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author | Jinjiang Tu <tujinjiang@huawei.com> | 2024-03-28 14:10:10 +0300 |
---|---|---|
committer | Andrew Morton <akpm@linux-foundation.org> | 2024-04-26 06:56:29 +0300 |
commit | 6c47de3be3a021d8b28d127802d590a49598a514 (patch) | |
tree | 51e56550889a7648c94ab6631186b6577e6ec3a6 /tools | |
parent | 7abaacb8e5f55c6adaabc1b6bcbc1915e159fd1d (diff) | |
download | linux-6c47de3be3a021d8b28d127802d590a49598a514.tar.xz |
selftest/mm: ksm_functional_tests: extend test case for ksm fork/exec
This extends test_prctl_fork() and test_prctl_fork_exec() to make sure
that deduplication really happens, instead of only testing the
MMF_VM_MERGE_ANY flag is set.
[colin.i.king@gmail.com: fix spelling mistake in ksft_test_result_skip message]
Link: https://lkml.kernel.org/r/20240402081537.1365939-1-colin.i.king@gmail.com
Link: https://lkml.kernel.org/r/20240328111010.1502191-4-tujinjiang@huawei.com
Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Stefan Roesch <shr@devkernel.io>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'tools')
-rw-r--r-- | tools/testing/selftests/mm/ksm_functional_tests.c | 49 |
1 files changed, 38 insertions, 11 deletions
diff --git a/tools/testing/selftests/mm/ksm_functional_tests.c b/tools/testing/selftests/mm/ksm_functional_tests.c index 5462873df84c..db845dca8d19 100644 --- a/tools/testing/selftests/mm/ksm_functional_tests.c +++ b/tools/testing/selftests/mm/ksm_functional_tests.c @@ -475,6 +475,36 @@ static void test_prctl(void) ksft_test_result_pass("Setting/clearing PR_SET_MEMORY_MERGE works\n"); } +static int test_child_ksm(void) +{ + const unsigned int size = 2 * MiB; + char *map; + + /* Test if KSM is enabled for the process. */ + if (prctl(PR_GET_MEMORY_MERGE, 0, 0, 0, 0) != 1) + return -1; + + /* Test if merge could really happen. */ + map = __mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_NONE); + if (map == MAP_MERGE_FAIL) + return -2; + else if (map == MAP_MERGE_SKIP) + return -3; + + munmap(map, size); + return 0; +} + +static void test_child_ksm_err(int status) +{ + if (status == -1) + ksft_test_result_fail("unexpected PR_GET_MEMORY_MERGE result in child\n"); + else if (status == -2) + ksft_test_result_fail("Merge in child failed\n"); + else if (status == -3) + ksft_test_result_skip("Merge in child skipped\n"); +} + /* Verify that prctl ksm flag is inherited. */ static void test_prctl_fork(void) { @@ -494,7 +524,7 @@ static void test_prctl_fork(void) child_pid = fork(); if (!child_pid) { - exit(prctl(PR_GET_MEMORY_MERGE, 0, 0, 0, 0)); + exit(test_child_ksm()); } else if (child_pid < 0) { ksft_test_result_fail("fork() failed\n"); return; @@ -503,8 +533,11 @@ static void test_prctl_fork(void) if (waitpid(child_pid, &status, 0) < 0) { ksft_test_result_fail("waitpid() failed\n"); return; - } else if (WEXITSTATUS(status) != 1) { - ksft_test_result_fail("unexpected PR_GET_MEMORY_MERGE result in child\n"); + } + + status = WEXITSTATUS(status); + if (status) { + test_child_ksm_err(status); return; } @@ -516,12 +549,6 @@ static void test_prctl_fork(void) ksft_test_result_pass("PR_SET_MEMORY_MERGE value is inherited\n"); } -static int ksm_fork_exec_child(void) -{ - /* Test if KSM is enabled for the process. */ - return prctl(PR_GET_MEMORY_MERGE, 0, 0, 0, 0) == 1; -} - static void test_prctl_fork_exec(void) { int ret, status; @@ -554,7 +581,7 @@ static void test_prctl_fork_exec(void) if (WIFEXITED(status)) { status = WEXITSTATUS(status); if (status) { - ksft_test_result_fail("KSM not enabled\n"); + test_child_ksm_err(status); return; } } else { @@ -635,7 +662,7 @@ int main(int argc, char **argv) int err; if (argc > 1 && !strcmp(argv[1], FORK_EXEC_CHILD_PRG_NAME)) { - exit(ksm_fork_exec_child() == 1 ? 0 : 1); + exit(test_child_ksm()); } #ifdef __NR_userfaultfd |