kernel/linux.git/lib/test_xarray.c, branch v6.18.21

xarray: make xa_alloc_cyclic() return 0 on all success cases

2025-05-12T00:48:19+00:00

Change xa_alloc_cyclic() to return 0 even on wrap-around. Do the same for xa_alloc_cyclic_irq() and xa_alloc_cyclic_bh(). This will prevent any future bug of treating return of 1 as an error: int ret = xa_alloc_cyclic(...) if (ret) // currently mishandles ret==1 goto failure; If there will be someone interested in when wrap-around occurs, there is still __xa_alloc_cyclic() that behaves as before. For now there is no such user. Link: https://lkml.kernel.org/r/20250320102219.8101-1-przemyslaw.kitszel@intel.com Signed-off-by: Przemek Kitszel Suggested-by: Matthew Wilcox Link: https://lore.kernel.org/netdev/Z9gUd-5t8b5NX2wE@casper.infradead.org Cc: Andriy Shevchenko Cc: Dave Hansen Cc: Michal Swiatkowski Cc: Przemek Kitszel Signed-off-by: Andrew Morton

xarray: add xas_try_split() to split a multi-index entry

2025-03-18T05:06:59+00:00

Patch series "Buddy allocator like (or non-uniform) folio split", v10. This patchset adds a new buddy allocator like (or non-uniform) large folio split from a order-n folio to order-m with m < n. It reduces 1. the total number of after-split folios from 2^(n-m) to n-m+1; 2. the amount of memory needed for multi-index xarray split from 2^(n/6-m/6) to n/6-m/6, assuming XA_CHUNK_SHIFT=6; 3. keep more large folios after a split from all order-m folios to order-(n-1) to order-m folios. For example, to split an order-9 to order-0, folio split generates 10 (or 11 for anonymous memory) folios instead of 512, allocates 1 xa_node instead of 8, and leaves 1 order-8, 1 order-7, ..., 1 order-1 and 2 order-0 folios (or 4 order-0 for anonymous memory) instead of 512 order-0 folios. Instead of duplicating existing split_huge_page*() code, __folio_split() is introduced as the shared backend code for both split_huge_page_to_list_to_order() and folio_split(). __folio_split() can support both uniform split and buddy allocator like (or non-uniform) split. All existing split_huge_page*() users can be gradually converted to use folio_split() if possible. In this patchset, I converted truncate_inode_partial_folio() to use folio_split(). xfstests quick group passed for both tmpfs and xfs. I also semi-replicated Hugh's test[12] and ran it without any issue for almost 24 hours. This patch (of 8): A preparation patch for non-uniform folio split, which always split a folio into half iteratively, and minimal xarray entry split. Currently, xas_split_alloc() and xas_split() always split all slots from a multi-index entry. They cost the same number of xa_node as the to-be-split slots. For example, to split an order-9 entry, which takes 2^(9-6)=8 slots, assuming XA_CHUNK_SHIFT is 6 (!CONFIG_BASE_SMALL), 8 xa_node are needed. Instead xas_try_split() is intended to be used iteratively to split the order-9 entry into 2 order-8 entries, then split one order-8 entry, based on the given index, to 2 order-7 entries, ..., and split one order-1 entry to 2 order-0 entries. When splitting the order-6 entry and a new xa_node is needed, xas_try_split() will try to allocate one if possible. As a result, xas_try_split() would only need 1 xa_node instead of 8. When a new xa_node is needed during the split, xas_try_split() can try to allocate one but no more. -ENOMEM will be return if a node cannot be allocated. -EINVAL will be return if a sibling node is split or cascade split happens, where two or more new nodes are needed, and these are not supported by xas_try_split(). xas_split_alloc() and xas_split() split an order-9 to order-0: --------------------------------- | | | | | | | | | | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | | | | | | | | | | --------------------------------- | | | | ------- --- --- ------- | | ... | | V V V V ----------- ----------- ----------- ----------- | xa_node | | xa_node | ... | xa_node | | xa_node | ----------- ----------- ----------- ----------- xas_try_split() splits an order-9 to order-0: --------------------------------- | | | | | | | | | | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | | | | | | | | | | --------------------------------- | | V ----------- | xa_node | ----------- Link: https://lkml.kernel.org/r/20250307174001.242794-1-ziy@nvidia.com Link: https://lkml.kernel.org/r/20250307174001.242794-2-ziy@nvidia.com Signed-off-by: Zi Yan Cc: Baolin Wang Cc: David Hildenbrand Cc: Hugh Dickins Cc: John Hubbard Cc: Kefeng Wang Cc: Kirill A. Shuemov Cc: Miaohe Lin Cc: Matthew Wilcox Cc: Ryan Roberts Cc: Yang Shi Cc: Yu Zhao Cc: Zi Yan Cc: Kairui Song Signed-off-by: Andrew Morton

test_xarray: fix failure in check_pause when CONFIG_XARRAY_MULTI is not defined

2025-02-18T06:40:04+00:00

In case CONFIG_XARRAY_MULTI is not defined, xa_store_order can store a multi-index entry but xas_for_each can't tell sbiling entry from valid entry. So the check_pause failed when we store a multi-index entry and wish xas_for_each can handle it normally. Avoid to store multi-index entry when CONFIG_XARRAY_MULTI is disabled to fix the failure. Link: https://lkml.kernel.org/r/20250213163659.414309-1-shikemeng@huaweicloud.com Fixes: c9ba5249ef8b ("Xarray: move forward index correctly in xas_pause()") Signed-off-by: Kemeng Shi Reported-by: Geert Uytterhoeven Closes: https://lore.kernel.org/r/CAMuHMdU_bfadUO=0OZ=AoQ9EAmQPA4wsLCBqohXR+QCeCKRn4A@mail.gmail.com Tested-by: Geert Uytterhoeven Cc: Matthew Wilcox Signed-off-by: Andrew Morton

revert "xarray: port tests to kunit"

2025-02-01T11:53:28+00:00

Revert c7bb5cf9fc4e ("xarray: port tests to kunit"). It broke the build when compiing the xarray userspace test harness code. Reported-by: Sidhartha Kumar Closes: https://lkml.kernel.org/r/07cf896e-adf8-414f-a629-a808fc26014a@oracle.com Cc: David Gow Cc: Matthew Wilcox Cc: Tamir Duberstein Cc: "Liam R. Howlett" Cc: Geert Uytterhoeven Cc: Lorenzo Stoakes Signed-off-by: Andrew Morton

Xarray: move forward index correctly in xas_pause()

2025-01-25T06:47:27+00:00

After xas_load(), xas->index could point to mid of found multi-index entry and xas->index's bits under node->shift maybe non-zero. The afterward xas_pause() will move forward xas->index with xa->node->shift with bits under node->shift un-masked and thus skip some index unexpectedly. Consider following case: Assume XA_CHUNK_SHIFT is 4. xa_store_range(xa, 16, 31, ...) xa_store(xa, 32, ...) XA_STATE(xas, xa, 17); xas_for_each(&xas,...) xas_load(&xas) /* xas->index = 17, xas->xa_offset = 1, xas->xa_node->xa_shift = 4 */ xas_pause() /* xas->index = 33, xas->xa_offset = 2, xas->xa_node->xa_shift = 4 */ As we can see, index of 32 is skipped unexpectedly. Fix this by mask bit under node->xa_shift when move forward index in xas_pause(). For now, this will not cause serious problems. Only minor problem like cachestat return less number of page status could happen. Link: https://lkml.kernel.org/r/20241213122523.12764-3-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi Cc: Mattew Wilcox Signed-off-by: Andrew Morton

xarray: port tests to kunit

2025-01-13T04:21:00+00:00

Minimally rewrite the XArray unit tests to use kunit. This integrates nicely with existing kunit tools which produce nicer human-readable output compared to the existing machinery. Running the xarray tests before this change requires an obscure invocation ``` tools/testing/kunit/kunit.py run --arch arm64 --make_options LLVM=1 \ --kconfig_add CONFIG_TEST_XARRAY=y --raw_output=all nothing ``` which on failure produces ``` BUG at check_reserve:513 ... XArray: 6782340 of 6782364 tests passed ``` and exits 0. Running the xarray tests after this change requires a simpler invocation ``` tools/testing/kunit/kunit.py run --arch arm64 --make_options LLVM=1 \ xarray ``` which on failure produces (colors omitted) ``` [09:50:53] ====================== check_reserve ====================== [09:50:53] [FAILED] param-0 [09:50:53] # check_reserve: EXPECTATION FAILED at lib/test_xarray.c:536 [09:50:53] xa_erase(xa, 12345678) != NULL ... [09:50:53] # module: test_xarray [09:50:53] # xarray: pass:26 fail:3 skip:0 total:29 [09:50:53] # Totals: pass:28 fail:3 skip:0 total:31 [09:50:53] ===================== [FAILED] xarray ====================== ``` and exits 1. Use of richer kunit assertions is intentionally omitted to reduce the scope of the change. [akpm@linux-foundation.org: fix cocci warning] Link: https://lore.kernel.org/oe-kbuild-all/202412081700.YXB3vBbg-lkp@intel.com/ Link: https://lkml.kernel.org/r/20241205-xarray-kunit-port-v1-1-ee44bc7aa201@gmail.com Signed-off-by: Tamir Duberstein Cc: Bill Wendling Cc: Christophe Leroy Cc: Geert Uytterhoeven Cc: Justin Stitt Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Nathan Chancellor Cc: Naveen N Rao Cc: Nicholas Piggin Cc: Nick Desaulniers Signed-off-by: Andrew Morton

test_xarray: add missing MODULE_DESCRIPTION() macro

2024-07-04T02:30:05+00:00

make allmodconfig && make W=1 C=1 reports: WARNING: modpost: missing MODULE_DESCRIPTION() in lib/test_xarray.o Add the missing invocation of the MODULE_DESCRIPTION() macro. Link: https://lkml.kernel.org/r/20240531-md-lib-test_xarray-v1-1-42fd6833bdd4@quicinc.com Signed-off-by: Jeff Johnson Cc: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton

Merge tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-05-19T16:21:03+00:00

Pull mm updates from Andrew Morton: "The usual shower of singleton fixes and minor series all over MM, documented (hopefully adequately) in the respective changelogs. Notable series include: - Lucas Stach has provided some page-mapping cleanup/consolidation/ maintainability work in the series "mm/treewide: Remove pXd_huge() API". - In the series "Allow migrate on protnone reference with MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one test. - In their series "Memory allocation profiling" Kent Overstreet and Suren Baghdasaryan have contributed a means of determining (via /proc/allocinfo) whereabouts in the kernel memory is being allocated: number of calls and amount of memory. - Matthew Wilcox has provided the series "Various significant MM patches" which does a number of rather unrelated things, but in largely similar code sites. - In his series "mm: page_alloc: freelist migratetype hygiene" Johannes Weiner has fixed the page allocator's handling of migratetype requests, with resulting improvements in compaction efficiency. - In the series "make the hugetlb migration strategy consistent" Baolin Wang has fixed a hugetlb migration issue, which should improve hugetlb allocation reliability. - Liu Shixin has hit an I/O meltdown caused by readahead in a memory-tight memcg. Addressed in the series "Fix I/O high when memory almost met memcg limit". - In the series "mm/filemap: optimize folio adding and splitting" Kairui Song has optimized pagecache insertion, yielding ~10% performance improvement in one test. - Baoquan He has cleaned up and consolidated the early zone initialization code in the series "mm/mm_init.c: refactor free_area_init_core()". - Baoquan has also redone some MM initializatio code in the series "mm/init: minor clean up and improvement". - MM helper cleanups from Christoph Hellwig in his series "remove follow_pfn". - More cleanups from Matthew Wilcox in the series "Various page->flags cleanups". - Vlastimil Babka has contributed maintainability improvements in the series "memcg_kmem hooks refactoring". - More folio conversions and cleanups in Matthew Wilcox's series: "Convert huge_zero_page to huge_zero_folio" "khugepaged folio conversions" "Remove page_idle and page_young wrappers" "Use folio APIs in procfs" "Clean up __folio_put()" "Some cleanups for memory-failure" "Remove page_mapping()" "More folio compat code removal" - David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb functions to work on folis". - Code consolidation and cleanup work related to GUP's handling of hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2". - Rick Edgecombe has developed some fixes to stack guard gaps in the series "Cover a guard gap corner case". - Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series "mm/ksm: fix ksm exec support for prctl". - Baolin Wang has implemented NUMA balancing for multi-size THPs. This is a simple first-cut implementation for now. The series is "support multi-size THP numa balancing". - Cleanups to vma handling helper functions from Matthew Wilcox in the series "Unify vma_address and vma_pgoff_address". - Some selftests maintenance work from Dev Jain in the series "selftests/mm: mremap_test: Optimizations and style fixes". - Improvements to the swapping of multi-size THPs from Ryan Roberts in the series "Swap-out mTHP without splitting". - Kefeng Wang has significantly optimized the handling of arm64's permission page faults in the series "arch/mm/fault: accelerate pagefault when badaccess" "mm: remove arch's private VM_FAULT_BADMAP/BADACCESS" - GUP cleanups from David Hildenbrand in "mm/gup: consistently call it GUP-fast". - hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to use struct vm_fault". - selftests build fixes from John Hubbard in the series "Fix selftests/mm build without requiring "make headers"". - Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes the initialization code so that migration between different memory types works as intended. - David Hildenbrand has improved follow_pte() and fixed an errant driver in the series "mm: follow_pte() improvements and acrn follow_pte() fixes". - David also did some cleanup work on large folio mapcounts in his series "mm: mapcount for large folios + page_mapcount() cleanups". - Folio conversions in KSM in Alex Shi's series "transfer page to folio in KSM". - Barry Song has added some sysfs stats for monitoring multi-size THP's in the series "mm: add per-order mTHP alloc and swpout counters". - Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled and limit checking cleanups". - Matthew Wilcox has been looking at buffer_head code and found the documentation to be lacking. The series is "Improve buffer head documentation". - Multi-size THPs get more work, this time from Lance Yang. His series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes the freeing of these things. - Kemeng Shi has added more userspace-visible writeback instrumentation in the series "Improve visibility of writeback". - Kemeng Shi then sent some maintenance work on top in the series "Fix and cleanups to page-writeback". - Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the series "Improve anon_vma scalability for anon VMAs". Intel's test bot reported an improbable 3x improvement in one test. - SeongJae Park adds some DAMON feature work in the series "mm/damon: add a DAMOS filter type for page granularity access recheck" "selftests/damon: add DAMOS quota goal test" - Also some maintenance work in the series "mm/damon/paddr: simplify page level access re-check for pageout" "mm/damon: misc fixes and improvements" - David Hildenbrand has disabled some known-to-fail selftests ni the series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL". - memcg metadata storage optimizations from Shakeel Butt in "memcg: reduce memory consumption by memcg stats". - DAX fixes and maintenance work from Vishal Verma in the series "dax/bus.c: Fixups for dax-bus locking"" * tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits) memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault selftests: cgroup: add tests to verify the zswap writeback path mm: memcg: make alloc_mem_cgroup_per_node_info() return bool mm/damon/core: fix return value from damos_wmark_metric_value mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED selftests: cgroup: remove redundant enabling of memory controller Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT Docs/mm/damon/design: use a list for supported filters Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file selftests/damon: classify tests for functionalities and regressions selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None' selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts selftests/damon/_damon_sysfs: check errors from nr_schemes file reads mm/damon/core: initialize ->esz_bp from damos_quota_init_priv() selftests/damon: add a test for DAMOS quota goal ...

XArray: set the marks correctly when splitting an entry

2024-05-06T00:28:08+00:00

If we created a new node to replace an entry which had search marks set, we were setting the search mark on every entry in that node. That works fine when we're splitting to order 0, but when splitting to a larger order, we must not set the search marks on the sibling entries. Link: https://lkml.kernel.org/r/20240501153120.4094530-1-willy@infradead.org Fixes: c010d47f107f ("mm: thp: split huge page to any lower order pages") Signed-off-by: Matthew Wilcox (Oracle) Reported-by: Luis Chamberlain Link: https://lore.kernel.org/r/ZjFGCOYk3FK_zVy3@bombadil.infradead.org Tested-by: Luis Chamberlain Cc: Zi Yan Signed-off-by: Andrew Morton

lib/test_xarray.c: fix error assumptions on check_xa_multi_store_adv_add()

2024-05-06T00:28:05+00:00

While testing lib/test_xarray in userspace I've noticed we can fail with: make -C tools/testing/radix-tree ./tools/testing/radix-tree/xarray BUG at check_xa_multi_store_adv_add:749 xarray: 0x55905fb21a00x head 0x55905fa1d8e0x flags 0 marks 0 0 0 0: 0x55905fa1d8e0x xarray: ../../../lib/test_xarray.c:749: check_xa_multi_store_adv_add: Assertion `0' failed. Aborted We get a failure with a BUG_ON(), and that is because we actually can fail due to -ENOMEM, the check in xas_nomem() will fix this for us so it makes no sense to expect no failure inside the loop. So modify the check and since this is also useful for instructional purposes clarify the situation. The check for XA_BUG_ON(xa, xa_load(xa, index) != p) is already done at the end of the loop so just remove the bogus on inside the loop. With this we now pass the test in both kernel and userspace: In userspace: ./tools/testing/radix-tree/xarray XArray: 149092856 of 149092856 tests passed In kernel space: XArray: 148257077 of 148257077 tests passed Link: https://lkml.kernel.org/r/20240423192221.301095-3-mcgrof@kernel.org Fixes: a60cc288a1a2 ("test_xarray: add tests for advanced multi-index use") Signed-off-by: Luis Chamberlain Cc: Daniel Gomez Cc: Darrick J. Wong Cc: Dave Chinner Cc: "Liam R. Howlett" Cc: Matthew Wilcox (Oracle) Cc: Pankaj Raghav Signed-off-by: Andrew Morton