On Sat, Aug 16, 2025 at 09:31:10AM +0530, Aboorva Devarajan wrote:
From: Donet Tom donettom@linux.ibm.com
The split_huge_page_test fails on systems with a 64KB base page size. This is because the order of a 2MB huge page is different:
On 64KB systems, the order is 5.
On 4KB systems, it's 9.
The test currently assumes a maximum huge page order of 9, which is only valid for 4KB base page systems. On systems with 64KB pages, attempting to split huge pages beyond their actual order (5) causes the test to fail.
In this patch, we calculate the huge page order based on the system's base page size. With this change, the tests now run successfully on both 64KB and 4KB page size systems.
Fixes: fa6c02315f745 ("mm: huge_memory: a new debugfs interface for splitting THP tests") Co-developed-by: Aboorva Devarajan aboorvad@linux.ibm.com Signed-off-by: Aboorva Devarajan aboorvad@linux.ibm.com Reviewed-by: Dev Jain dev.jain@arm.com Reviewed-by: Zi Yan ziy@nvidia.com Signed-off-by: Donet Tom donettom@linux.ibm.com
Reviewed-by: Wei Yang richard.weiyang@gmail.com
Nit below:
tools/testing/selftests/mm/cow.c | 5 ----- .../selftests/mm/split_huge_page_test.c | 22 ++++++++++++------- tools/testing/selftests/mm/uffd-wp-mremap.c | 5 ----- tools/testing/selftests/mm/vm_util.h | 5 +++++ 4 files changed, 19 insertions(+), 18 deletions(-)
diff --git a/tools/testing/selftests/mm/cow.c b/tools/testing/selftests/mm/cow.c index 90ee5779662f..e742d9313798 100644 --- a/tools/testing/selftests/mm/cow.c +++ b/tools/testing/selftests/mm/cow.c @@ -41,11 +41,6 @@ static size_t hugetlbsizes[10]; static int gup_fd; static bool has_huge_zeropage;
-static int sz2ord(size_t size) -{
- return __builtin_ctzll(size / pagesize);
-}
static int detect_thp_sizes(size_t sizes[], int max) { int count = 0; diff --git a/tools/testing/selftests/mm/split_huge_page_test.c b/tools/testing/selftests/mm/split_huge_page_test.c index eadbeb820d71..7cbeaebc9d71 100644 --- a/tools/testing/selftests/mm/split_huge_page_test.c +++ b/tools/testing/selftests/mm/split_huge_page_test.c @@ -523,6 +523,9 @@ int main(int argc, char **argv) const char *fs_loc; bool created_tmp; int offset;
unsigned int max_order;
unsigned int nr_pages;
unsigned int tests;
ksft_print_header();
@@ -534,35 +537,38 @@ int main(int argc, char **argv) if (argc > 1) optional_xfs_path = argv[1];
- ksft_set_plan(1+8+1+9+9+8*4+2);
- pagesize = getpagesize(); pageshift = ffs(pagesize) - 1; pmd_pagesize = read_pmd_pagesize(); if (!pmd_pagesize) ksft_exit_fail_msg("Reading PMD pagesize failed\n");
- nr_pages = pmd_pagesize / pagesize;
- max_order = sz2ord(pmd_pagesize);
^ extra space here
tests = 2 + (max_order - 1) + (2 * max_order) + (max_order - 1) * 4 + 2;
ksft_set_plan(tests);
fd_size = 2 * pmd_pagesize;
split_pmd_zero_pages();