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2025-03-22selftests/mm: speed up split_huge_page_testRyan Roberts1-4/+7
create_pagecache_thp_and_fd() was previously writing a file sized at twice the PMD size by making a per-byte write syscall. This was quite slow when the PMD size is 4M, but completely intolerable for 32M (PMD size for arm64's 16K page size), and 512M (PMD size for arm64's 64K page size). The byte pattern has a 256 byte period, so let's create a 1K buffer and fill it with exactly 4 periods. Then we can write the buffer as many times as is required to fill the file. This makes things much more tolerable. The test now passes for 16K page size. It still fails for 64K page size because MAX_PAGECACHE_ORDER is too small for 512M folio size (I think). Link: https://lkml.kernel.org/r/20250318174343.243631-3-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: Peter Xu <peterx@redhat.com> Acked-by: Rafael Aquini <raquini@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-18selftests/mm: add tests for folio_split(), buddy allocator like splitZi Yan1-7/+27
It splits page cache folios to orders from 0 to 8 at different in-folio offset. Link: https://lkml.kernel.org/r/20250307174001.242794-9-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Kairui Song <kasong@tencent.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17selftests/mm: test splitting file-backed THP to any lower orderZi Yan1-5/+6
Now split_huge_page*() supports shmem THP split to any lower order. Test it. The test now reads file content out after split to check if the split corrupts the file data. Link: https://lkml.kernel.org/r/20250122161928.1240637-3-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17selftests/mm: make file-backed THP split work by writing PMD size dataZi Yan1-8/+44
Commit acd7ccb284b8 ("mm: shmem: add large folio support for tmpfs") changes huge=always to allocate THP/mTHP based on write size and split_huge_page_test does not write PMD size data, so file-back THP is not created during the test. Fix it by writing PMD size data. Link: https://lkml.kernel.org/r/20250122161928.1240637-1-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-26selftests/mm: add tests for splitting pmd THPs to all lower ordersZi Yan1-5/+9
Kernel already supports splitting a folio to any lower order. Test it. [ziy@nvidia.com: no need to test splitting to order-1] Link: https://lkml.kernel.org/r/DDA202EA-4664-4F50-A7FD-B00CBB7A624B@nvidia.com Link: https://lkml.kernel.org/r/20250110235028.96824-2-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Cc: Alexander Zhu <alexlzhu@fb.com> Cc: Rik van Riel <riel@surriel.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Usama Arif <usamaarif642@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-26selftests/mm: use selftests framework to print test resultZi Yan1-22/+12
Otherwise the number of tests does not match the reality. Link: https://lkml.kernel.org/r/20250110235028.96824-1-ziy@nvidia.com Fixes: 391e86971161 ("mm: selftest to verify zero-filled pages are mapped to zeropage") Signed-off-by: Zi Yan <ziy@nvidia.com> Cc: Alexander Zhu <alexlzhu@fb.com> Cc: Rik van Riel <riel@surriel.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Usama Arif <usamaarif642@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-10mm: selftest to verify zero-filled pages are mapped to zeropageAlexander Zhu1-0/+71
When a THP is split, any subpage that is zero-filled will be mapped to the shared zeropage, hence saving memory. Add selftest to verify this by allocating zero-filled THP and comparing RssAnon before and after split. Link: https://lkml.kernel.org/r/20240830100438.3623486-4-usamaarif642@gmail.com Signed-off-by: Alexander Zhu <alexlzhu@fb.com> Signed-off-by: Usama Arif <usamaarif642@gmail.com> Acked-by: Rik van Riel <riel@surriel.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kairui Song <ryncsn@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nico Pache <npache@redhat.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Shuang Zhai <zhais@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Shuang Zhai <szhai2@cs.rochester.edu> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04selftests/mm: use asm volatile to not optimize mmap read variablePankaj Raghav1-1/+2
create_pagecache_thp_and_fd() in split_huge_page_test.c used the variable dummy to perform mmap read. However, this test was skipped even on XFS which has large folio support. The issue was compiler (gcc 13.2.0) was optimizing out the dummy variable, therefore, not creating huge page in the page cache. Use asm volatile() trick to force the compiler not to optimize out the loop where we read from the mmaped addr. This is similar to what is being done in other tests (cow.c, etc) As the variable is now used in the asm statement, remove the unused attribute. Link: https://lkml.kernel.org/r/20240606203619.677276-1-kernel@pankajraghav.com Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Pankaj Raghav <p.raghav@samsung.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25selftests: mm: fix unused and uninitialized variable warningMuhammad Usama Anjum1-1/+1
Fix the warnings by initializing and marking the variable as unused. I've caught the warnings by using clang. split_huge_page_test.c:303:6: warning: variable 'dummy' set but not used [-Wunused-but-set-variable] 303 | int dummy; | ^ split_huge_page_test.c:343:3: warning: variable 'dummy' is uninitialized when used here [-Wuninitialized] 343 | dummy += *(*addr + i); | ^~~~~ split_huge_page_test.c:303:11: note: initialize the variable 'dummy' to silence this warning 303 | int dummy; | ^ | = 0 2 warnings generated. Link: https://lkml.kernel.org/r/20240416162658.3353622-1-usama.anjum@collabora.com Fixes: fc4d182316bd ("mm: huge_memory: enable debugfs to split huge pages to any order") Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Bill Wendling <morbo@google.com> Cc: Justin Stitt <justinstitt@google.com> Cc: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-26selftests/mm: Fix build with _FORTIFY_SOURCEVitaly Chikunov1-1/+1
Add missing flags argument to open(2) call with O_CREAT. Some tests fail to compile if _FORTIFY_SOURCE is defined (to any valid value) (together with -O), resulting in similar error messages such as: In file included from /usr/include/fcntl.h:342, from gup_test.c:1: In function 'open', inlined from 'main' at gup_test.c:206:10: /usr/include/bits/fcntl2.h:50:11: error: call to '__open_missing_mode' declared with attribute error: open with O_CREAT or O_TMPFILE in second argument needs 3 arguments 50 | __open_missing_mode (); | ^~~~~~~~~~~~~~~~~~~~~~ _FORTIFY_SOURCE is enabled by default in some distributions, so the tests are not built by default and are skipped. open(2) man-page warns about missing flags argument: "if it is not supplied, some arbitrary bytes from the stack will be applied as the file mode." Link: https://lkml.kernel.org/r/20240318023445.3192922-1-vt@altlinux.org Fixes: aeb85ed4f41a ("tools/testing/selftests/vm/gup_benchmark.c: allow user specified file") Fixes: fbe37501b252 ("mm: huge_memory: debugfs for file-backed THP split") Fixes: c942f5bd17b3 ("selftests: soft-dirty: add test for mprotect") Signed-off-by: Vitaly Chikunov <vt@altlinux.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Keith Busch <kbusch@kernel.org> Cc: Peter Xu <peterx@redhat.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-05mm: huge_memory: enable debugfs to split huge pages to any orderZi Yan1-6/+162
It is used to test split_huge_page_to_list_to_order for pagecache THPs. Also add test cases for split_huge_page_to_list_to_order via both debugfs. [ziy@nvidia.com: fix issue discovered with NFS] Link: https://lkml.kernel.org/r/262E4DAA-4A78-4328-B745-1355AE356A07@nvidia.com Link: https://lkml.kernel.org/r/20240226205534.1603748-9-zi.yan@sent.com Signed-off-by: Zi Yan <ziy@nvidia.com> Tested-by: Aishwarya TCV <aishwarya.tcv@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michal Koutny <mkoutny@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zach O'Keefe <zokeefe@google.com> Cc: Aishwarya TCV <aishwarya.tcv@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-22selftests/mm: split_huge_page_test: conform test to TAP format outputMuhammad Usama Anjum1-92/+69
Conform the layout, informational and status messages to TAP. No functional change is intended other than the layout of output messages. Link: https://lkml.kernel.org/r/20240202113119.2047740-9-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-19selftests/mm: reuse read_pmd_pagesize() in COW selftestDavid Hildenbrand1-0/+4
Patch series "mm: (pte|pmd)_mkdirty() should not unconditionally allow for write access". This is the follow-up on [1], adding selftests (testing for known issues we added workarounds for and other issues that haven't been fixed yet), fixing sparc64, reverting the workarounds, and perform one cleanup. The patch from [1] was modified slightly (updated/extended patch description, dropped one unnecessary NOP instruction from the ASM in __pte_mkhwwrite()). Retested on x86_64 and sparc64 (sun4u in QEMU). I scanned most architectures to make sure their (pte|pmd)_mkdirty() handling is correct. To be sure, we can run the selftests and find out if other architectures are still affectes (loongarch was fixed recently as well). Based on master for now. I don't expect surprises regarding mm-tress, but I can rebase if there are any problems. This patch (of 6): The COW selftest can deal with THP not being configured. So move error handling of read_pmd_pagesize() into the callers such that we can reuse it in the COW selftest. Link: https://lkml.kernel.org/r/20230411142512.438404-1-david@redhat.com Link: https://lkml.kernel.org/r/20221212130213.136267-1-david@redhat.com [1] Link: https://lkml.kernel.org/r/20230411142512.438404-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-29selftests/mm: fix split huge page testsZi Yan1-3/+3
Fix two inputs to check_anon_huge() and one if condition, so the tests work as expected. Link: https://lkml.kernel.org/r/20230306160907.16804-1-zi.yan@sent.com Fixes: c07c343cda8e ("selftests/vm: dedup THP helpers") Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Zach O'Keefe <zokeefe@google.com> Tested-by: Zach O'Keefe <zokeefe@google.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-19selftests/vm: rename selftests/vm to selftests/mmSeongJae Park1-0/+309
Rename selftets/vm to selftests/mm for being more consistent with the code, documentation, and tools directories, and won't be confused with virtual machines. [sj@kernel.org: convert missing vm->mm changes] Link: https://lkml.kernel.org/r/20230107230643.252273-1-sj@kernel.org Link: https://lkml.kernel.org/r/20230103180754.129637-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>