ 2.275242] kasan_report+0xce/0x100 [ 2.275245] ? __mincore_unmapped_range+0x14f/0x190 [ 2.275248] __mincore_unmapped_range+0x14f/0x190 [ 2.275252] mincore_unmapped_range+0x45/0x70 [ 2.275254] walk_pgd_range+0xafc/0xfc0 [ 2.275261] ? __pfx_walk_pgd_range+0x10/0x10 [ 2.275264] ? __update_load_avg_se+0x3d1/0x670 [ 2.275275] __walk_page_range+0xc0/0x310 [ 2.275278] ? __pfx_find_vma+0x10/0x10 [ 2.275281] ? finish_task_switch.isra.0+0x16d/0x4f0 [ 2.275290] walk_page_range_mm_unsafe+0x26f/0x3a0 [ 2.275293] ? __pfx_mtree_load+0x10/0x10 [ 2.275298] ? __pfx_walk_page_range_mm_unsafe+0x10/0x10 [ 2.275302] ? __free_frozen_pages+0x54d/0x7e0 [ 2.275308] __do_sys_mincore+0x132/0x380 [ 2.275311] do_syscall_64+0xf9/0x540 [ 2.275316] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 2.275322] RIP: 0033:0x422ccd [ 2.275326] Code: b3 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 [ 2.275329] RSP: 002b:00007fffffffec18 EFLAGS: 00000287 ORIG_RAX: 000000000000001b [ 2.275337] RAX: ffffffffffffffda RBX: 0000000000000066 RCX: 0000000000422ccd [ 2.275339] RDX: 00000000004d0940 RSI: 0000000001000000 RDI: 00007ffff4000000 [ 2.275340] RBP: 00000000004d0940 R08: 0000000000000100 R09: 0000000000000100 [ 2.275342] R10: 0000000000000100 R11: 0000000000000287 R12: 20c49ba5e353f7cf [ 2.275343] R13: 00000000004990d3 R14: 0000000000000000 R15: 0000000000000001 [ 2.275346] </TASK> [ 2.275347] [ 2.296904] The buggy address belongs to the object at ffff888008d9b000 [ 2.296904] which belongs to the cache sigqueue of size 80 [ 2.298151] The buggy address is located 0 bytes inside of [ 2.298151] allocated 80-byte region [ffff888008d9b000, ffff888008d9b050) [ 2.299408] [ 2.299601] The buggy address belongs to the physical page: [ 2.300191] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x8d9b [ 2.301001] flags: 0x100000000000000(node=0|zone=1) [ 2.301535] page_type: f5(slab) [ 2.301884] raw: 0100000000000000 ffff888107e46780 dead000000000122 0000000000000000 [ 2.302687] raw: 0000000000000000 0000000800240024 00000000f5000000 0000000000000000 [ 2.303489] page dumped because: kasan: bad access detected [ 2.304092] [ 2.304276] Memory state around the buggy address: [ 2.304801] ffff888008d9af00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 2.305567] ffff888008d9af80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 2.306340] >ffff888008d9b000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 2.307115] ^ [ 2.307474] ffff888008d9b080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 2.308237] ffff888008d9b100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 2.308997] ================================================================== A specific example of this breaking things is mincore which walks an internal cursor data structure a byte at a time on assumption that page table entry callbacks are called only once for each entry. Fix the problem by resetting walk->action to ACTION_SUBTREE prior to the none check. The pattern also exists in walk_pud_range() so fix it there too. This issue was found through AI-based fuzzing. Link: https://lore.kernel.org/20260811161949.3879321-2-imv4bel@gmail.com Fixes: 3b89863c3fa4 ("mm/pagewalk: fix race between concurrent split and refault") Assisted-by: Claude:claude-opus-5 Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com> Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Max Boone <mboone@akamai.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-13mm, swap: don't free a hibernation slot that is in the swap cacheYoungjun Park1-1/+8
A slot with a folio in the swap cache is freed when the folio leaves the cache, not when its count drops. swap_put_entries_cluster() follows that rule. swap_free_hibernation_slot() does not, it calls __swap_cluster_free_entries() whether or not a folio sits on the slot. Cluster readahead can put one there. It walks a raw page_cluster sized window of offsets around the faulting entry, and a hibernation slot passes __swap_cache_add_check() because it is not a folio and its count is not zero. Freeing the slot then clears the entry under that folio. The folio is now unreachable from the swap table, and the offset goes back to the allocator. The folio is still on the LRU though, so reclaim can pick it up later. It then takes the old offset out of folio->swap and overwrites the table entry there, which by then may belong to someone else. This bug can trigger silent memory corruption, process crashes, or data instability across completely unrelated userspace applications - typically occurring when uswsusp is preparing the hibernation image. I found this while working on giving hibernation slots their own marker in the swap table, which I had discussed with Kairui. (https://lore.kernel.org/linux-mm/abp7aDgYLrxF3Me8@KASONG-MC4/) As far as I know there are no reports, so there is no Reported-by/Closes to add. Check for a cached folio before freeing. The slot is then left in the ordinary state where only the swap cache holds it, and it is freed when the folio leaves the cache, either through the reclaim below or through normal reclaim later. Link: https://lore.kernel.org/20260811132209.2862708-2-youngjun.park@lge.com Fixes: 0d6af9bcf383 ("mm, swap: use the swap table to track the swap count") Signed-off-by: Youngjun Park <youngjun.park@lge.com> Acked-by: Kairui Song <kasong@tencent.com> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Barry Song <baohua@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-13mm: memcg-v1: fix memsw and TCP failcnt accountingGuopeng Zhang1-0/+2
Commit 0e2759afcaf9 ("page_counter: track failcnt only for legacy cgroups") made failcnt accounting conditional on track_failcnt. It enabled the flag for memcg->memory, but not for memcg->memsw or memcg->tcpmem. Consequently, memory.memsw.failcnt remains zero when the memory+swap limit is hit. memory.kmem.tcp.limit_in_bytes still sets memcg->tcpmem.max, but TCP charge failures are not reflected in memory.kmem.tcp.failcnt. Enable failcnt accounting for both v1 counters. To reproduce memory.memsw.failcnt: CG=/sys/fs/cgroup/memory/memsw-test LIMIT=33554432 mkdir "$CG" echo "$LIMIT" > "$CG/memory.limit_in_bytes" echo "$LIMIT" > "$CG/memory.memsw.limit_in_bytes" Start a child process in the cgroup and make it allocate and touch 96 MiB of memory, causing a memcg OOM. cat "$CG/memory.memsw.failcnt" Without the patch, memory.memsw.failcnt is 0. With the patch, memory.memsw.failcnt is greater than 0. To reproduce memory.kmem.tcp.failcnt: CG=/sys/fs/cgroup/memory/tcpmem-test LIMIT=65536 mkdir "$CG" echo "$LIMIT" > "$CG/memory.kmem.tcp.limit_in_bytes" Start a child process in the cgroup, create a TCP socket, and reserve 1 MiB of socket memory with SO_RESERVE_MEM. The reservation fails with ENOMEM. cat "$CG/memory.kmem.tcp.failcnt" Without the patch, memory.kmem.tcp.failcnt is 0. With the patch, memory.kmem.tcp.failcnt is greater than 0. Link: https://lore.kernel.org/20260811030843.109104-1-guopeng.zhang@linux.dev Closes: https://sashiko.dev/#/patchset/20260810074247.52747-1-guopeng.zhang@linux.dev?part=1 Fixes: 0e2759afcaf9 ("page_counter: track failcnt only for legacy cgroups") Signed-off-by: Guopeng Zhang <zhangguopeng@kylinos.cn> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Tao Cui <cuitao@kylinos.cn> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-13mm/vmscan: report RCU-tasks quiescent states in shrink_lruvec()Breno Leitao1-1/+1
I am seeing some rcu_tasks stalls in the Meta fleet during reclaim. INFO: rcu_tasks detected stalls on tasks: 0000000088620d09: .. nvcsw: 6735/6735 holdout: 1 idle_cpu: -1/8 task:GlobalCPUThread state:R running task pid:2552016 tgid:2524552 Call Trace: shrink_lruvec mem_cgroup_iter shrink_node do_try_to_free_pages try_to_free_pages __alloc_frozen_pages_noprof alloc_pages_noprof pte_alloc_one __pte_alloc handle_mm_fault Nothing promises direct reclaim returns in bounded time, and the scan loop in shrink_lruvec() only calls cond_resched(), which is a no-op on PREEMPTION kernels. Involuntary preemption is not a Tasks-RCU quiescent state, so the reclaiming task never reports one and becomes a holdout. Upgrade it to cond_resched_tasks_rcu_qs(), which reports a quiescent state even when cond_resched() does nothing. PS: This has been discussed in [1] Link: https://lore.kernel.org/20260810-rcu_task_shrink_lruvec-v1-1-4d9f7d5251cb@debian.org Link: https://lore.kernel.org/all/amdWVTs0WKOxguxP@gmail.com/ [1] Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Kairui Song <kasong@tencent.com> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-13memcg: keep folio's objcg same as its nodeShakeel Butt1-17/+83
memcg_reparent_objcgs() has an inherent assumption that a folio's objcg is the objcg of the folio's node. Folio migration across nodes breaks that assumption: the new folio simply inherits the old folio's objcg while living on a different node. Once the assumption is broken, the reparenting of the folio's objcg and the reparenting of the folio's LRU list are no longer atomic. memcg_reparent_objcgs() handles one node per iteration and drops all the locks in between, so the objcg gets reparented in the iteration for the objcg's node while the LRU list gets spliced in the iteration for the folio's node. Any LRU operation on that folio in between resolves its lruvec through the objcg, and thus takes the lru_lock of the wrong memcg, not the lru_lock of the list the folio is actually on. Fix this by selecting the objcg by folio_nid() at charge time, and by re-deriving it for the destination node in mem_cgroup_migrate() and mem_cgroup_replace_folio(). Link: https://lore.kernel.org/20260807142406.443516-1-shakeel.butt@linux.dev Fixes: f1cf8d2f36dc ("mm: memcontrol: eliminate the problem of dying memory cgroup for LRU folios") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Reported-by: Karl Erik Hofseth <karl.e.hofseth@opoint.com> Closes: https://lore.kernel.org/all/anMmd1ADrDVwMO6v@work/ Co-developed-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Muchun Song <muchun.song@linux.dev> Acked-by: Qi Zheng <qi.zheng@linux.dev> Cc: Michal Hocko <mhocko@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-07Merge branch 'misc' into for-nextMike Rapoport (Microsoft)2-5/+1
2026-08-07Merge branch 'range-checks' into for-nextMike Rapoport (Microsoft)2-7/+3
2026-08-07Merge branch 'numa_memblks-redundant-work' into for-nextMike Rapoport (Microsoft)1-22/+19
2026-08-07Merge branch 'kernelcore-mirror' into for-nextMike Rapoport (Microsoft)1-57/+3
2026-08-07mm/mm_init: deferred_grow_zone(): fix out-of-range first_deferred_pfnAlexander Graf1-3/+6
With CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled, deferred_grow_zone() initializes struct pages early in boot to satisfy an allocation. With a large CMA reservation in place, the ranges deferred_init_memmap() finds may not add up to the allocation it was asked for, and the function ends up initializing the memory map of the entire zone and still falls short. That is fine in itself: the function accounts for it and leaves the caller to decide whether it now has enough memory. However, the update of pgdat->first_deferred_pfn that tracks where uninitialized memory map starts could overflow. If the node's RAM end is not aligned on PAGES_PER_SECTION boundaries and some deferred struct pages were initialized, pgdat->first_deferred_pfn would point past the end of the node's memory. deferred_init_memmap() later picks up from pgdat->first_deferred_pfn and hits a BUG_ON(), because it expects a pfn within its node. For example, when running a kernel with CONFIG_DEFERRED_STRUCT_PAGE_INIT=y and CONFIG_CMA=y using the following qemu command line qemu-system-x86_64 -enable-kvm -m 8032M -kernel bzImage \ -append "nokaslr cma=4768M@0x100000000" the kernel panics: kernel BUG at mm/mm_init.c:2131! CPU: 3 UID: 0 PID: 36 Comm: pgdatinit0 Not tainted 7.2.0-rc6 #1 RIP: 0010:deferred_init_memmap+0x1b8/0x1c0 RAX: 0000000000236000 R13: 0000000000238000 Call Trace: kthread+0xdf/0x120 ret_from_fork+0x187/0x250 Make sure that the update of pgdta->first_deferred_pfn does not overflow when the entire zone's (and therefore node's) memory map is initialized. Fixes: 3acb913c9d5b ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()") Cc: stable@vger.kernel.org Assisted-by: Kiro:claude-opus-5 Signed-off-by: Alexander Graf <graf@amazon.com> Link: https://patch.msgid.link/20260807031243.87904-1-graf@amazon.com [rppt: massaged the changelog] Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-08-06Merge tag 'mm-hotfixes-stable-2026-08-06-18-44' of ↵Linus Torvalds11-114/+230
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM fixes from Andrew Morton: "17 hotfixes. 15 are cc:stable. 16 are for MM. There's a patch series from Lorenzo "mm: fix UAF caused by race between ptdump and vmap pgtable freeing" which addresses a quite old bug in the ptdump code. And another series also from Lorenzo which fixes a four year old bug in the huge_zero_folio handling. A series from SJ fixes a few possible divide-by-zero issues which Sashiko sniffed out. And a series which fixes handling of the commit_inputs parameters. The remainder are singletons, please see their changelogs for details" * tag 'mm-hotfixes-stable-2026-08-06-18-44' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm/damon: adjust isolated pages stat for DAMOS_MIGRATE_{HOT,COLD} mm/damon/ops-common: putback folios on invalid migrate nid mm/huge_memory: initialise workingset state before folio split mm/page_table_check: skip special zero mappings mm/damon/lru_sort: skip damon_call() if ctx has not started mm/damon/reclaim: skip damon_call() if ctx has not started mm/damon/lru_sort: error out for >10000 active_mem_bp samples/damon/mtier: error out for zero quota goal target values mailmap: map old addresses to Danila Tikhonov mm/huge_memory: separate out CONFIG_PERSISTENT_HUGE_ZERO_FOLIO logic mm/huge_memory: fix huge_zero_pfn race MAINTAINERS: update address for Brendan Jackman mm/filemap: __filemap_add_folio() restore index before retrying microblaze: restore the page alignment of swapper_pg_dir arm64: remove redundant concurrent ptdump UAF mitigation mm/ptdump: always stabilise against page table freeing using init_mm mm/vmalloc: acquire init_mm lock on huge vmap to avoid ptdump UAF
2026-08-06mm/shmem: downgrade final i_blocks check in shmem_evict_inode() to pr_warn()Jiacheng Yu1-1/+4
shmem_evict_inode() ends with WARN_ON(inode->i_blocks) as a final consistency check of shmem's block accounting. When it fires, the inode-local counters die with the inode; what may linger is a small residue in accounting kept outside the inode, such as per-mount or per-user charges. No data is lost, and no corruption follows. On kernels running with panic_on_warn=1, this accounting inconsistency escalates to a full machine panic, which is disproportionate to the impact. Downgrade the WARN_ON() to a pr_warn() that reports the inode together with its accounting counters (i_blocks, alloced, swapped, nrpages), keeping the inconsistency visible in the logs. The accounting bugs this check has caught over the years -- the swapout race described in commit 0f3c42f522dc ("tmpfs: change final i_blocks BUG to WARNING") and the error recovery race fixed in commit 267a4c76bbdb ("tmpfs: fix shmem_evict_inode() warnings on i_blocks") -- are real and should still be fixed; this change only removes the disproportionate escalation. One way to hit this race: soft_offline_in_use_page()'s fast path drops a clean, unmapped shmem folio via mapping_evict_folio(), where the xas_store() and the nrpages decrement are not atomic against a concurrent shmem_evict_inode(); the final shmem_recalc_inode() can then read the pre-decrement nrpages, compute freed = 0, and leave one page charged. Same class as the races in 0f3c42f522dc and 267a4c76bbdb, this time in the under-count direction; reproduced on 7.2-rc4 with madvise(MADV_SOFT_OFFLINE) racing MAP_FIXED replacement of a shared-anonymous VMA. [yujiacheng3@huawei.com: drop redundant casts in shmem_evict_inode() pr_warn] Link: https://lore.kernel.org/20260729121201.776566-1-yujiacheng3@huawei.com Link: https://lore.kernel.org/20260728091014.3876715-1-yujiacheng3@huawei.com Fixes: 0f3c42f522dc ("tmpfs: change final i_blocks BUG to WARNING") Signed-off-by: Jiacheng Yu <yujiacheng3@huawei.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Yongqiang Liu <liuyongqiang13@huawei.com> Cc: Christian Brauner <brauner@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06mm/khugepaged: replace mutex_lock/mutex_unlock usage with guard macroJakov Novak1-16/+15
Currently, khugepaged locks the khugepaged_mutex in two functions: start_stop_khugepaged and khugepaged_min_free_kbytes_update. Remove mutex_lock/mutex_unlock usage in these functions and replace it with the guard macro. This makes the code more readable (removing a goto statement) and makes it harder to introduce bugs in the future. No functional changes introduced. Link: https://lore.kernel.org/20260730204724.16912-1-jakovnovak30@gmail.com Signed-off-by: Jakov Novak <jakovnovak30@gmail.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06mm/zsmalloc: fix release order of locks in zs_page_migrate()Richard Chang1-2/+2
In zs_page_migrate(), locks are acquired in the following order: 1. write_lock(&pool->lock) 2. spin_lock(&class->lock) 3. zspage_write_trylock(zspage) However, upon successful page migration, they were being released in forward acquisition (FIFO) order: 1. write_unlock(&pool->lock) 2. spin_unlock(&class->lock) 3. zspage_write_unlock(zspage) Fix the unlocking order to release locks in strict reverse (LIFO) order of acquisition: 3. zspage_write_unlock(zspage) 2. spin_unlock(&class->lock) 1. write_unlock(&pool->lock) Releasing locks in reverse order of acquisition adheres to standard kernel locking hygiene, prevents potential lock ordering and lockdep inconsistencies. Link: https://lore.kernel.org/20260728055333.421080-1-richardycc@google.com Signed-off-by: Richard Chang <richardycc@google.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Martin Liu <liumartin@google.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06ksm: stop iterating VMAs when ksm_test_exit returns trueWang Wensheng1-1/+1
In scan_get_next_rmap_item() the break statement only exits the inner while loop, leaving remaining VMAs to be iterated even if ksm_test_exit() returns true. Replace it with a goto statement to avoid the unnecessary work. Link: https://lore.kernel.org/20260726133501.504048-1-wsw9603@163.com Signed-off-by: Wang Wensheng <wsw9603@163.com> Reviewed-by: Xu Xin <xu.xin16@zte.com.cn> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Chengming Zhou <chengming.zhou@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()Breno Leitao1-1/+1
migrate_pages_batch() unmaps each folio before moving it, and every unmap runs the mmu_notifier invalidate callbacks. On KVM hosts try_to_migrate() ends up in kvm_mmu_notifier_invalidate_range_start() -> tdp_mmu_zap_leafs(), which is expensive, so unmapping a large batch keeps the CPU busy for a long time. The loop already calls cond_resched(), but on PREEMPTION kernels that is a no-op, and involuntary preemption is not a Tasks-RCU quiescent state. A long batch therefore never reports a quiescent state, and the migrating task (e.g. kcompactd) becomes a Tasks-RCU holdout, stalling the Tasks-RCU grace period for minutes, which is common at Meta fleet: INFO: rcu_tasks detected stalls on tasks: 0000000055349ecc: .. nvcsw: 1157401/1157401 holdout: 1 idle_cpu: -1/56 task:kcompactd0 state:R running task Call Trace: tdp_mmu_zap_leafs tdp_mmu_next_root gfn_to_pfn_cache_invalidate_start kvm_mmu_notifier_invalidate_range_start __mmu_notifier_invalidate_range_start try_to_migrate_one try_to_migrate migrate_pages_batch migrate_pages compact_zone compact_node kcompactd kthread Use cond_resched_tasks_rcu_qs() so a quiescent state is reported even when cond_resched() does nothing. This has also been discussed at [1] Link: https://lore.kernel.org/20260727-kcompact-v1-1-bdfefddd6874@debian.org Link: https://lore.kernel.org/all/amdWVTs0WKOxguxP@gmail.com/ [1] Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Gregory Price <gourry@gourry.net> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Byungchul Park <byungchul@sk.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06mm: page_alloc: fix non-movable reclaim storm in defrag_modeJohannes Weiner3-6/+33
As we deployed defrag_mode into Meta production, pressure spikes and excessive swapping were observed on some workloads. Tracing confirmed that this is unmovable/reclaimable requests spinning in the allocator and direct reclaim, causing excessive amounts of swap. The initial plan for defrag_mode was to rely on kswapd/kcompactd to produce blocks, and if those are overwhelmed under high pressure, let the allocator fall back (__rmqueue_steal()) after its retry loops. However, that retrying results in more reclaim on some of these workloads than we'd hoped, sometimes excessively so, spurred on by the !costly order conditions in should_reclaim_retry(). The storms are dependent on the request type. Reclaim will inevitably make room in existing movable blocks, since that's where the LRU pages live. So if movable requests retry on reclaim, they make progress. When non-movable requests spin in reclaim that isn't productive. They cannot use the individually freed pages, and the process is unlikely to accidentally free whole blocks to meet the ALLOC_NOFRAGMENT bar. They spin and overreclaim excessively, which tanks performance and triggers userspace guards like swap exhaustion or pressure based OOM. To fix this, send non-movable requests, regardless of order, into pageblock reclaim/compaction. This way, they help move things along to meet the ALLOC_NOFRAGMENT bar. After this patch, the reclaim storms and excess OOM rates are no longer observed in production. The longer-term plan is still to have all requests, including the movable ones, help make blocks to spread the cost of defragmenting more evenly and fairly; combined with proper watermarking to reduce allocation latencies in the common case. However, doing this naively unearths scaling and concurrency limitations in compaction that need to be addressed first. Promoting just non-movables for now is the minimally viable bug fix for the above issue. [brendan.jackman@linux.dev: fix try_to_compact_pages() kerneldoc] Link: https://lore.kernel.org/DK7NM9RPUJOD.11PNJJ5N2OBED@linux.dev Link: https://lore.kernel.org/20260722150006.3848560-5-hannes@cmpxchg.org Fixes: e3aa7df331bc ("mm: page_alloc: defrag_mode") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: "Brendan Jackman" <brendan.jackman@linux.dev> Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Brendan Jackman <brendan.jackman@linux.dev> Cc: David Hildenbrand <david@kernel.org> Cc: Gregory Price <gourry@gourry.net> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Zi Yan <ziy@nvidia.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06mm: page_alloc: move capture_control to the page allocatorVlastimil Babka (SUSE)3-44/+55
The compaction capturing code assumes the allocation request order and compaction target order are the same. That won't be true once defrag_mode promotes sub-block allocations to pageblock-order compaction: compaction targets the larger order, while capture should remain at the original allocation order. Move the capture_control to the page allocator and give it its own copies of what the page freeing path matches against - zone, migratetype and the allocation order - rather than reaching into compaction's live compact_control. __alloc_pages_direct_compact() fills in migratetype and order, and installs and hides current->capture_control around the whole compaction call; try_to_compact_pages() aims capc->zone at each zone while it is being compacted. compact_zone_order() no longer deals with capture at all. Pass the capture_control through try_to_compact_pages() / compact_zone_order() in place of the bare struct page **. No functional change. Link: https://lore.kernel.org/20260722150006.3848560-4-hannes@cmpxchg.org Fixes: e3aa7df331bc ("mm: page_alloc: defrag_mode") Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Co-developed-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Gregory Price <gourry@gourry.net> Cc: Brendan Jackman <brendan.jackman@linux.dev> Cc: Brendan Jackman <jackmanb@google.com> Cc: David Hildenbrand <david@kernel.org> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Zi Yan <ziy@nvidia.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06mm: compaction: support non-movable compaction for pageblock requestsJohannes Weiner1-7/+39
While trying to fix a reclaim storm in defrag_mode, I noticed that non-movable direct compaction is extremely inefficient. When searching for space to evacuate, compaction only allows blocks of the same type as the incoming request. This is to prevent migratetype pollution, where a small non-movable request frees space in a movable block and provokes the allocator to fall back and pollute it. This protection is reasonable on one hand, but the downside is that it makes non-movable direct compaction nearly useless: if we get the type annotations right, by definition there aren't any movable pages inside the non-movable blocks it is allowed to scan. With defrag_mode, the goal is the production of whole blocks, which are essentially type neutral: __rmqueue_claim() will convert them wholesale on alloc. This makes type mixing and pollution a non-issue. Fix the pollution gates to take the requested order into account, and allow whole-block requests to scan blocks of other types. The only exception is CMA blocks. That type is sticky and these blocks cannot be claimed to other types. Continue to be strict with them, and allow only explicit ALLOC_CMA requests and kcompactd to evacuate them. Link: https://lore.kernel.org/20260722150006.3848560-3-hannes@cmpxchg.org Fixes: e3aa7df331bc ("mm: page_alloc: defrag_mode") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Reviewed-by: Gregory Price <gourry@gourry.net> Cc: Brendan Jackman <brendan.jackman@linux.dev> Cc: Brendan Jackman <jackmanb@google.com> Cc: David Hildenbrand <david@kernel.org> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Zi Yan <ziy@nvidia.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06mm: page_alloc: __GFP_FS lockdep annotation for direct compactionJohannes Weiner1-0/+2
Patch series "mm: fix reclaim storms in defrag_mode", v2. As we deployed vm.defrag_mode=1 in Meta production, some workloads regressed with recurring pressure spikes and swap storms (which in turn triggered userspace OOM rules on pressure and swap utilization levels). Tracing pinned this to non-movable requests spinning and reclaiming unproductively when kswapd/kcompactd are overwhelmed. Direct reclaim predominantly frees up pages in movable blocks, but those requests cannot use that space under defrag_mode rules; and it is unlikely to free up whole blocks incidentally for __rmqueue_claim() to work. This series fixes it by making non-movable requests participate in pageblock production in the allocator slowpath - meaning, they will invoke direct reclaim and direct compaction with pageblock_order. That requires some small-ish adjustments up front in the allocator and the compaction code: three prep patches and the fix last. The series has been in production against one of the affected workloads for several weeks and restores the OOM kill rate to !defrag_mode baseline. This patch (of 4): A subsequent patch will have some order-0 allocations participate in compaction under defrag_mode, to stave off extfrag events. Since this is a sprawling expansion of entry points, and compaction can enter filesystem paths, add lockdep annotations that catches __GFP_FS passing errors. Direct reclaim has had this annotation for a while, and since reclaim and compaction are usually used in conjunction, this is unlikely to unearth old bugs. It's more about future proofing and peace of mind. Link: https://lore.kernel.org/20260722150006.3848560-1-hannes@cmpxchg.org Link: https://lore.kernel.org/20260722150006.3848560-2-hannes@cmpxchg.org Fixes: e3aa7df331bc ("mm: page_alloc: defrag_mode") Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Brendan Jackman <jackmanb@google.com> Cc: Brendan Jackman <brendan.jackman@linux.dev> Cc: David Hildenbrand <david@kernel.org> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Brendan Jackman <brendan.jackman@linux.dev> Cc: Gregory Price <gourry@gourry.net> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06hugetlb: evaluate subpool free state while lockedYichong Chen1-2/+4
unlock_or_release_subpool() drops spool->lock before calling subpool_is_free(). However, subpool_is_free() reads fields that are updated under spool->lock, including count, used_hpages and rsv_hpages. Keep the free-state evaluation under the same lock that protects those fields. The reservation accounting and kfree() calls still happen after dropping spool->lock. Link: https://lore.kernel.org/20260721035207.1437935-1-chenyichong@uniontech.com Signed-off-by: Yichong Chen <chenyichong@uniontech.com> Reviewed-by: Joshua Hahn <joshua.hahnjy@gmail.com> Reviewed-by: Jane Chu <jane.chu@oracle.com> Cc: David Hildenbrand <david@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06mm/damon: remove trailing semicolons after function definitionsXuewen Wang3-3/+3
Three function definitions terminate with '};' instead of '}', which is unnecessary and inconsistent with kernel coding style: - damon_pa_initcall() in paddr.c - damon_va_initcall() in vaddr.c - damos_get_some_mem_psi_total() in core.c No functional change intended. Link: https://lore.kernel.org/20260721135333.241106-1-sj@kernel.org Signed-off-by: Xuewen Wang <wangxuewen@kylinos.cn> Reviewed-by: SJ Park <sj@kernel.org> Signed-off-by: SJ Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06mm/damon/ops-common: prevent migration fallback to non-target nodesJiahui Zhang1-1/+1
DAMOS_MIGRATE_{HOT,COLD} passes a target NUMA node to migrate_pages(). But alloc_migration_target() only treats mtc->nid as a preferred node unless __GFP_THISNODE is set. Hence target allocation can fall back to another node, and migrate_pages() can report success without placing the folio on the requested target node. Consider a two-node tiered system where node 0 is a fast tier and node 1 is a CPU-less slow tier such as CXL memory, and the user wants to promote hot regions from node 1 to node 0 with a command like: sudo damo start --ops vaddr --target_pid ${workload_pid} \ --damos_action migrate_hot 0 \ --damos_access_rate 70% max Without the __GFP_THISNODE flag, when the memory allocator finds that node 0 is nearly full, it can fall back to node 1 without waking up kswapd. Then the pages allocated for migrate_pages() are still on node 1, and the regions that are expected to be promoted to node 0 are only moved to different physical pages on node 1. Meanwhile, both the mm_migrate_pages tracepoint and DAMOS's own sz_applied statistics (reported via the damos_stat_after_apply_interval tracepoint) show the migrations as successful, which makes the failure practically invisible and hard to investigate. Running a demotion-purpose DAMOS scheme alongside the promotion scheme does not fully avoid this either. If demotion cannot keep up with the promotion rate, allocation can still fall back to node 1 during promotion, and the same misleading statistics show up. Make DAMON's migration target allocation strict by setting __GFP_THISNODE, so that a failed allocation on the target node is reported as a failure instead of silently landing on a different node. This is consistent with alloc_misplaced_dst_folio(), alloc_demote_folio(), and with do_move_pages_to_node(), which all use __GFP_THISNODE for migrations to an explicit destination node. Link: https://lore.kernel.org/20260721135607.251869-1-sj@kernel.org Signed-off-by: Jiahui Zhang <jiahuitry@outlook.com> Reviewed-by: SJ Park <sj@kernel.org> Signed-off-by: SJ Park <sj@kernel.org> Cc: Honggyu Kim <honggyu.kim@sk.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06mm/early_ioremap: clarify early_ioremap_reset() semanticsSang-Heon Jeon1-3/+7
Patch series "mm/early_ioremap: clarify and clean up early_ioremap_reset()". __late_set_fixmap() and __late_clear_fixmap() are only used after early_ioremap_reset() has been called, but the comment above them does not say anything about that. So arm64, riscv and powerpc, whose __set_fixmap() works before and after paging_init(), describe the same situation in three different ways: calls reset defines the macros arm64 yes yes riscv no yes powerpc no no Patch 1 documents when early_ioremap_reset() needs to be called and that only architectures calling it need to define the macros. Patches 2 and 3 remove the unneeded riscv macros, which are unreachable, and the arm64 reset call and macros, which change nothing. No functional change. This patch (of 3): __late_set_fixmap() and __late_clear_fixmap() are only used after early_ioremap_reset() has been called. arm64, riscv and powerpc all have a __set_fixmap() that works before and after paging_init(), so they do not need to call early_ioremap_reset() or define the macros, but they describe the same situation in three different ways: calls reset defines the macros arm64 yes yes riscv no yes powerpc no no The existing comment is vague and allows all three. Replace it with comments that make it clear when the reset and the macros are needed. No functional change. Link: https://lore.kernel.org/20260708170647.362562-1-ekffu200098@gmail.com Link: https://lore.kernel.org/20260708170647.362562-2-ekffu200098@gmail.com Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@kernel.org> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06mm/rmap: batch unmap file folios belonging to uffd-wp VMAsDev Jain1-4/+2
Commit a67fe41e214f ("mm: rmap: support batched unmapping for file large folios") extended batched unmapping for file folios. That also required making pte_install_uffd_wp_if_needed() support batching, but that was left out for the time being. Correctness was maintained by stopping batching if the VMA the folio belongs to is marked uffd-wp. Now that cond_install_uffd_wp_ptes() supports batching, call it with the full batch length and allow folio_unmap_pte_batch() to batch file folios belonging to uffd-wp VMAs. For file folios, if the uffd-wp bit is set, unmapping converts present PTEs into uffd-wp markers. We must ensure that the same PTE range is not reprocessed by the try_to_unmap_one() loop. The page_vma_mapped_walk API ensures this: check_pte() only returns true if any PFN in [pvmw->pfn, pvmw->pfn + nr_pages) is mapped by the PTE. There is no PFN underlying a uffd-wp marker PTE, so check_pte() returns false and the walk skips ahead until it reaches a present entry again. Link: https://lore.kernel.org/20260720065508.2695106-4-dev.jain@arm.com Signed-off-by: Dev Jain <dev.jain@arm.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Barry Song <baohua@kernel.org> Cc: Harry Yoo <harry@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Kairui Song <kasong@tencent.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06mm/memory: batch set uffd-wp markers during zappingDev Jain3-39/+29
Enable batch setting of uffd-wp PTE markers. The code paths passing nr > 1 to zap_install_uffd_wp_if_needed() produce that nr through either folio_pte_batch() or swap_pte_batch(), therefore batching is correct: 1) All PTEs belong to the same type of VMA: anonymous or non-anonymous, wp-armed or non-wp-armed. 2) All PTEs are either marked with uffd-wp or not marked with uffd-wp; the same applies to the pte_swp_uffd_any() check. 3) uffd_supports_wp_marker() is independent of the function parameters. Use set_pte_at() in a loop instead of set_ptes(), because set_ptes() cannot handle nonpresent to nonpresent conversion for nr_pages > 1. Rename the helper to cond_install_uffd_wp_ptes(). Link: https://lore.kernel.org/20260720065508.2695106-3-dev.jain@arm.com Signed-off-by: Dev Jain <dev.jain@arm.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Barry Song <baohua@kernel.org> Cc: Harry Yoo <harry@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Kairui Song <kasong@tencent.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>