mirror of https://github.com/torvalds/linux.git
221 Commits
| Author | SHA1 | Message | Date |
|---|---|---|---|
Linus Torvalds
|
8804d970fa |
Summary of significant series in this pull request:
- The 3 patch series "mm, swap: improve cluster scan strategy" from Kairui Song improves performance and reduces the failure rate of swap cluster allocation. - The 4 patch series "support large align and nid in Rust allocators" from Vitaly Wool permits Rust allocators to set NUMA node and large alignment when perforning slub and vmalloc reallocs. - The 2 patch series "mm/damon/vaddr: support stat-purpose DAMOS" from Yueyang Pan extend DAMOS_STAT's handling of the DAMON operations sets for virtual address spaces for ops-level DAMOS filters. - The 3 patch series "execute PROCMAP_QUERY ioctl under per-vma lock" from Suren Baghdasaryan reduces mmap_lock contention during reads of /proc/pid/maps. - The 2 patch series "mm/mincore: minor clean up for swap cache checking" from Kairui Song performs some cleanup in the swap code. - The 11 patch series "mm: vm_normal_page*() improvements" from David Hildenbrand provides code cleanup in the pagemap code. - The 5 patch series "add persistent huge zero folio support" from Pankaj Raghav provides a block layer speedup by optionalls making the huge_zero_pagepersistent, instead of releasing it when its refcount falls to zero. - The 3 patch series "kho: fixes and cleanups" from Mike Rapoport adds a few touchups to the recently added Kexec Handover feature. - The 10 patch series "mm: make mm->flags a bitmap and 64-bit on all arches" from Lorenzo Stoakes turns mm_struct.flags into a bitmap. To end the constant struggle with space shortage on 32-bit conflicting with 64-bit's needs. - The 2 patch series "mm/swapfile.c and swap.h cleanup" from Chris Li cleans up some swap code. - The 7 patch series "selftests/mm: Fix false positives and skip unsupported tests" from Donet Tom fixes a few things in our selftests code. - The 7 patch series "prctl: extend PR_SET_THP_DISABLE to only provide THPs when advised" from David Hildenbrand "allows individual processes to opt-out of THP=always into THP=madvise, without affecting other workloads on the system". It's a long story - the [1/N] changelog spells out the considerations. - The 11 patch series "Add and use memdesc_flags_t" from Matthew Wilcox gets us started on the memdesc project. Please see https://kernelnewbies.org/MatthewWilcox/Memdescs and https://blogs.oracle.com/linux/post/introducing-memdesc. - The 3 patch series "Tiny optimization for large read operations" from Chi Zhiling improves the efficiency of the pagecache read path. - The 5 patch series "Better split_huge_page_test result check" from Zi Yan improves our folio splitting selftest code. - The 2 patch series "test that rmap behaves as expected" from Wei Yang adds some rmap selftests. - The 3 patch series "remove write_cache_pages()" from Christoph Hellwig removes that function and converts its two remaining callers. - The 2 patch series "selftests/mm: uffd-stress fixes" from Dev Jain fixes some UFFD selftests issues. - The 3 patch series "introduce kernel file mapped folios" from Boris Burkov introduces the concept of "kernel file pages". Using these permits btrfs to account its metadata pages to the root cgroup, rather than to the cgroups of random inappropriate tasks. - The 2 patch series "mm/pageblock: improve readability of some pageblock handling" from Wei Yang provides some readability improvements to the page allocator code. - The 11 patch series "mm/damon: support ARM32 with LPAE" from SeongJae Park teaches DAMON to understand arm32 highmem. - The 4 patch series "tools: testing: Use existing atomic.h for vma/maple tests" from Brendan Jackman performs some code cleanups and deduplication under tools/testing/. - The 2 patch series "maple_tree: Fix testing for 32bit compiles" from Liam Howlett fixes a couple of 32-bit issues in tools/testing/radix-tree.c. - The 2 patch series "kasan: unify kasan_enabled() and remove arch-specific implementations" from Sabyrzhan Tasbolatov moves KASAN arch-specific initialization code into a common arch-neutral implementation. - The 3 patch series "mm: remove zpool" from Johannes Weiner removes zspool - an indirection layer which now only redirects to a single thing (zsmalloc). - The 2 patch series "mm: task_stack: Stack handling cleanups" from Pasha Tatashin makes a couple of cleanups in the fork code. - The 37 patch series "mm: remove nth_page()" from David Hildenbrand makes rather a lot of adjustments at various nth_page() callsites, eventually permitting the removal of that undesirable helper function. - The 2 patch series "introduce kasan.write_only option in hw-tags" from Yeoreum Yun creates a KASAN read-only mode for ARM, using that architecture's memory tagging feature. It is felt that a read-only mode KASAN is suitable for use in production systems rather than debug-only. - The 3 patch series "mm: hugetlb: cleanup hugetlb folio allocation" from Kefeng Wang does some tidying in the hugetlb folio allocation code. - The 12 patch series "mm: establish const-correctness for pointer parameters" from Max Kellermann makes quite a number of the MM API functions more accurate about the constness of their arguments. This was getting in the way of subsystems (in this case CEPH) when they attempt to improving their own const/non-const accuracy. - The 7 patch series "Cleanup free_pages() misuse" from Vishal Moola fixes a number of code sites which were confused over when to use free_pages() vs __free_pages(). - The 3 patch series "Add Rust abstraction for Maple Trees" from Alice Ryhl makes the mapletree code accessible to Rust. Required by nouveau and by its forthcoming successor: the new Rust Nova driver. - The 2 patch series "selftests/mm: split_huge_page_test: split_pte_mapped_thp improvements" from David Hildenbrand adds a fix and some cleanups to the thp selftesting code. - The 14 patch series "mm, swap: introduce swap table as swap cache (phase I)" from Chris Li and Kairui Song is the first step along the path to implementing "swap tables" - a new approach to swap allocation and state tracking which is expected to yield speed and space improvements. This patchset itself yields a 5-20% performance benefit in some situations. - The 3 patch series "Some ptdesc cleanups" from Matthew Wilcox utilizes the new memdesc layer to clean up the ptdesc code a little. - The 3 patch series "Fix va_high_addr_switch.sh test failure" from Chunyu Hu fixes some issues in our 5-level pagetable selftesting code. - The 2 patch series "Minor fixes for memory allocation profiling" from Suren Baghdasaryan addresses a couple of minor issues in relatively new memory allocation profiling feature. - The 3 patch series "Small cleanups" from Matthew Wilcox has a few cleanups in preparation for more memdesc work. - The 2 patch series "mm/damon: add addr_unit for DAMON_LRU_SORT and DAMON_RECLAIM" from Quanmin Yan makes some changes to DAMON in furtherance of supporting arm highmem. - The 2 patch series "selftests/mm: Add -Wunreachable-code and fix warnings" from Muhammad Anjum adds that compiler check to selftests code and fixes the fallout, by removing dead code. - The 10 patch series "Improvements to Victim Process Thawing and OOM Reaper Traversal Order" from zhongjinji makes a number of improvements in the OOM killer: mainly thawing a more appropriate group of victim threads so they can release resources. - The 5 patch series "mm/damon: misc fixups and improvements for 6.18" from SeongJae Park is a bunch of small and unrelated fixups for DAMON. - The 7 patch series "mm/damon: define and use DAMON initialization check function" from SeongJae Park implement reliability and maintainability improvements to a recently-added bug fix. - The 2 patch series "mm/damon/stat: expose auto-tuned intervals and non-idle ages" from SeongJae Park provides additional transparency to userspace clients of the DAMON_STAT information. - The 2 patch series "Expand scope of khugepaged anonymous collapse" from Dev Jain removes some constraints on khubepaged's collapsing of anon VMAs. It also increases the success rate of MADV_COLLAPSE against an anon vma. - The 2 patch series "mm: do not assume file == vma->vm_file in compat_vma_mmap_prepare()" from Lorenzo Stoakes moves us further towards removal of file_operations.mmap(). This patchset concentrates upon clearing up the treatment of stacked filesystems. - The 6 patch series "mm: Improve mlock tracking for large folios" from Kiryl Shutsemau provides some fixes and improvements to mlock's tracking of large folios. /proc/meminfo's "Mlocked" field became more accurate. - The 2 patch series "mm/ksm: Fix incorrect accounting of KSM counters during fork" from Donet Tom fixes several user-visible KSM stats inaccuracies across forks and adds selftest code to verify these counters. - The 2 patch series "mm_slot: fix the usage of mm_slot_entry" from Wei Yang addresses some potential but presently benign issues in KSM's mm_slot handling. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCaN3cywAKCRDdBJ7gKXxA jtaPAQDmIuIu7+XnVUK5V11hsQ/5QtsUeLHV3OsAn4yW5/3dEQD/UddRU08ePN+1 2VRB0EwkLAdfMWW7TfiNZ+yhuoiL/AA= =4mhY -----END PGP SIGNATURE----- Merge tag 'mm-stable-2025-10-01-19-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - "mm, swap: improve cluster scan strategy" from Kairui Song improves performance and reduces the failure rate of swap cluster allocation - "support large align and nid in Rust allocators" from Vitaly Wool permits Rust allocators to set NUMA node and large alignment when perforning slub and vmalloc reallocs - "mm/damon/vaddr: support stat-purpose DAMOS" from Yueyang Pan extend DAMOS_STAT's handling of the DAMON operations sets for virtual address spaces for ops-level DAMOS filters - "execute PROCMAP_QUERY ioctl under per-vma lock" from Suren Baghdasaryan reduces mmap_lock contention during reads of /proc/pid/maps - "mm/mincore: minor clean up for swap cache checking" from Kairui Song performs some cleanup in the swap code - "mm: vm_normal_page*() improvements" from David Hildenbrand provides code cleanup in the pagemap code - "add persistent huge zero folio support" from Pankaj Raghav provides a block layer speedup by optionalls making the huge_zero_pagepersistent, instead of releasing it when its refcount falls to zero - "kho: fixes and cleanups" from Mike Rapoport adds a few touchups to the recently added Kexec Handover feature - "mm: make mm->flags a bitmap and 64-bit on all arches" from Lorenzo Stoakes turns mm_struct.flags into a bitmap. To end the constant struggle with space shortage on 32-bit conflicting with 64-bit's needs - "mm/swapfile.c and swap.h cleanup" from Chris Li cleans up some swap code - "selftests/mm: Fix false positives and skip unsupported tests" from Donet Tom fixes a few things in our selftests code - "prctl: extend PR_SET_THP_DISABLE to only provide THPs when advised" from David Hildenbrand "allows individual processes to opt-out of THP=always into THP=madvise, without affecting other workloads on the system". It's a long story - the [1/N] changelog spells out the considerations - "Add and use memdesc_flags_t" from Matthew Wilcox gets us started on the memdesc project. Please see https://kernelnewbies.org/MatthewWilcox/Memdescs and https://blogs.oracle.com/linux/post/introducing-memdesc - "Tiny optimization for large read operations" from Chi Zhiling improves the efficiency of the pagecache read path - "Better split_huge_page_test result check" from Zi Yan improves our folio splitting selftest code - "test that rmap behaves as expected" from Wei Yang adds some rmap selftests - "remove write_cache_pages()" from Christoph Hellwig removes that function and converts its two remaining callers - "selftests/mm: uffd-stress fixes" from Dev Jain fixes some UFFD selftests issues - "introduce kernel file mapped folios" from Boris Burkov introduces the concept of "kernel file pages". Using these permits btrfs to account its metadata pages to the root cgroup, rather than to the cgroups of random inappropriate tasks - "mm/pageblock: improve readability of some pageblock handling" from Wei Yang provides some readability improvements to the page allocator code - "mm/damon: support ARM32 with LPAE" from SeongJae Park teaches DAMON to understand arm32 highmem - "tools: testing: Use existing atomic.h for vma/maple tests" from Brendan Jackman performs some code cleanups and deduplication under tools/testing/ - "maple_tree: Fix testing for 32bit compiles" from Liam Howlett fixes a couple of 32-bit issues in tools/testing/radix-tree.c - "kasan: unify kasan_enabled() and remove arch-specific implementations" from Sabyrzhan Tasbolatov moves KASAN arch-specific initialization code into a common arch-neutral implementation - "mm: remove zpool" from Johannes Weiner removes zspool - an indirection layer which now only redirects to a single thing (zsmalloc) - "mm: task_stack: Stack handling cleanups" from Pasha Tatashin makes a couple of cleanups in the fork code - "mm: remove nth_page()" from David Hildenbrand makes rather a lot of adjustments at various nth_page() callsites, eventually permitting the removal of that undesirable helper function - "introduce kasan.write_only option in hw-tags" from Yeoreum Yun creates a KASAN read-only mode for ARM, using that architecture's memory tagging feature. It is felt that a read-only mode KASAN is suitable for use in production systems rather than debug-only - "mm: hugetlb: cleanup hugetlb folio allocation" from Kefeng Wang does some tidying in the hugetlb folio allocation code - "mm: establish const-correctness for pointer parameters" from Max Kellermann makes quite a number of the MM API functions more accurate about the constness of their arguments. This was getting in the way of subsystems (in this case CEPH) when they attempt to improving their own const/non-const accuracy - "Cleanup free_pages() misuse" from Vishal Moola fixes a number of code sites which were confused over when to use free_pages() vs __free_pages() - "Add Rust abstraction for Maple Trees" from Alice Ryhl makes the mapletree code accessible to Rust. Required by nouveau and by its forthcoming successor: the new Rust Nova driver - "selftests/mm: split_huge_page_test: split_pte_mapped_thp improvements" from David Hildenbrand adds a fix and some cleanups to the thp selftesting code - "mm, swap: introduce swap table as swap cache (phase I)" from Chris Li and Kairui Song is the first step along the path to implementing "swap tables" - a new approach to swap allocation and state tracking which is expected to yield speed and space improvements. This patchset itself yields a 5-20% performance benefit in some situations - "Some ptdesc cleanups" from Matthew Wilcox utilizes the new memdesc layer to clean up the ptdesc code a little - "Fix va_high_addr_switch.sh test failure" from Chunyu Hu fixes some issues in our 5-level pagetable selftesting code - "Minor fixes for memory allocation profiling" from Suren Baghdasaryan addresses a couple of minor issues in relatively new memory allocation profiling feature - "Small cleanups" from Matthew Wilcox has a few cleanups in preparation for more memdesc work - "mm/damon: add addr_unit for DAMON_LRU_SORT and DAMON_RECLAIM" from Quanmin Yan makes some changes to DAMON in furtherance of supporting arm highmem - "selftests/mm: Add -Wunreachable-code and fix warnings" from Muhammad Anjum adds that compiler check to selftests code and fixes the fallout, by removing dead code - "Improvements to Victim Process Thawing and OOM Reaper Traversal Order" from zhongjinji makes a number of improvements in the OOM killer: mainly thawing a more appropriate group of victim threads so they can release resources - "mm/damon: misc fixups and improvements for 6.18" from SeongJae Park is a bunch of small and unrelated fixups for DAMON - "mm/damon: define and use DAMON initialization check function" from SeongJae Park implement reliability and maintainability improvements to a recently-added bug fix - "mm/damon/stat: expose auto-tuned intervals and non-idle ages" from SeongJae Park provides additional transparency to userspace clients of the DAMON_STAT information - "Expand scope of khugepaged anonymous collapse" from Dev Jain removes some constraints on khubepaged's collapsing of anon VMAs. It also increases the success rate of MADV_COLLAPSE against an anon vma - "mm: do not assume file == vma->vm_file in compat_vma_mmap_prepare()" from Lorenzo Stoakes moves us further towards removal of file_operations.mmap(). This patchset concentrates upon clearing up the treatment of stacked filesystems - "mm: Improve mlock tracking for large folios" from Kiryl Shutsemau provides some fixes and improvements to mlock's tracking of large folios. /proc/meminfo's "Mlocked" field became more accurate - "mm/ksm: Fix incorrect accounting of KSM counters during fork" from Donet Tom fixes several user-visible KSM stats inaccuracies across forks and adds selftest code to verify these counters - "mm_slot: fix the usage of mm_slot_entry" from Wei Yang addresses some potential but presently benign issues in KSM's mm_slot handling * tag 'mm-stable-2025-10-01-19-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (372 commits) mm: swap: check for stable address space before operating on the VMA mm: convert folio_page() back to a macro mm/khugepaged: use start_addr/addr for improved readability hugetlbfs: skip VMAs without shareable locks in hugetlb_vmdelete_list alloc_tag: fix boot failure due to NULL pointer dereference mm: silence data-race in update_hiwater_rss mm/memory-failure: don't select MEMORY_ISOLATION mm/khugepaged: remove definition of struct khugepaged_mm_slot mm/ksm: get mm_slot by mm_slot_entry() when slot is !NULL hugetlb: increase number of reserving hugepages via cmdline selftests/mm: add fork inheritance test for ksm_merging_pages counter mm/ksm: fix incorrect KSM counter handling in mm_struct during fork drivers/base/node: fix double free in register_one_node() mm: remove PMD alignment constraint in execmem_vmalloc() mm/memory_hotplug: fix typo 'esecially' -> 'especially' mm/rmap: improve mlock tracking for large folios mm/filemap: map entire large folio faultaround mm/fault: try to map the entire file folio in finish_fault() mm/rmap: mlock large folios in try_to_unmap_one() mm/rmap: fix a mlock race condition in folio_referenced_one() ... |
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Liam R. Howlett
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719a42e563 |
maple_tree: Convert forking to use the sheaf interface
Use the generic interface which should result in less bulk allocations during a forking. A part of this is to abstract the freeing of the sheaf or maple state allocations into its own function so mas_destroy() and the tree duplication code can use the same functionality to return any unused resources. [andriy.shevchenko@linux.intel.com: remove unused mt_alloc_bulk()] Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> |
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Liam R. Howlett
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6bf377b06c |
maple_tree: Add single node allocation support to maple state
The fast path through a write will require replacing a single node in the tree. Using a sheaf (32 nodes) is too heavy for the fast path, so special case the node store operation by just allocating one node in the maple state. Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> |
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Liam R. Howlett
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9b05890a25 |
maple_tree: Prefilled sheaf conversion and testing
Use prefilled sheaves instead of bulk allocations. This should speed up the allocations and the return path of unused allocations. Remove the push and pop of nodes from the maple state as this is now handled by the slab layer with sheaves. Testing has been removed as necessary since the features of the tree have been reduced. Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> |
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Pedro Falcato
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025f93101b |
maple_tree: Replace mt_free_one() with kfree()
kfree() is a little shorter and works with kmem_cache_alloc'd pointers too. Also lets us remove one more helper. Signed-off-by: Pedro Falcato <pfalcato@suse.de> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> |
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Pedro Falcato
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9b60811cb3 |
maple_tree: Use kfree_rcu in ma_free_rcu
kfree_rcu is an optimized version of call_rcu + kfree. It used to not be
possible to call it on non-kmalloc objects, but this restriction was
lifted ever since SLOB was dropped from the kernel, and since commit
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Vlastimil Babka
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59faa4da7c |
maple_tree: use percpu sheaves for maple_node_cache
Setup the maple_node_cache with percpu sheaves of size 32 to hopefully improve its performance. Note this will not immediately take advantage of sheaf batching of kfree_rcu() operations due to the maple tree using call_rcu with custom callbacks. The followup changes to maple tree will change that and also make use of the prefilled sheaves functionality. Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> |
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Liam R. Howlett
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e3852a1213 |
maple_tree: Drop bulk insert support
Bulk insert mode was added to facilitate forking faster, but forking now uses __mt_dup() to duplicate the tree. The addition of sheaves has made the bulk allocations difficult to maintain - since the expected entries would preallocate into the maple state. A big part of the maple state node allocation was the ability to push nodes back onto the state for later use, which was essential to the bulk insert algorithm. Remove mas_expected_entries() and mas_destroy_rebalance() functions as well as the MA_STATE_BULK and MA_STATE_REBALANCE maple state flags since there are no users anymore. Drop the associated testing as well. Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> |
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Qianfeng Rong
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a8541957e7 |
maple_tree: remove redundant __GFP_NOWARN
Commit
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Sidhartha Kumar
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ef49b7b39d |
maple_tree: fix MAPLE_PARENT_RANGE32 and parent pointer docs
MAPLE_PARENT_RANGE32 should be 0x02 as a 32 bit node is indicated by the
bit pattern 0b010 which is the hex value 0x02. There are no users
currently, so there is no associated bug with this wrong value.
Fix typo Note -> Node and replace x with b to indicate binary values.
Link: https://lkml.kernel.org/r/20250826151344.403286-1-sidhartha.kumar@oracle.com
Fixes:
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Dev Jain
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526f36f3f4 |
maple tree: add some comments
Add comments explaining the fields for maple_metadata, since "end" is ambiguous and "gap" can be confused as the largest gap, whereas it is actually the offset of the largest gap. Add comment for mas_ascend() to explain, whose min and max we are trying to find. Explain that, for example, if we are already on offset zero, then the parent min is mas->min, otherwise we need to walk up to find the implied pivot min. Link: https://lkml.kernel.org/r/20250703063338.51509-1-dev.jain@arm.com Signed-off-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Andrew Morton
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cac3d177c0 |
Merge branch 'mm-hotfixes-stable' into mm-stable to pick up changes which
are required for a merge of the series "mm: folio_pte_batch() improvements". |
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Liam R. Howlett
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12f1d79312 |
maple_tree: fix status setup on restore to active
During the initial call with a maple state, an error status may be set
before a valid node is populated into the maple state node. Subsequent
calls with the maple state may restore the state into an active state with
no node set. This was masked by the mas_walk() always resetting the
status to ma_start and result in an extra walk in this rare scenario.
Don't restore the state to active unless there is a value in the structs
node. This also allows mas_walk() to be fixed to use the active state
without exposing an issue.
User visible results are marginal performance improvements when an active
state can be restored and used instead of rewalking the tree.
Stable is not Cc'ed because the existing code is stable and the
performance gains are not worth the risk.
Link: https://lore.kernel.org/all/20250611011253.19515-1-richard.weiyang@gmail.com/
Link: https://lore.kernel.org/all/20250407231354.11771-1-richard.weiyang@gmail.com/
Link: https://lore.kernel.org/all/202506191556.6bfc7b93-lkp@intel.com/
Link: https://lkml.kernel.org/r/20250624154823.52221-1-Liam.Howlett@oracle.com
Fixes:
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Dev Jain
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592b939b59 |
maple tree: use goto label to simplify code
Use the underflow goto label to set the status to ma_underflow and return NULL, as is being done elsewhere. [akpm@linux-foundation.org: add newline, per Liam (and remove one, per akpm)] Link: https://lkml.kernel.org/r/20250624080748.4855-1-dev.jain@arm.com Signed-off-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Wei Yang
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ea9b77f98d |
maple_tree: fix mt_destroy_walk() on root leaf node
On destroy, we should set each node dead. But current code miss this when
the maple tree has only the root node.
The reason is mt_destroy_walk() leverage mte_destroy_descend() to set node
dead, but this is skipped since the only root node is a leaf.
Fixes this by setting the node dead if it is a leaf.
Link: https://lore.kernel.org/all/20250407231354.11771-1-richard.weiyang@gmail.com/
Link: https://lkml.kernel.org/r/20250624191841.64682-1-Liam.Howlett@oracle.com
Fixes:
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Liam R. Howlett
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fba46a5d83 |
maple_tree: fix MA_STATE_PREALLOC flag in mas_preallocate()
Temporarily clear the preallocation flag when explicitly requesting
allocations. Pre-existing allocations are already counted against the
request through mas_node_count_gfp(), but the allocations will not happen
if the MA_STATE_PREALLOC flag is set. This flag is meant to avoid
re-allocating in bulk allocation mode, and to detect issues with
preallocation calculations.
The MA_STATE_PREALLOC flag should also always be set on zero allocations
so that detection of underflow allocations will print a WARN_ON() during
consumption.
User visible effect of this flaw is a WARN_ON() followed by a null pointer
dereference when subsequent requests for larger number of nodes is
ignored, such as the vma merge retry in mmap_region() caused by drivers
altering the vma flags (which happens in v6.6, at least)
Link: https://lkml.kernel.org/r/20250616184521.3382795-3-Liam.Howlett@oracle.com
Fixes:
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Sidhartha Kumar
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2a6ed1b411 |
maple_tree: reorder mas->store_type case statements
Move the unlikely case that mas->store_type is invalid to be the last evaluated case and put liklier cases higher up. Link: https://lkml.kernel.org/r/20250410191446.2474640-7-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Suggested-by: Liam R. Howlett <liam.howlett@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Sidhartha Kumar
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271152a973 |
maple_tree: add sufficient height
In order to support rebalancing and spanning stores using less than the worst case number of nodes, we need to track more than just the vacant height. Using only vacant height to reduce the worst case maple node allocation count can lead to a shortcoming of nodes in the following scenarios. For rebalancing writes, when a leaf node becomes insufficient, it may be combined with a sibling into a single node. This means that the parent node which has entries for this children will lose one entry. If this parent node was just meeting the minimum entries, losing one entry will now cause this parent node to be insufficient. This leads to a cascading operation of rebalancing at different levels and can lead to more node allocations than simply using vacant height can return. For spanning writes, a similar situation occurs. At the location at which a spanning write is detected, the number of ancestor nodes may similarly need to rebalanced into a smaller number of nodes and the same cascading situation could occur. To use less than the full height of the tree for the number of allocations, we also need to track the height at which a non-leaf node cannot become insufficient. This means even if a rebalance occurs to a child of this node, it currently has enough entries that it can lose one without any further action. This field is stored in the maple write state as sufficient height. In mas_prealloc_calc() when figuring out how many nodes to allocate, we check if the vacant node is lower in the tree than a sufficient node (has a larger value). If it is, we cannot use the vacant height and must use the difference in the height and sufficient height as the basis for the number of nodes needed. An off by one bug was also discovered in mast_overflow() where it is using >= rather than >. This caused extra iterations of the mas_spanning_rebalance() loop and lead to unneeded allocations. A test is also added to check the number of allocations is correct. Link: https://lkml.kernel.org/r/20250410191446.2474640-6-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Sidhartha Kumar
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300a5b4ffe |
maple_tree: break on convergence in mas_spanning_rebalance()
This allows support for using the vacant height to calculate the worst case number of nodes needed for wr_rebalance operation. mas_spanning_rebalance() was seen to perform unnecessary node allocations. We can reduce allocations by breaking early during the rebalancing loop once we realize that we have ascended to a common ancestor. Link: https://lkml.kernel.org/r/20250410191446.2474640-5-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Suggested-by: Liam Howlett <liam.howlett@oracle.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Sidhartha Kumar
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ad88fc17d2 |
maple_tree: use vacant nodes to reduce worst case allocations
In order to determine the store type for a maple tree operation, a walk of the tree is done through mas_wr_walk(). This function descends the tree until a spanning write is detected or we reach a leaf node. While descending, keep track of the height at which we encounter a node with available space. This is done by checking if mas->end is less than the number of slots a given node type can fit. Now that the height of the vacant node is tracked, we can use the difference between the height of the tree and the height of the vacant node to know how many levels we will have to propagate creating new nodes. Update mas_prealloc_calc() to consider the vacant height and reduce the number of worst-case allocations. Rebalancing and spanning stores are not supported and fall back to using the full height of the tree for allocations. Update preallocation testing assertions to take into account vacant height. Link: https://lkml.kernel.org/r/20250410191446.2474640-4-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Sidhartha Kumar
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f9d3a963fe |
maple_tree: use height and depth consistently
For the maple tree, the root node is defined to have a depth of 0 with a height of 1. Each level down from the node, these values are incremented by 1. Various code paths define a root with depth 1 which is inconsisent with the definition. Modify the code to be consistent with this definition. In mas_spanning_rebalance(), l_mas.depth was being used to track the height based on the number of iterations done in the main loop. This information was then used in mas_put_in_tree() to set the height. Rather than overload the l_mas.depth field to track height, simply keep track of height in the local variable new_height and directly pass this to mas_wmb_replace() which will be passed into mas_put_in_tree(). This allows up to remove writes to l_mas.depth. Link: https://lkml.kernel.org/r/20250410191446.2474640-3-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Sidhartha Kumar
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28092a652f |
maple_tree: convert mas_prealloc_calc() to take in a maple write state
Patch series "Track node vacancy to reduce worst case allocation counts", v5. ================ overview ======================== Currently, the maple tree preallocates the worst case number of nodes for given store type by taking into account the whole height of the tree. This comes from a worst case scenario of every node in the tree being full and having to propagate node allocation upwards until we reach the root of the tree. This can be optimized if there are vacancies in nodes that are at a lower depth than the root node. This series implements tracking the level at which there is a vacant node so we only need to allocate until this level is reached, rather than always using the full height of the tree. The ma_wr_state struct is modified to add a field which keeps track of the vacant height and is updated during walks of the tree. This value is then read in mas_prealloc_calc() when we decide how many nodes to allocate. For rebalancing and spanning stores, we also need to track the lowest height at which a node has 1 more entry than the minimum sufficient number of entries. This is because rebalancing can cause a parent node to become insufficient which results in further node allocations. In this case, we need to use the sufficient height as the worst case rather than the vacant height. patch 1-2: preparatory patches patch 3: implement vacant height tracking + update the tests patch 4: support vacant height tracking for rebalancing writes patch 5: implement sufficient height tracking patch 6: reorder switch case statements ================ results ========================= Bpftrace was used to profile the allocation path for requesting new maple nodes while running stress-ng mmap 120s. The histograms below represent requests to kmem_cache_alloc_bulk() and show the count argument. This represnts how many maple nodes the caller is requesting in kmem_cache_alloc_bulk() command: stress-ng --mmap 4 --timeout 120 mm-unstable @bulk_alloc_req: [3, 4) 4 | | [4, 5) 54170 |@ | [5, 6) 0 | | [6, 7) 893057 |@@@@@@@@@@@@@@@@@@@@ | [7, 8) 4 | | [8, 9) 2230287 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [9, 10) 55811 |@ | [10, 11) 77834 |@ | [11, 12) 0 | | [12, 13) 1368684 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ | [13, 14) 0 | | [14, 15) 0 | | [15, 16) 367197 |@@@@@@@@ | @maple_node_total: 46,630,160 @total_vmas: 46184591 mm-unstable + this series @bulk_alloc_req: [2, 3) 198 | | [3, 4) 4 | | [4, 5) 43 | | [5, 6) 0 | | [6, 7) 1069503 |@@@@@@@@@@@@@@@@@@@@@ | [7, 8) 4 | | [8, 9) 2597268 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@| [9, 10) 472191 |@@@@@@@@@ | [10, 11) 191904 |@@@ | [11, 12) 0 | | [12, 13) 247316 |@@@@ | [13, 14) 0 | | [14, 15) 0 | | [15, 16) 98769 |@ | @maple_node_total: 37,813,856 @total_vmas: 43493287 This represents a ~19% reduction in the number of bulk maple nodes allocated. For more reproducible results, a historgram of the return value of mas_prealloc_calc() is displayed while running the maple_tree_tests whcih have a deterministic store pattern mas_prealloc_calc() return value mm-unstable 1 : (12068) 3 : (11836) 5 : ***** (271192) 7 : ************************************************** (2329329) 9 : *********** (534186) 10 : (435) 11 : *************** (704306) 13 : ******** (409781) mas_prealloc_calc() return value mm-unstable + this series 1 : (12070) 3 : ************************************************** (3548777) 5 : ******** (633458) 7 : (65081) 9 : (11224) 10 : (341) 11 : (2973) 13 : (68) do_mmap latency was also measured for regressions: command: stress-ng --mmap 4 --timeout 120 mm-unstable: avg = 7162 nsecs, total: 16101821292 nsecs, count: 2248034 mm-unstable + this series: avg = 6689 nsecs, total: 15135391764 nsecs, count: 2262726 stress-ng --mmap4 --timeout 120 with vacant_height: stress-ng: info: [257] 21526312 Maple Tree Read 0.176 M/sec stress-ng: info: [257] 339979348 Maple Tree Write 2.774 M/sec without vacant_height: stress-ng: info: [8228] 20968900 Maple Tree Read 0.171 M/sec stress-ng: info: [8228] 312214648 Maple Tree Write 2.547 M/sec This represents an increase of ~3% read throughput and ~9% increase in write throughput. This patch (of 6): In a subsequent patch, mas_prealloc_calc() will need to access fields only in the ma_wr_state. Convert the function to take in a ma_wr_state and modify all callers. There is no functional change. Link: https://lkml.kernel.org/r/20250410191446.2474640-1-sidhartha.kumar@oracle.com Link: https://lkml.kernel.org/r/20250410191446.2474640-2-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Petr Tesarik
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18ea595a07 |
maple_tree: remove a BUG_ON() in mas_alloc_nodes()
Remove a BUG_ON() right before a WARN_ON() with the same condition.
Calling WARN_ON() and BUG_ON() here is definitely wrong. Since the goal is
generally to remove BUG_ON() invocations from the kernel, keep only the
WARN_ON().
Link: https://lkml.kernel.org/r/20250213114453.1078318-1-ptesarik@suse.com
Fixes:
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I Hsin Cheng
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6fbea85271 |
maple_tree: use ma_dead_node() in mte_dead_node()
Utilize ma_dead_node() in mte_dead_node(). It can prevent decoding the maple enode for a second time. Use the "node" to find parent for comparison. Link: https://lkml.kernel.org/r/20250211071850.330632-1-richard120310@gmail.com Signed-off-by: I Hsin Cheng <richard120310@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw> Cc: Shuah khan <skhan@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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I Hsin Cheng
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67254c7d70 |
maple_tree: correct comment for mas_start()
There's no mas->status of "mas_start", what the function is checking is whether mas->status equals to "ma_start". Correct the comment for the function. Link: https://lkml.kernel.org/r/20250209181023.228856-1-richard120310@gmail.com Signed-off-by: I Hsin Cheng <richard120310@gmail.com> Reviewed-by: Liam R. Howlett <howlett@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Wei Yang
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7318f95ba4 |
maple_tree: only root node could be deficient
Each level's rightmost node should have (max == ULONG_MAX). This means current validation skips the right most node on each level. Only the root node may be below the minimum data threshold. Link: https://lkml.kernel.org/r/20241113031616.10530-4-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Wei Yang
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4f6a6bed0b |
maple_tree: simplify split calculation
Patch series "simplify split calculation", v3.
This patch (of 3):
The current calculation for splitting nodes tries to enforce a minimum
span on the leaf nodes. This code is complex and never worked correctly
to begin with, due to the min value being passed as 0 for all leaves.
The calculation should just split the data as equally as possible
between the new nodes. Note that b_end will be one more than the data,
so the left side is still favoured in the calculation.
The current code may also lead to a deficient node by not leaving enough
data for the right side of the split. This issue is also addressed with
the split calculation change.
[Liam.Howlett@Oracle.com: rephrase the change log]
Link: https://lkml.kernel.org/r/20241113031616.10530-1-richard.weiyang@gmail.com
Link: https://lkml.kernel.org/r/20241113031616.10530-2-richard.weiyang@gmail.com
Fixes:
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Wei Yang
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f2760364ad |
maple_tree: we don't set offset to MAPLE_NODE_SLOTS on error
When mas_anode_descend() not find gap, it sets -EBUSY instead of setting offset to MAPLE_NODE_SLOTS. Link: https://lkml.kernel.org/r/20241116014805.11547-4-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Wei Yang
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f5bd418727 |
maple_tree: not possible to be a root node after loop
Empty tree and single entry tree is handled else whether, so the maple tree here must be a tree with nodes. If the height is 1 and we found the gap, it will jump to *done* since it is also a leaf. If the height is more than one, and there may be an available range, we will descend the tree, which is not root anymore. If there is no available range, we will set error and return. This means the check for root node here is not necessary. Link: https://lkml.kernel.org/r/20241116014805.11547-3-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Wei Yang
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5f8db8d428 |
maple_tree: index has been checked to be smaller than pivot
Patch series "mas_anode_descend() related cleanup". Some cleanup related to mas_anode_descend(). This patch (of 3): At the beginning of loop, it has checked the range is in lower bounds. Link: https://lkml.kernel.org/r/20241116014805.11547-1-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20241116014805.11547-2-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Wei Yang
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002ebb925e |
maple_tree: use mas_next_slot() directly
The loop condition makes sure (mas.last < max), so we can directly use mas_next_slot() here. Since no other use of mas_next_entry(), it is removed. Link: https://lkml.kernel.org/r/20241125024156.26093-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Yang Erkun
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1fd8bc7cd8 |
maple_tree: reload mas before the second call for mas_empty_area
Change the LONG_MAX in simple_offset_add to 1024, and do latter:
[root@fedora ~]# mkdir /tmp/dir
[root@fedora ~]# for i in {1..1024}; do touch /tmp/dir/$i; done
touch: cannot touch '/tmp/dir/1024': Device or resource busy
[root@fedora ~]# rm /tmp/dir/123
[root@fedora ~]# touch /tmp/dir/1024
[root@fedora ~]# rm /tmp/dir/100
[root@fedora ~]# touch /tmp/dir/1025
touch: cannot touch '/tmp/dir/1025': Device or resource busy
After we delete file 100, actually this is a empty entry, but the latter
create failed unexpected.
mas_alloc_cyclic has two chance to find empty entry. First find the entry
with range range_lo and range_hi, if no empty entry exist, and range_lo >
min, retry find with range min and range_hi. However, the first call
mas_empty_area may mark mas as EBUSY, and the second call for
mas_empty_area will return false directly. Fix this by reload mas before
second call for mas_empty_area.
[Liam.Howlett@Oracle.com: fix mas_alloc_cyclic() second search]
Link: https://lore.kernel.org/all/20241216060600.287B4C4CED0@smtp.kernel.org/
Link: https://lkml.kernel.org/r/20241216190113.1226145-2-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20241214093005.72284-1-yangerkun@huaweicloud.com
Fixes:
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Wei Yang
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0ea120b278 |
maple_tree: refine mas_store_root() on storing NULL
Currently, when storing NULL on mas_store_root(), the behavior could be
improved.
Storing NULLs over the entire tree may result in a node being used to
store a single range. Further stores of NULL may cause the node and
tree to be corrupt and cause incorrect behaviour. Fixing the store to
the root null fixes the issue by ensuring that a range of 0 - ULONG_MAX
results in an empty tree.
Users of the tree may experience incorrect values returned if the tree
was expanded to store values, then overwritten by all NULLS, then
continued to store NULLs over the empty area.
For example possible cases are:
* store NULL at any range result a new node
* store NULL at range [m, n] where m > 0 to a single entry tree result
a new node with range [m, n] set to NULL
* store NULL at range [m, n] where m > 0 to an empty tree result
consecutive NULL slot
* it allows for multiple NULL entries by expanding root
to store NULLs to an empty tree
This patch tries to improve in:
* memory efficient by setting to empty tree instead of using a node
* remove the possibility of consecutive NULL slot which will prohibit
extended null in later operation
Link: https://lkml.kernel.org/r/20241031231627.14316-5-richard.weiyang@gmail.com
Fixes:
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Wei Yang
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8c836f1712 |
maple_tree: not necessary to check index/last again
Before calling mas_new_root(), the range has been checked. Link: https://lkml.kernel.org/r/20241031231627.14316-4-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Wei Yang
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cefbcf206f |
maple_tree: the return value of mas_root_expand() is not used
No user of the return value now, just remove it. Link: https://lkml.kernel.org/r/20241031231627.14316-3-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Wei Yang
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04dafdd208 |
maple_tree: print empty for an empty tree on mt_dump()
Patch series "refine storing null", v5. When overwriting the whole range with NULL, current behavior is not correct. An empty tree is represented by having the tree point to NULL directly. An empty tree indicates the entire range (0-ULONG_MAX) is NULL. A store operation into an existing node that causes 0 - ULONG_MAX to be equal to NULL may not be restored to an empty state - a node is used to store the single range instead. This is wasteful and different from the initial setup of the tree. Once the tree is using a single node to store 0 - ULONG_MAX, problems may arise when storing more values into a tree with the unexpected state of 0 - ULONG being a single range in a node. User visible issues may mean a corrupt tree and incorrect storage of information within the tree. This would be limited to users who create and then empty a tree by overwriting all values, then try to store more NULLs into the empty tree. I cannot come up with an example of any user doing this (users usually destroy the tree and generally don't keep trying to store NULLs over NULLs), but patch 4/5 "maple_tree: refine mas_store_root() on storing NULL" should be backported just in case. This patch (of 5): Currently for an empty tree, it would print: maple_tree(0x7ffcd02c6ee0) flags 1, height 0 root (nil) 0: (nil) This is a little misleading. Let's print (empty) for an empty tree. Link: https://lkml.kernel.org/r/20241031231627.14316-1-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20241031231627.14316-2-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Wei Yang
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38dc8f4952 |
maple_tree: remove sanity check from mas_wr_slot_store()
After commit
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Wei Yang
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61e9df7085 |
maple_tree: calculate new_end when needed
Patch series "Following cleanup after introduce mas_wr_store_type()", v2. Patch 1 postpone new_end calculation when needed. Patch 2 removes a unnecessary sanity check in mas_wr_slot_store(). This patch (of 2): For wr_exact_fit/wr_new_root, we don't need to calculate new_end. Let's postpone it until necessary. Link: https://lkml.kernel.org/r/20241017015809.23392-1-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20241017015809.23392-2-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Wei Yang
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908378a30b |
maple_tree: simplify mas_push_node()
When count is not 0, we know head is valid. So we can put the assignment in if (count) instead of checking the head pointer again. Also count represents current total, we can assign the new total by increasing the count by one. Link: https://lkml.kernel.org/r/20241015120746.15850-4-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Wei Yang
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4223dd93bf |
maple_tree: total is not changed for nomem_one case
If it jumps to nomem_one, the total allocated number is not changed. So we don't need to adjust it. For the nomem_bulk case, we know there is a valid mas->alloc. So we don't need to do the check. Link: https://lkml.kernel.org/r/20241015120746.15850-3-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Wei Yang
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e852cb1d00 |
maple_tree: clear request_count for new allocated one
Patch series "maple_tree: simplify mas_push_node()", v2. When count is not 0, we know head is valid. So we can put the assignment in if (count) instead of checking the head pointer again. Also count represents current total, we can assign the new total by increasing the count by one. This patch (of 3): If this is not a new allocated one, the request_count has already been cleared in mas_set_alloc_req(). Link: https://lkml.kernel.org/r/20241015120746.15850-1-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20241015120746.15850-2-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Wei Yang
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0cc8d68abe |
maple_tree: root node could be handled by !p_slot too
For a root node, mte_parent_slot() return 0, this exactly fits the following !p_slot check. So we can remove the special handling for root node. Link: https://lkml.kernel.org/r/20240913063128.27391-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Jiazi Li
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5b2100f723 |
maple_tree: fix alloc node fail issue
In the following code, the second call to the mas_node_count will return
-ENOMEM:
mas_node_count(mas, MAPLE_ALLOC_SLOTS + 1);
mas_node_count(mas, MAPLE_ALLOC_SLOTS * 2 + 2);
This is because there may be some full maple_alloc node in current maple
state. Use full maple_alloc node will make max_req equal to 0. And it
leads to mt_alloc_bulk return 0. As a result, mas_node_count set mas.node
to MA_ERROR(-ENOMEM).
Find a non-full maple_alloc node, and if necessary, use this non-full node
in the next while loop.
Link: https://lkml.kernel.org/r/20240626160631.3636515-1-Liam.Howlett@oracle.com
Fixes:
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Sidhartha Kumar
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f0c99037a0 |
maple_tree: refactor mas_wr_store_type()
In mas_wr_store_type(), we check if new_end < mt_slots[wr_mas->type]. If this check fails, we know that ,after this, new_end is >= mt_min_slots. Checking this again when we detect a wr_node_store later in the function is reduntant. Because this check is part of an OR statement, the statement will always evaluate to true, therefore we can just get rid of it. We also refactor mas_wr_store_type() to return the store type rather than set it directly as it greatly cleans up the function. Link: https://lkml.kernel.org/r/20241011214451.7286-2-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha <sidhartha.kumar@oracle.com> Suggested-by: Liam Howlett <liam.howlett@oracle.com> Suggested-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam Howlett <liam.howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Lorenzo Stoakes
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b314e21596 |
maple_tree: do not hash pointers on dump in debug mode
Many maple tree values output when an mt_validate() or equivalent hits an issue utilise tagged pointers, most notably parent nodes. Also some pivots/slots contain meaningful values, output as pointers, such as the index of the last entry with data for example. All pointer values such as this are destroyed by kernel pointer hashing rendering the debug output obtained from CONFIG_DEBUG_VM_MAPLE_TREE considerably less usable. Update this code to output the raw pointers using %px rather than %p when CONFIG_DEBUG_VM_MAPLE_TREE is defined. This is justified, as the use of this configuration flag indicates that this is a test environment. Userland does not understand %px, so use %p there. In an abundance of caution, if CONFIG_DEBUG_VM_MAPLE_TREE is not set, also use %p to avoid exposing raw kernel pointers except when we are positive a testing mode is enabled. This was inspired by the investigation performed in recent debugging efforts around a maple tree regression [0] where kernel pointer tagging had to be disabled in order to obtain truly meaningful and useful data. [0]:https://lore.kernel.org/all/20241001023402.3374-1-spasswolf@web.de/ Link: https://lkml.kernel.org/r/20241007115335.90104-1-lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Wei Yang
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5059aa6334 |
maple_tree: memset maple_big_node as a whole
In mast_fill_bnode(), we first clear some fields of maple_big_node and set the 'type' unconditionally before return. This means we won't leverage any information in maple_big_node and it is safe to clear the whole structure. In maple_big_node, we define slot and padding/gap in a union. And based on current definition of MAPLE_BIG_NODE_SLOTS/GAPS, padding is always less than slot and part of the gap is overlapped by slot. For example on 64bit system: MAPLE_BIG_NODE_SLOT is 34 MAPLE_BIG_NODE_GAP is 21 With this knowledge, current code may clear some space by twice. And this could be avoid by clearing the structure as a whole. Link: https://lkml.kernel.org/r/20240908140554.20378-3-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Wei Yang
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f36ba81081 |
maple_tree: remove maple_big_node.parent
Patch series "Reduce the space to be cleared for maple_big_node", v2. Found current code may clear maple_big_node redundantly. First we define a field parent, which is never used. After removing this, we reduce the size of memory to be cleared by memset. Then mast_fill_bnode() clears part of the structure twice, since slot and gap share some space. By clearing the whole structure, we can avoid this. This patch (of 2): The member parent of maple_big_node is never used. Let's remove it which could reduce the number of space to be cleared on memset. Link: https://lkml.kernel.org/r/20240908140554.20378-1-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20240908140554.20378-2-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Wei Yang
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1c148069b2 |
maple_tree: goto complete directly on a pivot of 0
When we break the loop after assigning a pivot, the index i/j is not changed. Then the following code assign pivot, which means we do the assignment with same i/j by mas_safe_pivot. Since the loop condition is (i < piv_end), from which we can get i is less than mt_pivots[mt]. It implies mas_safe_pivot() return pivot[i] which is the same value we get in loop. Now we can conclude it does a redundant assignment on a pivot of 0. Let's just go to complete to avoid it. Link: https://lkml.kernel.org/r/20240911142759.20989-3-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Wei Yang
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8c7904a8cd |
maple_tree: i is always less than or equal to mas_end
Patch series "refine mas_mab_cp()".
By analysis of the code, one condition check can be removed and one case
would hit a redundant assignment.
This patch (of 2):
mas_mab_cp() copy range [mas_start, mas_end] inclusively from a
maple_node to maple_big_node. This implies mas_start <= mas_end.
Based on the relationship of mas_start and mas_end, we can have the
following four cases:
| mas_start == mas_end | mas_start < mas_end
---------------+----------------------+----------------------
mas_start == 0 | 1 | 2
---------------+----------------------+----------------------
mas_start != 0 | 3 | 4
We can see in all these four cases, i is always less than or equal to
mas_end after finish the loop:
Case 1: After assign pivot 0, i is set to 1, which is bigger than
mas_end 0. So it jumps to complete and skip the check.
Case 2: After assign pivot 0, i is set to 1.
∵ (mas_start < mas_end) && (mas_start == 0)
==> (1 <= mas_end)
∵ (i == 1) && (1 <= mas_end)
==> (i <= mas_end)
∴ Before loop, we have (i <= mas_end). And we still hold this
if it skips the loop. For example, (i == mas_end).
Now let's see what happens in the loop:
∵ piv_end = min(mas_end, mt_pivots[mt])
==> (piv_end <= mas_end)
∵ loop condition is (i < piv_end)
==> (i <= piv_end) on finish the loop both normally or break
∵ (i <= piv_end) && (piv_end <= mas_end)
==> (i <= mas_end)
∴ After loop, we still get (i <= mas_end) in this case
Case 3: This case would skip both if clause and loop. So when it comes
to the check, i is still mas_start which equals to mas_end.
Case 4: This case would skip the if clause.
∵ (mas_start < mas_end) && (i == mas_start)
==> (i < mas_end)
∴ Before loop, we have (i < mas_end).
The loop process is similar with Case 2, so we get the same
result.
Now we can conclude in all cases, we get (i <= mas_end) when doing
check. Then it is not necessary to do the check.
Link: https://lkml.kernel.org/r/20240911142759.20989-1-richard.weiyang@gmail.com
Link: https://lkml.kernel.org/r/20240911142759.20989-2-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Lorenzo Stoakes
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bea07fd631 |
maple_tree: correct tree corruption on spanning store
Patch series "maple_tree: correct tree corruption on spanning store", v3. There has been a nasty yet subtle maple tree corruption bug that appears to have been in existence since the inception of the algorithm. This bug seems far more likely to happen since commit |