In order to extend test_prctl_fork() and test_prctl_fork_exec() to make
sure that deduplication really happens, mmap_and_merge_range() needs to be
refactored.
Firstly, mmap_and_merge_range() will be called with no need to call enable
KSM by madvise or prctl. So, switch the 'bool use_prctl' parameter to enum
ksm_merge_mode.
Secondly, mmap_and_merge_range() will be called in child process in the
two testcases, it isn't appropriate to call ksft_test_result_{fail, skip},
because the global variables ksft_{fail, skip} aren't consistent with the
parent process. Thus, convert calls of ksft_test_result_{fail, skip} to
ksft_print_msg() and return differrent error according to the two cases.
The callers of mmap_and_merge_range() then call ksft_test_result_{fail,
skip} according to the return value. Introduce mmap_and_merge_err_print()
helper to make it easier.
Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Jinjiang Tu <tujinjiang@xxxxxxxxxx>
---
.../selftests/mm/ksm_functional_tests.c | 93 +++++++++++++------
1 file changed, 63 insertions(+), 30 deletions(-)
diff --git a/tools/testing/selftests/mm/ksm_functional_tests.c b/tools/testing/selftests/mm/ksm_functional_tests.c
index d615767e396b..da58545e58e1 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;
@@ -147,32 +156,33 @@ static int ksm_unmerge(void)
}
static char *mmap_and_merge_range(char val, unsigned long size, int prot,
- bool use_prctl)
+ 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 +228,28 @@ 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 inline int mmap_and_merge_err_print(char *map)
+{
+ int ret = -1;
+
+ if (map == MAP_MERGE_FAIL)
+ ksft_test_result_fail("Merging memory failed");
+ else if (map == MAP_MERGE_FAIL)
+ ksft_test_result_skip("Merging memory skiped");
+ else
+ ret = 0;
+
+ return ret;
}
static void test_unmerge(void)
@@ -226,8 +259,8 @@ static void test_unmerge(void)
ksft_print_msg("[RUN] %s\n", __func__);
- map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, false);
- if (map == MAP_FAILED)
+ map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE);
+ if (mmap_and_merge_err_print(map))
return;
if (madvise(map, size, MADV_UNMERGEABLE)) {
@@ -264,8 +297,8 @@ static void test_unmerge_zero_pages(void)
}
/* Let KSM deduplicate zero pages. */
- map = mmap_and_merge_range(0x00, size, PROT_READ | PROT_WRITE, false);
- if (map == MAP_FAILED)
+ map = mmap_and_merge_range(0x00, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE);
+ if (mmap_and_merge_err_print(map))
return;
/* Check if ksm_zero_pages is updated correctly after KSM merging */
@@ -312,8 +345,8 @@ 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);
- if (map == MAP_FAILED)
+ map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE);
+ if (mmap_and_merge_err_print(map))
return;
/* Discard half of all mapped pages so we have pte_none() entries. */
@@ -344,8 +377,8 @@ 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);
- if (map == MAP_FAILED)
+ map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_MADVISE);
+ if (mmap_and_merge_err_print(map))
return;
/* See if UFFD is around. */
@@ -545,8 +578,8 @@ 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);
- if (map == MAP_FAILED)
+ map = mmap_and_merge_range(0xcf, size, PROT_READ | PROT_WRITE, KSM_MERGE_PRCTL);
+ if (mmap_and_merge_err_print(map))
return;
if (prctl(PR_SET_MEMORY_MERGE, 0, 0, 0, 0)) {
@@ -568,8 +601,8 @@ static void test_prot_none(void)
ksft_print_msg("[RUN] %s\n", __func__);
- map = mmap_and_merge_range(0x11, size, PROT_NONE, false);
- if (map == MAP_FAILED)
+ map = mmap_and_merge_range(0x11, size, PROT_NONE, KSM_MERGE_MADVISE);
+ if (mmap_and_merge_err_print(map))
goto unmap;
/* Store a unique value in each page on one half using ptrace */
--
2.25.1
