Currently, mshare doesn't support madvise(MADV_HUGEPAGE) to make pages become THP page.
Thus we need to set /sys/kernel/mm/transparent_hugepage/shmem_enabled to 'always', enabling mshare to acquire THP pages in a best effort way. This case is quit simple that set up a mshare memory with 2MB size, than use memset to fill the physical memory and verify whether THP was allocated by reading memory.stat. Signed-off-by: Yongting Lin <[email protected]> --- tools/testing/selftests/mshare/memory.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/tools/testing/selftests/mshare/memory.c b/tools/testing/selftests/mshare/memory.c index 4bb0d22b9c03..5132210b1465 100644 --- a/tools/testing/selftests/mshare/memory.c +++ b/tools/testing/selftests/mshare/memory.c @@ -68,4 +68,22 @@ TEST_F(memory, swap) ASSERT_GT(swap_size, MB(2) * 9 / 10); } +TEST_F(memory, thp) +{ + /* fill physical memory */ + memset(self->addr, 0x01, MB(2)); + + size_t huge = read_huge_from_cgroup(self->cgroup); + + /* + * mshare only allocate in the best effort way, and + * don't support madvise(MADV_HUGEPAGE) to change pages + * into THP or khuged to replace pages with THP. + */ + ksft_print_msg("Tip: Please enable transparent hugepages for shmem before running this test.\n" + "For example: echo always > /sys/kernel/mm/transparent_hugepage/shmem_enabled\n"); + + ASSERT_GE(huge, MB(2)); +} + TEST_HARNESS_MAIN -- 2.20.1
