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2023-04-05zsmalloc: document freeable statsSergey Senozhatsky
When freeable class stat was added to classes file (back in 2016) we forgot to update zsmalloc documentation. Fix that. Link: https://lkml.kernel.org/r/20230325024631.2817153-3-senozhatsky@chromium.org Fixes: 1120ed548394 ("mm/zsmalloc: add `freeable' column to pool stat") Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Minchan Kim <minchan@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05zsmalloc: document new fullness groupingSergey Senozhatsky
Patch series "zsmalloc: minor documentation updates". Two minor patches that bring zsmalloc documentation up to date. This patch (of 2): Update documentation and reflect new zspages fullness grouping (we don't use almost_empty and almost_full anymore). Link: https://lkml.kernel.org/r/20230325024631.2817153-1-senozhatsky@chromium.org Link: https://lkml.kernel.org/r/20230325024631.2817153-2-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Fixes: 67e157eb3639 ("zsmalloc: show per fullness group class stats") Cc: Minchan Kim <minchan@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-07docs/mm: hugetlbfs_reserv: fix a reference to a file that doesn't existMike Rapoport (IBM)
kbuild reports: >> Warning: Documentation/mm/hugetlbfs_reserv.rst references a file that doesn't exist: Documentation/mm/hugetlbpage.rst >> Warning: Documentation/translations/zh_CN/mm/hugetlbfs_reserv.rst references a file that doesn't exist: Documentation/mm/hugetlbpage.rst Fix the filename to be 'Documentation/admin-guide/mm/hugetlbpage.rst'. Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/oe-kbuild-all/202302231854.sKlCmx9K-lkp@intel.com/ Fixes: ee86588960e2 ("docs/mm: remove useless markup") Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Link: https://lore.kernel.org/r/20230224100306.2287696-2-rppt@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-03-07docs/mm: Physical Memory: fix a reference to a file that doesn't existMike Rapoport (IBM)
kbuild reports: >> Warning: Documentation/mm/physical_memory.rst references a file that doesn't exist: Documentation/admin-guide/mm/memory_hotplug.rst Fix the filename to be 'Documentation/admin-guide/mm/memory-hotplug.rst'. Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/oe-kbuild-all/202302231311.567PAoS2-lkp@intel.com/ Fixes: 353c7dd636ed ("docs/mm: Physical Memory: remove useless markup") Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Link: https://lore.kernel.org/r/20230224100306.2287696-1-rppt@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-02-23Merge tag 'mm-stable-2023-02-20-13-37' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Daniel Verkamp has contributed a memfd series ("mm/memfd: add F_SEAL_EXEC") which permits the setting of the memfd execute bit at memfd creation time, with the option of sealing the state of the X bit. - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare") which addresses a rare race condition related to PMD unsharing. - Several folioification patch serieses from Matthew Wilcox, Vishal Moola, Sidhartha Kumar and Lorenzo Stoakes - Johannes Weiner has a series ("mm: push down lock_page_memcg()") which does perform some memcg maintenance and cleanup work. - SeongJae Park has added DAMOS filtering to DAMON, with the series "mm/damon/core: implement damos filter". These filters provide users with finer-grained control over DAMOS's actions. SeongJae has also done some DAMON cleanup work. - Kairui Song adds a series ("Clean up and fixes for swap"). - Vernon Yang contributed the series "Clean up and refinement for maple tree". - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It adds to MGLRU an LRU of memcgs, to improve the scalability of global reclaim. - David Hildenbrand has added some userfaultfd cleanup work in the series "mm: uffd-wp + change_protection() cleanups". - Christoph Hellwig has removed the generic_writepages() library function in the series "remove generic_writepages". - Baolin Wang has performed some maintenance on the compaction code in his series "Some small improvements for compaction". - Sidhartha Kumar is doing some maintenance work on struct page in his series "Get rid of tail page fields". - David Hildenbrand contributed some cleanup, bugfixing and generalization of pte management and of pte debugging in his series "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs". - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation flag in the series "Discard __GFP_ATOMIC". - Sergey Senozhatsky has improved zsmalloc's memory utilization with his series "zsmalloc: make zspage chain size configurable". - Joey Gouly has added prctl() support for prohibiting the creation of writeable+executable mappings. The previous BPF-based approach had shortcomings. See "mm: In-kernel support for memory-deny-write-execute (MDWE)". - Waiman Long did some kmemleak cleanup and bugfixing in the series "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF". - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series "mm: multi-gen LRU: improve". - Jiaqi Yan has provided some enhancements to our memory error statistics reporting, mainly by presenting the statistics on a per-node basis. See the series "Introduce per NUMA node memory error statistics". - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog regression in compaction via his series "Fix excessive CPU usage during compaction". - Christoph Hellwig does some vmalloc maintenance work in the series "cleanup vfree and vunmap". - Christoph Hellwig has removed block_device_operations.rw_page() in ths series "remove ->rw_page". - We get some maple_tree improvements and cleanups in Liam Howlett's series "VMA tree type safety and remove __vma_adjust()". - Suren Baghdasaryan has done some work on the maintainability of our vm_flags handling in the series "introduce vm_flags modifier functions". - Some pagemap cleanup and generalization work in Mike Rapoport's series "mm, arch: add generic implementation of pfn_valid() for FLATMEM" and "fixups for generic implementation of pfn_valid()" - Baoquan He has done some work to make /proc/vmallocinfo and /proc/kcore better represent the real state of things in his series "mm/vmalloc.c: allow vread() to read out vm_map_ram areas". - Jason Gunthorpe rationalized the GUP system's interface to the rest of the kernel in the series "Simplify the external interface for GUP". - SeongJae Park wishes to migrate people from DAMON's debugfs interface over to its sysfs interface. To support this, we'll temporarily be printing warnings when people use the debugfs interface. See the series "mm/damon: deprecate DAMON debugfs interface". - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes and clean-ups" series. - Huang Ying has provided a dramatic reduction in migration's TLB flush IPI rates with the series "migrate_pages(): batch TLB flushing". - Arnd Bergmann has some objtool fixups in "objtool warning fixes". * tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits) include/linux/migrate.h: remove unneeded externs mm/memory_hotplug: cleanup return value handing in do_migrate_range() mm/uffd: fix comment in handling pte markers mm: change to return bool for isolate_movable_page() mm: hugetlb: change to return bool for isolate_hugetlb() mm: change to return bool for isolate_lru_page() mm: change to return bool for folio_isolate_lru() objtool: add UACCESS exceptions for __tsan_volatile_read/write kmsan: disable ftrace in kmsan core code kasan: mark addr_has_metadata __always_inline mm: memcontrol: rename memcg_kmem_enabled() sh: initialize max_mapnr m68k/nommu: add missing definition of ARCH_PFN_OFFSET mm: percpu: fix incorrect size in pcpu_obj_full_size() maple_tree: reduce stack usage with gcc-9 and earlier mm: page_alloc: call panic() when memoryless node allocation fails mm: multi-gen LRU: avoid futile retries migrate_pages: move THP/hugetlb migration support check to simplify code migrate_pages: batch flushing TLB migrate_pages: share more code between _unmap and _move ...
2023-02-16docs/mm: Physical Memory: correct spelling in reference to CONFIG_PAGE_EXTENSIONLukas Bulwahn
Commit 5d8c5e430a63 ("docs/mm: Physical Memory: add structure, introduction and nodes description") slips in a minor spelling mistake for the config PAGE_EXTENSION. Correct the config name in the physical-memory documentation. Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Link: https://lore.kernel.org/r/20230215100808.9613-1-lukas.bulwahn@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-02-13Documentation/mm: update hugetlbfs documentation to mention alloc_hugetlb_folioSidhartha Kumar
Link: https://lkml.kernel.org/r/20230125170537.96973-9-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02mm: multi-gen LRU: section for memcg LRUT.J. Alumbaugh
Move memcg LRU code into a dedicated section. Improve the design doc to outline its architecture. Link: https://lkml.kernel.org/r/20230118001827.1040870-5-talumbau@google.com Signed-off-by: T.J. Alumbaugh <talumbau@google.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02mm: multi-gen LRU: section for Bloom filtersT.J. Alumbaugh
Move Bloom filters code into a dedicated section. Improve the design doc to explain Bloom filter usage and connection between aging and eviction in their use. Link: https://lkml.kernel.org/r/20230118001827.1040870-4-talumbau@google.com Signed-off-by: T.J. Alumbaugh <talumbau@google.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02mm: multi-gen LRU: section for rmap/PT walk feedbackT.J. Alumbaugh
Add a section for lru_gen_look_around() in the code and the design doc. Link: https://lkml.kernel.org/r/20230118001827.1040870-3-talumbau@google.com Signed-off-by: T.J. Alumbaugh <talumbau@google.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02mm: multi-gen LRU: section for working set protectionT.J. Alumbaugh
Patch series "mm: multi-gen LRU: improve". This patch series improves a few MGLRU functions, collects related functions, and adds additional documentation. This patch (of 7): Add a section for working set protection in the code and the design doc. The admin doc already contains its usage. Link: https://lkml.kernel.org/r/20230118001827.1040870-1-talumbau@google.com Link: https://lkml.kernel.org/r/20230118001827.1040870-2-talumbau@google.com Signed-off-by: T.J. Alumbaugh <talumbau@google.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02Documentation: mm: use `s/higmem/highmem/` fix typo for highmemDeming Wang
We should use highmem replace higmem. Link: https://lkml.kernel.org/r/20230118025403.1531-1-wangdeming@inspur.com Signed-off-by: Deming Wang <wangdeming@inspur.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: "Fabio M. De Francesco" <fmdefrancesco@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02zsmalloc: make zspage chain size configurableSergey Senozhatsky
Remove hard coded limit on the maximum number of physical pages per-zspage. This will allow tuning of zsmalloc pool as zspage chain size changes `pages per-zspage` and `objects per-zspage` characteristics of size classes which also affects size classes clustering (the way size classes are merged). Link: https://lkml.kernel.org/r/20230118005210.2814763-4-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02mm: clean up mlock_page / munlock_page references in commentsMatthew Wilcox (Oracle)
Change documentation and comments that refer to now-renamed functions. Link: https://lkml.kernel.org/r/20230116192827.2146732-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02mm: remove munlock_vma_page()Matthew Wilcox (Oracle)
All callers now have a folio and can call munlock_vma_folio(). Update the documentation to refer to munlock_vma_folio(). Link: https://lkml.kernel.org/r/20230116192827.2146732-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02mm: remove mlock_vma_page()Matthew Wilcox (Oracle)
All callers now have a folio and can call mlock_vma_folio(). Update the documentation to refer to mlock_vma_folio(). Link: https://lkml.kernel.org/r/20230116192827.2146732-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02mm: remove page_evictable()Matthew Wilcox (Oracle)
Patch series "Remove leftover mlock/munlock page wrappers". We no longer need the various mlock page functions as all callers have folios. This patch (of 4): This function now has no users. Also update the unevictable-lru documentation to discuss folios instead of pages (mostly). [akpm@linux-foundation.org: fix Documentation/mm/unevictable-lru.rst underlining] Link: https://lkml.kernel.org/r/20230117145106.585b277b@canb.auug.org.au Link: https://lkml.kernel.org/r/20230116192827.2146732-1-willy@infradead.org Link: https://lkml.kernel.org/r/20230116192827.2146732-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02mm: discard __GFP_ATOMICNeilBrown
__GFP_ATOMIC serves little purpose. Its main effect is to set ALLOC_HARDER which adds a few little boosts to increase the chance of an allocation succeeding, one of which is to lower the water-mark at which it will succeed. It is *always* paired with __GFP_HIGH which sets ALLOC_HIGH which also adjusts this watermark. It is probable that other users of __GFP_HIGH should benefit from the other little bonuses that __GFP_ATOMIC gets. __GFP_ATOMIC also gives a warning if used with __GFP_DIRECT_RECLAIM. There is little point to this. We already get a might_sleep() warning if __GFP_DIRECT_RECLAIM is set. __GFP_ATOMIC allows the "watermark_boost" to be side-stepped. It is probable that testing ALLOC_HARDER is a better fit here. __GFP_ATOMIC is used by tegra-smmu.c to check if the allocation might sleep. This should test __GFP_DIRECT_RECLAIM instead. This patch: - removes __GFP_ATOMIC - allows __GFP_HIGH allocations to ignore watermark boosting as well as GFP_ATOMIC requests. - makes other adjustments as suggested by the above. The net result is not change to GFP_ATOMIC allocations. Other allocations that use __GFP_HIGH will benefit from a few different extra privileges. This affects: xen, dm, md, ntfs3 the vermillion frame buffer hibernation ksm swap all of which likely produce more benefit than cost if these selected allocation are more likely to succeed quickly. [mgorman: Minor adjustments to rework on top of a series] Link: https://lkml.kernel.org/r/163712397076.13692.4727608274002939094@noble.neil.brown.name Link: https://lkml.kernel.org/r/20230113111217.14134-7-mgorman@techsingularity.net Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02Documentation/mm: update references to __m[un]lock_page() to *_folio()Lorenzo Stoakes
We now pass folios to these functions, so update the documentation accordingly. Additionally, correct the outdated reference to __pagevec_lru_add_fn(), the referenced action occurs in __munlock_folio() directly now, replace reference to lru_cache_add_inactive_or_unevictable() with the modern folio equivalent folio_add_lru_vma() and reference folio flags by the flag name rather than accessor. Link: https://lkml.kernel.org/r/898c487169d98a7f09c1c1e57a7dfdc2b3f6bf0f.1673526881.git.lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christian Brauner <brauner@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Hugh Dickins <hughd@google.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: William Kucharski <william.kucharski@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02mm: convert deferred_split_huge_page() to deferred_split_folio()Matthew Wilcox (Oracle)
Now that both callers use a folio, pass the folio in and save a call to compound_head(). Link: https://lkml.kernel.org/r/20230111142915.1001531-28-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02doc: clarify refcount section by referring to folios & pagesMatthew Wilcox (Oracle)
Include the rename of subpages_mapcount to _nr_pages_mapped. Link: https://lkml.kernel.org/r/20230111142915.1001531-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02Docs/mm/damon: add a maintainer-profile for DAMONSeongJae Park
Document the basic policies and expectations for DAMON development. Link: https://lkml.kernel.org/r/20230110190400.119388-6-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02Docs/mm/damon/index: mention DAMOS on the introSeongJae Park
What DAMON aims to do is not only access monitoring but efficient and effective access-aware system operations. And DAMon-based Operation Schemes (DAMOS) is the important feature of DAMON for the goal. Make the intro of DAMON documentation to emphasize the goal and mention DAMOS. Link: https://lkml.kernel.org/r/20230110190400.119388-4-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02mm/highmem: add notes about conversions from kmap{,_atomic}()Fabio M. De Francesco
kmap() and kmap_atomic() have been deprecated. kmap_local_page() should always be used in new code and the call sites of the two deprecated functions should be converted. This latter task can lead to errors if it is not carried out with the necessary attention to the context around and between the maps and unmaps. Therefore, add further information to the Highmem's documentation for the purpose to make it clearer that (1) kmap() and kmap_atomic() must not any longer be called in new code and (2) developers doing conversions from kmap() amd kmap_atomic() are expected to take care of the context around and between the maps and unmaps, in order to not break the code. Relevant parts of this patch have been taken from messages exchanged privately with Ira Weiny (thanks!). [fmdefrancesco@gmail.com: merge two sentences into one, per Bagas] Link: https://lkml.kernel.org/r/20230119123945.10471-1-fmdefrancesco@gmail.com Link: https://lkml.kernel.org/r/20221207225308.8290-1-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02docs/mm: remove useless markupMike Rapoport (IBM)
It is enough to use a file name to cross-reference another rst document. Jon says: The right things will happen in the HTML output, readers of the plain-text will know immediately where to go, and we don't have to add the label clutter. Drop reference markup and unnecessary labels and use plain file names. Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Link: https://lore.kernel.org/r/20230201094156.991542-3-rppt@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-02-02docs/mm: Physical Memory: remove useless markupMike Rapoport (IBM)
Jon says: > +See also :ref:`Page Reclaim <page_reclaim>`. Can also just be "See also Documentation/mm/page_reclaim.rst". The right things will happen in the HTML output, readers of the plain-text will know immediately where to go, and we don't have to add the label clutter. Remove reference markup and unnecessary labes and use plain file names. Fixes: 5d8c5e430a63 ("docs/mm: Physical Memory: add structure, introduction and nodes description") Suggested-by: Jonathan Corbet <corbet@lwn.net> Acked-by: Bagas Sanjaya <bagasdotme@gmail.com> Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Link: https://lore.kernel.org/r/20230201094156.991542-2-rppt@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-01-26docs/mm: Physical Memory: add structure, introduction and nodes descriptionMike Rapoport (IBM)
Add structure, introduction and Nodes section to Physical Memory chapter. As the new documentation references core-api/dma-api and mm/page_reclaim, add page labels to those documents. Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Link: https://lore.kernel.org/r/20230125192841.25342-2-rppt@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-01-26Documentation/mm: Fix typo emluation -> emulationJules Maselbas
Fix typo emluation -> emulation Signed-off-by: Jules Maselbas <jmaselbas@kalray.eu> Link: https://lore.kernel.org/r/20230126173217.12912-1-jmaselbas@kalray.eu Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-01-24Docs/subsystem-apis: Remove '[The ]Linux' prefixes from titles of listed ↵SeongJae Park
documents Some documents that listed on subsystem-apis have 'Linux' or 'The Linux' title prefixes. It's duplicated information, and makes finding the document of interest with human eyes not easy. Remove the prefixes from the titles. Signed-off-by: SeongJae Park <sj@kernel.org> Acked-by: Iwona Winiarska <iwona.winiarska@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/20230122184834.181977-1-sj@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-01-18tools/vm: rename tools/vm to tools/mmSeongJae Park
Rename tools/vm to tools/mm for being more consistent with the code and documentation directories, and won't be confused with virtual machines. Link: https://lkml.kernel.org/r/20230103180754.129637-4-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18mm: multi-gen LRU: rename lrugen->lists[] to lrugen->folios[]Yu Zhao
lru_gen_folio will be chained into per-node lists by the coming lrugen->list. Link: https://lkml.kernel.org/r/20221222041905.2431096-3-yuzhao@google.com Signed-off-by: Yu Zhao <yuzhao@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michael Larabel <Michael@MichaelLarabel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-02docs: mm/page_owner: fix spelling mistakesChen Xiao
Fix several spelling mistakes in page_owner documentation. Signed-off-by: Chen Xiao <abigwc@gmail.com> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/1670479443-8484-1-git-send-email-abigwc@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-12-13Merge tag 'mm-stable-2022-12-13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - More userfaultfs work from Peter Xu - Several convert-to-folios series from Sidhartha Kumar and Huang Ying - Some filemap cleanups from Vishal Moola - David Hildenbrand added the ability to selftest anon memory COW handling - Some cpuset simplifications from Liu Shixin - Addition of vmalloc tracing support by Uladzislau Rezki - Some pagecache folioifications and simplifications from Matthew Wilcox - A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use it - Miguel Ojeda contributed some cleanups for our use of the __no_sanitize_thread__ gcc keyword. This series should have been in the non-MM tree, my bad - Naoya Horiguchi improved the interaction between memory poisoning and memory section removal for huge pages - DAMON cleanups and tuneups from SeongJae Park - Tony Luck fixed the handling of COW faults against poisoned pages - Peter Xu utilized the PTE marker code for handling swapin errors - Hugh Dickins reworked compound page mapcount handling, simplifying it and making it more efficient - Removal of the autonuma savedwrite infrastructure from Nadav Amit and David Hildenbrand - zram support for multiple compression streams from Sergey Senozhatsky - David Hildenbrand reworked the GUP code's R/O long-term pinning so that drivers no longer need to use the FOLL_FORCE workaround which didn't work very well anyway - Mel Gorman altered the page allocator so that local IRQs can remnain enabled during per-cpu page allocations - Vishal Moola removed the try_to_release_page() wrapper - Stefan Roesch added some per-BDI sysfs tunables which are used to prevent network block devices from dirtying excessive amounts of pagecache - David Hildenbrand did some cleanup and repair work on KSM COW breaking - Nhat Pham and Johannes Weiner have implemented writeback in zswap's zsmalloc backend - Brian Foster has fixed a longstanding corner-case oddity in file[map]_write_and_wait_range() - sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang Chen - Shiyang Ruan has done some work on fsdax, to make its reflink mode work better under xfstests. Better, but still not perfect - Christoph Hellwig has removed the .writepage() method from several filesystems. They only need .writepages() - Yosry Ahmed wrote a series which fixes the memcg reclaim target beancounting - David Hildenbrand has fixed some of our MM selftests for 32-bit machines - Many singleton patches, as usual * tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (313 commits) mm/hugetlb: set head flag before setting compound_order in __prep_compound_gigantic_folio mm: mmu_gather: allow more than one batch of delayed rmaps mm: fix typo in struct pglist_data code comment kmsan: fix memcpy tests mm: add cond_resched() in swapin_walk_pmd_entry() mm: do not show fs mm pc for VM_LOCKONFAULT pages selftests/vm: ksm_functional_tests: fixes for 32bit selftests/vm: cow: fix compile warning on 32bit selftests/vm: madv_populate: fix missing MADV_POPULATE_(READ|WRITE) definitions mm/gup_test: fix PIN_LONGTERM_TEST_READ with highmem mm,thp,rmap: fix races between updates of subpages_mapcount mm: memcg: fix swapcached stat accounting mm: add nodes= arg to memory.reclaim mm: disable top-tier fallback to reclaim on proactive reclaim selftests: cgroup: make sure reclaim target memcg is unprotected selftests: cgroup: refactor proactive reclaim code to reclaim_until() mm: memcg: fix stale protection of reclaim target memcg mm/mmap: properly unaccount memory on mas_preallocate() failure omfs: remove ->writepage jfs: remove ->writepage ...
2022-11-30documentation/mm: update pmd_present() in arch_pgtable_helpers.rstAnshuman Khandual
Although pmd_present() might seem to indicate a valid and mapped pmd entry, in reality it returns true when pmd_page() points to a valid page in memory , regardless whether the pmd entry is mapped or not. Andrea Arcangeli had earlier explained [1] the required semantics for pmd_present(). This just updates the documentation for pmd_present() as required. [1] https://lore.kernel.org/lkml/20181017020930.GN30832@redhat.com/ Link: https://lkml.kernel.org/r/20221123051319.1312582-1-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mike Rapoport <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30mm,thp,rmap: subpages_mapcount COMPOUND_MAPPED if PMD-mappedHugh Dickins
Can the lock_compound_mapcount() bit_spin_lock apparatus be removed now? Yes. Not by atomic64_t or cmpxchg games, those get difficult on 32-bit; but if we slightly abuse subpages_mapcount by additionally demanding that one bit be set there when the compound page is PMD-mapped, then a cascade of two atomic ops is able to maintain the stats without bit_spin_lock. This is harder to reason about than when bit_spin_locked, but I believe safe; and no drift in stats detected when testing. When there are racing removes and adds, of course the sequence of operations is less well- defined; but each operation on subpages_mapcount is atomically good. What might be disastrous, is if subpages_mapcount could ever fleetingly appear negative: but the pte lock (or pmd lock) these rmap functions are called under, ensures that a last remove cannot race ahead of a first add. Continue to make an exception for hugetlb (PageHuge) pages, though that exception can be easily removed by a further commit if necessary: leave subpages_mapcount 0, don't bother with COMPOUND_MAPPED in its case, just carry on checking compound_mapcount too in folio_mapped(), page_mapped(). Evidence is that this way goes slightly faster than the previous implementation in all cases (pmds after ptes now taking around 103ms); and relieves us of worrying about contention on the bit_spin_lock. Link: https://lkml.kernel.org/r/3978f3ca-5473-55a7-4e14-efea5968d892@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dan Carpenter <error27@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: James Houghton <jthoughton@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev> Cc: Peter Xu <peterx@redhat.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30mm,thp,rmap: subpages_mapcount of PTE-mapped subpagesHugh Dickins
Patch series "mm,thp,rmap: rework the use of subpages_mapcount", v2. This patch (of 3): Following suggestion from Linus, instead of counting every PTE map of a compound page in subpages_mapcount, just count how many of its subpages are PTE-mapped: this yields the exact number needed for NR_ANON_MAPPED and NR_FILE_MAPPED stats, without any need for a locked scan of subpages; and requires updating the count less often. This does then revert total_mapcount() and folio_mapcount() to needing a scan of subpages; but they are inherently racy, and need no locking, so Linus is right that the scans are much better done there. Plus (unlike in 6.1 and previous) subpages_mapcount lets us avoid the scan in the common case of no PTE maps. And page_mapped() and folio_mapped() remain scanless and just as efficient with the new meaning of subpages_mapcount: those are the functions which I most wanted to remove the scan from. The updated page_dup_compound_rmap() is no longer suitable for use by anon THP's __split_huge_pmd_locked(); but page_add_anon_rmap() can be used for that, so long as its VM_BUG_ON_PAGE(!PageLocked) is deleted. Evidence is that this way goes slightly faster than the previous implementation for most cases; but significantly faster in the (now scanless) pmds after ptes case, which started out at 870ms and was brought down to 495ms by the previous series, now takes around 105ms. Link: https://lkml.kernel.org/r/a5849eca-22f1-3517-bf29-95d982242742@google.com Link: https://lkml.kernel.org/r/eec17e16-4e1-7c59-f1bc-5bca90dac919@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dan Carpenter <error27@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: James Houghton <jthoughton@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev> Cc: Peter Xu <peterx@redhat.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30mm,thp,rmap: lock_compound_mapcounts() on THP mapcountsHugh Dickins
Fix the races in maintaining compound_mapcount, subpages_mapcount and subpage _mapcount by using PG_locked in the first tail of any compound page for a bit_spin_lock() on such modifications; skipping the usual atomic operations on those fields in this case. Bring page_remove_file_rmap() and page_remove_anon_compound_rmap() back into page_remove_rmap() itself. Rearrange page_add_anon_rmap() and page_add_file_rmap() and page_remove_rmap() to follow the same "if (compound) {lock} else if (PageCompound) {lock} else {atomic}" pattern (with a PageTransHuge in the compound test, like before, to avoid BUG_ONs and optimize away that block when THP is not configured). Move all the stats updates outside, after the bit_spin_locked section, so that it is sure to be a leaf lock. Add page_dup_compound_rmap() to manage compound locking versus atomics in sync with the rest. In particular, hugetlb pages are still using the atomics: to avoid unnecessary interference there, and because they never have subpage mappings; but this exception can easily be changed. Conveniently, page_dup_compound_rmap() turns out to suit an anon THP's __split_huge_pmd_locked() too. bit_spin_lock() is not popular with PREEMPT_RT folks: but PREEMPT_RT sensibly excludes TRANSPARENT_HUGEPAGE already, so its only exposure is to the non-hugetlb non-THP pte-mapped compound pages (with large folios being currently dependent on TRANSPARENT_HUGEPAGE). There is never any scan of subpages in this case; but we have chosen to use PageCompound tests rather than PageTransCompound tests to gate the use of lock_compound_mapcounts(), so that page_mapped() is correct on all compound pages, whether or not TRANSPARENT_HUGEPAGE is enabled: could that be a problem for PREEMPT_RT, when there is contention on the lock - under heavy concurrent forking for example? If so, then it can be turned into a sleeping lock (like folio_lock()) when PREEMPT_RT. A simple 100 X munmap(mmap(2GB, MAP_SHARED|MAP_POPULATE, tmpfs), 2GB) took 18 seconds on small pages, and used to take 1 second on huge pages, but now takes 115 milliseconds on huge pages. Mapping by pmds a second time used to take 860ms and now takes 86ms; mapping by pmds after mapping by ptes (when the scan is needed) used to take 870ms and now takes 495ms. Mapping huge pages by ptes is largely unaffected but variable: between 5% faster and 5% slower in what I've recorded. Contention on the lock is likely to behave worse than contention on the atomics behaved. Link: https://lkml.kernel.org/r/1b42bd1a-8223-e827-602f-d466c2db7d3c@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: James Houghton <jthoughton@google.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev> Cc: Peter Xu <peterx@redhat.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yang Shi <shy828301@gmail.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30mm,thp,rmap: simplify compound page mapcount handlingHugh Dickins
Compound page (folio) mapcount calculations have been different for anon and file (or shmem) THPs, and involved the obscure PageDoubleMap flag. And each huge mapping and unmapping of a file (or shmem) THP involved atomically incrementing and decrementing the mapcount of every subpage of that huge page, dirtying many struct page cachelines. Add subpages_mapcount field to the struct folio and first tail page, so that the total of subpage mapcounts is available in one place near the head: then page_mapcount() and total_mapcount() and page_mapped(), and their folio equivalents, are so quick that anon and file and hugetlb don't need to be optimized differently. Delete the unloved PageDoubleMap. page_add and page_remove rmap functions must now maintain the subpages_mapcount as well as the subpage _mapcount, when dealing with pte mappings of huge pages; and correct maintenance of NR_ANON_MAPPED and NR_FILE_MAPPED statistics still needs reading through the subpages, using nr_subpages_unmapped() - but only when first or last pmd mapping finds subpages_mapcount raised (double-map case, not the common case). But are those counts (used to decide when to split an anon THP, and in vmscan's pagecache_reclaimable heuristic) correctly maintained? Not quite: since page_remove_rmap() (and also split_huge_pmd()) is often called without page lock, there can be races when a subpage pte mapcount 0<->1 while compound pmd mapcount 0<->1 is scanning - races which the previous implementation had prevented. The statistics might become inaccurate, and even drift down until they underflow through 0. That is not good enough, but is better dealt with in a followup patch. Update a few comments on first and second tail page overlaid fields. hugepage_add_new_anon_rmap() has to "increment" compound_mapcount, but subpages_mapcount and compound_pincount are already correctly at 0, so delete its reinitialization of compound_pincount. A simple 100 X munmap(mmap(2GB, MAP_SHARED|MAP_POPULATE, tmpfs), 2GB) took 18 seconds on small pages, and used to take 1 second on huge pages, but now takes 119 milliseconds on huge pages. Mapping by pmds a second time used to take 860ms and now takes 92ms; mapping by pmds after mapping by ptes (when the scan is needed) used to take 870ms and now takes 495ms. But there might be some benchmarks which would show a slowdown, because tail struct pages now fall out of cache until final freeing checks them. Link: https://lkml.kernel.org/r/47ad693-717-79c8-e1ba-46c3a6602e48@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: James Houghton <jthoughton@google.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev> Cc: Peter Xu <peterx@redhat.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yang Shi <shy828301@gmail.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-24mm: Make failslab writable againAlexander Atanasov
In (060807f841ac mm, slub: make remaining slub_debug related attributes read-only) failslab was made read-only. I think it became a collateral victim to the two other options for which the reasons are perfectly valid. Here is why: - sanity_checks and trace are slab internal debug options, failslab is used for fault injection. - for fault injections, which by presumption are random, it does not matter if it is not set atomically. And you need to set atleast one more option to trigger fault injection. - in a testing scenario you may need to change it at runtime example: module loading - you test all allocations limited by the space option. Then you move to test only your module's own slabs. - when set by command line flags it effectively disables all cache merges. Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: Roman Gushchin <guro@fb.com> Cc: Christoph Lameter <cl@linux.com> Cc: Jann Horn <jannh@google.com> Cc: Vijayanand Jitta <vjitta@codeaurora.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Link: http://lkml.kernel.org/r/20200610163135.17364-5-vbabka@suse.cz Signed-off-by: Alexander Atanasov <alexander.atanasov@virtuozzo.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2022-10-13Merge tag 'docs-6.1-2' of git://git.lwn.net/linuxLinus Torvalds
Pull documentation fixes from Jonathan Corbet: "A handful of relatively simple documentation fixes, plus a set of patches catching the Chinese translation up with the front-page rework" * tag 'docs-6.1-2' of git://git.lwn.net/linux: Documentation: rtla: Correct command line example docs/zh_CN: add a man-pages link to zh_CN/index.rst docs/zh_CN: Rewrite the Chinese translation front page docs/zh_CN: add zh_CN/arch.rst docs/zh_CN: promote the title of zh_CN/process/index.rst docs/zh_CN: Update the translation of page_owner to 6.0-rc7 docs/zh_CN: Update the translation of ksm to 6.0-rc7 docs/howto: Replace abundoned URL of gmane.org Documentation: ubifs: Fix compression idiom Documentation/mm/page_owner.rst: delete frequently changing experimental data docs/zh_CN: Fix build warning docs: ftrace: Correct access mode
2022-10-10Merge tag 'mm-stable-2022-10-08' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam Howlett. An overlapping range-based tree for vmas. It it apparently slightly more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat at [1]. This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1] * tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits) hugetlb: allocate vma lock for all sharable vmas hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer hugetlb: fix vma lock handling during split vma and range unmapping mglru: mm/vmscan.c: fix imprecise comments mm/mglru: don't sync disk for each aging cycle mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol mm: memcontrol: use do_memsw_account() in a few more places mm: memcontrol: deprecate swapaccounting=0 mode mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled mm/secretmem: remove reduntant return value mm/hugetlb: add available_huge_pages() func mm: remove unused inline functions from include/linux/mm_inline.h selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd selftests/vm: add thp collapse shmem testing selftests/vm: add thp collapse file and tmpfs testing selftests/vm: modularize thp collapse memory operations selftests/vm: dedup THP helpers mm/khugepaged: add tracepoint to hpage_collapse_scan_file() mm/madvise: add file and shmem support to MADV_COLLAPSE ...
2022-10-10Documentation/mm/page_owner.rst: delete frequently changing experimental dataYixuan Cao
The kernel size changes due to many factors, such as compiler version, configuration, and the build environment. This makes size comparison figures irrelevant to reader's setup. Remove these figures and describe the effects of page owner to the kernel size in general instead. Thanks for Jonathan Corbet, Bagas Sanjaya and Mike Rapoport's constructive suggestions. Signed-off-by: Yixuan Cao <caoyixuan2019@email.szu.edu.cn> Link: https://lore.kernel.org/r/20221005145525.10359-1-caoyixuan2019@email.szu.edu.cn Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-10-10Merge tag 'slab-for-6.1-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab fixes from Vlastimil Babka: - The "common kmalloc v4" series [1] by Hyeonggon Yoo. While the plan after LPC is to try again if it's possible to get rid of SLOB and SLAB (and if any critical aspect of those is not possible to achieve with SLUB today, modify it accordingly), it will take a while even in case there are no objections. Meanwhile this is a nice cleanup and some parts (e.g. to the tracepoints) will be useful even if we end up with a single slab implementation in the future: - Improves the mm/slab_common.c wrappers to allow deleting duplicated code between SLAB and SLUB. - Large kmalloc() allocations in SLAB are passed to page allocator like in SLUB, reducing number of kmalloc caches. - Removes the {kmem_cache_alloc,kmalloc}_node variants of tracepoints, node id parameter added to non-_node variants. - Addition of kmalloc_size_roundup() The first two patches from a series by Kees Cook [2] that introduce kmalloc_size_roundup(). This will allow merging of per-subsystem patches using the new function and ultimately stop (ab)using ksize() in a way that causes ongoing trouble for debugging functionality and static checkers. - Wasted kmalloc() memory tracking in debugfs alloc_traces A patch from Feng Tang that enhances the existing debugfs alloc_traces file for kmalloc caches with information about how much space is wasted by allocations that needs less space than the particular kmalloc cache provides. - My series [3] to fix validation races for caches with enabled debugging: - By decoupling the debug cache operation more from non-debug fastpaths, extra locking simplifications were possible and thus done afterwards. - Additional cleanup of PREEMPT_RT specific code on top, by Thomas Gleixner. - A late fix for slab page leaks caused by the series, by Feng Tang. - Smaller fixes and cleanups: - Unneeded variable removals, by ye xingchen - A cleanup removing a BUG_ON() in create_unique_id(), by Chao Yu Link: https://lore.kernel.org/all/20220817101826.236819-1-42.hyeyoo@gmail.com/ [1] Link: https://lore.kernel.org/all/20220923202822.2667581-1-keescook@chromium.org/ [2] Link: https://lore.kernel.org/all/20220823170400.26546-1-vbabka@suse.cz/ [3] * tag 'slab-for-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: (30 commits) mm/slub: fix a slab missed to be freed problem slab: Introduce kmalloc_size_roundup() slab: Remove __malloc attribute from realloc functions mm/slub: clean up create_unique_id() mm/slub: enable debugging memory wasting of kmalloc slub: Make PREEMPT_RT support less convoluted mm/slub: simplify __cmpxchg_double_slab() and slab_[un]lock() mm/slub: convert object_map_lock to non-raw spinlock mm/slub: remove slab_lock() usage for debug operations mm/slub: restrict sysfs validation to debug caches and make it safe mm/sl[au]b: check if large object is valid in __ksize() mm/slab_common: move declaration of __ksize() to mm/slab.h mm/slab_common: drop kmem_alloc & avoid dereferencing fields when not using mm/slab_common: unify NUMA and UMA version of tracepoints mm/sl[au]b: cleanup kmem_cache_alloc[_node]_trace() mm/sl[au]b: generalize kmalloc subsystem mm/slub: move free_debug_processing() further mm/sl[au]b: introduce common alloc/free functions without tracepoint mm/slab: kmalloc: pass requests larger than order-1 page to page allocator mm/slab_common: cleanup kmalloc_large() ...
2022-10-03ksm: add the ksm prefix to the names of the ksm private structuresQi Zheng
In order to prevent the name of the private structure of ksm from being the same as the name of the common structure used in subsequent patches, prefix their names with ksm in advance. Link: https://lkml.kernel.org/r/20220831031951.43152-5-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-29Documentation/mm: modify page_referenced to folio_referencedVernon Yang
Since commit b3ac04132c4b ("mm/rmap: Turn page_referenced() into folio_referenced()") the page_referenced function name was modified, so fix it up to use the correct one. Signed-off-by: Vernon Yang <vernon2gm@gmail.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Link: https://lore.kernel.org/r/20220926152032.74621-1-vernon2gm@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-26mm: multi-gen LRU: design docYu Zhao
Add a design doc. Link: https://lkml.kernel.org/r/20220918080010.2920238-15-yuzhao@google.com Signed-off-by: Yu Zhao <yuzhao@google.com> Acked-by: Brian Geffon <bgeffon@google.com> Acked-by: Jan Alexander Steffens (heftig) <heftig@archlinux.org> Acked-by: Oleksandr Natalenko <oleksandr@natalenko.name> Acked-by: Steven Barrett <steven@liquorix.net> Acked-by: Suleiman Souhlal <suleiman@google.com> Tested-by: Daniel Byrne <djbyrne@mtu.edu> Tested-by: Donald Carr <d@chaos-reins.com> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Tested-by: Konstantin Kharlamov <Hi-Angel@yandex.ru> Tested-by: Shuang Zhai <szhai2@cs.rochester.edu> Tested-by: Sofia Trinh <sofia.trinh@edi.works> Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Barry Song <baohua@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Larabel <Michael@MichaelLarabel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-23mm/slub: enable debugging memory wasting of kmallocFeng Tang
kmalloc's API family is critical for mm, with one nature that it will round up the request size to a fixed one (mostly power of 2). Say when user requests memory for '2^n + 1' bytes, actually 2^(n+1) bytes could be allocated, so in worst case, there is around 50% memory space waste. The wastage is not a big issue for requests that get allocated/freed quickly, but may cause problems with objects that have longer life time. We've met a kernel boot OOM panic (v5.10), and from the dumped slab info: [ 26.062145] kmalloc-2k 814056KB 814056KB From debug we found there are huge number of 'struct iova_magazine', whose size is 1032 bytes (1024 + 8), so each allocation will waste 1016 bytes. Though the issue was solved by giving the right (bigger) size of RAM, it is still nice to optimize the size (either use a kmalloc friendly size or create a dedicated slab for it). And from lkml archive, there was another crash kernel OOM case [1] back in 2019, which seems to be related with the similar slab waste situation, as the log is similar: [ 4.332648] iommu: Adding device 0000:20:02.0 to group 16 [ 4.338946] swapper/0 invoked oom-killer: gfp_mask=0x6040c0(GFP_KERNEL|__GFP_COMP), nodemask=(null), order=0, oom_score_adj=0 ... [ 4.857565] kmalloc-2048 59164KB 59164KB The crash kernel only has 256M memory, and 59M is pretty big here. (Note: the related code has been changed and optimised in recent kernel [2], these logs are just picked to demo the problem, also a patch changing its size to 1024 bytes has been merged) So add an way to track each kmalloc's memory waste info, and leverage the existing SLUB debug framework (specifically SLUB_STORE_USER) to show its call stack of original allocation, so that user can evaluate the waste situation, identify some hot spots and optimize accordingly, for a better utilization of memory. The waste info is integrated into existing interface: '/sys/kernel/debug/slab/kmalloc-xx/alloc_traces', one example of 'kmalloc-4k' after boot is: 126 ixgbe_alloc_q_vector+0xbe/0x830 [ixgbe] waste=233856/1856 age=280763/281414/282065 pid=1330 cpus=32 nodes=1 __kmem_cache_alloc_node+0x11f/0x4e0 __kmalloc_node+0x4e/0x140 ixgbe_alloc_q_vector+0xbe/0x830 [ixgbe] ixgbe_init_interrupt_scheme+0x2ae/0xc90 [ixgbe] ixgbe_probe+0x165f/0x1d20 [ixgbe] local_pci_probe+0x78/0xc0 work_for_cpu_fn+0x26/0x40 ... which means in 'kmalloc-4k' slab, there are 126 requests of 2240 bytes which got a 4KB space (wasting 1856 bytes each and 233856 bytes in total), from ixgbe_alloc_q_vector(). And when system starts some real workload like multiple docker instances, there could are more severe waste. [1]. https://lkml.org/lkml/2019/8/12/266 [2]. https://lore.kernel.org/lkml/2920df89-9975-5785-f79b-257d3052dfaf@huawei.com/ [Thanks Hyeonggon for pointing out several bugs about sorting/format] [Thanks Vlastimil for suggesting way to reduce memory usage of orig_size and keep it only for kmalloc objects] Signed-off-by: Feng Tang <feng.tang@intel.com> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: John Garry <john.garry@huawei.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2022-09-11mm/page_owner.c: add llseek for page_ownerKassey Li
It is too slow to dump all the pages, in some usage we just want to dump a given start pfn, for example: a CMA range or a single page. To speed up and save time, this change allows specifying of a start pfn by adding llseek for page_owner. Link: https://lkml.kernel.org/r/20220818022425.31056-1-quic_yingangl@quicinc.com Signed-off-by: Kassey Li <quic_yingangl@quicinc.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08Documentation/mm: add details about kmap_local_page() and preemptionFabio M. De Francesco
What happens if a thread is preempted after mapping pages with kmap_local_page() was questioned recently.[1] Commit f3ba3c710ac5 ("mm/highmem: Provide kmap_local*") from Thomas Gleixner explains clearly that on context switch, the maps of an outgoing task are removed and the map of the incoming task are restored and that kmap_local_page() can be invoked from both preemptible and atomic contexts.[2] Therefore, for the purpose to make it clearer that users can call kmap_local_page() from contexts that allow preemption, rework a couple of sentences and add further information in highmem.rst. [1] https://lore.kernel.org/lkml/5303077.Sb9uPGUboI@opensuse/ [2] https://lore.kernel.org/all/20201118204007.468533059@linutronix.de/ Link: https://lkml.kernel.org/r/20220728154844.10874-8-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Peter Collingbourne <pcc@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08Documentation/mm: rrefer kmap_local_page() and avoid kmap()Fabio M. De Francesco
The reasoning for converting kmap() to kmap_local_page() was questioned recently.[1] There are two main problems with kmap(): (1) It comes with an overhead as mapping space is restricted and protected by a global lock for synchronization and (2) kmap() also requires global TLB invalidation when its pool wraps and it might block when the mapping space is fully utilized until a slot becomes available. Warn users to avoid the use of kmap() and instead use kmap_local_page(), by designing their code to map pages in the same context the mapping will be used. [1] https://lore.kernel.org/lkml/1891319.taCxCBeP46@opensuse/ Link: https://lkml.kernel.org/r/20220728154844.10874-6-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Peter Collingbourne <pcc@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>