@@ -23,6 +23,11 @@ struct ksm_sysfs {
unsigned long use_zero_pages;
};
+enum ksm_test_name {
+ CHECK_KSM_MERGE,
+ CHECK_KSM_UNMERGE
+};
+
static int ksm_write_sysfs(const char *file_path, unsigned long val)
{
FILE *f = fopen(file_path, "w");
@@ -75,7 +80,12 @@ static int str_to_prot(char *prot_str)
static void print_help(void)
{
- printf("usage: ksm_tests [-h] [-a prot] [-p page_count] [-l timeout]\n");
+ printf("usage: ksm_tests [-h] <test type> [-a prot] [-p page_count] [-l timeout]\n");
+
+ printf("Supported <test type>:\n"
+ " -M (page merging)\n"
+ " -U (page unmerging)\n\n");
+
printf(" -a: specify the access protections of pages.\n"
" <prot> must be of the form [rwx].\n"
" Default: %s\n", KSM_PROT_STR_DEFAULT);
@@ -239,6 +249,46 @@ err_out:
return KSFT_FAIL;
}
+static int check_ksm_unmerge(int mapping, int prot, int timeout, size_t page_size)
+{
+ void *map_ptr;
+ struct timespec start_time;
+ int page_count = 2;
+
+ if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
+ perror("clock_gettime");
+ return KSFT_FAIL;
+ }
+
+ /* fill pages with the same data and merge them */
+ map_ptr = allocate_memory(NULL, prot, mapping, '*', page_size * page_count);
+ if (!map_ptr)
+ return KSFT_FAIL;
+
+ if (ksm_merge_pages(map_ptr, page_size * page_count, start_time, timeout))
+ goto err_out;
+
+ /* change 1 byte in each of the 2 pages -- KSM must automatically unmerge them */
+ memset(map_ptr, '-', 1);
+ memset(map_ptr + page_size, '+', 1);
+
+ /* get at least 1 scan, so KSM can detect that the pages were modified */
+ if (ksm_do_scan(1, start_time, timeout))
+ goto err_out;
+
+ /* check that unmerging was successful and 0 pages are currently merged */
+ if (assert_ksm_pages_count(0)) {
+ printf("OK\n");
+ munmap(map_ptr, page_size * page_count);
+ return KSFT_PASS;
+ }
+
+err_out:
+ printf("Not OK\n");
+ munmap(map_ptr, page_size * page_count);
+ return KSFT_FAIL;
+}
+
int main(int argc, char *argv[])
{
int ret, opt;
@@ -247,8 +297,9 @@ int main(int argc, char *argv[])
long page_count = KSM_PAGE_COUNT_DEFAULT;
size_t page_size = sysconf(_SC_PAGESIZE);
struct ksm_sysfs ksm_sysfs_old;
+ int test_name = CHECK_KSM_MERGE;
- while ((opt = getopt(argc, argv, "ha:p:l:")) != -1) {
+ while ((opt = getopt(argc, argv, "ha:p:l:MU")) != -1) {
switch (opt) {
case 'a':
prot = str_to_prot(optarg);
@@ -270,6 +321,11 @@ int main(int argc, char *argv[])
case 'h':
print_help();
break;
+ case 'M':
+ break;
+ case 'U':
+ test_name = CHECK_KSM_UNMERGE;
+ break;
default:
return KSFT_FAIL;
}
@@ -294,8 +350,16 @@ int main(int argc, char *argv[])
ksm_write_sysfs(KSM_FP("pages_to_scan"), page_count))
return KSFT_FAIL;
- ret = check_ksm_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count, ksm_scan_limit_sec,
- page_size);
+ switch (test_name) {
+ case CHECK_KSM_MERGE:
+ ret = check_ksm_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count,
+ ksm_scan_limit_sec, page_size);
+ break;
+ case CHECK_KSM_UNMERGE:
+ ret = check_ksm_unmerge(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec,
+ page_size);
+ break;
+ }
if (ksm_restore(&ksm_sysfs_old)) {
printf("Cannot restore default tunables\n");
@@ -380,7 +380,23 @@ fi
echo "-------------------------------------------------------"
echo "running KSM MADV_MERGEABLE test with 10 identical pages"
echo "-------------------------------------------------------"
-./ksm_tests -p 10
+./ksm_tests -M -p 10
+ret_val=$?
+
+if [ $ret_val -eq 0 ]; then
+ echo "[PASS]"
+elif [ $ret_val -eq $ksft_skip ]; then
+ echo "[SKIP]"
+ exitcode=$ksft_skip
+else
+ echo "[FAIL]"
+ exitcode=1
+fi
+
+echo "------------------------"
+echo "running KSM unmerge test"
+echo "------------------------"
+./ksm_tests -U
ret_val=$?
if [ $ret_val -eq 0 ]; then