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Diffstat (limited to 'tools/testing/selftests/mm/ksm_functional_tests.c')
-rw-r--r--tools/testing/selftests/mm/ksm_functional_tests.c137
1 files changed, 100 insertions, 37 deletions
diff --git a/tools/testing/selftests/mm/ksm_functional_tests.c b/tools/testing/selftests/mm/ksm_functional_tests.c
index d615767e396b..37de82da9be7 100644
--- a/tools/testing/selftests/mm/ksm_functional_tests.c
+++ b/tools/testing/selftests/mm/ksm_functional_tests.c
@@ -28,6 +28,15 @@
#define MiB (1024 * KiB)
#define FORK_EXEC_CHILD_PRG_NAME "ksm_fork_exec_child"
+#define MAP_MERGE_FAIL ((void *)-1)
+#define MAP_MERGE_SKIP ((void *)-2)
+
+enum ksm_merge_mode {
+ KSM_MERGE_PRCTL,
+ KSM_MERGE_MADVISE,
+ KSM_MERGE_NONE, /* PRCTL already set */
+};
+
static int mem_fd;
static int ksm_fd;
static int ksm_full_scans_fd;
@@ -146,33 +155,34 @@ static int ksm_unmerge(void)
return 0;
}
-static char *mmap_and_merge_range(char val, unsigned long size, int prot,
- bool use_prctl)
+static char *__mmap_and_merge_range(char val, unsigned long size, int prot,
+ enum ksm_merge_mode mode)
{
char *map;
+ char *err_map = MAP_MERGE_FAIL;
int ret;
/* Stabilize accounting by disabling KSM completely. */
if (ksm_unmerge()) {
- ksft_test_result_fail("Disabling (unmerging) KSM failed\n");
- return MAP_FAILED;
+ ksft_print_msg("Disabling (unmerging) KSM failed\n");
+ return err_map;
}
if (get_my_merging_pages() > 0) {
- ksft_test_result_fail("Still pages merged\n");
- return MAP_FAILED;
+ ksft_print_msg("Still pages merged\n");
+ return err_map;
}
map = mmap(NULL, size, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_ANON, -1, 0);
if (map == MAP_FAILED) {
- ksft_test_result_fail("mmap() failed\n");
- return MAP_FAILED;
+ ksft_print_msg("mmap() failed\n");
+ return err_map;
}
/* Don't use THP. Ignore if THP are not around on a kernel. */
if (madvise(map, size, MADV_NOHUGEPAGE) && errno != EINVAL) {
- ksft_test_result_fail("MADV_NOHUGEPAGE failed\n");
+ ksft_print_msg("MADV_NOHUGEPAGE failed\n");
goto unmap;
}
@@ -180,27 +190,36 @@ static char *mmap_and_merge_range(char val, unsigned long size, int prot,
memset(map, val, size);
if (mprotect(map, size, prot)) {
- ksft_test_result_skip("mprotect() failed\n");
+ ksft_print_msg("mprotect() failed\n");
+ err_map = MAP_MERGE_SKIP;
goto unmap;
}
- if (use_prctl) {
+ switch (mode) {
+ case KSM_MERGE_PRCTL:
ret = prctl(PR_SET_MEMORY_MERGE, 1, 0, 0, 0);
if (ret < 0 && errno == EINVAL) {
- ksft_test_result_skip("PR_SET_MEMORY_MERGE not supported\n");
+ ksft_print_msg("PR_SET_MEMORY_MERGE not supported\n");
+ err_map = MAP_MERGE_SKIP;
goto unmap;
} else if (ret) {
- ksft_test_result_fail("PR_SET_MEMORY_MERGE=1 failed\n");
+ ksft_print_msg("PR_SET_MEMORY_MERGE=1 failed\n");
goto unmap;
}
- } else if (madvise(map, size, MADV_MERGEABLE)) {
- ksft_test_result_fail("MADV_MERGEABLE failed\n");
- goto unmap;
+ break;
+ case KSM_MERGE_MADVISE:
+ if (madvise(map, size, MADV_MERGEABLE)) {
+ ksft_print_msg("MADV_MERGEABLE failed\n");
+ goto unmap;
+ }
+ break;
+ case KSM_MERGE_NONE:
+ break;
}
/* Run KSM to trigger merging and wait. */
if (ksm_merge()) {
- ksft_test_result_fail("Running KSM failed\n");
+ ksft_print_msg("Running KSM failed\n");
goto unmap;
}
@@ -209,14 +228,31 @@ static char *mmap_and_merge_range(char val, unsigned long size, int prot,
* accounted differently (depending on kernel support).
*/
if (val && !get_my_merging_pages()) {
- ksft_test_result_fail("No pages got merged\n");
+ ksft_print_msg("No pages got merged\n");
goto unmap;
}
return map;
unmap:
munmap(map, size);
- return MAP_FAILED;
+ return err_map;
+}
+
+static char *mmap_and_merge_range(char val, unsigned long size, int prot,
+ enum ksm_merge_mode mode)
+{
+ char *map;
+ char *ret = MAP_FAILED;
+
+ map = __mmap_and_merge_range(val, size, prot, mode);
+ if (map == MAP_MERGE_FAIL)
+ ksft_test_result_fail("Merging memory failed");
+ else if (map == MAP_MERGE_SKIP)
+ ksft_test_result_skip("Merging memory skipped");
+ else
+ ret = map;
+
+ return ret;
}
static void test_unmerge(void)
@@ -226,7 +262,7 @@ static void test_unmerge(void)
ksft_print_msg("[RUN] %s\n", __func__);
- map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, false);
+ map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE);
if (map == MAP_FAILED)
return;
@@ -264,7 +300,7 @@ static void test_unmerge_zero_pages(void)
}
/* Let KSM deduplicate zero pages. */
- map = mmap_and_merge_range(0x00, size, PROT_READ | PROT_WRITE, false);
+ map = mmap_and_merge_range(0x00, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE);
if (map == MAP_FAILED)
return;
@@ -312,7 +348,7 @@ static void test_unmerge_discarded(void)
ksft_print_msg("[RUN] %s\n", __func__);
- map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, false);
+ map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE);
if (map == MAP_FAILED)
return;
@@ -344,7 +380,7 @@ static void test_unmerge_uffd_wp(void)
ksft_print_msg("[RUN] %s\n", __func__);
- map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, false);
+ map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE);
if (map == MAP_FAILED)
return;
@@ -439,6 +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)
{
@@ -458,7 +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;
@@ -467,8 +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;
}
@@ -480,12 +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;
@@ -518,7 +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 {
@@ -545,7 +608,7 @@ static void test_prctl_unmerge(void)
ksft_print_msg("[RUN] %s\n", __func__);
- map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, true);
+ map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_PRCTL);
if (map == MAP_FAILED)
return;
@@ -568,7 +631,7 @@ static void test_prot_none(void)
ksft_print_msg("[RUN] %s\n", __func__);
- map = mmap_and_merge_range(0x11, size, PROT_NONE, false);
+ map = mmap_and_merge_range(0x11, size, PROT_NONE, KSM_MERGE_MADVISE);
if (map == MAP_FAILED)
goto unmap;
@@ -599,7 +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
@@ -646,5 +709,5 @@ int main(int argc, char **argv)
if (err)
ksft_exit_fail_msg("%d out of %d tests failed\n",
err, ksft_test_num());
- return ksft_exit_pass();
+ ksft_exit_pass();
}
generated by cgit v1.2.3-70-g09d2 (git 2.51.1) at 2025-11-04 12:10:08 +0000