From: "Kiryl Shutsemau (Meta)" <[email protected]> collapse_swapin_single_pte and collapse_max_ptes_swap swap pages out with MADV_PAGEOUT and then require them to be swapped. With no swap area configured MADV_PAGEOUT is a no-op, so check_swap() finds nothing and the tests report a failure that only reflects the environment, not khugepaged.
Skip both when /proc/swaps shows no swap area, so a missing swap device yields a SKIP rather than a spurious failure. A real swap-out failure with swap present still fails as before. Assisted-by: Claude-Code:claude-opus-5 Signed-off-by: Kiryl Shutsemau (Meta) <[email protected]> --- tools/testing/selftests/mm/khugepaged.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c index b43e060b4118..b074b005b62f 100644 --- a/tools/testing/selftests/mm/khugepaged.c +++ b/tools/testing/selftests/mm/khugepaged.c @@ -181,6 +181,21 @@ static void get_finfo(const char *dir) ksft_exit_fail_msg("%s: Could not read: %s\n", __func__, path); } +static bool has_swap(void) +{ + FILE *fp = fopen("/proc/swaps", "r"); + char line[MAX_LINE_LENGTH]; + bool ret = false; + + if (!fp) + return false; + /* First line is the header; any following line is a swap area. */ + if (fgets(line, sizeof(line), fp) && fgets(line, sizeof(line), fp)) + ret = true; + fclose(fp); + return ret; +} + static bool check_swap(void *addr, unsigned long size) { bool swap = false; @@ -739,6 +754,10 @@ static void collapse_swapin_single_pte(struct collapse_context *c, struct mem_op void *p; p = ops->setup_area(1); + if (!has_swap()) { + skip("Skip (no swap configured)"); + goto out; + } ops->fault(p, 0, hpage_pmd_size); ksft_print_msg("Swapout one page..."); @@ -765,6 +784,10 @@ static void collapse_max_ptes_swap(struct collapse_context *c, struct mem_ops *o void *p; p = ops->setup_area(1); + if (!has_swap()) { + skip("Skip (no swap configured)"); + goto out; + } ops->fault(p, 0, hpage_pmd_size); ksft_print_msg("Swapout %d of %d pages...", max_ptes_swap + 1, hpage_pmd_nr); -- 2.54.0
