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

Signed-off-by: Li Wang liwang@redhat.com Cc: Aruna Ramakrishna aruna.ramakrishna@oracle.com Cc: Bagas Sanjaya bagasdotme@gmail.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: Dave Hansen dave.hansen@linux.intel.com Cc: David Hildenbrand david@redhat.com Cc: Joey Gouly joey.gouly@arm.com Cc: Johannes Weiner hannes@cmpxchg.org Cc: Keith Lucas keith.lucas@oracle.com Cc: Ryan Roberts ryan.roberts@arm.com Cc: Shuah Khan shuah@kernel.org Cc: Lorenzo Stoakes lorenzo.stoakes@oracle.com ---

Notes: v1 --> v2: * replaces printf() + return KSFT_SKIP with a standardized ksft_test_result_skip() call and return in soft-dirty.c to avoid test build issue.

tools/testing/selftests/mm/khugepaged.c | 5 +++++ tools/testing/selftests/mm/ksm_tests.c | 6 ++++++ tools/testing/selftests/mm/migration.c | 8 ++++++++ tools/testing/selftests/mm/soft-dirty.c | 9 ++++++++- tools/testing/selftests/mm/thp_settings.c | 11 +++++++++++ tools/testing/selftests/mm/thp_settings.h | 2 ++ 6 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c index 8a4d34cce36b..6822eb7ea58e 100644 --- a/tools/testing/selftests/mm/khugepaged.c +++ b/tools/testing/selftests/mm/khugepaged.c @@ -1190,6 +1190,11 @@ 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 e80deac1436b..b77462b5c240 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/vdso/time64.h> #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 1e3a595fbf01..a306f8bab087 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 <strings.h> #include <pthread.h> #include <numa.h> @@ -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 8e1462ce0532..8a3f2b4b2186 100644 --- a/tools/testing/selftests/mm/soft-dirty.c +++ b/tools/testing/selftests/mm/soft-dirty.c @@ -6,8 +6,10 @@ #include <stdint.h> #include <malloc.h> #include <sys/mman.h> + #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 ad872af1c81a..bad60ac52874 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 fc131d23d593..6c07f70beee9 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__ */