On 28.03.24 12:10, Jinjiang Tu wrote:
This extends test_prctl_fork() and test_prctl_fork_exec() to make sure that deduplication really happens, instead of only testing the MMF_VM_MERGE_ANY flag is set. Suggested-by: David Hildenbrand <david@xxxxxxxxxx> Signed-off-by: Jinjiang Tu <tujinjiang@xxxxxxxxxx> --- .../selftests/mm/ksm_functional_tests.c | 49 ++++++++++++++----- 1 file changed, 38 insertions(+), 11 deletions(-) diff --git a/tools/testing/selftests/mm/ksm_functional_tests.c b/tools/testing/selftests/mm/ksm_functional_tests.c index 5462873df84c..2d277620fad2 100644 --- a/tools/testing/selftests/mm/ksm_functional_tests.c +++ b/tools/testing/selftests/mm/ksm_functional_tests.c @@ -475,6 +475,36 @@ static void test_prctl(void) ksft_test_result_pass("Setting/clearing PR_SET_MEMORY_MERGE works\n"); }+static int test_child_ksm(void)+{ + const unsigned int size = 2 * MiB; + char *map; + + /* Test if KSM is enabled for the process. */ + if (prctl(PR_GET_MEMORY_MERGE, 0, 0, 0, 0) != 1) + return -1; + + /* Test if merge could really happen. */ + map = __mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_NONE); + if (map == MAP_MERGE_FAIL) + return -2; + else if (map == MAP_MERGE_SKIP) + return -3; + + munmap(map, size); + return 0; +} + +static void test_child_ksm_err(int status)
Maybe better "handle_child_ksm_err" because you only call it if status != 0. Thanks! Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> -- Cheers, David / dhildenb
