From: "Kiryl Shutsemau (Meta)" <[email protected]> collapse_order_mixed_sources() faults its region as order-2 folios and collapses them to the -c target. Order 2 is below the contpte size on every arm64 page size, so nothing in this suite collapses a contpte-mapped source on purpose.
Let -s name the source order alongside -c. The case then faults at that order, keeping order 2 when -s is absent, and the source order has to be a supported mTHP order below the target. The other mTHP cases are unaffected: mthp_push_target_order() enables only the target order. "-s 5 -c 7" on arm64/64K then collapses contpte-mapped sources into a larger mTHP. Assisted-by: LLM Acked-by: Lorenzo Stoakes (ARM) <[email protected]> Tested-by: Muhammad Usama Anjum <[email protected]> Signed-off-by: Kiryl Shutsemau (Meta) <[email protected]> --- tools/testing/selftests/mm/khugepaged.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c index fb4efaf67c40..b15cd07fc0b3 100644 --- a/tools/testing/selftests/mm/khugepaged.c +++ b/tools/testing/selftests/mm/khugepaged.c @@ -1352,11 +1352,13 @@ static void collapse_order_max_ptes_none(struct collapse_context *c, static void collapse_order_mixed_sources(struct collapse_context *c, struct mem_ops *ops) { + int source_order = anon_order ? anon_order : MIN_MTHP_ORDER; struct thp_settings settings; void *p; - if (collapse_order <= MIN_MTHP_ORDER) { - ksft_test_result_skip("%s: no source order below target\n", + if (source_order >= collapse_order || + !(thp_supported_orders() & (1UL << source_order))) { + ksft_test_result_skip("%s: no supported source order below target\n", __func__); return; } @@ -1364,7 +1366,7 @@ static void collapse_order_mixed_sources(struct collapse_context *c, mthp_push_target_order(); settings = *thp_current_settings(); - settings.hugepages[MIN_MTHP_ORDER].enabled = THP_ALWAYS; + settings.hugepages[source_order].enabled = THP_ALWAYS; thp_push_settings(&settings); p = ops->setup_area(1); ops->fault(p, 0, hpage_pmd_size); @@ -1374,10 +1376,9 @@ static void collapse_order_mixed_sources(struct collapse_context *c, * The allocator can fall back to smaller folios under fragmentation; * having nothing to collapse from is not a failure. */ - if (!is_range_backed_by_order(p, hpage_pmd_size, MIN_MTHP_ORDER, + if (!is_range_backed_by_order(p, hpage_pmd_size, source_order, pagemap_fd, kpageflags_fd)) { - ksft_print_msg("No order-%d sources to collapse...", - MIN_MTHP_ORDER); + ksft_print_msg("No order-%d sources to collapse...", source_order); skip("Skip"); ops->cleanup_area(p, hpage_pmd_size); thp_pop_settings(); @@ -1387,7 +1388,8 @@ static void collapse_order_mixed_sources(struct collapse_context *c, if (madvise(p, hpage_pmd_size, MADV_HUGEPAGE)) ksft_exit_fail_perror("madvise(MADV_HUGEPAGE)"); - ksft_print_msg("Collapse region backed by smaller large folios..."); + ksft_print_msg("Collapse region backed by order-%d sources...", + source_order); if (!khugepaged_full_pass(MTHP_PASS_TIMEOUT_S)) fail("Timeout"); else if (all_windows_at_order(p, hpage_pmd_size)) @@ -1418,6 +1420,7 @@ static void usage(void) fprintf(stderr, "\t\t-s: mTHP size, expressed as page order.\n"); fprintf(stderr, "\t\t Defaults to 0. Use this size for anon or shmem allocations.\n"); fprintf(stderr, "\t\t-c: collapse order for mTHP collapse, expressed as page order.\n"); + fprintf(stderr, "\t\t -s, if set, is the source order for the mixed-source case.\n"); exit(1); } -- 2.54.0
