kernel/linux.git/include/linux/pagemap.h, branch v6.18.21

writeback: don't block sync for filesystems with no data integrity guarantees

2026-04-02T11:23:20+00:00

commit 76f9377cd2ab7a9220c25d33940d9ca20d368172 upstream. Add a SB_I_NO_DATA_INTEGRITY superblock flag for filesystems that cannot guarantee data persistence on sync (eg fuse). For superblocks with this flag set, sync kicks off writeback of dirty inodes but does not wait for the flusher threads to complete the writeback. This replaces the per-inode AS_NO_DATA_INTEGRITY mapping flag added in commit f9a49aa302a0 ("fs/writeback: skip AS_NO_DATA_INTEGRITY mappings in wait_sb_inodes()"). The flag belongs at the superblock level because data integrity is a filesystem-wide property, not a per-inode one. Having this flag at the superblock level also allows us to skip having to iterate every dirty inode in wait_sb_inodes() only to skip each inode individually. Prior to this commit, mappings with no data integrity guarantees skipped waiting on writeback completion but still waited on the flusher threads to finish initiating the writeback. Waiting on the flusher threads is unnecessary. This commit kicks off writeback but does not wait on the flusher threads. This change properly addresses a recent report [1] for a suspend-to-RAM hang seen on fuse-overlayfs that was caused by waiting on the flusher threads to finish: Workqueue: pm_fs_sync pm_fs_sync_work_fn Call Trace: __schedule+0x457/0x1720 schedule+0x27/0xd0 wb_wait_for_completion+0x97/0xe0 sync_inodes_sb+0xf8/0x2e0 __iterate_supers+0xdc/0x160 ksys_sync+0x43/0xb0 pm_fs_sync_work_fn+0x17/0xa0 process_one_work+0x193/0x350 worker_thread+0x1a1/0x310 kthread+0xfc/0x240 ret_from_fork+0x243/0x280 ret_from_fork_asm+0x1a/0x30 On fuse this is problematic because there are paths that may cause the flusher thread to block (eg if systemd freezes the user session cgroups first, which freezes the fuse daemon, before invoking the kernel suspend. The kernel suspend triggers ->write_node() which on fuse issues a synchronous setattr request, which cannot be processed since the daemon is frozen. Or if the daemon is buggy and cannot properly complete writeback, initiating writeback on a dirty folio already under writeback leads to writeback_get_folio() -> folio_prepare_writeback() -> unconditional wait on writeback to finish, which will cause a hang). This commit restores fuse to its prior behavior before tmp folios were removed, where sync was essentially a no-op. [1] https://lore.kernel.org/linux-fsdevel/CAJnrk1a-asuvfrbKXbEwwDSctvemF+6zfhdnuzO65Pt8HsFSRw@mail.gmail.com/T/#m632c4648e9cafc4239299887109ebd880ac6c5c1 Fixes: 0c58a97f919c ("fuse: remove tmp folio for writebacks and internal rb tree") Reported-by: John Cc: stable@vger.kernel.org Signed-off-by: Joanne Koong Link: https://patch.msgid.link/20260320005145.2483161-2-joannelkoong@gmail.com Reviewed-by: Jan Kara Reviewed-by: David Hildenbrand (Arm) Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman

fs/writeback: skip AS_NO_DATA_INTEGRITY mappings in wait_sb_inodes()

2026-01-30T09:32:15+00:00

commit f9a49aa302a05e91ca01f69031cb79a0ea33031f upstream. Above the while() loop in wait_sb_inodes(), we document that we must wait for all pages under writeback for data integrity. Consequently, if a mapping, like fuse, traditionally does not have data integrity semantics, there is no need to wait at all; we can simply skip these inodes. This restores fuse back to prior behavior where syncs are no-ops. This fixes a user regression where if a system is running a faulty fuse server that does not reply to issued write requests, this causes wait_sb_inodes() to wait forever. Link: https://lkml.kernel.org/r/20260105211737.4105620-2-joannelkoong@gmail.com Fixes: 0c58a97f919c ("fuse: remove tmp folio for writebacks and internal rb tree") Signed-off-by: Joanne Koong Reported-by: Athul Krishna Reported-by: J. Neuschäfer Reviewed-by: Bernd Schubert Tested-by: J. Neuschäfer Cc: Alexander Viro Cc: Bernd Schubert Cc: Bonaccorso Salvatore Cc: Christian Brauner Cc: David Hildenbrand Cc: Jan Kara Cc: "Liam R. Howlett" Cc: Lorenzo Stoakes Cc: "Matthew Wilcox (Oracle)" Cc: Michal Hocko Cc: Mike Rapoport Cc: Miklos Szeredi Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

Merge tag 'nfs-for-6.18-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

2025-10-03T21:20:40+00:00

Pull NFS client updates from Anna Schumaker: "New Features: - Add a Kconfig option to redirect dfprintk() to the trace buffer - Enable use of the RWF_DONTCACHE flag on the NFS client - Add striped layout handling to pNFS flexfiles - Add proper localio handling for READ and WRITE O_DIRECT Bugfixes: - Handle NFS4ERR_GRACE errors during delegation recall - Fix NFSv4.1 backchannel max_resp_sz verification check - Fix mount hang after CREATE_SESSION failure - Fix d_parent->d_inode locking in nfs4_setup_readdir() Other Cleanups and Improvements: - Improvements to write handling tracepoints - Fix a few trivial spelling mistakes - Cleanups to the rpcbind cleanup call sites - Convert the SUNRPC xdr_buf to use a scratch folio instead of scratch page - Remove unused NFS_WBACK_BUSY() macro - Remove __GFP_NOWARN flags - Unexport rpc_malloc() and rpc_free()" * tag 'nfs-for-6.18-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (46 commits) NFS: add basic STATX_DIOALIGN and STATX_DIO_READ_ALIGN support nfs/localio: add tracepoints for misaligned DIO READ and WRITE support nfs/localio: add proper O_DIRECT support for READ and WRITE nfs/localio: refactor iocb initialization nfs/localio: refactor iocb and iov_iter_bvec initialization nfs/localio: avoid issuing misaligned IO using O_DIRECT nfs/localio: make trace_nfs_local_open_fh more useful NFSD: filecache: add STATX_DIOALIGN and STATX_DIO_READ_ALIGN support sunrpc: unexport rpc_malloc() and rpc_free() NFSv4/flexfiles: Add support for striped layouts NFSv4/flexfiles: Update layout stats & error paths for striped layouts NFSv4/flexfiles: Write path updates for striped layouts NFSv4/flexfiles: Commit path updates for striped layouts NFSv4/flexfiles: Read path updates for striped layouts NFSv4/flexfiles: Update low level helper functions to be DS stripe aware. NFSv4/flexfiles: Add data structure support for striped layouts NFSv4/flexfiles: Use ds_commit_idx when marking a write commit NFSv4/flexfiles: Remove cred local variable dependency nfs4_setup_readdir(): insufficient locking for ->d_parent->d_inode dereferencing NFS: Enable use of the RWF_DONTCACHE flag on the NFS client ...

filemap: Add a version of folio_end_writeback that ignores dropbehind

2025-09-23T17:29:50+00:00

Filesystems such as NFS may need to defer dropbehind until after their 2-stage writes are done. This adds a helper folio_end_writeback_no_dropbehind() that allows them to release the writeback flag without immediately dropping the folio. Signed-off-by: Trond Myklebust Signed-off-by: Anna Schumaker

filemap: Add a helper for filesystems implementing dropbehind

2025-09-23T17:29:50+00:00

Add a helper to allow filesystems to attempt to free the 'dropbehind' folio. Signed-off-by: Trond Myklebust Link: https://lore.kernel.org/all/5588a06f6d5a2cf6746828e2d36e7ada668b1739.1745381692.git.trond.myklebust@hammerspace.com/ Reviewed-by: Mike Snitzer Signed-off-by: Anna Schumaker

mm/filemap: align last_index to folio size

2025-09-21T21:22:15+00:00

On XFS systems with pagesize=4K, blocksize=16K, and CONFIG_TRANSPARENT_HUGEPAGE enabled, We observed the following readahead behaviors: # echo 3 > /proc/sys/vm/drop_caches # dd if=test of=/dev/null bs=64k count=1 # ./tools/mm/page-types -r -L -f /mnt/xfs/test foffset offset flags 0 136d4c __RU_l_________H______t_________________F_1 1 136d4d __RU_l__________T_____t_________________F_1 2 136d4e __RU_l__________T_____t_________________F_1 3 136d4f __RU_l__________T_____t_________________F_1 ... c 136bb8 __RU_l_________H______t_________________F_1 d 136bb9 __RU_l__________T_____t_________________F_1 e 136bba __RU_l__________T_____t_________________F_1 f 136bbb __RU_l__________T_____t_________________F_1 <-- first read 10 13c2cc ___U_l_________H______t______________I__F_1 <-- readahead flag 11 13c2cd ___U_l__________T_____t______________I__F_1 12 13c2ce ___U_l__________T_____t______________I__F_1 13 13c2cf ___U_l__________T_____t______________I__F_1 ... 1c 1405d4 ___U_l_________H______t_________________F_1 1d 1405d5 ___U_l__________T_____t_________________F_1 1e 1405d6 ___U_l__________T_____t_________________F_1 1f 1405d7 ___U_l__________T_____t_________________F_1 [ra_size = 32, req_count = 16, async_size = 16] # echo 3 > /proc/sys/vm/drop_caches # dd if=test of=/dev/null bs=60k count=1 # ./page-types -r -L -f /mnt/xfs/test foffset offset flags 0 136048 __RU_l_________H______t_________________F_1 ... c 110a40 __RU_l_________H______t_________________F_1 d 110a41 __RU_l__________T_____t_________________F_1 e 110a42 __RU_l__________T_____t_________________F_1 <-- first read f 110a43 __RU_l__________T_____t_________________F_1 <-- first readahead flag 10 13e7a8 ___U_l_________H______t_________________F_1 ... 20 137a00 ___U_l_________H______t_______P______I__F_1 <-- second readahead flag (20 - 2f) 21 137a01 ___U_l__________T_____t_______P______I__F_1 ... 3f 10d4af ___U_l__________T_____t_______P_________F_1 [first readahead: ra_size = 32, req_count = 15, async_size = 17] When reading 64k data (same for 61-63k range, where last_index is page-aligned in filemap_get_pages()), 128k readahead is triggered via page_cache_sync_ra() and the PG_readahead flag is set on the next folio (the one containing 0x10 page). When reading 60k data, 128k readahead is also triggered via page_cache_sync_ra(). However, in this case the readahead flag is set on the 0xf page. Although the requested read size (req_count) is 60k, the actual read will be aligned to folio size (64k), which triggers the readahead flag and initiates asynchronous readahead via page_cache_async_ra(). This results in two readahead operations totaling 256k. The root cause is that when the requested size is smaller than the actual read size (due to folio alignment), it triggers asynchronous readahead. By changing last_index alignment from page size to folio size, we ensure the requested size matches the actual read size, preventing the case where a single read operation triggers two readahead operations. After applying the patch: # echo 3 > /proc/sys/vm/drop_caches # dd if=test of=/dev/null bs=60k count=1 # ./page-types -r -L -f /mnt/xfs/test foffset offset flags 0 136d4c __RU_l_________H______t_________________F_1 1 136d4d __RU_l__________T_____t_________________F_1 2 136d4e __RU_l__________T_____t_________________F_1 3 136d4f __RU_l__________T_____t_________________F_1 ... c 136bb8 __RU_l_________H______t_________________F_1 d 136bb9 __RU_l__________T_____t_________________F_1 e 136bba __RU_l__________T_____t_________________F_1 <-- first read f 136bbb __RU_l__________T_____t_________________F_1 10 13c2cc ___U_l_________H______t______________I__F_1 <-- readahead flag 11 13c2cd ___U_l__________T_____t______________I__F_1 12 13c2ce ___U_l__________T_____t______________I__F_1 13 13c2cf ___U_l__________T_____t______________I__F_1 ... 1c 1405d4 ___U_l_________H______t_________________F_1 1d 1405d5 ___U_l__________T_____t_________________F_1 1e 1405d6 ___U_l__________T_____t_________________F_1 1f 1405d7 ___U_l__________T_____t_________________F_1 [ra_size = 32, req_count = 16, async_size = 16] The same phenomenon will occur when reading from 49k to 64k. Set the readahead flag to the next folio. Because the minimum order of folio in address_space equals the block size (at least in xfs and bcachefs that already support bs > ps), having request_count aligned to block size will not cause overread. [klarasmodin@gmail.com: fix overflow on 32-bit] Link: https://lkml.kernel.org/r/yru7qf5gvyzccq5ohhpylvxug5lr5tf54omspbjh4sm6pcdb2r@fpjgj2pxw7va [akpm@linux-foundation.org: update it for Max's constification efforts] Link: https://lkml.kernel.org/r/20250711055509.91587-1-youling.tang@linux.dev Co-developed-by: Chi Zhiling Signed-off-by: Chi Zhiling Signed-off-by: Youling Tang Signed-off-by: Klara Modin Reviewed-by: Ryan Roberts Reviewed-by: Jan Kara Cc: Matthew Wilcox (Oracle) Cc: Youling Tang Cc: David Hildenbrand Cc: Klara Modin Signed-off-by: Andrew Morton

mm, s390: constify mapping related test/getter functions

2025-09-21T21:22:13+00:00

For improved const-correctness. We select certain test functions which either invoke each other, functions that are already const-ified, or no further functions. It is therefore relatively trivial to const-ify them, which provides a basis for further const-ification further up the call stack. (Even though seemingly unrelated, this also constifies the pointer parameter of mmap_is_legacy() in arch/s390/mm/mmap.c because a copy of the function exists in mm/util.c.) Link: https://lkml.kernel.org/r/20250901205021.3573313-7-max.kellermann@ionos.com Signed-off-by: Max Kellermann Reviewed-by: Vishal Moola (Oracle) Reviewed-by: Lorenzo Stoakes Acked-by: David Hildenbrand Acked-by: Vlastimil Babka Acked-by: Mike Rapoport (Microsoft) Acked-by: Shakeel Butt Cc: Alexander Gordeev Cc: Al Viro Cc: Andreas Larsson Cc: Andy Lutomirski Cc: Axel Rasmussen Cc: Baolin Wang Cc: Borislav Betkov Cc: Christian Borntraeger Cc: Christian Brauner Cc: Christian Zankel Cc: David Rientjes Cc: David S. Miller Cc: Gerald Schaefer Cc: Heiko Carstens Cc: Helge Deller Cc: "H. Peter Anvin" Cc: Hugh Dickins Cc: Ingo Molnar Cc: James Bottomley Cc: Jan Kara Cc: Jocelyn Falempe Cc: Liam Howlett Cc: Mark Brown Cc: Matthew Wilcox (Oracle) Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Hocko Cc: "Nysal Jan K.A" Cc: Oscar Salvador Cc: Peter Zijlstra Cc: Russel King Cc: Suren Baghdasaryan Cc: Sven Schnelle Cc: Thomas Gleinxer Cc: Thomas Huth Cc: Vasily Gorbik Cc: Wei Xu Cc: Yuanchu Xie Signed-off-by: Andrew Morton

mm: constify pagemap related test/getter functions

2025-09-21T21:22:12+00:00

For improved const-correctness. We select certain test functions which either invoke each other, functions that are already const-ified, or no further functions. It is therefore relatively trivial to const-ify them, which provides a basis for further const-ification further up the call stack. Link: https://lkml.kernel.org/r/20250901205021.3573313-3-max.kellermann@ionos.com Signed-off-by: Max Kellermann Reviewed-by: Vishal Moola (Oracle) Reviewed-by: Lorenzo Stoakes Acked-by: David Hildenbrand Acked-by: Vlastimil Babka Acked-by: Mike Rapoport (Microsoft) Acked-by: Shakeel Butt Cc: Alexander Gordeev Cc: Al Viro Cc: Andreas Larsson Cc: Andy Lutomirski Cc: Axel Rasmussen Cc: Baolin Wang Cc: Borislav Betkov Cc: Christian Borntraeger Cc: Christian Brauner Cc: Christian Zankel Cc: David Rientjes Cc: David S. Miller Cc: Gerald Schaefer Cc: Heiko Carstens Cc: Helge Deller Cc: "H. Peter Anvin" Cc: Hugh Dickins Cc: Ingo Molnar Cc: James Bottomley Cc: Jan Kara Cc: Jocelyn Falempe Cc: Liam Howlett Cc: Mark Brown Cc: Matthew Wilcox (Oracle) Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Hocko Cc: "Nysal Jan K.A" Cc: Oscar Salvador Cc: Peter Zijlstra Cc: Russel King Cc: Suren Baghdasaryan Cc: Sven Schnelle Cc: Thomas Gleinxer Cc: Thomas Huth Cc: Vasily Gorbik Cc: Wei Xu Cc: Yuanchu Xie Signed-off-by: Andrew Morton

mm/filemap: add AS_KERNEL_FILE

2025-09-13T23:55:20+00:00

Patch series "introduce kernel file mapped folios", v4. Btrfs currently tracks its metadata pages in the page cache, using a fake inode (fs_info->btree_inode) with offsets corresponding to where the metadata is stored in the filesystem's full logical address space. A consequence of this is that when btrfs uses filemap_add_folio(), this usage is charged to the cgroup of whichever task happens to be running at the time. These folios don't belong to any particular user cgroup, so I don't think it makes much sense for them to be charged in that way. Some negative consequences as a result: - A task can be holding some important btrfs locks, then need to lookup some metadata and go into reclaim, extending the duration it holds that lock for, and unfairly pushing its own reclaim pain onto other cgroups. - If that cgroup goes into reclaim, it might reclaim these folios a different non-reclaiming cgroup might need soon. This is naturally offset by LRU reclaim, but still. We have two options for how to manage such file pages: 1. charge them to the root cgroup. 2. don't charge them to any cgroup at all. 2. breaks the invariant that every mapped page has a cgroup. This is workable, but unnecessarily risky. Therefore, go with 1. A very similar proposal to use the root cgroup was previously made by Qu, where he eventually proposed the idea of setting it per address_space. This makes good sense for the btrfs use case, as the behavior should apply to all use of the address_space, not select allocations. I.e., if someone adds another filemap_add_folio() call using btrfs's btree_inode, we would almost certainly want to account that to the root cgroup as well. This patch (of 3): Add the flag AS_KERNEL_FILE to the address_space to indicate that this mapping's memory is exempt from the usual memcg accounting. [boris@bur.io: fix CONFIG_MEMCG build for AS_KERNEL_FILE] Link: https://lkml.kernel.org/r/6de59ddeec81b5c294d337c001ba0061631d4ec6.1755816635.git.boris@bur.io Link: https://lore.kernel.org/linux-mm/b5fef5372ae454a7b6da4f2f75c427aeab6a07d6.1727498749.git.wqu@suse.com/ Link: https://lkml.kernel.org/r/f09c4e2c90351d4cb30a1969f7a863b9238bd291.1755812945.git.boris@bur.io Signed-off-by: Boris Burkov Suggested-by: Qu Wenruo Suggested-by: Shakeel Butt Acked-by: Shakeel Butt Cc: Johannes Weiner Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Muchun Song Cc: Roman Gushchin Signed-off-by: Andrew Morton

Merge tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-07-31T21:57:54+00:00

Pull MM updates from Andrew Morton: "As usual, many cleanups. The below blurbiage describes 42 patchsets. 21 of those are partially or fully cleanup work. "cleans up", "cleanup", "maintainability", "rationalizes", etc. I never knew the MM code was so dirty. "mm: ksm: prevent KSM from breaking merging of new VMAs" (Lorenzo Stoakes) addresses an issue with KSM's PR_SET_MEMORY_MERGE mode: newly mapped VMAs were not eligible for merging with existing adjacent VMAs. "mm/damon: introduce DAMON_STAT for simple and practical access monitoring" (SeongJae Park) adds a new kernel module which simplifies the setup and usage of DAMON in production environments. "stop passing a writeback_control to swap/shmem writeout" (Christoph Hellwig) is a cleanup to the writeback code which removes a couple of pointers from struct writeback_control. "drivers/base/node.c: optimization and cleanups" (Donet Tom) contains largely uncorrelated cleanups to the NUMA node setup and management code. "mm: userfaultfd: assorted fixes and cleanups" (Tal Zussman) does some maintenance work on the userfaultfd code. "Readahead tweaks for larger folios" (Ryan Roberts) implements some tuneups for pagecache readahead when it is reading into order>0 folios. "selftests/mm: Tweaks to the cow test" (Mark Brown) provides some cleanups and consistency improvements to the selftests code. "Optimize mremap() for large folios" (Dev Jain) does that. A 37% reduction in execution time was measured in a memset+mremap+munmap microbenchmark. "Remove zero_user()" (Matthew Wilcox) expunges zero_user() in favor of the more modern memzero_page(). "mm/huge_memory: vmf_insert_folio_*() and vmf_insert_pfn_pud() fixes" (David Hildenbrand) addresses some warts which David noticed in the huge page code. These were not known to be causing any issues at this time. "mm/damon: use alloc_migrate_target() for DAMOS_MIGRATE_{HOT,COLD" (SeongJae Park) provides some cleanup and consolidation work in DAMON. "use vm_flags_t consistently" (Lorenzo Stoakes) uses vm_flags_t in places where we were inappropriately using other types. "mm/memfd: Reserve hugetlb folios before allocation" (Vivek Kasireddy) increases the reliability of large page allocation in the memfd code. "mm: Remove pXX_devmap page table bit and pfn_t type" (Alistair Popple) removes several now-unneeded PFN_* flags. "mm/damon: decouple sysfs from core" (SeongJae Park) implememnts some cleanup and maintainability work in the DAMON sysfs layer. "madvise cleanup" (Lorenzo Stoakes) does quite a lot of cleanup/maintenance work in the madvise() code. "madvise anon_name cleanups" (Vlastimil Babka) provides additional cleanups on top or Lorenzo's effort. "Implement numa node notifier" (Oscar Salvador) creates a standalone notifier for NUMA node memory state changes. Previously these were lumped under the more general memory on/offline notifier. "Make MIGRATE_ISOLATE a standalone bit" (Zi Yan) cleans up the pageblock isolation code and fixes a potential issue which doesn't seem to cause any problems in practice. "selftests/damon: add python and drgn based DAMON sysfs functionality tests" (SeongJae Park) adds additional drgn- and python-based DAMON selftests which are more comprehensive than the existing selftest suite. "Misc rework on hugetlb faulting path" (Oscar Salvador) fixes a rather obscure deadlock in the hugetlb fault code and follows that fix with a series of cleanups. "cma: factor out allocation logic from __cma_declare_contiguous_nid" (Mike Rapoport) rationalizes and cleans up the highmem-specific code in the CMA allocator. "mm/migration: rework movable_ops page migration (part 1)" (David Hildenbrand) provides cleanups and future-preparedness to the migration code. "mm/damon: add trace events for auto-tuned monitoring intervals and DAMOS quota" (SeongJae Park) adds some tracepoints to some DAMON auto-tuning code. "mm/damon: fix misc bugs in DAMON modules" (SeongJae Park) does that. "mm/damon: misc cleanups" (SeongJae Park) also does what it claims. "mm: folio_pte_batch() improvements" (David Hildenbrand) cleans up the large folio PTE batching code. "mm/damon/vaddr: Allow interleaving in migrate_{hot,cold} actions" (SeongJae Park) facilitates dynamic alteration of DAMON's inter-node allocation policy. "Remove unmap_and_put_page()" (Vishal Moola) provides a couple of page->folio conversions. "mm: per-node proactive reclaim" (Davidlohr Bueso) implements a per-node control of proactive reclaim - beyond the current memcg-based implementation. "mm/damon: remove damon_callback" (SeongJae Park) replaces the damon_callback interface with a more general and powerful damon_call()+damos_walk() interface. "mm/mremap: permit mremap() move of multiple VMAs" (Lorenzo Stoakes) implements a number of mremap cleanups (of course) in preparation for adding new mremap() functionality: newly permit the remapping of multiple VMAs when the user is specifying MREMAP_FIXED. It still excludes some specialized situations where this cannot be performed reliably. "drop hugetlb_free_pgd_range()" (Anthony Yznaga) switches some sparc hugetlb code over to the generic version and removes the thus-unneeded hugetlb_free_pgd_range(). "mm/damon/sysfs: support periodic and automated stats update" (SeongJae Park) augments the present userspace-requested update of DAMON sysfs monitoring files. Automatic update is now provided, along with a tunable to control the update interval. "Some randome fixes and cleanups to swapfile" (Kemeng Shi) does what is claims. "mm: introduce snapshot_page" (Luiz Capitulino and David Hildenbrand) provides (and uses) a means by which debug-style functions can grab a copy of a pageframe and inspect it locklessly without tripping over the races inherent in operating on the live pageframe directly. "use per-vma locks for /proc/pid/maps reads" (Suren Baghdasaryan) addresses the large contention issues which can be triggered by reads from that procfs file. Latencies are reduced by more than half in some situations. The series also introduces several new selftests for the /proc/pid/maps interface. "__folio_split() clean up" (Zi Yan) cleans up __folio_split()! "Optimize mprotect() for large folios" (Dev Jain) provides some quite large (>3x) speedups to mprotect() when dealing with large folios. "selftests/mm: reuse FORCE_READ to replace "asm volatile("" : "+r" (XXX));" and some cleanup" (wang lian) does some cleanup work in the selftests code. "tools/testing: expand mremap testing" (Lorenzo Stoakes) extends the mremap() selftest in several ways, including adding more checking of Lorenzo's recently added "permit mremap() move of multiple VMAs" feature. "selftests/damon/sysfs.py: test all parameters" (SeongJae Park) extends the DAMON sysfs interface selftest so that it tests all possible user-requested parameters. Rather than the present minimal subset" * tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (370 commits) MAINTAINERS: add missing headers to mempory policy & migration section MAINTAINERS: add missing file to cgroup section MAINTAINERS: add MM MISC section, add missing files to MISC and CORE MAINTAINERS: add missing zsmalloc file MAINTAINERS: add missing files to page alloc section MAINTAINERS: add missing shrinker files MAINTAINERS: move memremap.[ch] to hotplug section MAINTAINERS: add missing mm_slot.h file THP section MAINTAINERS: add missing interval_tree.c to memory mapping section MAINTAINERS: add missing percpu-internal.h file to per-cpu section mm/page_alloc: remove trace_mm_alloc_contig_migrate_range_info() selftests/damon: introduce _common.sh to host shared function selftests/damon/sysfs.py: test runtime reduction of DAMON parameters selftests/damon/sysfs.py: test non-default parameters runtime commit selftests/damon/sysfs.py: generalize DAMON context commit assertion selftests/damon/sysfs.py: generalize monitoring attributes commit assertion selftests/damon/sysfs.py: generalize DAMOS schemes commit assertion selftests/damon/sysfs.py: test DAMOS filters commitment selftests/damon/sysfs.py: generalize DAMOS scheme commit assertion selftests/damon/sysfs.py: test DAMOS destinations commitment ...