kernel/linux.git/lib/test_maple_tree.c, branch v6.6.131

maple_tree: add GFP_KERNEL to allocations in mas_expected_entries()

2023-10-18T19:12:41+00:00

Users complained about OOM errors during fork without triggering compaction. This can be fixed by modifying the flags used in mas_expected_entries() so that the compaction will be triggered in low memory situations. Since mas_expected_entries() is only used during fork, the extra argument does not need to be passed through. Additionally, the two test_maple_tree test cases and one benchmark test were altered to use the correct locking type so that allocations would not trigger sleeping and thus fail. Testing was completed with lockdep atomic sleep detection. The additional locking change requires rwsem support additions to the tools/ directory through the use of pthreads pthread_rwlock_t. With this change test_maple_tree works in userspace, as a module, and in-kernel. Users may notice that the system gave up early on attempting to start new processes instead of attempting to reclaim memory. Link: https://lkml.kernel.org/r/20230915093243epcms1p46fa00bbac1ab7b7dca94acb66c44c456@epcms1p4 Link: https://lkml.kernel.org/r/20231012155233.2272446-1-Liam.Howlett@oracle.com Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Liam R. Howlett Reviewed-by: Peng Zhang Cc: Cc: Signed-off-by: Andrew Morton

maple_tree: add MAS_UNDERFLOW and MAS_OVERFLOW states

2023-09-30T00:20:46+00:00

When updating the maple tree iterator to avoid rewalks, an issue was introduced when shifting beyond the limits. This can be seen by trying to go to the previous address of 0, which would set the maple node to MAS_NONE and keep the range as the last entry. Subsequent calls to mas_find() would then search upwards from mas->last and skip the value at mas->index/mas->last. This showed up as a bug in mprotect which skips the actual VMA at the current range after attempting to go to the previous VMA from 0. Since MAS_NONE may already be set when searching for a value that isn't contained within a node, changing the handling of MAS_NONE in mas_find() would make the code more complicated and error prone. Furthermore, there was no way to tell which limit was hit, and thus which action to take (next or the entry at the current range). This solution is to add two states to track what happened with the previous iterator action. This allows for the expected behaviour of the next command to return the correct item (either the item at the range requested, or the next/previous). Tests are also added and updated accordingly. Link: https://lkml.kernel.org/r/20230921181236.509072-3-Liam.Howlett@oracle.com Link: https://gist.github.com/heatd/85d2971fae1501b55b6ea401fbbe485b Link: https://lore.kernel.org/linux-mm/20230921181236.509072-1-Liam.Howlett@oracle.com/ Fixes: 39193685d585 ("maple_tree: try harder to keep active node with mas_prev()") Signed-off-by: Liam R. Howlett Reported-by: Pedro Falcato Closes: https://gist.github.com/heatd/85d2971fae1501b55b6ea401fbbe485b Closes: https://bugs.archlinux.org/task/79656 Cc: Signed-off-by: Andrew Morton

maple_tree: add benchmarking for mas_prev()

2023-08-18T17:12:47+00:00

Add some benchmarking functions in testing for mas_prev(). This is useful to ensure there are no regressions added during modifications. Link: https://lkml.kernel.org/r/20230724183157.3939892-3-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett Cc: Peng Zhang Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton

maple_tree: add benchmarking for mas_for_each

2023-08-18T17:12:47+00:00

Patch series "Reduce preallocations for maple tree", v3. Initial work on preallocations showed no regression in performance during testing, but recently some users (both on [1] and off [android] list) have reported that preallocating the worst-case number of nodes has caused some slow down. This patch set addresses the number of allocations in a few ways. During munmap() most munmap() operations will remove a single VMA, so leverage the fact that the maple tree can place a single pointer at range 0 - 0 without allocating. This is done by changing the index of the VMAs to be indexed by the count, starting at 0. Re-introduce the entry argument to mas_preallocate() so that a more intelligent guess of the node count can be made. Implement the more intelligent guess of the node count, although there is more work to be done. During development of v2 of this patch set, I also noticed that the number of nodes being allocated for a rebalance was beyond what could possibly be needed. This is addressed in patch 0008. This patch (of 15): Add a way to test the speed of mas_for_each() to the testing code. Link: https://lkml.kernel.org/r/20230724183157.3939892-1-Liam.Howlett@oracle.com Link: https://lkml.kernel.org/r/20230724183157.3939892-2-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett Cc: Peng Zhang Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton

maple_tree: add test for mas_wr_modify() fast path

2023-08-18T17:12:05+00:00

Patch series "Optimize the fast path of mas_store()", v4. Add fast paths for mas_wr_append() and mas_wr_slot_store() respectively. The newly added fast path of mas_wr_append() is used in fork() and how much it benefits fork() depends on how many VMAs are duplicated. Thanks Liam for the review. This patch (of 4): Add tests for all cases of mas_wr_append() and mas_wr_slot_store(). Link: https://lkml.kernel.org/r/20230628073657.75314-1-zhangpeng.00@bytedance.com Link: https://lkml.kernel.org/r/20230628073657.75314-2-zhangpeng.00@bytedance.com Signed-off-by: Peng Zhang Reviewed-by: Liam R. Howlett Signed-off-by: Andrew Morton

maple_tree: fix 32 bit mas_next testing

2023-07-17T19:53:22+00:00

The test setup of mas_next is dependent on node entry size to create a 2 level tree, but the tests did not account for this in the expected value when shifting beyond the scope of the tree. Fix this by setting up the test to succeed depending on the node entries which is dependent on the 32/64 bit setup. Link: https://lkml.kernel.org/r/20230712173916.168805-1-Liam.Howlett@oracle.com Fixes: 120b116208a0 ("maple_tree: reorganize testing to restore module testing") Signed-off-by: Liam R. Howlett Reported-by: Geert Uytterhoeven Closes: https://lore.kernel.org/linux-mm/CAMuHMdV4T53fOw7VPoBgPR7fP6RYqf=CBhD_y_vOg53zZX_DnA@mail.gmail.com/ Tested-by: Geert Uytterhoeven Cc: Signed-off-by: Andrew Morton

maple_tree: update testing code for mas_{next,prev,walk}

2023-06-09T23:25:35+00:00

Now that the functions have changed the limits, update the testing of the maple tree to test these new settings. Link: https://lkml.kernel.org/r/20230518145544.1722059-34-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett Cc: David Binderman Cc: Peng Zhang Cc: Sergey Senozhatsky Cc: Vernon Yang Cc: Wei Yang Signed-off-by: Andrew Morton

maple_tree: fix testing mas_empty_area()

2023-06-09T23:25:33+00:00

Empty area will return -EINVAL if the search window is smaller than the requested size. Fix the test case to check for this error code. Link: https://lkml.kernel.org/r/20230518145544.1722059-27-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett Cc: David Binderman Cc: Peng Zhang Cc: Sergey Senozhatsky Cc: Vernon Yang Cc: Wei Yang Signed-off-by: Andrew Morton

maple_tree: revise limit checks in mas_empty_area{_rev}()

2023-06-09T23:25:33+00:00

Since the maple tree is inclusive in range, ensure that a range of 1 (min = max) works for searching for a gap in either direction, and make sure the size is at least 1 but not larger than the delta between min and max. This commit also updates the testing. Unfortunately there isn't a way to safely update the tests and code without a test failure. Link: https://lkml.kernel.org/r/20230518145544.1722059-26-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett Suggested-by: Peng Zhang Cc: David Binderman Cc: Sergey Senozhatsky Cc: Vernon Yang Cc: Wei Yang Signed-off-by: Andrew Morton

maple_tree: add init and exit to test module

2023-06-09T23:25:31+00:00

The test functions are not needed after the module is removed, so mark them as such. Add __exit to the module removal function. Some other variables have been marked as const static as well. Link: https://lkml.kernel.org/r/20230518145544.1722059-20-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett Suggested-by: Andrew Morton Cc: David Binderman Cc: Peng Zhang Cc: Sergey Senozhatsky Cc: Vernon Yang Cc: Wei Yang Signed-off-by: Andrew Morton

kernel/linux.git/lib/test_maple_tree.c, branch v6.6.131

maple_tree: add GFP_KERNEL to allocations in mas_expected_entries()

maple_tree: add MAS_UNDERFLOW and MAS_OVERFLOW states

maple_tree: add benchmarking for mas_prev()

maple_tree: add benchmarking for mas_for_each

maple_tree: add test for mas_wr_modify() fast path

maple_tree: fix 32 bit mas_next testing

maple_tree: update testing code for mas_{next,prev,walk}

maple_tree: fix testing mas_empty_area()

maple_tree: revise limit checks in mas_empty_area{_rev}()

maple_tree: add __init and __exit to test module

maple_tree: add init and exit to test module