// SPDX-License-Identifier: GPL-2.0
#include <sys/mman.h>
#include <sys/prctl.h>
#include <sys/wait.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 "vm_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 KSM_MERGE_TYPE_DEFAULT 0
#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_merge_type {
KSM_MERGE_MADVISE,
KSM_MERGE_PRCTL,
KSM_MERGE_LAST = KSM_MERGE_PRCTL
};
enum ksm_test_name {
CHECK_KSM_MERGE,
CHECK_KSM_UNMERGE,
CHECK_KSM_GET_MERGE_TYPE,
CHECK_KSM_ZERO_PAGE_MERGE,
CHECK_KSM_NUMA_MERGE,
KSM_MERGE_TIME,
KSM_MERGE_TIME_HUGE_PAGES,
KSM_UNMERGE_TIME,
KSM_COW_TIME
};
int debug;
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 void ksm_print_sysfs(void)
{
unsigned long max_page_sharing, pages_sharing, pages_shared;
unsigned long full_scans, pages_unshared, pages_volatile;
unsigned long stable_node_chains, stable_node_dups;
long general_profit;
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) ||
ksm_read_sysfs(KSM_FP("full_scans"), &full_scans) ||
ksm_read_sysfs(KSM_FP("pages_unshared"), &pages_unshared) ||
ksm_read_sysfs(KSM_FP("pages_volatile"), &pages_volatile) ||
ksm_read_sysfs(KSM_FP("stable_node_chains"), &stable_node_chains) ||
ksm_read_sysfs(KSM_FP("stable_node_dups"), &stable_node_dups) ||
ksm_read_sysfs(KSM_FP("general_profit"), (unsigned long *)&general_profit))
return;
printf("pages_shared : %lu\n", pages_shared);
printf("pages_sharing : %lu\n", pages_sharing);
printf("max_page_sharing : %lu\n", max_page_sharing);
printf("full_scans : %lu\n", full_scans);
printf("pages_unshared : %lu\n", pages_unshared);
printf("pages_volatile : %lu\n", pages_volatile);
printf("stable_node_chains: %lu\n", stable_node_chains);
printf("stable_node_dups : %lu\n", stable_node_dups);
printf("general_profit : %ld\n", general_profit);
}
static void ksm_print_procfs(void)
{
const char *file_name = "/proc/self/ksm_stat";
char buffer[512];
FILE *f = fopen(file_name, "r");
if (!f) {
fprintf(stderr, "f %s\n", file_name);
perror("fopen");
return;
}
while (fgets(buffer, sizeof(buffer), f))
printf("%s", buffer);
fclose(f);
}
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"
" -D evaluate unmerging time and speed when disabling KSM.\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(" -d: turn debugging output on\n");
printf(" -s: the size of duplicated memory area (in MiB)\n");
printf(" -t: KSM merge type\n"
" Default: 0\n"
" 0: madvise merging\n"
" 1: prctl merging\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(int merge_type, void *addr, size_t size,
struct timespec start_time, int timeout)
{
if (merge_type == KSM_MERGE_MADVISE) {
if (madvise(addr, size, MADV_MERGEABLE)) {
perror("madvise");
return 1;
}
} else if (merge_type == KSM_MERGE_PRCTL) {
if (prctl(PR_SET_MEMORY_MERGE, 1, 0, 0, 0)) {
perror("prctl");
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 int ksm_unmerge_pages(void *addr, size_t size,
struct timespec start_time, int timeout)
{
if (madvise(addr, size, MADV_UNMERGEABLE)) {
perror("madvise");
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;
if (debug) {
ksm_print_sysfs();
ksm_print_procfs();
}
/*
* 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 merge_type, 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(merge_type, 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);
if (merge_type == KSM_MERGE_PRCTL)
prctl(PR_SET_MEMORY_MERGE, 0, 0, 0, 0);
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 merge_type, 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(merge_type, 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 merge_type, 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(merge_type, 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 merge_type, 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(merge_type, numa1_map_ptr, page_size, start_time, timeout) ||
ksm_merge_pages(merge_type, 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 merge_type, 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, 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(merge_type, 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 merge_type, 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(merge_type, 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_unmerge_time(int merge_type, 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(merge_type, map_ptr, map_size, start_time, timeout))
goto err_out;
if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
perror("clock_gettime");
goto err_out;
}
if (ksm_unmerge_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 merge_type, 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(merge_type, 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;
int merge_type = KSM_MERGE_TYPE_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, "dha:p:l:z:m:s:t:MUZNPCHD")) != -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 'd':
debug = 1;
break;
case 's':
size_MB = atoi(optarg);
if (size_MB <= 0) {
printf("Size must be greater than 0\n");
return KSFT_FAIL;
}
break;
case 't':
{
int tmp = atoi(optarg);
if (tmp < 0 || tmp > KSM_MERGE_LAST) {
printf("Invalid merge type\n");
return KSFT_FAIL;
}
merge_type = tmp;
}
break;
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 'D':
test_name = KSM_UNMERGE_TIME;
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(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count,
ksm_scan_limit_sec, page_size);
break;
case CHECK_KSM_UNMERGE:
ret = check_ksm_unmerge(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
ksm_scan_limit_sec, page_size);
break;
case CHECK_KSM_ZERO_PAGE_MERGE:
ret = check_ksm_zero_page_merge(merge_type, 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(merge_type, 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(merge_type, 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(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
ksm_scan_limit_sec, size_MB);
break;
case KSM_UNMERGE_TIME:
if (size_MB == 0) {
printf("Option '-s' is required.\n");
return KSFT_FAIL;
}
ret = ksm_unmerge_time(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
ksm_scan_limit_sec, size_MB);
break;
case KSM_COW_TIME:
ret = ksm_cow_time(merge_type, 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;
}
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