diff options
Diffstat (limited to 'tools/testing/selftests/vm/ksm_tests.c')
-rw-r--r-- | tools/testing/selftests/vm/ksm_tests.c | 70 |
1 files changed, 67 insertions, 3 deletions
diff --git a/tools/testing/selftests/vm/ksm_tests.c b/tools/testing/selftests/vm/ksm_tests.c index 80302bb8f64c..5843526471e1 100644 --- a/tools/testing/selftests/vm/ksm_tests.c +++ b/tools/testing/selftests/vm/ksm_tests.c @@ -12,6 +12,7 @@ #define KSM_SCAN_LIMIT_SEC_DEFAULT 120 #define KSM_PAGE_COUNT_DEFAULT 10l #define KSM_PROT_STR_DEFAULT "rw" +#define KSM_USE_ZERO_PAGES_DEFAULT false struct ksm_sysfs { unsigned long max_page_sharing; @@ -25,7 +26,8 @@ struct ksm_sysfs { enum ksm_test_name { CHECK_KSM_MERGE, - CHECK_KSM_UNMERGE + CHECK_KSM_UNMERGE, + CHECK_KSM_ZERO_PAGE_MERGE }; static int ksm_write_sysfs(const char *file_path, unsigned long val) @@ -80,10 +82,12 @@ static int str_to_prot(char *prot_str) static void print_help(void) { - printf("usage: ksm_tests [-h] <test type> [-a prot] [-p page_count] [-l timeout]\n"); + printf("usage: ksm_tests [-h] <test type> [-a prot] [-p page_count] [-l timeout]\n" + "[-z use_zero_pages]\n"); printf("Supported <test type>:\n" " -M (page merging)\n" + " -Z (zero pages merging)\n" " -U (page unmerging)\n\n"); printf(" -a: specify the access protections of pages.\n" @@ -93,6 +97,8 @@ static void print_help(void) " Default: %ld\n", KSM_PAGE_COUNT_DEFAULT); printf(" -l: limit the maximum running time (in seconds) for a test.\n" " Default: %d seconds\n", KSM_SCAN_LIMIT_SEC_DEFAULT); + printf(" -z: change use_zero_pages tunable\n" + " Default: %d\n", KSM_USE_ZERO_PAGES_DEFAULT); exit(0); } @@ -289,6 +295,50 @@ err_out: return KSFT_FAIL; } +static int check_ksm_zero_page_merge(int mapping, int prot, long page_count, int timeout, + bool use_zero_pages, size_t page_size) +{ + void *map_ptr; + struct timespec start_time; + + if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) { + perror("clock_gettime"); + return KSFT_FAIL; + } + + if (ksm_write_sysfs(KSM_FP("use_zero_pages"), use_zero_pages)) + return KSFT_FAIL; + + /* fill pages with zero and try to merge them */ + map_ptr = allocate_memory(NULL, prot, mapping, 0, 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; + + /* + * verify that the right number of pages are merged: + * 1) if use_zero_pages is set to 1, empty pages are merged + * with the kernel zero page instead of with each other; + * 2) if use_zero_pages is set to 0, empty pages are not treated specially + * and merged as usual. + */ + if (use_zero_pages && !assert_ksm_pages_count(0)) + goto err_out; + else if (!use_zero_pages && !assert_ksm_pages_count(page_count)) + goto err_out; + + 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; @@ -298,8 +348,9 @@ int main(int argc, char *argv[]) size_t page_size = sysconf(_SC_PAGESIZE); struct ksm_sysfs ksm_sysfs_old; int test_name = CHECK_KSM_MERGE; + bool use_zero_pages = KSM_USE_ZERO_PAGES_DEFAULT; - while ((opt = getopt(argc, argv, "ha:p:l:MU")) != -1) { + while ((opt = getopt(argc, argv, "ha:p:l:z:MUZ")) != -1) { switch (opt) { case 'a': prot = str_to_prot(optarg); @@ -321,11 +372,20 @@ int main(int argc, char *argv[]) case 'h': print_help(); break; + case 'z': + if (strcmp(optarg, "0") == 0) + use_zero_pages = 0; + else + use_zero_pages = 1; + break; case 'M': break; case 'U': test_name = CHECK_KSM_UNMERGE; break; + case 'Z': + test_name = CHECK_KSM_ZERO_PAGE_MERGE; + break; default: return KSFT_FAIL; } @@ -359,6 +419,10 @@ int main(int argc, char *argv[]) ret = check_ksm_unmerge(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec, page_size); break; + case CHECK_KSM_ZERO_PAGE_MERGE: + ret = check_ksm_zero_page_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count, + ksm_scan_limit_sec, use_zero_pages, page_size); + break; } if (ksm_restore(&ksm_sysfs_old)) { |