From: Li Wang Date: Tue, 24 Jun 2025 03:27:48 +0000 (+0800) Subject: ksm_tests: skip hugepage test when Transparent Hugepages are disabled X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fdc3bc3497946c6b416a17628907581657102e60;p=thirdparty%2Fkernel%2Flinux.git ksm_tests: skip hugepage test when Transparent Hugepages are disabled Some systems (e.g. minimal or real-time kernels) may not enable Transparent Hugepages (THP), causing MADV_HUGEPAGE to return EINVAL. This patch introduces a runtime check using the existing THP sysfs interface and skips the hugepage merging test (`-H`) when THP is not available. To avoid those failures: # ----------------------------- # running ./ksm_tests -H -s 100 # ----------------------------- # ksm_tests: MADV_HUGEPAGE: Invalid argument # [FAIL] not ok 1 ksm_tests -H -s 100 # exit=2 # -------------------- # running ./khugepaged # -------------------- # Reading PMD pagesize failed# [FAIL] not ok 1 khugepaged # exit=1 # -------------------- # running ./soft-dirty # -------------------- # TAP version 13 # 1..15 # ok 1 Test test_simple # ok 2 Test test_vma_reuse dirty bit of allocated page # ok 3 Test test_vma_reuse dirty bit of reused address page # Bail out! Reading PMD pagesize failed# Planned tests != run tests (15 != 3) # # Totals: pass:3 fail:0 xfail:0 xpass:0 skip:0 error:0 # [FAIL] not ok 1 soft-dirty # exit=1 # SUMMARY: PASS=0 SKIP=0 FAIL=1 # ------------------- # running ./migration # ------------------- # TAP version 13 # 1..3 # # Starting 3 tests from 1 test cases. # # RUN migration.private_anon ... # # OK migration.private_anon # ok 1 migration.private_anon # # RUN migration.shared_anon ... # # OK migration.shared_anon # ok 2 migration.shared_anon # # RUN migration.private_anon_thp ... # # migration.c:196:private_anon_thp:Expected madvise(ptr, TWOMEG, MADV_HUGEPAGE) (-1) == 0 (0) # # private_anon_thp: Test terminated by assertion # # FAIL migration.private_anon_thp # not ok 3 migration.private_anon_thp # # FAILED: 2 / 3 tests passed. # # Totals: pass:2 fail:1 xfail:0 xpass:0 skip:0 error:0 # [FAIL] not ok 1 migration # exit=1 It's true that CONFIG_TRANSPARENT_HUGEPAGE=y is explicitly enabled in tools/testing/selftests/mm/config, so ideally the runtime environment should also support THP. However, in practice, we've found that on some systems: - THP is disabled at boot time (transparent_hugepage=never) - Or manually disabled via sysfs - Or unavailable in RT kernels, containers, or minimal CI environments In these cases, the test will fail with EINVAL on madvise(MADV_HUGEPAGE), even though the kernel config is correct. To make the test suite more robust and avoid false negatives, this patch adds a runtime check for /sys/kernel/mm/transparent_hugepage/enabled. If THP is not available, the hugepage test (-H) is skipped with a clear message. Link: https://lkml.kernel.org/r/20250624032748.393836-1-liwang@redhat.com Signed-off-by: Li Wang Cc: Aruna Ramakrishna Cc: Bagas Sanjaya Cc: Catalin Marinas Cc: Dave Hansen Cc: David Hildenbrand Cc: Joey Gouly Cc: Johannes Weiner Cc: Keith Lucas Cc: Ryan Roberts Cc: Shuah Khan Cc: Lorenzo Stoakes Signed-off-by: Andrew Morton --- diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c index 4341ce6b3b382..a18c50d511418 100644 --- a/tools/testing/selftests/mm/khugepaged.c +++ b/tools/testing/selftests/mm/khugepaged.c @@ -1188,6 +1188,11 @@ int main(int argc, char **argv) .read_ahead_kb = 0, }; + if (!thp_is_enabled()) { + printf("Transparent Hugepages not available\n"); + return KSFT_SKIP; + } + parse_test_type(argc, argv); setbuf(stdout, NULL); diff --git a/tools/testing/selftests/mm/ksm_tests.c b/tools/testing/selftests/mm/ksm_tests.c index e80deac1436be..b77462b5c240b 100644 --- a/tools/testing/selftests/mm/ksm_tests.c +++ b/tools/testing/selftests/mm/ksm_tests.c @@ -15,6 +15,7 @@ #include "../kselftest.h" #include #include "vm_util.h" +#include "thp_settings.h" #define KSM_SYSFS_PATH "/sys/kernel/mm/ksm/" #define KSM_FP(s) (KSM_SYSFS_PATH s) @@ -527,6 +528,11 @@ static int ksm_merge_hugepages_time(int merge_type, int mapping, int prot, unsigned long scan_time_ns; int pagemap_fd, n_normal_pages, n_huge_pages; + if (!thp_is_enabled()) { + printf("Transparent Hugepages not available\n"); + return KSFT_SKIP; + } + map_size *= MB; size_t len = map_size; diff --git a/tools/testing/selftests/mm/migration.c b/tools/testing/selftests/mm/migration.c index 1e3a595fbf012..a306f8bab0870 100644 --- a/tools/testing/selftests/mm/migration.c +++ b/tools/testing/selftests/mm/migration.c @@ -5,6 +5,8 @@ */ #include "../kselftest_harness.h" +#include "thp_settings.h" + #include #include #include @@ -185,6 +187,9 @@ TEST_F_TIMEOUT(migration, private_anon_thp, 2*RUNTIME) uint64_t *ptr; int i; + if (!thp_is_enabled()) + SKIP(return, "Transparent Hugepages not available"); + if (self->nthreads < 2 || self->n1 < 0 || self->n2 < 0) SKIP(return, "Not enough threads or NUMA nodes available"); @@ -214,6 +219,9 @@ TEST_F_TIMEOUT(migration, shared_anon_thp, 2*RUNTIME) uint64_t *ptr; int i; + if (!thp_is_enabled()) + SKIP(return, "Transparent Hugepages not available"); + if (self->nthreads < 2 || self->n1 < 0 || self->n2 < 0) SKIP(return, "Not enough threads or NUMA nodes available"); diff --git a/tools/testing/selftests/mm/soft-dirty.c b/tools/testing/selftests/mm/soft-dirty.c index 8e1462ce05326..8a3f2b4b21869 100644 --- a/tools/testing/selftests/mm/soft-dirty.c +++ b/tools/testing/selftests/mm/soft-dirty.c @@ -6,8 +6,10 @@ #include #include #include + #include "../kselftest.h" #include "vm_util.h" +#include "thp_settings.h" #define PAGEMAP_FILE_PATH "/proc/self/pagemap" #define TEST_ITERATIONS 10000 @@ -78,8 +80,13 @@ static void test_hugepage(int pagemap_fd, int pagesize) { char *map; int i, ret; - size_t hpage_len = read_pmd_pagesize(); + if (!thp_is_enabled()) { + ksft_test_result_skip("Transparent Hugepages not available\n"); + return; + } + + size_t hpage_len = read_pmd_pagesize(); if (!hpage_len) ksft_exit_fail_msg("Reading PMD pagesize failed"); diff --git a/tools/testing/selftests/mm/thp_settings.c b/tools/testing/selftests/mm/thp_settings.c index ad872af1c81aa..bad60ac52874a 100644 --- a/tools/testing/selftests/mm/thp_settings.c +++ b/tools/testing/selftests/mm/thp_settings.c @@ -381,3 +381,14 @@ unsigned long thp_shmem_supported_orders(void) { return __thp_supported_orders(true); } + +bool thp_is_enabled(void) +{ + if (access(THP_SYSFS, F_OK) != 0) + return false; + + int mode = thp_read_string("enabled", thp_enabled_strings); + + /* THP is considered enabled if it's either "always" or "madvise" */ + return mode == 1 || mode == 3; +} diff --git a/tools/testing/selftests/mm/thp_settings.h b/tools/testing/selftests/mm/thp_settings.h index fc131d23d5930..6c07f70beee97 100644 --- a/tools/testing/selftests/mm/thp_settings.h +++ b/tools/testing/selftests/mm/thp_settings.h @@ -84,4 +84,6 @@ void thp_set_read_ahead_path(char *path); unsigned long thp_supported_orders(void); unsigned long thp_shmem_supported_orders(void); +bool thp_is_enabled(void); + #endif /* __THP_SETTINGS_H__ */