kernel/linux.git/Documentation/core-api/mm-api.rst, branch v6.18.21

mm: remove unused zpool layer

2025-09-21T21:21:59+00:00

With zswap using zsmalloc directly, there are no more in-tree users of this code. Remove it. With zpool gone, zsmalloc is now always a simple dependency and no longer something the user needs to configure. Hide CONFIG_ZSMALLOC from the user and have zswap and zram pull it in as needed. Link: https://lkml.kernel.org/r/20250829162212.208258-3-hannes@cmpxchg.org Signed-off-by: Johannes Weiner Acked-by: SeongJae Park Acked-by: Yosry Ahmed Cc: Chengming Zhou Cc: Nhat Pham Cc: Vitaly Wool Signed-off-by: Andrew Morton

Merge tag 'mm-stable-2025-08-03-12-35' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-08-05T13:02:07+00:00

Pull more MM updates from Andrew Morton: "Significant patch series in this pull request: - "mseal cleanups" (Lorenzo Stoakes) Some mseal cleaning with no intended functional change. - "Optimizations for khugepaged" (David Hildenbrand) Improve khugepaged throughput by batching PTE operations for large folios. This gain is mainly for arm64. - "x86: enable EXECMEM_ROX_CACHE for ftrace and kprobes" (Mike Rapoport) A bugfix, additional debug code and cleanups to the execmem code. - "mm/shmem, swap: bugfix and improvement of mTHP swap in" (Kairui Song) Bugfixes, cleanups and performance improvememnts to the mTHP swapin code" * tag 'mm-stable-2025-08-03-12-35' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (38 commits) mm: mempool: fix crash in mempool_free() for zero-minimum pools mm: correct type for vmalloc vm_flags fields mm/shmem, swap: fix major fault counting mm/shmem, swap: rework swap entry and index calculation for large swapin mm/shmem, swap: simplify swapin path and result handling mm/shmem, swap: never use swap cache and readahead for SWP_SYNCHRONOUS_IO mm/shmem, swap: tidy up swap entry splitting mm/shmem, swap: tidy up THP swapin checks mm/shmem, swap: avoid redundant Xarray lookup during swapin x86/ftrace: enable EXECMEM_ROX_CACHE for ftrace allocations x86/kprobes: enable EXECMEM_ROX_CACHE for kprobes allocations execmem: drop writable parameter from execmem_fill_trapping_insns() execmem: add fallback for failures in vmalloc(VM_ALLOW_HUGE_VMAP) execmem: move execmem_force_rw() and execmem_restore_rox() before use execmem: rework execmem_cache_free() execmem: introduce execmem_alloc_rw() execmem: drop unused execmem_update_copy() mm: fix a UAF when vma->mm is freed after vma->vm_refcnt got dropped mm/rmap: add anon_vma lifetime debug check mm: remove mm/io-mapping.c ...

mm: remove mm/io-mapping.c

2025-08-02T19:06:10+00:00

This is dead code, which was used from commit b739f125e4eb ("i915: use io_mapping_map_user") but reverted a month later by commit 0e4fe0c9f2f9 ("Revert "i915: use io_mapping_map_user"") back in 2021. Since then nobody has used it, so remove it. [akpm@linux-foundation.org: update Documentation/core-api/mm-api.rst, per Vlastimil] Link: https://lkml.kernel.org/r/20250725142901.81502-1-lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Acked-by: David Hildenbrand Acked-by: Vlastimil Babka Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton

docs: dma-api: remove duplicate description of the DMA pool API

2025-07-01T19:56:05+00:00

Move the DMA pool API documentation from Memory Management APIs to dma-api.rst, replacing the outdated duplicate description there. Signed-off-by: Petr Tesarik Tested-by: Randy Dunlap Acked-by: Marek Szyprowski Signed-off-by: Jonathan Corbet Link: https://lore.kernel.org/r/20250627101015.1600042-6-ptesarik@suse.com

docs: dma-api: add a kernel-doc comment for dma_pool_zalloc()

2025-07-01T19:55:37+00:00

Document the dma_pool_zalloc() wrapper. Signed-off-by: Petr Tesarik Reviewed-by: Randy Dunlap Tested-by: Randy Dunlap Acked-by: Marek Szyprowski [jc: fixed up dma_pool_alloc() reference in dmapool.h] Signed-off-by: Jonathan Corbet Link: https://lore.kernel.org/r/20250627101015.1600042-5-ptesarik@suse.com

mm/slab, docs: switch mm-api docs generation from slab.c to slub.c

2023-12-05T10:11:34+00:00

The SLAB implementation is going to be removed, and mm-api.rst currently uses mm/slab.c to obtain kerneldocs for some API functions. Switch it to mm/slub.c and move the relevant kerneldocs of exported functions from one to the other. The rest of kerneldocs in slab.c is for static SLAB implementation-specific functions that don't have counterparts in slub.c and thus can be simply removed with the implementation. Acked-by: David Rientjes Tested-by: David Rientjes Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Vlastimil Babka

mm: add orphaned kernel-doc to the rst files.

2023-08-24T23:20:31+00:00

There are many files in mm/ that contain kernel-doc which is not currently published on kernel.org. Some of it is easily categorisable, but most of it is going into the miscellaneous documentation section to be organised later. Some files aren't ready to be included; they contain documentation with build errors. Or they're nommu.c which duplicates documentation from "real" MMU systems. Those files are noted with a # mark (although really anything which isn't a recognised directive would do to prevent inclusion) Link: https://lkml.kernel.org/r/20230818200630.2719595-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Mike Rapoport (IBM) Cc: Randy Dunlap Signed-off-by: Andrew Morton

mm/page_alloc: remove obsolete gfpflags_normal_context()

2022-10-03T21:03:30+00:00

Since commit dacb5d8875cc ("tcp: fix page frag corruption on page fault"), there's no caller of gfpflags_normal_context(). Remove it as this helper is strictly tied to the sk page frag usage and there won't be other user in the future. [linmiaohe@huawei.com: fix htmldocs] Link: https://lkml.kernel.org/r/1bc55727-9b66-0e9e-c306-f10c4716ea89@huawei.com Link: https://lkml.kernel.org/r/20220916072257.9639-16-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Reviewed-by: David Hildenbrand Reviewed-by: Anshuman Khandual Reviewed-by: Oscar Salvador Cc: Matthew Wilcox Signed-off-by: Andrew Morton

headers/deps: mm: align MANITAINERS and Docs with new gfp.h structure

2022-07-15T13:35:54+00:00

After moving gfp types out of gfp.h, we have to align MAINTAINERS and Docs, to avoid warnings like this: >> include/linux/gfp.h:1: warning: 'Page mobility and placement hints' not found >> include/linux/gfp.h:1: warning: 'Watermark modifiers' not found >> include/linux/gfp.h:1: warning: 'Reclaim modifiers' not found >> include/linux/gfp.h:1: warning: 'Useful GFP flag combinations' not found Signed-off-by: Yury Norov

mm: document and polish read-ahead code

2022-03-22T22:57:00+00:00

Add some "big-picture" documentation for read-ahead and polish the code to make it fit this documentation. The meaning of ->async_size is clarified to match its name. i.e. Any request to ->readahead() has a sync part and an async part. The caller will wait for the sync pages to complete, but will not wait for the async pages. The first async page is still marked PG_readahead Note that the current function names page_cache_sync_ra() and page_cache_async_ra() are misleading. All ra request are partly sync and partly async, so either part can be empty. A page_cache_sync_ra() request will usually set ->async_size non-zero, implying it is not all synchronous. When a non-zero req_count is passed to page_cache_async_ra(), the implication is that some prefix of the request is synchronous, though the calculation made there is incorrect - I haven't tried to fix it. Link: https://lkml.kernel.org/r/164549983734.9187.11586890887006601405.stgit@noble.brown Signed-off-by: NeilBrown Cc: Anna Schumaker Cc: Chao Yu Cc: Darrick J. Wong Cc: Ilya Dryomov Cc: Jaegeuk Kim Cc: Jan Kara Cc: Jeff Layton Cc: Jens Axboe Cc: Lars Ellenberg Cc: Miklos Szeredi Cc: Paolo Valente Cc: Philipp Reisner Cc: Ryusuke Konishi Cc: Trond Myklebust Cc: Wu Fengguang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds