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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /tools/testing/selftests/vm/ksm_tests.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/vm/ksm_tests.c')
-rw-r--r--tools/testing/selftests/vm/ksm_tests.c777
1 files changed, 777 insertions, 0 deletions
diff --git a/tools/testing/selftests/vm/ksm_tests.c b/tools/testing/selftests/vm/ksm_tests.c
new file mode 100644
index 000000000..0d85be235
--- /dev/null
+++ b/tools/testing/selftests/vm/ksm_tests.c
@@ -0,0 +1,777 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <sys/mman.h>
+#include <stdbool.h>
+#include <time.h>
+#include <string.h>
+#include <numa.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <err.h>
+
+#include "../kselftest.h"
+#include <include/vdso/time64.h>
+#include "util.h"
+
+#define KSM_SYSFS_PATH "/sys/kernel/mm/ksm/"
+#define KSM_FP(s) (KSM_SYSFS_PATH s)
+#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
+#define KSM_MERGE_ACROSS_NODES_DEFAULT true
+#define MB (1ul << 20)
+
+struct ksm_sysfs {
+ unsigned long max_page_sharing;
+ unsigned long merge_across_nodes;
+ unsigned long pages_to_scan;
+ unsigned long run;
+ unsigned long sleep_millisecs;
+ unsigned long stable_node_chains_prune_millisecs;
+ unsigned long use_zero_pages;
+};
+
+enum ksm_test_name {
+ CHECK_KSM_MERGE,
+ CHECK_KSM_UNMERGE,
+ CHECK_KSM_ZERO_PAGE_MERGE,
+ CHECK_KSM_NUMA_MERGE,
+ KSM_MERGE_TIME,
+ KSM_MERGE_TIME_HUGE_PAGES,
+ KSM_COW_TIME
+};
+
+static int ksm_write_sysfs(const char *file_path, unsigned long val)
+{
+ FILE *f = fopen(file_path, "w");
+
+ if (!f) {
+ fprintf(stderr, "f %s\n", file_path);
+ perror("fopen");
+ return 1;
+ }
+ if (fprintf(f, "%lu", val) < 0) {
+ perror("fprintf");
+ fclose(f);
+ return 1;
+ }
+ fclose(f);
+
+ return 0;
+}
+
+static int ksm_read_sysfs(const char *file_path, unsigned long *val)
+{
+ FILE *f = fopen(file_path, "r");
+
+ if (!f) {
+ fprintf(stderr, "f %s\n", file_path);
+ perror("fopen");
+ return 1;
+ }
+ if (fscanf(f, "%lu", val) != 1) {
+ perror("fscanf");
+ fclose(f);
+ return 1;
+ }
+ fclose(f);
+
+ return 0;
+}
+
+static int str_to_prot(char *prot_str)
+{
+ int prot = 0;
+
+ if ((strchr(prot_str, 'r')) != NULL)
+ prot |= PROT_READ;
+ if ((strchr(prot_str, 'w')) != NULL)
+ prot |= PROT_WRITE;
+ if ((strchr(prot_str, 'x')) != NULL)
+ prot |= PROT_EXEC;
+
+ return prot;
+}
+
+static void print_help(void)
+{
+ printf("usage: ksm_tests [-h] <test type> [-a prot] [-p page_count] [-l timeout]\n"
+ "[-z use_zero_pages] [-m merge_across_nodes] [-s size]\n");
+
+ printf("Supported <test type>:\n"
+ " -M (page merging)\n"
+ " -Z (zero pages merging)\n"
+ " -N (merging of pages in different NUMA nodes)\n"
+ " -U (page unmerging)\n"
+ " -P evaluate merging time and speed.\n"
+ " For this test, the size of duplicated memory area (in MiB)\n"
+ " must be provided using -s option\n"
+ " -H evaluate merging time and speed of area allocated mostly with huge pages\n"
+ " For this test, the size of duplicated memory area (in MiB)\n"
+ " must be provided using -s option\n"
+ " -C evaluate the time required to break COW of merged pages.\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);
+ printf(" -p: specify the number of pages to test.\n"
+ " 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);
+ printf(" -m: change merge_across_nodes tunable\n"
+ " Default: %d\n", KSM_MERGE_ACROSS_NODES_DEFAULT);
+ printf(" -s: the size of duplicated memory area (in MiB)\n");
+
+ exit(0);
+}
+
+static void *allocate_memory(void *ptr, int prot, int mapping, char data, size_t map_size)
+{
+ void *map_ptr = mmap(ptr, map_size, PROT_WRITE, mapping, -1, 0);
+
+ if (!map_ptr) {
+ perror("mmap");
+ return NULL;
+ }
+ memset(map_ptr, data, map_size);
+ if (mprotect(map_ptr, map_size, prot)) {
+ perror("mprotect");
+ munmap(map_ptr, map_size);
+ return NULL;
+ }
+
+ return map_ptr;
+}
+
+static int ksm_do_scan(int scan_count, struct timespec start_time, int timeout)
+{
+ struct timespec cur_time;
+ unsigned long cur_scan, init_scan;
+
+ if (ksm_read_sysfs(KSM_FP("full_scans"), &init_scan))
+ return 1;
+ cur_scan = init_scan;
+
+ while (cur_scan < init_scan + scan_count) {
+ if (ksm_read_sysfs(KSM_FP("full_scans"), &cur_scan))
+ return 1;
+ if (clock_gettime(CLOCK_MONOTONIC_RAW, &cur_time)) {
+ perror("clock_gettime");
+ return 1;
+ }
+ if ((cur_time.tv_sec - start_time.tv_sec) > timeout) {
+ printf("Scan time limit exceeded\n");
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+static int ksm_merge_pages(void *addr, size_t size, struct timespec start_time, int timeout)
+{
+ if (madvise(addr, size, MADV_MERGEABLE)) {
+ perror("madvise");
+ return 1;
+ }
+ if (ksm_write_sysfs(KSM_FP("run"), 1))
+ return 1;
+
+ /* Since merging occurs only after 2 scans, make sure to get at least 2 full scans */
+ if (ksm_do_scan(2, start_time, timeout))
+ return 1;
+
+ return 0;
+}
+
+static bool assert_ksm_pages_count(long dupl_page_count)
+{
+ unsigned long max_page_sharing, pages_sharing, pages_shared;
+
+ if (ksm_read_sysfs(KSM_FP("pages_shared"), &pages_shared) ||
+ ksm_read_sysfs(KSM_FP("pages_sharing"), &pages_sharing) ||
+ ksm_read_sysfs(KSM_FP("max_page_sharing"), &max_page_sharing))
+ return false;
+
+ /*
+ * Since there must be at least 2 pages for merging and 1 page can be
+ * shared with the limited number of pages (max_page_sharing), sometimes
+ * there are 'leftover' pages that cannot be merged. For example, if there
+ * are 11 pages and max_page_sharing = 10, then only 10 pages will be
+ * merged and the 11th page won't be affected. As a result, when the number
+ * of duplicate pages is divided by max_page_sharing and the remainder is 1,
+ * pages_shared and pages_sharing values will be equal between dupl_page_count
+ * and dupl_page_count - 1.
+ */
+ if (dupl_page_count % max_page_sharing == 1 || dupl_page_count % max_page_sharing == 0) {
+ if (pages_shared == dupl_page_count / max_page_sharing &&
+ pages_sharing == pages_shared * (max_page_sharing - 1))
+ return true;
+ } else {
+ if (pages_shared == (dupl_page_count / max_page_sharing + 1) &&
+ pages_sharing == dupl_page_count - pages_shared)
+ return true;
+ }
+
+ return false;
+}
+
+static int ksm_save_def(struct ksm_sysfs *ksm_sysfs)
+{
+ if (ksm_read_sysfs(KSM_FP("max_page_sharing"), &ksm_sysfs->max_page_sharing) ||
+ numa_available() ? 0 :
+ ksm_read_sysfs(KSM_FP("merge_across_nodes"), &ksm_sysfs->merge_across_nodes) ||
+ ksm_read_sysfs(KSM_FP("sleep_millisecs"), &ksm_sysfs->sleep_millisecs) ||
+ ksm_read_sysfs(KSM_FP("pages_to_scan"), &ksm_sysfs->pages_to_scan) ||
+ ksm_read_sysfs(KSM_FP("run"), &ksm_sysfs->run) ||
+ ksm_read_sysfs(KSM_FP("stable_node_chains_prune_millisecs"),
+ &ksm_sysfs->stable_node_chains_prune_millisecs) ||
+ ksm_read_sysfs(KSM_FP("use_zero_pages"), &ksm_sysfs->use_zero_pages))
+ return 1;
+
+ return 0;
+}
+
+static int ksm_restore(struct ksm_sysfs *ksm_sysfs)
+{
+ if (ksm_write_sysfs(KSM_FP("max_page_sharing"), ksm_sysfs->max_page_sharing) ||
+ numa_available() ? 0 :
+ ksm_write_sysfs(KSM_FP("merge_across_nodes"), ksm_sysfs->merge_across_nodes) ||
+ ksm_write_sysfs(KSM_FP("pages_to_scan"), ksm_sysfs->pages_to_scan) ||
+ ksm_write_sysfs(KSM_FP("run"), ksm_sysfs->run) ||
+ ksm_write_sysfs(KSM_FP("sleep_millisecs"), ksm_sysfs->sleep_millisecs) ||
+ ksm_write_sysfs(KSM_FP("stable_node_chains_prune_millisecs"),
+ ksm_sysfs->stable_node_chains_prune_millisecs) ||
+ ksm_write_sysfs(KSM_FP("use_zero_pages"), ksm_sysfs->use_zero_pages))
+ return 1;
+
+ return 0;
+}
+
+static int check_ksm_merge(int mapping, int prot, long page_count, int timeout, 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;
+ }
+
+ /* 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;
+
+ /* verify that the right number of pages are merged */
+ if (assert_ksm_pages_count(page_count)) {
+ 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;
+}
+
+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;
+}
+
+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;
+}
+
+static int get_next_mem_node(int node)
+{
+
+ long node_size;
+ int mem_node = 0;
+ int i, max_node = numa_max_node();
+
+ for (i = node + 1; i <= max_node + node; i++) {
+ mem_node = i % (max_node + 1);
+ node_size = numa_node_size(mem_node, NULL);
+ if (node_size > 0)
+ break;
+ }
+ return mem_node;
+}
+
+static int get_first_mem_node(void)
+{
+ return get_next_mem_node(numa_max_node());
+}
+
+static int check_ksm_numa_merge(int mapping, int prot, int timeout, bool merge_across_nodes,
+ size_t page_size)
+{
+ void *numa1_map_ptr, *numa2_map_ptr;
+ struct timespec start_time;
+ int page_count = 2;
+ int first_node;
+
+ if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
+ perror("clock_gettime");
+ return KSFT_FAIL;
+ }
+
+ if (numa_available() < 0) {
+ perror("NUMA support not enabled");
+ return KSFT_SKIP;
+ }
+ if (numa_num_configured_nodes() <= 1) {
+ printf("At least 2 NUMA nodes must be available\n");
+ return KSFT_SKIP;
+ }
+ if (ksm_write_sysfs(KSM_FP("merge_across_nodes"), merge_across_nodes))
+ return KSFT_FAIL;
+
+ /* allocate 2 pages in 2 different NUMA nodes and fill them with the same data */
+ first_node = get_first_mem_node();
+ numa1_map_ptr = numa_alloc_onnode(page_size, first_node);
+ numa2_map_ptr = numa_alloc_onnode(page_size, get_next_mem_node(first_node));
+ if (!numa1_map_ptr || !numa2_map_ptr) {
+ perror("numa_alloc_onnode");
+ return KSFT_FAIL;
+ }
+
+ memset(numa1_map_ptr, '*', page_size);
+ memset(numa2_map_ptr, '*', page_size);
+
+ /* try to merge the pages */
+ if (ksm_merge_pages(numa1_map_ptr, page_size, start_time, timeout) ||
+ ksm_merge_pages(numa2_map_ptr, page_size, start_time, timeout))
+ goto err_out;
+
+ /*
+ * verify that the right number of pages are merged:
+ * 1) if merge_across_nodes was enabled, 2 duplicate pages will be merged;
+ * 2) if merge_across_nodes = 0, there must be 0 merged pages, since there is
+ * only 1 unique page in each node and they can't be shared.
+ */
+ if (merge_across_nodes && !assert_ksm_pages_count(page_count))
+ goto err_out;
+ else if (!merge_across_nodes && !assert_ksm_pages_count(0))
+ goto err_out;
+
+ numa_free(numa1_map_ptr, page_size);
+ numa_free(numa2_map_ptr, page_size);
+ printf("OK\n");
+ return KSFT_PASS;
+
+err_out:
+ numa_free(numa1_map_ptr, page_size);
+ numa_free(numa2_map_ptr, page_size);
+ printf("Not OK\n");
+ return KSFT_FAIL;
+}
+
+static int ksm_merge_hugepages_time(int mapping, int prot, int timeout, size_t map_size)
+{
+ void *map_ptr, *map_ptr_orig;
+ struct timespec start_time, end_time;
+ unsigned long scan_time_ns;
+ int pagemap_fd, n_normal_pages, n_huge_pages;
+
+ map_size *= MB;
+ size_t len = map_size;
+
+ len -= len % HPAGE_SIZE;
+ map_ptr_orig = mmap(NULL, len + HPAGE_SIZE, PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_NORESERVE | MAP_PRIVATE, -1, 0);
+ map_ptr = map_ptr_orig + HPAGE_SIZE - (uintptr_t)map_ptr_orig % HPAGE_SIZE;
+
+ if (map_ptr_orig == MAP_FAILED)
+ err(2, "initial mmap");
+
+ if (madvise(map_ptr, len + HPAGE_SIZE, MADV_HUGEPAGE))
+ err(2, "MADV_HUGEPAGE");
+
+ pagemap_fd = open("/proc/self/pagemap", O_RDONLY);
+ if (pagemap_fd < 0)
+ err(2, "open pagemap");
+
+ n_normal_pages = 0;
+ n_huge_pages = 0;
+ for (void *p = map_ptr; p < map_ptr + len; p += HPAGE_SIZE) {
+ if (allocate_transhuge(p, pagemap_fd) < 0)
+ n_normal_pages++;
+ else
+ n_huge_pages++;
+ }
+ printf("Number of normal pages: %d\n", n_normal_pages);
+ printf("Number of huge pages: %d\n", n_huge_pages);
+
+ memset(map_ptr, '*', len);
+
+ if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
+ perror("clock_gettime");
+ goto err_out;
+ }
+ if (ksm_merge_pages(map_ptr, map_size, start_time, timeout))
+ goto err_out;
+ if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) {
+ perror("clock_gettime");
+ goto err_out;
+ }
+
+ scan_time_ns = (end_time.tv_sec - start_time.tv_sec) * NSEC_PER_SEC +
+ (end_time.tv_nsec - start_time.tv_nsec);
+
+ printf("Total size: %lu MiB\n", map_size / MB);
+ printf("Total time: %ld.%09ld s\n", scan_time_ns / NSEC_PER_SEC,
+ scan_time_ns % NSEC_PER_SEC);
+ printf("Average speed: %.3f MiB/s\n", (map_size / MB) /
+ ((double)scan_time_ns / NSEC_PER_SEC));
+
+ munmap(map_ptr_orig, len + HPAGE_SIZE);
+ return KSFT_PASS;
+
+err_out:
+ printf("Not OK\n");
+ munmap(map_ptr_orig, len + HPAGE_SIZE);
+ return KSFT_FAIL;
+}
+
+static int ksm_merge_time(int mapping, int prot, int timeout, size_t map_size)
+{
+ void *map_ptr;
+ struct timespec start_time, end_time;
+ unsigned long scan_time_ns;
+
+ map_size *= MB;
+
+ map_ptr = allocate_memory(NULL, prot, mapping, '*', map_size);
+ if (!map_ptr)
+ return KSFT_FAIL;
+
+ if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
+ perror("clock_gettime");
+ goto err_out;
+ }
+ if (ksm_merge_pages(map_ptr, map_size, start_time, timeout))
+ goto err_out;
+ if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) {
+ perror("clock_gettime");
+ goto err_out;
+ }
+
+ scan_time_ns = (end_time.tv_sec - start_time.tv_sec) * NSEC_PER_SEC +
+ (end_time.tv_nsec - start_time.tv_nsec);
+
+ printf("Total size: %lu MiB\n", map_size / MB);
+ printf("Total time: %ld.%09ld s\n", scan_time_ns / NSEC_PER_SEC,
+ scan_time_ns % NSEC_PER_SEC);
+ printf("Average speed: %.3f MiB/s\n", (map_size / MB) /
+ ((double)scan_time_ns / NSEC_PER_SEC));
+
+ munmap(map_ptr, map_size);
+ return KSFT_PASS;
+
+err_out:
+ printf("Not OK\n");
+ munmap(map_ptr, map_size);
+ return KSFT_FAIL;
+}
+
+static int ksm_cow_time(int mapping, int prot, int timeout, size_t page_size)
+{
+ void *map_ptr;
+ struct timespec start_time, end_time;
+ unsigned long cow_time_ns;
+
+ /* page_count must be less than 2*page_size */
+ size_t page_count = 4000;
+
+ map_ptr = allocate_memory(NULL, prot, mapping, '*', page_size * page_count);
+ if (!map_ptr)
+ return KSFT_FAIL;
+
+ if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
+ perror("clock_gettime");
+ return KSFT_FAIL;
+ }
+ for (size_t i = 0; i < page_count - 1; i = i + 2)
+ memset(map_ptr + page_size * i, '-', 1);
+ if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) {
+ perror("clock_gettime");
+ return KSFT_FAIL;
+ }
+
+ cow_time_ns = (end_time.tv_sec - start_time.tv_sec) * NSEC_PER_SEC +
+ (end_time.tv_nsec - start_time.tv_nsec);
+
+ printf("Total size: %lu MiB\n\n", (page_size * page_count) / MB);
+ printf("Not merged pages:\n");
+ printf("Total time: %ld.%09ld s\n", cow_time_ns / NSEC_PER_SEC,
+ cow_time_ns % NSEC_PER_SEC);
+ printf("Average speed: %.3f MiB/s\n\n", ((page_size * (page_count / 2)) / MB) /
+ ((double)cow_time_ns / NSEC_PER_SEC));
+
+ /* Create 2000 pairs of duplicate pages */
+ for (size_t i = 0; i < page_count - 1; i = i + 2) {
+ memset(map_ptr + page_size * i, '+', i / 2 + 1);
+ memset(map_ptr + page_size * (i + 1), '+', i / 2 + 1);
+ }
+ if (ksm_merge_pages(map_ptr, page_size * page_count, start_time, timeout))
+ goto err_out;
+
+ if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
+ perror("clock_gettime");
+ goto err_out;
+ }
+ for (size_t i = 0; i < page_count - 1; i = i + 2)
+ memset(map_ptr + page_size * i, '-', 1);
+ if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) {
+ perror("clock_gettime");
+ goto err_out;
+ }
+
+ cow_time_ns = (end_time.tv_sec - start_time.tv_sec) * NSEC_PER_SEC +
+ (end_time.tv_nsec - start_time.tv_nsec);
+
+ printf("Merged pages:\n");
+ printf("Total time: %ld.%09ld s\n", cow_time_ns / NSEC_PER_SEC,
+ cow_time_ns % NSEC_PER_SEC);
+ printf("Average speed: %.3f MiB/s\n", ((page_size * (page_count / 2)) / MB) /
+ ((double)cow_time_ns / NSEC_PER_SEC));
+
+ 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;
+ int prot = 0;
+ int ksm_scan_limit_sec = KSM_SCAN_LIMIT_SEC_DEFAULT;
+ 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;
+ bool use_zero_pages = KSM_USE_ZERO_PAGES_DEFAULT;
+ bool merge_across_nodes = KSM_MERGE_ACROSS_NODES_DEFAULT;
+ long size_MB = 0;
+
+ while ((opt = getopt(argc, argv, "ha:p:l:z:m:s:MUZNPCH")) != -1) {
+ switch (opt) {
+ case 'a':
+ prot = str_to_prot(optarg);
+ break;
+ case 'p':
+ page_count = atol(optarg);
+ if (page_count <= 0) {
+ printf("The number of pages must be greater than 0\n");
+ return KSFT_FAIL;
+ }
+ break;
+ case 'l':
+ ksm_scan_limit_sec = atoi(optarg);
+ if (ksm_scan_limit_sec <= 0) {
+ printf("Timeout value must be greater than 0\n");
+ return KSFT_FAIL;
+ }
+ break;
+ case 'h':
+ print_help();
+ break;
+ case 'z':
+ if (strcmp(optarg, "0") == 0)
+ use_zero_pages = 0;
+ else
+ use_zero_pages = 1;
+ break;
+ case 'm':
+ if (strcmp(optarg, "0") == 0)
+ merge_across_nodes = 0;
+ else
+ merge_across_nodes = 1;
+ break;
+ case 's':
+ size_MB = atoi(optarg);
+ if (size_MB <= 0) {
+ printf("Size must be greater than 0\n");
+ return KSFT_FAIL;
+ }
+ case 'M':
+ break;
+ case 'U':
+ test_name = CHECK_KSM_UNMERGE;
+ break;
+ case 'Z':
+ test_name = CHECK_KSM_ZERO_PAGE_MERGE;
+ break;
+ case 'N':
+ test_name = CHECK_KSM_NUMA_MERGE;
+ break;
+ case 'P':
+ test_name = KSM_MERGE_TIME;
+ break;
+ case 'H':
+ test_name = KSM_MERGE_TIME_HUGE_PAGES;
+ break;
+ case 'C':
+ test_name = KSM_COW_TIME;
+ break;
+ default:
+ return KSFT_FAIL;
+ }
+ }
+
+ if (prot == 0)
+ prot = str_to_prot(KSM_PROT_STR_DEFAULT);
+
+ if (access(KSM_SYSFS_PATH, F_OK)) {
+ printf("Config KSM not enabled\n");
+ return KSFT_SKIP;
+ }
+
+ if (ksm_save_def(&ksm_sysfs_old)) {
+ printf("Cannot save default tunables\n");
+ return KSFT_FAIL;
+ }
+
+ if (ksm_write_sysfs(KSM_FP("run"), 2) ||
+ ksm_write_sysfs(KSM_FP("sleep_millisecs"), 0) ||
+ numa_available() ? 0 :
+ ksm_write_sysfs(KSM_FP("merge_across_nodes"), 1) ||
+ ksm_write_sysfs(KSM_FP("pages_to_scan"), page_count))
+ return KSFT_FAIL;
+
+ 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;
+ 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;
+ case CHECK_KSM_NUMA_MERGE:
+ ret = check_ksm_numa_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec,
+ merge_across_nodes, page_size);
+ break;
+ case KSM_MERGE_TIME:
+ if (size_MB == 0) {
+ printf("Option '-s' is required.\n");
+ return KSFT_FAIL;
+ }
+ ret = ksm_merge_time(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec,
+ size_MB);
+ break;
+ case KSM_MERGE_TIME_HUGE_PAGES:
+ if (size_MB == 0) {
+ printf("Option '-s' is required.\n");
+ return KSFT_FAIL;
+ }
+ ret = ksm_merge_hugepages_time(MAP_PRIVATE | MAP_ANONYMOUS, prot,
+ ksm_scan_limit_sec, size_MB);
+ break;
+ case KSM_COW_TIME:
+ ret = ksm_cow_time(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec,
+ page_size);
+ break;
+ }
+
+ if (ksm_restore(&ksm_sysfs_old)) {
+ printf("Cannot restore default tunables\n");
+ return KSFT_FAIL;
+ }
+
+ return ret;
+}