Re: [PATCH] selftests/mm: directly add pagesize instead of increase until page size

On Sat, 30 Aug 2025 02:31:02 +0000 Wei Yang richard.weiyang@gmail.com wrote:

The check of is_backed_by_folio() is done on each page.

Directly move pointer to next page instead of increase one and check if it is page size aligned.

Why?

--- a/tools/testing/selftests/mm/split_huge_page_test.c +++ b/tools/testing/selftests/mm/split_huge_page_test.c @@ -423,9 +423,8 @@ static void split_pte_mapped_thp(void) /* smap does not show THPs after mremap, use kpageflags instead */ thp_size = 0;

• for (i = 0; i < pagesize * 4; i++)

• if (i % pagesize == 0 &&
  

•     is_backed_by_folio(&pte_mapped[i], pmd_order, pagemap_fd, kpageflags_fd))
  

• for (i = 0; i < pagesize * 4; i += pagesize)

• if (is_backed_by_folio(&pte_mapped[i], pmd_order, pagemap_fd, kpageflags_fd))
  thp_size++;
  

Looks like we're doing more work. Is there something wrong with the existing code?