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2025-04-01Merge tag 'mm-stable-2025-03-30-16-52' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - The series "Enable strict percpu address space checks" from Uros Bizjak uses x86 named address space qualifiers to provide compile-time checking of percpu area accesses. This has caused a small amount of fallout - two or three issues were reported. In all cases the calling code was found to be incorrect. - The series "Some cleanup for memcg" from Chen Ridong implements some relatively monir cleanups for the memcontrol code. - The series "mm: fixes for device-exclusive entries (hmm)" from David Hildenbrand fixes a boatload of issues which David found then using device-exclusive PTE entries when THP is enabled. More work is needed, but this makes thins better - our own HMM selftests now succeed. - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed remove the z3fold and zbud implementations. They have been deprecated for half a year and nobody has complained. - The series "mm: further simplify VMA merge operation" from Lorenzo Stoakes implements numerous simplifications in this area. No runtime effects are anticipated. - The series "mm/madvise: remove redundant mmap_lock operations from process_madvise()" from SeongJae Park rationalizes the locking in the madvise() implementation. Performance gains of 20-25% were observed in one MADV_DONTNEED microbenchmark. - The series "Tiny cleanup and improvements about SWAP code" from Baoquan He contains a number of touchups to issues which Baoquan noticed when working on the swap code. - The series "mm: kmemleak: Usability improvements" from Catalin Marinas implements a couple of improvements to the kmemleak user-visible output. - The series "mm/damon/paddr: fix large folios access and schemes handling" from Usama Arif provides a couple of fixes for DAMON's handling of large folios. - The series "mm/damon/core: fix wrong and/or useless damos_walk() behaviors" from SeongJae Park fixes a few issues with the accuracy of kdamond's walking of DAMON regions. - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo Stoakes changes the interaction between framebuffer deferred-io and core MM. No functional changes are anticipated - this is preparatory work for the future removal of page structure fields. - The series "mm/damon: add support for hugepage_size DAMOS filter" from Usama Arif adds a DAMOS filter which permits the filtering by huge page sizes. - The series "mm: permit guard regions for file-backed/shmem mappings" from Lorenzo Stoakes extends the guard region feature from its present "anon mappings only" state. The feature now covers shmem and file-backed mappings. - The series "mm: batched unmap lazyfree large folios during reclamation" from Barry Song cleans up and speeds up the unmapping for pte-mapped large folios. - The series "reimplement per-vma lock as a refcount" from Suren Baghdasaryan puts the vm_lock back into the vma. Our reasons for pulling it out were largely bogus and that change made the code more messy. This patchset provides small (0-10%) improvements on one microbenchmark. - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and improves" from SeongJae Park does some maintenance work on the DAMON docs. - The series "hugetlb/CMA improvements for large systems" from Frank van der Linden addresses a pile of issues which have been observed when using CMA on large machines. - The series "mm/damon: introduce DAMOS filter type for unmapped pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the page's mapped/unmapped status. - The series "zsmalloc/zram: there be preemption" from Sergey Senozhatsky teaches zram to run its compression and decompression operations preemptibly. - The series "selftests/mm: Some cleanups from trying to run them" from Brendan Jackman fixes a pile of unrelated issues which Brendan encountered while runnimg our selftests. - The series "fs/proc/task_mmu: add guard region bit to pagemap" from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to determine whether a particular page is a guard page. - The series "mm, swap: remove swap slot cache" from Kairui Song removes the swap slot cache from the allocation path - it simply wasn't being effective. - The series "mm: cleanups for device-exclusive entries (hmm)" from David Hildenbrand implements a number of unrelated cleanups in this code. - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual implements a number of preparatoty cleanups to the GENERIC_PTDUMP Kconfig logic. - The series "mm/damon: auto-tune aggregation interval" from SeongJae Park implements a feedback-driven automatic tuning feature for DAMON's aggregation interval tuning. - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in powerpc, sparc and x86 lazy MMU implementations. Ryan did this in preparation for implementing lazy mmu mode for arm64 to optimize vmalloc. - The series "mm/page_alloc: Some clarifications for migratetype fallback" from Brendan Jackman reworks some commentary to make the code easier to follow. - The series "page_counter cleanup and size reduction" from Shakeel Butt cleans up the page_counter code and fixes a size increase which we accidentally added late last year. - The series "Add a command line option that enables control of how many threads should be used to allocate huge pages" from Thomas Prescher does that. It allows the careful operator to significantly reduce boot time by tuning the parallalization of huge page initialization. - The series "Fix calculations in trace_balance_dirty_pages() for cgwb" from Tang Yizhou fixes the tracing output from the dirty page balancing code. - The series "mm/damon: make allow filters after reject filters useful and intuitive" from SeongJae Park improves the handling of allow and reject filters. Behaviour is made more consistent and the documention is updated accordingly. - The series "Switch zswap to object read/write APIs" from Yosry Ahmed updates zswap to the new object read/write APIs and thus permits the removal of some legacy code from zpool and zsmalloc. - The series "Some trivial cleanups for shmem" from Baolin Wang does as it claims. - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from Alistair Popple regularizes the weird ZONE_DEVICE page refcount handling in DAX, permittig the removal of a number of special-case checks. - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a preparatoty refactoring and cleanup of the mremap() code. - The series "mm: MM owner tracking for large folios (!hugetlb) + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in which we determine whether a large folio is known to be mapped exclusively into a single MM. - The series "mm/damon: add sysfs dirs for managing DAMOS filters based on handling layers" from SeongJae Park adds a couple of new sysfs directories to ease the management of DAMON/DAMOS filters. - The series "arch, mm: reduce code duplication in mem_init()" from Mike Rapoport consolidates many per-arch implementations of mem_init() into code generic code, where that is practical. - The series "mm/damon/sysfs: commit parameters online via damon_call()" from SeongJae Park continues the cleaning up of sysfs access to DAMON internal data. - The series "mm: page_ext: Introduce new iteration API" from Luiz Capitulino reworks the page_ext initialization to fix a boot-time crash which was observed with an unusual combination of compile and cmdline options. - The series "Buddy allocator like (or non-uniform) folio split" from Zi Yan reworks the code to split a folio into smaller folios. The main benefit is lessened memory consumption: fewer post-split folios are generated. - The series "Minimize xa_node allocation during xarry split" from Zi Yan reduces the number of xarray xa_nodes which are generated during an xarray split. - The series "drivers/base/memory: Two cleanups" from Gavin Shan performs some maintenance work on the drivers/base/memory code. - The series "Add tracepoints for lowmem reserves, watermarks and totalreserve_pages" from Martin Liu adds some more tracepoints to the page allocator code. - The series "mm/madvise: cleanup requests validations and classifications" from SeongJae Park cleans up some warts which SeongJae observed during his earlier madvise work. - The series "mm/hwpoison: Fix regressions in memory failure handling" from Shuai Xue addresses two quite serious regressions which Shuai has observed in the memory-failure implementation. - The series "mm: reliable huge page allocator" from Johannes Weiner makes huge page allocations cheaper and more reliable by reducing fragmentation. - The series "Minor memcg cleanups & prep for memdescs" from Matthew Wilcox is preparatory work for the future implementation of memdescs. - The series "track memory used by balloon drivers" from Nico Pache introduces a way to track memory used by our various balloon drivers. - The series "mm/damon: introduce DAMOS filter type for active pages" from Nhat Pham permits users to filter for active/inactive pages, separately for file and anon pages. - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia separates the proactive reclaim statistics from the direct reclaim statistics. - The series "mm/vmscan: don't try to reclaim hwpoison folio" from Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim code. * tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits) mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex() x86/mm: restore early initialization of high_memory for 32-bits mm/vmscan: don't try to reclaim hwpoison folio mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper cgroup: docs: add pswpin and pswpout items in cgroup v2 doc mm: vmscan: split proactive reclaim statistics from direct reclaim statistics selftests/mm: speed up split_huge_page_test selftests/mm: uffd-unit-tests support for hugepages > 2M docs/mm/damon/design: document active DAMOS filter type mm/damon: implement a new DAMOS filter type for active pages fs/dax: don't disassociate zero page entries MM documentation: add "Unaccepted" meminfo entry selftests/mm: add commentary about 9pfs bugs fork: use __vmalloc_node() for stack allocation docs/mm: Physical Memory: Populate the "Zones" section xen: balloon: update the NR_BALLOON_PAGES state hv_balloon: update the NR_BALLOON_PAGES state balloon_compaction: update the NR_BALLOON_PAGES state meminfo: add a per node counter for balloon drivers mm: remove references to folio in __memcg_kmem_uncharge_page() ...
2025-03-21docs/mm/damon/design: document active DAMOS filter typeNhat Pham
Document availability and meaning of "active" DAMOS filter type on design document. Since introduction of the type requires no additional user ABI, usage and ABI document need no update. Link: https://lkml.kernel.org/r/20250318183029.2062917-3-nphamcs@gmail.com Signed-off-by: Nhat Pham <nphamcs@gmail.com> Suggested-by: SeongJae Park <sj@kernel.org> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-21docs/mm: Physical Memory: Populate the "Zones" sectionJiwen Qi
Briefly describe what zones are and the fields of struct zone. Link: https://lkml.kernel.org/r/20250315211317.27612-1-jiwen7.qi@gmail.com Signed-off-by: Jiwen Qi <jiwen7.qi@gmail.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17mm: stop maintaining the per-page mapcount of large folios ↵David Hildenbrand
(CONFIG_NO_PAGE_MAPCOUNT) Everything is in place to stop using the per-page mapcounts in large folios: the mapcount of tail pages will always be logically 0 (-1 value), just like it currently is for hugetlb folios already, and the page mapcount of the head page is either 0 (-1 value) or contains a page type (e.g., hugetlb). Maintaining _nr_pages_mapped without per-page mapcounts is impossible, so that one also has to go with CONFIG_NO_PAGE_MAPCOUNT. There are two remaining implications: (1) Per-node, per-cgroup and per-lruvec stats of "NR_ANON_MAPPED" ("mapped anonymous memory") and "NR_FILE_MAPPED" ("mapped file memory"): As soon as any page of the folio is mapped -- folio_mapped() -- we now account the complete folio as mapped. Once the last page is unmapped -- !folio_mapped() -- we account the complete folio as unmapped. This implies that ... * "AnonPages" and "Mapped" in /proc/meminfo and /sys/devices/system/node/*/meminfo * cgroup v2: "anon" and "file_mapped" in "memory.stat" and "memory.numa_stat" * cgroup v1: "rss" and "mapped_file" in "memory.stat" and "memory.numa_stat ... can now appear higher than before. But note that these folios do consume that memory, simply not all pages are actually currently mapped. It's worth nothing that other accounting in the kernel (esp. cgroup charging on allocation) is not affected by this change. [why oh why is "anon" called "rss" in cgroup v1] (2) Detecting partial mappings Detecting whether anon THPs are partially mapped gets a bit more unreliable. As long as a single MM maps such a large folio ("exclusively mapped"), we can reliably detect it. Especially before fork() / after a short-lived child process quit, we will detect partial mappings reliably, which is the common case. In essence, if the average per-page mapcount in an anon THP is < 1, we know for sure that we have a partial mapping. However, as soon as multiple MMs are involved, we might miss detecting partial mappings: this might be relevant with long-lived child processes. If we have a fully-mapped anon folio before fork(), once our child processes and our parent all unmap (zap/COW) the same pages (but not the complete folio), we might not detect the partial mapping. However, once the child processes quit we would detect the partial mapping. How relevant this case is in practice remains to be seen. Swapout/migration will likely mitigate this. In the future, RMAP walkers could check for that for that case (e.g., when collecting access bits during reclaim) and simply flag them for deferred-splitting. Link: https://lkml.kernel.org/r/20250303163014.1128035-21-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Andy Lutomirks^H^Hski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: Michal Koutn <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: tejun heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17mm/rmap: basic MM owner tracking for large folios (!hugetlb)David Hildenbrand
For small folios, we traditionally use the mapcount to decide whether it was "certainly mapped exclusively" by a single MM (mapcount == 1) or whether it "maybe mapped shared" by multiple MMs (mapcount > 1). For PMD-sized folios that were PMD-mapped, we were able to use a similar mechanism (single PMD mapping), but for PTE-mapped folios and in the future folios that span multiple PMDs, this does not work. So we need a different mechanism to handle large folios. Let's add a new mechanism to detect whether a large folio is "certainly mapped exclusively", or whether it is "maybe mapped shared". We'll use this information next to optimize CoW reuse for PTE-mapped anonymous THP, and to convert folio_likely_mapped_shared() to folio_maybe_mapped_shared(), independent of per-page mapcounts. For each large folio, we'll have two slots, whereby a slot stores: (1) an MM id: unique id assigned to each MM (2) a per-MM mapcount If a slot is unoccupied, it can be taken by the next MM that maps folio page. In addition, we'll remember the current state -- "mapped exclusively" vs. "maybe mapped shared" -- and use a bit spinlock to sync on updates and to reduce the total number of atomic accesses on updates. In the future, it might be possible to squeeze a proper spinlock into "struct folio". For now, keep it simple, as we require the whole thing with THP only, that is incompatible with RT. As we have to squeeze this information into the "struct folio" of even folios of order-1 (2 pages), and we generally want to reduce the required metadata, we'll assign each MM a unique ID that can fit into an int. In total, we can squeeze everything into 4x int (2x long) on 64bit. 32bit support is a bit challenging, because we only have 2x long == 2x int in order-1 folios. But we can make it work for now, because we neither expect many MMs nor very large folios on 32bit. We will reliably detect folios as "mapped exclusively" vs. "mapped shared" as long as only two MMs map pages of a folio at one point in time -- for example with fork() and short-lived child processes, or with apps that hand over state from one instance to another. As soon as three MMs are involved at the same time, we might detect "maybe mapped shared" although the folio is "mapped exclusively". Example 1: (1) App1 faults in a (shmem/file-backed) folio page -> Tracked as MM0 (2) App2 faults in a folio page -> Tracked as MM1 (4) App1 unmaps all folio pages -> We will detect "mapped exclusively". Example 2: (1) App1 faults in a (shmem/file-backed) folio page -> Tracked as MM0 (2) App2 faults in a folio page -> Tracked as MM1 (3) App3 faults in a folio page -> No slot available, tracked as "unknown" (4) App1 and App2 unmap all folio pages -> We will detect "maybe mapped shared". Make use of __always_inline to keep possible performance degradation when (un)mapping large folios to a minimum. Note: by squeezing the two flags into the "unsigned long" that stores the MM ids, we can use non-atomic __bit_spin_unlock() and non-atomic setting/clearing of the "maybe mapped shared" bit, effectively not adding any new atomics on the hot path when updating the large mapcount + new metadata, which further helps reduce the runtime overhead in micro-benchmarks. Link: https://lkml.kernel.org/r/20250303163014.1128035-13-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Andy Lutomirks^H^Hski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: Michal Koutn <mkoutny@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: tejun heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17mm: zsmalloc: remove object mapping APIs and per-CPU map areasYosry Ahmed
zs_map_object() and zs_unmap_object() are no longer used, remove them. Since these are the only users of per-CPU mapping_areas, remove them and the associated CPU hotplug callbacks too. [yosry.ahmed@linux.dev: update the docs] Link: https://lkml.kernel.org/r/Z8ier-ZZp8T6MOTH@google.com Link: https://lkml.kernel.org/r/20250305061134.4105762-5-yosry.ahmed@linux.dev Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev> Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Nhat Pham <nphamcs@gmail.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Minchan Kim <minchan@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17Docs/mm/damon/design: update for changed filter-default behaviorSeongJae Park
Update the design documentation for changed DAMOS filters default allowance behaviors. Link: https://lkml.kernel.org/r/20250304211913.53574-10-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17Docs/admin-guide/mm/damon/usage: add intervals_goal directory on the hierarchySeongJae Park
Document DAMON sysfs interface usage for DAMON sampling and aggregation intervals auto-tuning. Link: https://lkml.kernel.org/r/20250303221726.484227-9-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17Docs/mm/damon/design: document for intervals auto-tuningSeongJae Park
Document the design of DAMON sampling and aggregation intervals auto-tuning. [sj@kernel.org: fix a typo on 'intervals auto-tuning' section] Link: https://lkml.kernel.org/r/20250305182744.56125-1-sj@kernel.org Link: https://lkml.kernel.org/r/20250303221726.484227-7-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16Docs/mm/damon/design: document unmapped DAMOS filter typeSeongJae Park
Document availability and meaning of unmapped DAMOS filter type on design document. Since introduction of the type requires no additional user ABI, usage and ABI document need no update. Link: https://lkml.kernel.org/r/20250219220146.133650-3-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16Docs/mm/damon/design: categorize DAMOS filter types based on handling layerSeongJae Park
On what DAMON layer a DAMOS filter is handled is important to expect in what order filters will be evaluated. Re-organize the DAMOS filter types list on the design doc to categorize types based on the handling layer, to let users more easily understand the handling order. Link: https://lkml.kernel.org/r/20250218223708.53437-6-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16Docs/mm/damon/design: clarify handling layer based filters evaluation sequenceSeongJae Park
If an element of memory matches a DAMOS filter, filters that installed after that get no chance to make any effect to the element. Hence in what order DAMOS filters are handled is important, if both allow filters and reject filters are used together. The ordering is affected by both the installation order and which layter the filters are handled. The design document is not clearly documenting the latter part. Clarify it on the design doc. Link: https://lkml.kernel.org/r/20250218223708.53437-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16Docs/damon: move DAMOS filter type names and meaning to design docSeongJae Park
DAMON sysfs usage doc is describing DAMOS filter type names and their meanings in short. The design doc is providing the short meaning and detailed descriptions, too. This is unnecessary duplicates and confuses where to document new DAMOS filter types and features. Move the details from usage to design doc. Link: https://lkml.kernel.org/r/20250218223708.53437-4-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16Docs/mm/damon/design: document hugepage_size filterSeongJae Park
'hugepage_size' DAMOS filter type is not documented on the design doc. Add a description of the type. Link: https://lkml.kernel.org/r/20250218223708.53437-3-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16Docs/mm/damon/design: fix typo on DAMOS filters usage doc linkSeongJae Park
Patch series "Docs/mm/damon: misc DAMOS filters documentation fixes and improves". Fix and improve DAMOS filters documentation by fixing a copy-paste typo, adding hugepage_size filter documentation on design doc, moving logic details from usage to design, clarify DAMOS filters handling sequence based on handling layer, and re-organizing the filters type list for easier understanding of the handling sequence. This patch (of 5): The link from DAMOS filters design doc to usage doc has a typo calling filters as watermarks. Fix it. Link: https://lkml.kernel.org/r/20250218223708.53437-1-sj@kernel.org Link: https://lkml.kernel.org/r/20250218223708.53437-2-sj@kernel.org Fixes: d31f5626a0e1 ("Docs/mm/damon/design: add links to sections of DAMON sysfs interface usage doc") Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16Documentation/mm: fix spelling mistakeSuchit K
The word watermark was misspelled as "watemark". Link: https://lkml.kernel.org/r/CAO9wTFhe4sf1eVVgijt2cdLPPsUHBj7B=HN-380_JSpve5KbvQ@mail.gmail.com Signed-off-by: Suchit <suchitkarunakaran@gmail.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16Docs/mm/damon: fix spelling and grammar in ↵Marcelo Moreira
monitoring_intervals_tuning_example.rst This patch fixes some spelling and grammar mistakes in the documentation, improving the readability. - multipled -> multiplied - idential -> identical - minuts -> minutes - efficieny -> efficiency Link: https://lkml.kernel.org/r/20250217215512.12833-1-marcelomoreira1905@gmail.com Signed-off-by: Marcelo Moreira <marcelomoreira1905@gmail.com> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Shuah khan <skhan@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16docs/mm: document latest changes to vm_lockSuren Baghdasaryan
Change the documentation to reflect that vm_lock is integrated into vma and replaced with vm_refcnt. Document newly introduced vma_start_read_locked{_nested} functions. Link: https://lkml.kernel.org/r/20250213224655.1680278-19-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Tested-by: Shivank Garg <shivankg@amd.com> Link: https://lkml.kernel.org/r/5e19ec93-8307-47c2-bb13-3ddf7150624e@amd.com Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Klara Modin <klarasmodin@gmail.com> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Sourav Panda <souravpanda@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16mm: z3fold: remove z3foldYosry Ahmed
Patch series "mm: zswap: remove z3fold and zbud", v2. After 2 cycles of deprecating z3fold, remove it as well as zbud (rationale in specific patches). This patch (of 2): Z3fold has been marked as deprecated for 2 cycles and no one complained, as expected. As there are no known users, remove the code now. Link: https://lkml.kernel.org/r/20250129180633.3501650-1-yosry.ahmed@linux.dev Link: https://lkml.kernel.org/r/20250129180633.3501650-2-yosry.ahmed@linux.dev Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Nhat Pham <nphamcs@gmail.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: WANG Xuerui <kernel@xen0n.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16mm/rmap: convert make_device_exclusive_range() to make_device_exclusive()David Hildenbrand
The single "real" user in the tree of make_device_exclusive_range() always requests making only a single address exclusive. The current implementation is hard to fix for properly supporting anonymous THP / large folios and for avoiding messing with rmap walks in weird ways. So let's always process a single address/page and return folio + page to minimize page -> folio lookups. This is a preparation for further changes. Reject any non-anonymous or hugetlb folios early, directly after GUP. While at it, extend the documentation of make_device_exclusive() to clarify some things. Link: https://lkml.kernel.org/r/20250210193801.781278-4-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Simona Vetter <simona.vetter@ffwll.ch> Reviewed-by: Alistair Popple <apopple@nvidia.com> Tested-by: Alistair Popple <apopple@nvidia.com> Cc: Alex Shi <alexs@kernel.org> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dave Airlie <airlied@gmail.com> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Karol Herbst <kherbst@redhat.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Lyude <lyude@redhat.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: SeongJae Park <sj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yanteng Si <si.yanteng@linux.dev> Cc: Barry Song <v-songbaohua@oppo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-02-04mm: pgtable: Fix grammar errorI Hsin Cheng
Fix "due high contention" to "due to high contention". Signed-off-by: I Hsin Cheng <richard120310@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20250204093326.206007-1-richard120310@gmail.com
2025-01-26Merge tag 'mm-stable-2025-01-26-14-59' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "The various patchsets are summarized below. Plus of course many indivudual patches which are described in their changelogs. - "Allocate and free frozen pages" from Matthew Wilcox reorganizes the page allocator so we end up with the ability to allocate and free zero-refcount pages. So that callers (ie, slab) can avoid a refcount inc & dec - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to use large folios other than PMD-sized ones - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance and fixes for this small built-in kernel selftest - "mas_anode_descend() related cleanup" from Wei Yang tidies up part of the mapletree code - "mm: fix format issues and param types" from Keren Sun implements a few minor code cleanups - "simplify split calculation" from Wei Yang provides a few fixes and a test for the mapletree code - "mm/vma: make more mmap logic userland testable" from Lorenzo Stoakes continues the work of moving vma-related code into the (relatively) new mm/vma.c - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David Hildenbrand cleans up and rationalizes handling of gfp flags in the page allocator - "readahead: Reintroduce fix for improper RA window sizing" from Jan Kara is a second attempt at fixing a readahead window sizing issue. It should reduce the amount of unnecessary reading - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng addresses an issue where "huge" amounts of pte pagetables are accumulated: https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/ Qi's series addresses this windup by synchronously freeing PTE memory within the context of madvise(MADV_DONTNEED) - "selftest/mm: Remove warnings found by adding compiler flags" from Muhammad Usama Anjum fixes some build warnings in the selftests code when optional compiler warnings are enabled - "mm: don't use __GFP_HARDWALL when migrating remote pages" from David Hildenbrand tightens the allocator's observance of __GFP_HARDWALL - "pkeys kselftests improvements" from Kevin Brodsky implements various fixes and cleanups in the MM selftests code, mainly pertaining to the pkeys tests - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to estimate application working set size - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn provides some cleanups to memcg's hugetlb charging logic - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song removes the global swap cgroup lock. A speedup of 10% for a tmpfs-based kernel build was demonstrated - "zram: split page type read/write handling" from Sergey Senozhatsky has several fixes and cleaups for zram in the area of zram_write_page(). A watchdog softlockup warning was eliminated - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin Brodsky cleans up the pagetable destructor implementations. A rare use-after-free race is fixed - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes simplifies and cleans up the debugging code in the VMA merging logic - "Account page tables at all levels" from Kevin Brodsky cleans up and regularizes the pagetable ctor/dtor handling. This results in improvements in accounting accuracy - "mm/damon: replace most damon_callback usages in sysfs with new core functions" from SeongJae Park cleans up and generalizes DAMON's sysfs file interface logic - "mm/damon: enable page level properties based monitoring" from SeongJae Park increases the amount of information which is presented in response to DAMOS actions - "mm/damon: remove DAMON debugfs interface" from SeongJae Park removes DAMON's long-deprecated debugfs interfaces. Thus the migration to sysfs is completed - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from Peter Xu cleans up and generalizes the hugetlb reservation accounting - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino removes a never-used feature of the alloc_pages_bulk() interface - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park extends DAMOS filters to support not only exclusion (rejecting), but also inclusion (allowing) behavior - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi introduces a new memory descriptor for zswap.zpool that currently overlaps with struct page for now. This is part of the effort to reduce the size of struct page and to enable dynamic allocation of memory descriptors - "mm, swap: rework of swap allocator locks" from Kairui Song redoes and simplifies the swap allocator locking. A speedup of 400% was demonstrated for one workload. As was a 35% reduction for kernel build time with swap-on-zram - "mm: update mips to use do_mmap(), make mmap_region() internal" from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that mmap_region() can be made MM-internal - "mm/mglru: performance optimizations" from Yu Zhao fixes a few MGLRU regressions and otherwise improves MGLRU performance - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae Park updates DAMON documentation - "Cleanup for memfd_create()" from Isaac Manjarres does that thing - "mm: hugetlb+THP folio and migration cleanups" from David Hildenbrand provides various cleanups in the areas of hugetlb folios, THP folios and migration - "Uncached buffered IO" from Jens Axboe implements the new RWF_DONTCACHE flag which provides synchronous dropbehind for pagecache reading and writing. To permite userspace to address issues with massive buildup of useless pagecache when reading/writing fast devices - "selftests/mm: virtual_address_range: Reduce memory" from Thomas Weißschuh fixes and optimizes some of the MM selftests" * tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits) mm/compaction: fix UBSAN shift-out-of-bounds warning s390/mm: add missing ctor/dtor on page table upgrade kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags() tools: add VM_WARN_ON_VMG definition mm/damon/core: use str_high_low() helper in damos_wmark_wait_us() seqlock: add missing parameter documentation for raw_seqcount_try_begin() mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh mm/page_alloc: remove the incorrect and misleading comment zram: remove zcomp_stream_put() from write_incompressible_page() mm: separate move/undo parts from migrate_pages_batch() mm/kfence: use str_write_read() helper in get_access_type() selftests/mm/mkdirty: fix memory leak in test_uffdio_copy() kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags() selftests/mm: virtual_address_range: avoid reading from VM_IO mappings selftests/mm: vm_util: split up /proc/self/smaps parsing selftests/mm: virtual_address_range: unmap chunks after validation selftests/mm: virtual_address_range: mmap() without PROT_WRITE selftests/memfd/memfd_test: fix possible NULL pointer dereference mm: add FGP_DONTCACHE folio creation flag mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue ...
2025-01-25Docs/mm/damon: add an example monitoring intervals tuningSeongJae Park
Add a DAMON monitoring intervals tuning example that contains output from a demonstration of the guide on a real server workload system. The example with real world numbers will help users better understanding the guide instructions and what outputs they can expect and verify. Those will again help finding the rooms for improvements on the guide. Link: https://lkml.kernel.org/r/20250110185232.54907-3-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Honggyu Kim <honggyu.kim@sk.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Yunjeong Mun <yunjeong.mun@sk.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25Docs/mm/damon/design: add monitoring parameters tuning guideSeongJae Park
Patch series "Docs/mm/damon: add tuning guide and misc updates". Add DAMON monitoring parameters tuning guide (patches 1 and 2), with misc documentation fixes (patch 3), updates (patch 4) and clarifications (patch 5). This patch (of 5): DAMON monitoring parameters including sampling and aggregation intervals should be tuned for given workloads. However, the fact is not explicitly documented. Also there is no official guide to help the tuning. This apparently confused a number of people[1] at best, or made people forgive DAMON without tuning. Add a guide on the design document. [1] https://lore.kernel.org/20241202175459.2005526-1-sj@kernel.org Link: https://lkml.kernel.org/r/20250110185232.54907-1-sj@kernel.org Link: https://lkml.kernel.org/r/20250110185232.54907-2-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Honggyu Kim <honggyu.kim@sk.com> Cc: Yunjeong Mun <yunjeong.mun@sk.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25Docs/mm/damon/design: document allow/reject DAMOS filter behaviorsSeongJae Park
Update DAMOS filters design document to describe the allow/reject behavior of filters. Link: https://lkml.kernel.org/r/20250109175126.57878-8-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25Docs/mm/damon/design: update for removal of DAMON debugfs interfaceSeongJae Park
It's time to remove DAMON debugfs interface, which has deprecated long before in February 2023. Read the cover letter of this patch series for more details. Update DAMON design documentation to stop mentioning about the interface, to avoid unnecessary confuses. Link: https://lkml.kernel.org/r/20250106191941.107070-4-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Alex Shi <alexs@kernel.org> Cc: Brendan Higgins <brendan.higgins@linux.dev> Cc: David Gow <davidgow@google.com> Cc: Hu Haowen <2023002089@link.tyut.edu.cn> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Rae Moar <rmoar@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Yanteng Si <si.yanteng@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25Docs/mm/damon/design: document per-region sz_filter_passed statSeongJae Park
Update 'Regions Walking' section of design document for the newly added per-region operations set handling DAMOS filters-passed bytes. Link: https://lkml.kernel.org/r/20250106193401.109161-15-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25Docs/mm/damon/design: document sz_ops_filter_passedSeongJae Park
Document the new per-scheme accumulated stat for total bytes that passed the operations set layer-handled DAMOS filters on the design document. Link: https://lkml.kernel.org/r/20250106193401.109161-10-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25Docs/admin-guide/mm/damon/usage: link damos stat design docSeongJae Park
DAMON sysfs usage document focuses on usage, rather than the detail of the stat metric itself. Add a link to the design document on DAMOS stat usage section. Link: https://lkml.kernel.org/r/20250106193401.109161-4-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25Docs/mm/damon/design: add 'statistics' sectionSeongJae Park
DAMOS stats are important feature for tuning of DAMOS-based access-aware system operation, and efficient access pattern monitoring. But not well documented on the design document. Add a section on the document. Link: https://lkml.kernel.org/r/20250106193401.109161-3-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25Docs/mm/damon/design: document DAMOS regions walkingSeongJae Park
DAMOS' regions walking is a feature for efficiently retrieving monitoring results or DAMOS-internal behavior. It can be useful for multiple purposes including investigations and tuning. Add a section for it on the design document. Link: https://lkml.kernel.org/r/20250103174400.54890-9-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25mm: pgtable: introduce pagetable_dtor()Qi Zheng
The pagetable_p*_dtor() are exactly the same except for the handling of ptlock. If we make ptlock_free() handle the case where ptdesc->ptl is NULL and remove VM_BUG_ON_PAGE() from pmd_ptlock_free(), we can unify pagetable_p*_dtor() into one function. Let's introduce pagetable_dtor() to do this. Later, pagetable_dtor() will be moved to tlb_remove_ptdesc(), so that ptlock and page table pages can be freed together (regardless of whether RCU is used). This prevents the use-after-free problem where the ptlock is freed immediately but the page table pages is freed later via RCU. Link: https://lkml.kernel.org/r/47f44fff9dc68d9d9e9a0d6c036df275f820598a.1736317725.git.zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Originally-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> [s390] Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-21Merge tag 'docs-6.14' of git://git.lwn.net/linuxLinus Torvalds
Pull Documentation updates from Jonathan Corbet: - Quite a bit of Chinese and Spanish translation work - Clarifying that Git commit IDs >12chars are OK - A new nvme-multipath document - A reorganization of the admin-guide top-level page to make it readable - Clarification of the role of Acked-by and maintainer discretion on their acceptance - Some reorganization of debugging-oriented docs ... and typo fixes, documentation updates, etc as usual * tag 'docs-6.14' of git://git.lwn.net/linux: (50 commits) Documentation: Fix x86_64 UEFI outdated references to elilo Documentation/sysctl: Add timer_migration to kernel.rst docs/mm: Physical memory: Remove zone_t docs: submitting-patches: clarify that signers may use their discretion on tags docs: submitting-patches: clarify difference between Acked-by and Reviewed-by docs: submitting-patches: clarify Acked-by and introduce "# Suffix" Documentation: bug-hunting.rst: remove odd contact information docs/zh_CN: Add sak index Chinese translation doc: module: DEFAULT_SYMBOL_NAMESPACE must be defined before #includes doc: module: Fix documented type of namespace Documentation/kernel-parameters: Fix a reference to vga-softcursor.rst docs/zh_CN: Add landlock index Chinese translation Documentation: Fix typo localmodonfig -> localmodconfig overlayfs.rst: Fix and improve grammar docs/zh_CN: Add siphash index Chinese translation docs/zh_CN: Add security IMA-templates Chinese translation docs/zh_CN: Add security digsig Chinese translation Align git commit ID abbreviation guidelines and checks docs: process: submitting-patches: split canonical patch format section docs/zh_CN: Add security lsm Chinese translation ...
2025-01-16docs/mm: Physical memory: Remove zone_tI Hsin Cheng
"zone_t" doesn't exist in current code base anymore, remove the description of it. Signed-off-by: I Hsin Cheng <richard120310@gmail.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20250115070355.41769-1-richard120310@gmail.com
2025-01-13mm: khugepaged: recheck pmd state in retract_page_tables()Qi Zheng
Patch series "synchronously scan and reclaim empty user PTE pages", v4. Previously, we tried to use a completely asynchronous method to reclaim empty user PTE pages [1]. After discussing with David Hildenbrand, we decided to implement synchronous reclaimation in the case of madvise(MADV_DONTNEED) as the first step. So this series aims to synchronously free the empty PTE pages in madvise(MADV_DONTNEED) case. We will detect and free empty PTE pages in zap_pte_range(), and will add zap_details.reclaim_pt to exclude cases other than madvise(MADV_DONTNEED). In zap_pte_range(), mmu_gather is used to perform batch tlb flushing and page freeing operations. Therefore, if we want to free the empty PTE page in this path, the most natural way is to add it to mmu_gather as well. Now, if CONFIG_MMU_GATHER_RCU_TABLE_FREE is selected, mmu_gather will free page table pages by semi RCU: - batch table freeing: asynchronous free by RCU - single table freeing: IPI + synchronous free But this is not enough to free the empty PTE page table pages in paths other that munmap and exit_mmap path, because IPI cannot be synchronized with rcu_read_lock() in pte_offset_map{_lock}(). So we should let single table also be freed by RCU like batch table freeing. As a first step, we supported this feature on x86_64 and selectd the newly introduced CONFIG_ARCH_SUPPORTS_PT_RECLAIM. For other cases such as madvise(MADV_FREE), consider scanning and freeing empty PTE pages asynchronously in the future. Note: issues related to TLB flushing are not new to this series and are tracked in the separate RFC patch [3]. And more context please refer to this thread [4]. [1]. https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/ [2]. https://lore.kernel.org/lkml/cover.1727332572.git.zhengqi.arch@bytedance.com/ [3]. https://lore.kernel.org/lkml/20240815120715.14516-1-zhengqi.arch@bytedance.com/ [4]. https://lore.kernel.org/lkml/6f38cb19-9847-4f70-bbe7-06881bb016be@bytedance.com/ This patch (of 11): In retract_page_tables(), the lock of new_folio is still held, we will be blocked in the page fault path, which prevents the pte entries from being set again. So even though the old empty PTE page may be concurrently freed and a new PTE page is filled into the pmd entry, it is still empty and can be removed. So just refactor the retract_page_tables() a little bit and recheck the pmd state after holding the pmd lock. Link: https://lkml.kernel.org/r/cover.1733305182.git.zhengqi.arch@bytedance.com Link: https://lkml.kernel.org/r/70a51804cd19d44ccaf031825d9fb6eaf92f2bad.1733305182.git.zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Suggested-by: Jann Horn <jannh@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Muchun Song <muchun.song@linux.dev> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will@kernel.org> Cc: Zach O'Keefe <zokeefe@google.com> Cc: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-12-18docs/mm: add VMA locks documentationLorenzo Stoakes
Locking around VMAs is complicated and confusing. While we have a number of disparate comments scattered around the place, we seem to be reaching a level of complexity that justifies a serious effort at clearly documenting how locks are expected to be used when it comes to interacting with mm_struct and vm_area_struct objects. This is especially pertinent as regards the efforts to find sensible abstractions for these fundamental objects in kernel rust code whose compiler strictly requires some means of expressing these rules (and through this expression, self-document these requirements as well as enforce them). The document limits scope to mmap and VMA locks and those that are immediately adjacent and relevant to them - so additionally covers page table locking as this is so very closely tied to VMA operations (and relies upon us handling these correctly). The document tries to cover some of the nastier and more confusing edge cases and concerns especially around lock ordering and page table teardown. The document is split between generally useful information for users of mm interfaces, and separately a section intended for mm kernel developers providing a discussion around internal implementation details. [lorenzo.stoakes@oracle.com: v3] Link: https://lkml.kernel.org/r/20241114205402.859737-1-lorenzo.stoakes@oracle.com [lorenzo.stoakes@oracle.com: docs/mm: minor corrections] Link: https://lkml.kernel.org/r/d3de735a-25ae-4eb2-866c-a9624fe6f795@lucifer.local [jannh@google.com: docs/mm: add more warnings around page table access] Link: https://lkml.kernel.org/r/20241118-vma-docs-addition1-onv3-v2-1-c9d5395b72ee@google.com Link: https://lkml.kernel.org/r/20241108135708.48567-1-lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Qi Zheng <zhengqi.arch@bytedance.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com> Reviewed-by: Jann Horn <jannh@google.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: SeongJae Park <sj@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-25Merge tag 'slab-for-6.13-v2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab updates from Vlastimil Babka: - Add new slab_strict_numa boot parameter to enforce per-object memory policies on top of slab folio policies, for systems where saving cost of remote accesses is more important than minimizing slab allocation overhead (Christoph Lameter) - Fix for freeptr_offset alignment check being too strict for m68k (Geert Uytterhoeven) - krealloc() fixes for not violating __GFP_ZERO guarantees on krealloc() when slub_debug (redzone and object tracking) is enabled (Feng Tang) - Fix a memory leak in case sysfs registration fails for a slab cache, and also no longer fail to create the cache in that case (Hyeonggon Yoo) - Fix handling of detected consistency problems (due to buggy slab user) with slub_debug enabled, so that it does not cause further list corruption bugs (yuan.gao) - Code cleanup and kerneldocs polishing (Zhen Lei, Vlastimil Babka) * tag 'slab-for-6.13-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: slab: Fix too strict alignment check in create_cache() mm/slab: Allow cache creation to proceed even if sysfs registration fails mm/slub: Avoid list corruption when removing a slab from the full list mm/slub, kunit: Add testcase for krealloc redzone and zeroing mm/slub: Improve redzone check and zeroing for krealloc() mm/slub: Consider kfence case for get_orig_size() SLUB: Add support for per object memory policies mm, slab: add kerneldocs for common SLAB_ flags mm/slab: remove duplicate check in create_cache() mm/slub: Move krealloc() and related code to slub.c mm/kasan: Don't store metadata inside kmalloc object when slub_debug_orig_size is on
2024-11-23Merge tag 'mm-stable-2024-11-18-19-27' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - The series "zram: optimal post-processing target selection" from Sergey Senozhatsky improves zram's post-processing selection algorithm. This leads to improved memory savings. - Wei Yang has gone to town on the mapletree code, contributing several series which clean up the implementation: - "refine mas_mab_cp()" - "Reduce the space to be cleared for maple_big_node" - "maple_tree: simplify mas_push_node()" - "Following cleanup after introduce mas_wr_store_type()" - "refine storing null" - The series "selftests/mm: hugetlb_fault_after_madv improvements" from David Hildenbrand fixes this selftest for s390. - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng implements some rationaizations and cleanups in the page mapping code. - The series "mm: optimize shadow entries removal" from Shakeel Butt optimizes the file truncation code by speeding up the handling of shadow entries. - The series "Remove PageKsm()" from Matthew Wilcox completes the migration of this flag over to being a folio-based flag. - The series "Unify hugetlb into arch_get_unmapped_area functions" from Oscar Salvador implements a bunch of consolidations and cleanups in the hugetlb code. - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain takes away the wp-fault time practice of turning a huge zero page into small pages. Instead we replace the whole thing with a THP. More consistent cleaner and potentiall saves a large number of pagefaults. - The series "percpu: Add a test case and fix for clang" from Andy Shevchenko enhances and fixes the kernel's built in percpu test code. - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett optimizes mremap() by avoiding doing things which we didn't need to do. - The series "Improve the tmpfs large folio read performance" from Baolin Wang teaches tmpfs to copy data into userspace at the folio size rather than as individual pages. A 20% speedup was observed. - The series "mm/damon/vaddr: Fix issue in damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON splitting. - The series "memcg-v1: fully deprecate charge moving" from Shakeel Butt removes the long-deprecated memcgv2 charge moving feature. - The series "fix error handling in mmap_region() and refactor" from Lorenzo Stoakes cleanup up some of the mmap() error handling and addresses some potential performance issues. - The series "x86/module: use large ROX pages for text allocations" from Mike Rapoport teaches x86 to use large pages for read-only-execute module text. - The series "page allocation tag compression" from Suren Baghdasaryan is followon maintenance work for the new page allocation profiling feature. - The series "page->index removals in mm" from Matthew Wilcox remove most references to page->index in mm/. A slow march towards shrinking struct page. - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs interface tests" from Andrew Paniakin performs maintenance work for DAMON's self testing code. - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar improves zswap's batching of compression and decompression. It is a step along the way towards using Intel IAA hardware acceleration for this zswap operation. - The series "kasan: migrate the last module test to kunit" from Sabyrzhan Tasbolatov completes the migration of the KASAN built-in tests over to the KUnit framework. - The series "implement lightweight guard pages" from Lorenzo Stoakes permits userapace to place fault-generating guard pages within a single VMA, rather than requiring that multiple VMAs be created for this. Improved efficiencies for userspace memory allocators are expected. - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses tracepoints to provide increased visibility into memcg stats flushing activity. - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky fixes a zram buglet which potentially affected performance. - The series "mm: add more kernel parameters to control mTHP" from Maíra Canal enhances our ability to control/configuremultisize THP from the kernel boot command line. - The series "kasan: few improvements on kunit tests" from Sabyrzhan Tasbolatov has a couple of fixups for the KASAN KUnit tests. - The series "mm/list_lru: Split list_lru lock into per-cgroup scope" from Kairui Song optimizes list_lru memory utilization when lockdep is enabled. * tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits) cma: enforce non-zero pageblock_order during cma_init_reserved_mem() mm/kfence: add a new kunit test test_use_after_free_read_nofault() zram: fix NULL pointer in comp_algorithm_show() memcg/hugetlb: add hugeTLB counters to memcg vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount zram: ZRAM_DEF_COMP should depend on ZRAM MAINTAINERS/MEMORY MANAGEMENT: add document files for mm Docs/mm/damon: recommend academic papers to read and/or cite mm: define general function pXd_init() kmemleak: iommu/iova: fix transient kmemleak false positive mm/list_lru: simplify the list_lru walk callback function mm/list_lru: split the lock to per-cgroup scope mm/list_lru: simplify reparenting and initial allocation mm/list_lru: code clean up for reparenting mm/list_lru: don't export list_lru_add mm/list_lru: don't pass unnecessary key parameters kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols ...
2024-11-20Merge tag 'docs-6.13' of git://git.lwn.net/linuxLinus Torvalds
Pull documentation updates from Jonathan Corbet: "Another moderately busy cycle in docsland: - Work on Chinese translations has picked up again. Happily, they are maintaining the existing translations and not just adding new ones. - Some maintenance of the Japanese and Italian translations as well. - The removal of the venerable "dontdiff" file. It has long outlived its usefulness and contained entries ("parse.*") that would actively mask actual source change. - The addition of enforcement information to the code-of-conduct documentation. Along with some build-system fixes and a lot of typo and language fixes" * tag 'docs-6.13' of git://git.lwn.net/linux: (52 commits) Documentation/CoC: spell out enforcement for unacceptable behaviors docs: fix typos and whitespace in Documentation/process/backporting.rst docs/zh_CN: fix one sentence in llvm.rst docs: bug-bisect: add a note about bisecting -next docs/zh_CN: add the translation of kbuild/llvm.rst Documentation: Fix incorrect paths/magic in magic numbers rst Documentation/maintainer-tip: Fix typos Documentation: Improve crash_kexec_post_notifiers description Docs/zh_CN: Translate physical_memory.rst to Simplified Chinese Documentation: admin: reorganize kernel-parameters intro docs/zh_CN: update the translation of process/programming-language.rst docs/zh_CN: update the translation of mm/page_owner.rst docs/zh_CN: update the translation of mm/page_table_check.rst docs/zh_CN: update the translation of mm/overcommit-accounting.rst docs/zh_CN: update the translation of mm/admon/faq.rst docs/zh_CN: update the translation of mm/active_mm.rst docs/zh_CN: update the translation of mm/hmm.rst docs: remove Documentation/dontdiff docs/zh_CN: Add a entry in Chinese glossary Docs/zh_CN: Fix the pfn calculation error in page_tables.rst ...
2024-11-11Docs/mm/damon: recommend academic papers to read and/or citeSeongJae Park
Kernel documentation is the most up-to-date and recommended resource for DAMON. It doesn't cover non-kernel part of the entire project[1], though. Also it is not optimum for formal long-term citations. Depending on cases, DAMON academic papers[2,3] could be better to be read and cited. However, there is no clear guidance for those. Add a paragraph for DAMON academic papers on the kernel documentation for DAMON. [1] https://damonitor.github.io [2] https://dl.acm.org/doi/abs/10.1145/3366626.3368125 [3] https://dl.acm.org/doi/abs/10.1145/3502181.353146 Link: https://lkml.kernel.org/r/20241101203557.55210-1-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-07alloc_tag: support for page allocation tag compressionSuren Baghdasaryan
Implement support for storing page allocation tag references directly in the page flags instead of page extensions. sysctl.vm.mem_profiling boot parameter it extended to provide a way for a user to request this mode. Enabling compression eliminates memory overhead caused by page_ext and results in better performance for page allocations. However this mode will not work if the number of available page flag bits is insufficient to address all kernel allocations. Such condition can happen during boot or when loading a module. If this condition is detected, memory allocation profiling gets disabled with an appropriate warning. By default compression mode is disabled. Link: https://lkml.kernel.org/r/20241023170759.999909-7-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Christoph Hellwig <hch@infradead.org> Cc: Daniel Gomez <da.gomez@samsung.com> Cc: David Hildenbrand <david@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: David Rientjes <rientjes@google.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Minchan Kim <minchan@google.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Petr Pavlu <petr.pavlu@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Sourav Panda <souravpanda@google.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Huth <thuth@redhat.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xiongwei Song <xiongwei.song@windriver.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-05mm: pgtable: remove pte_offset_map_nolock()Qi Zheng
Now no users are using the pte_offset_map_nolock(), remove it. Link: https://lkml.kernel.org/r/d04f9bbbcde048fb6ffa6f2bdbc6f9b22d5286f9.1727332572.git.zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Muchun Song <muchun.song@linux.dev> Acked-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-05mm: pgtable: introduce pte_offset_map_{ro|rw}_nolock()Qi Zheng
Patch series "introduce pte_offset_map_{ro|rw}_nolock()", v5. As proposed by David Hildenbrand [1], this series introduces the following two new helper functions to replace pte_offset_map_nolock(). 1. pte_offset_map_ro_nolock() 2. pte_offset_map_rw_nolock() As the name suggests, pte_offset_map_ro_nolock() is used for read-only case. In this case, only read-only operations will be performed on PTE page after the PTL is held. The RCU lock in pte_offset_map_nolock() will ensure that the PTE page will not be freed, and there is no need to worry about whether the pmd entry is modified. Therefore pte_offset_map_ro_nolock() is just a renamed version of pte_offset_map_nolock(). pte_offset_map_rw_nolock() is used for may-write case. In this case, the pte or pmd entry may be modified after the PTL is held, so we need to ensure that the pmd entry has not been modified concurrently. So in addition to the name change, it also outputs the pmdval when successful. The users should make sure the page table is stable like checking pte_same() or checking pmd_same() by using the output pmdval before performing the write operations. This series will convert all pte_offset_map_nolock() into the above two helper functions one by one, and finally completely delete it. This also a preparation for reclaiming the empty user PTE page table pages. This patch (of 13): Currently, the usage of pte_offset_map_nolock() can be divided into the following two cases: 1) After acquiring PTL, only read-only operations are performed on the PTE page. In this case, the RCU lock in pte_offset_map_nolock() will ensure that the PTE page will not be freed, and there is no need to worry about whether the pmd entry is modified. 2) After acquiring PTL, the pte or pmd entries may be modified. At this time, we need to ensure that the pmd entry has not been modified concurrently. To more clearing distinguish between these two cases, this commit introduces two new helper functions to replace pte_offset_map_nolock(). For 1), just rename it to pte_offset_map_ro_nolock(). For 2), in addition to changing the name to pte_offset_map_rw_nolock(), it also outputs the pmdval when successful. It is applicable for may-write cases where any modification operations to the page table may happen after the corresponding spinlock is held afterwards. But the users should make sure the page table is stable like checking pte_same() or checking pmd_same() by using the output pmdval before performing the write operations. Note: "RO" / "RW" expresses the intended semantics, not that the *kmap* will be read-only/read-write protected. Subsequent commits will convert pte_offset_map_nolock() into the above two functions one by one, and finally completely delete it. Link: https://lkml.kernel.org/r/cover.1727332572.git.zhengqi.arch@bytedance.com Link: https://lkml.kernel.org/r/5aeecfa131600a454b1f3a038a1a54282ca3b856.1727332572.git.zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Muchun Song <muchun.song@linux.dev> Acked-by: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-29SLUB: Add support for per object memory policiesChristoph Lameter
The old SLAB allocator used to support memory policies on a per allocation bases. In SLUB the memory policies are applied on a per page frame / folio bases. Doing so avoids having to check memory policies in critical code paths for kmalloc and friends. This worked on general well on Intel/AMD/PowerPC because the interconnect technology is mature and can minimize the latencies through intelligent caching even if a small object is not placed optimally. However, on ARM we have an emergence of new NUMA interconnect technology based more on embedded devices. Caching of remote content can currently be ineffective using the standard building blocks / mesh available on that platform. Such architectures benefit if each slab object is individually placed according to memory policies and other restrictions. This patch adds another kernel parameter slab_strict_numa If that is set then a static branch is activated that will cause the hotpaths of the allocator to evaluate the current memory allocation policy. Each object will be properly placed by paying the price of extra processing and SLUB will no longer defer to the page allocator to apply memory policies at the folio level. This patch improves performance of memcached running on Ampere Altra 2P system (ARM Neoverse N1 processor) by 3.6% due to accurate placement of small kernel objects. Tested-by: Huang Shijie <shijie@os.amperecomputing.com> Signed-off-by: Christoph Lameter (Ampere) <cl@gentwo.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2024-10-17Docs/damon/maintainer-profile: update deprecated awslabs GitHub URLsSeongJae Park
DAMON GitHub repos have moved from awslabs GitHub org to damonitor org[1]. Following the change, URLs on documents are also updated[2]. However, commit 2e9b3d6e2e59 ("Docs/damon/maintainer-profile: add links in place"), which was added just after the update, was using the deprecated GitHub URLs. Update those to use damonitor GitHub URLs instead. [1] https://lore.kernel.org/20240813232158.83903-1-sj@kernel.org [2] https://lore.kernel.org/20240826015741.80707-2-sj@kernel.org Link: https://lkml.kernel.org/r/20241011170154.70651-3-sj@kernel.org Fixes: 2e9b3d6e2e59 ("Docs/damon/maintainer-profile: add links in place") Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-17Docs/damon/maintainer-profile: add missing '_' suffixes for external web linksSeongJae Park
Patch series "Docs/damon/maintainer-profile: a couple of minor hotfixes". DAMON maintainer-profile.rst file patches[1] that were merged into the v6.12-rc1 have a couple of minor mistakes. Fix those. [1] https://lore.kernel.org/20240826015741.80707-1-sj@kernel.org This patch (of 2): Links to external web pages on DAMON's maintainer-profile.rst are missing '_' suffixes. As a result, rendered document is having only verbose URLs that cannot be clicked. Fix those. Also, update the link texts for git trees to contain the names of the trees, for better readability and avoiding below Sphinx warning. maintainer-profile.rst:4: WARNING: Duplicate explicit target name: "tree". Link: https://lkml.kernel.org/r/20241011170154.70651-1-sj@kernel.org Link: https://lkml.kernel.org/r/20241011170154.70651-2-sj@kernel.org Fixes: 2e9b3d6e2e59 ("Docs/damon/maintainer-profile: add links in place") Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-14Docs/mm: Fix a mistake for pfn in page_tables.rstPengyu Zhang
The documentation incorrectly calculate the pfn value as 0x3fffff, which should be 0x3ffff instead. It is obtained by right-shifting 0xffffc000 by 14 bits. This patch corrects the value to prevent any potential confusion for developers referencing this document. Signed-off-by: Pengyu Zhang <zpenya1314@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Zenghui Yu <zenghui.yu@linux.dev> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20241009144135.12453-1-zpenya1314@gmail.com
2024-09-21Merge tag 'mm-stable-2024-09-20-02-31' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Along with the usual shower of singleton patches, notable patch series in this pull request are: - "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds consistency to the APIs and behaviour of these two core allocation functions. This also simplifies/enables Rustification. - "Some cleanups for shmem" from Baolin Wang. No functional changes - mode code reuse, better function naming, logic simplifications. - "mm: some small page fault cleanups" from Josef Bacik. No functional changes - code cleanups only. - "Various memory tiering fixes" from Zi Yan. A small fix and a little cleanup. - "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and simplifications and .text shrinkage. - "Kernel stack usage histogram" from Pasha Tatashin and Shakeel Butt. This is a feature, it adds new feilds to /proc/vmstat such as $ grep kstack /proc/vmstat kstack_1k 3 kstack_2k 188 kstack_4k 11391 kstack_8k 243 kstack_16k 0 which tells us that 11391 processes used 4k of stack while none at all used 16k. Useful for some system tuning things, but partivularly useful for "the dynamic kernel stack project". - "kmemleak: support for percpu memory leak detect" from Pavel Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory. - "mm: memcg: page counters optimizations" from Roman Gushchin. "3 independent small optimizations of page counters". - "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from David Hildenbrand. Improves PTE/PMD splitlock detection, makes powerpc/8xx work correctly by design rather than by accident. - "mm: remove arch_make_page_accessible()" from David Hildenbrand. Some folio conversions which make arch_make_page_accessible() unneeded. - "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David Finkel. Cleans up and fixes our handling of the resetting of the cgroup/process peak-memory-use detector. - "Make core VMA operations internal and testable" from Lorenzo Stoakes. Rationalizaion and encapsulation of the VMA manipulation APIs. With a view to better enable testing of the VMA functions, even from a userspace-only harness. - "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix issues in the zswap global shrinker, resulting in improved performance. - "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill in some missing info in /proc/zoneinfo. - "mm: replace follow_page() by folio_walk" from David Hildenbrand. Code cleanups and rationalizations (conversion to folio_walk()) resulting in the removal of follow_page(). - "improving dynamic zswap shrinker protection scheme" from Nhat Pham. Some tuning to improve zswap's dynamic shrinker. Significant reductions in swapin and improvements in performance are shown. - "mm: Fix several issues with unaccepted memory" from Kirill Shutemov. Improvements to the new unaccepted memory feature, - "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on DAX PUDs. This was missing, although nobody seems to have notied yet. - "Introduce a store type enum for the Maple tree" from Sidhartha Kumar. Cleanups and modest performance improvements for the maple tree library code. - "memcg: further decouple v1 code from v2" from Shakeel Butt. Move more cgroup v1 remnants away from the v2 memcg code. - "memcg: initiate deprecation of v1 features" from Shakeel Butt. Adds various warnings telling users that memcg v1 features are deprecated. - "mm: swap: mTHP swap allocator base on swap cluster order" from Chris Li. Greatly improves the success rate of the mTHP swap allocation. - "mm: introduce numa_memblks" from Mike Rapoport. Moves various disparate per-arch implementations of numa_memblk code into generic code. - "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly improves the performance of munmap() of swap-filled ptes. - "support large folio swap-out and swap-in for shmem" from Baolin Wang. With this series we no longer split shmem large folios into simgle-page folios when swapping out shmem. - "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice performance improvements and code reductions for gigantic folios. - "support shmem mTHP collapse" from Baolin Wang. Adds support for khugepaged's collapsing of shmem mTHP folios. - "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect() performance regression due to the addition of mseal(). - "Increase the number of bits available in page_type" from Matthew Wilcox. Increases the number of bits available in page_type! - "Simplify the page flags a little" from Matthew Wilcox. Many legacy page flags are now folio flags, so the page-based flags and their accessors/mutators can be removed. - "mm: store zero pages to be swapped out in a bitmap" from Usama Arif. An optimization which permits us to avoid writing/reading zero-filled zswap pages to backing store. - "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race window which occurs when a MAP_FIXED operqtion is occurring during an unrelated vma tree walk. - "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of the vma_merge() functionality, making ot cleaner, more testable and better tested. - "misc fixups for DAMON {self,kunit} tests" from SeongJae Park. Minor fixups of DAMON selftests and kunit tests. - "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang. Code cleanups and folio conversions. - "Shmem mTHP controls and stats improvements" from Ryan Roberts. Cleanups for shmem controls and stats. - "mm: count the number of anonymous THPs per size" from Barry Song. Expose additional anon THP stats to userspace for improved tuning. - "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more folio conversions and removal of now-unused page-based APIs. - "replace per-quota region priorities histogram buffer with per-context one" from SeongJae Park. DAMON histogram rationalization. - "Docs/damon: update GitHub repo URLs and maintainer-profile" from SeongJae Park. DAMON documentation updates. - "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and improve related doc and warn" from Jason Wang: fixes usage of page allocator __GFP_NOFAIL and GFP_ATOMIC flags. - "mm: split underused THPs" from Yu Zhao. Improve THP=always policy. This was overprovisioning THPs in sparsely accessed memory areas. - "zram: introduce custom comp backends API" frm Sergey Senozhatsky. Add support for zram run-time compression algorithm tuning. - "mm: Care about shadow stack guard gap when getting an unmapped area" from Mark Brown. Fix up the various arch_get_unmapped_area() implementations to better respect guard areas. - "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability of mem_cgroup_iter() and various code cleanups. - "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge pfnmap support. - "resource: Fix region_intersects() vs add_memory_driver_managed()" from Huang Ying. Fix a bug in region_intersects() for systems with CXL memory. - "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches a couple more code paths to correctly recover from the encountering of poisoned memry. - "mm: enable large folios swap-in support" from Barry Song. Support the swapin of mTHP memory into appropriately-sized folios, rather than into single-page folios" * tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits) zram: free secondary algorithms names uprobes: turn xol_area->pages[2] into xol_area->page uprobes: introduce the global struct vm_special_mapping xol_mapping Revert "uprobes: use vm_special_mapping close() functionality" mm: support large folios swap-in for sync io devices mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios mm: fix swap_read_folio_zeromap() for large folios with partial zeromap mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries set_memory: add __must_check to generic stubs mm/vma: return the exact errno in vms_gather_munmap_vmas() memcg: cleanup with !CONFIG_MEMCG_V1 mm/show_mem.c: report alloc tags in human readable units mm: support poison recovery from copy_present_page() mm: support poison recovery from do_cow_fault() resource, kunit: add test case for region_intersects() resource: make alloc_free_mem_region() works for iomem_resource mm: z3fold: deprecate CONFIG_Z3FOLD vfio/pci: implement huge_fault support mm/arm64: support large pfn mappings mm/x86: support large pfn mappings ...
2024-09-10docs:mm: fixed spelling and grammar mistakes on vmalloc kernel stack pageDennis Lam
Signed-off-by: Dennis Lam <dennis.lamerice@gmail.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20240906204914.42698-2-dennis.lamerice@gmail.com>
2024-09-10docs:mm: fix spelling mistakes in heterogeneous memory management pageDennis Lam
Signed-off-by: Dennis Lam <dennis.lamerice@gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20240908161928.3700-1-dennis.lamerice@gmail.com>