The collapse_swapin_single_pte and collapse_max_ptes_swap tests use MADV_PAGEOUT to swap out pages before verifying khugepaged collapse behavior. On systems without swap configured, MADV_PAGEOUT succeeds but the pages are not actually swapped out, so check_swap() returns false and the tests report a failure.
These tests cannot run meaningfully without swap, so a missing swap area is an environment limitation rather than a test failure. Detect the absence of swap via /proc/swaps and skip the affected tests instead of failing them. Signed-off-by: Jaeyeon Lee <[email protected]> --- tools/testing/selftests/mm/khugepaged.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c index 10e8dedcb087..f9b4ebe733ce 100644 --- a/tools/testing/selftests/mm/khugepaged.c +++ b/tools/testing/selftests/mm/khugepaged.c @@ -100,6 +100,22 @@ static void skip(const char *msg) exit_status = KSFT_SKIP; } +static bool swap_available(void) +{ + char buf[256]; + bool ret; + FILE *fp = fopen("/proc/swaps", "r"); + + if (!fp) + return false; + + fgets(buf, sizeof(buf), fp); + ret = !!fgets(buf, sizeof(buf), fp); + + fclose(fp); + return ret; +} + static void save_settings(void) { ksft_print_msg("Save THP and khugepaged settings..."); @@ -742,6 +758,9 @@ static void collapse_swapin_single_pte(struct collapse_context *c, struct mem_op ksft_exit_fail_perror("madvise(MADV_PAGEOUT)"); if (check_swap(p, page_size)) { success("OK"); + } else if (!swap_available()) { + skip("Swap is not available"); + goto out; } else { fail("Fail"); goto out; @@ -768,6 +787,9 @@ static void collapse_max_ptes_swap(struct collapse_context *c, struct mem_ops *o ksft_exit_fail_perror("madvise(MADV_PAGEOUT)"); if (check_swap(p, (max_ptes_swap + 1) * page_size)) { success("OK"); + } else if (!swap_available()) { + skip("Swap is not available"); + goto out; } else { fail("Fail"); goto out; @@ -785,6 +807,9 @@ static void collapse_max_ptes_swap(struct collapse_context *c, struct mem_ops *o ksft_exit_fail_perror("madvise(MADV_PAGEOUT)"); if (check_swap(p, max_ptes_swap * page_size)) { success("OK"); + } else if (!swap_available()) { + skip("Swap is not available"); + goto out; } else { fail("Fail"); goto out; base-commit: 7081238c5ca29839924f13bf5daa80763bc589f2 -- 2.43.0
