kernel/tools/testing/selftests/vm/split_huge_page_test.c, branch linux-6.2.y

selftests/vm: dedup THP helpers

2022-10-03T21:03:34Z

These files: tools/testing/selftests/vm/vm_util.c tools/testing/selftests/vm/khugepaged.c Both contain logic to: 1) Determine hugepage size on current system 2) Read /proc/self/smaps to determine number of THPs at an address Refactor selftests/vm/khugepaged.c to use the vm_util common helpers and add it as a build dependency. Since selftests/vm/khugepaged.c is the largest user of check_huge(), change the signature of check_huge() to match selftests/vm/khugepaged.c's useage: take an expected number of hugepages, and return a bool indicating if the correct number of hugepages were found. Add a wrapper, check_huge_anon(), in anticipation of checking smaps for file and shmem hugepages. Update existing callsites to use the new pattern / function. Likewise, check_for_pattern() was duplicated, and it's a general enough helper to include in vm_util helpers as well. Link: https://lkml.kernel.org/r/20220907144521.3115321-6-zokeefe@google.com Link: https://lkml.kernel.org/r/20220922224046.1143204-6-zokeefe@google.com Signed-off-by: Zach O'Keefe Reviewed-by: Zi Yan Cc: Axel Rasmussen Cc: Chris Kennelly Cc: David Hildenbrand Cc: David Rientjes Cc: Hugh Dickins Cc: James Houghton Cc: "Kirill A. Shutemov" Cc: Matthew Wilcox Cc: Miaohe Lin Cc: Minchan Kim Cc: Pasha Tatashin Cc: Peter Xu Cc: Rongwei Wang Cc: SeongJae Park Cc: Song Liu Cc: Vlastimil Babka Cc: Yang Shi Signed-off-by: Andrew Morton

selftests: vm: bring common functions to a new file

2022-04-29T06:16:11Z

Bring common functions to a new file while keeping code as much same as possible. These functions can be used in the new tests. This helps in avoiding code duplication. Link: https://lkml.kernel.org/r/20220420084036.4101604-1-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum Acked-by: David Hildenbrand Cc: Gabriel Krisman Bertazi Cc: Shuah Khan Cc: Will Deacon Signed-off-by: Andrew Morton

tools/testing/selftests/vm/split_huge_page_test.c: fix application of sizeof to pointer

2021-10-29T00:18:55Z

The coccinelle check report: ./tools/testing/selftests/vm/split_huge_page_test.c:344:36-42: ERROR: application of sizeof to pointer Use "strlen" to fix it. Link: https://lkml.kernel.org/r/20211012030116.184027-1-davidcomponentone@gmail.com Signed-off-by: David Yang Reported-by: Zeal Robot Cc: Zi Yan Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: huge_memory: debugfs for file-backed THP split

2021-05-05T18:27:21Z

Further extend /split_huge_pages to accept ",," for file-backed THP split tests since tmpfs may have file backed by THP that mapped nowhere. Update selftest program to test file-backed THP split too. Link: https://lkml.kernel.org/r/20210331235309.332292-2-zi.yan@sent.com Signed-off-by: Zi Yan Suggested-by: Kirill A. Shutemov Reviewed-by: Yang Shi Cc: "Kirill A . Shutemov" Cc: Shuah Khan Cc: John Hubbard Cc: Sandipan Das Cc: David Hildenbrand Cc: Mika Penttila Cc: David Rientjes Cc: Matthew Wilcox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: huge_memory: a new debugfs interface for splitting THP tests

2021-05-05T18:27:21Z

We did not have a direct user interface of splitting the compound page backing a THP and there is no need unless we want to expose the THP implementation details to users. Make /split_huge_pages accept a new command to do that. By writing ",," to /split_huge_pages, THPs within the given virtual address range from the process with the given pid are split. It is used to test split_huge_page function. In addition, a selftest program is added to tools/testing/selftests/vm to utilize the interface by splitting PMD THPs and PTE-mapped THPs. This does not change the old behavior, i.e., writing 1 to the interface to split all THPs in the system. Link: https://lkml.kernel.org/r/20210331235309.332292-1-zi.yan@sent.com Signed-off-by: Zi Yan Reviewed-by: Yang Shi Cc: David Hildenbrand Cc: David Rientjes Cc: John Hubbard Cc: "Kirill A . Shutemov" Cc: Matthew Wilcox Cc: Mika Penttila Cc: Sandipan Das Cc: Shuah Khan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds