1 // SPDX-License-Identifier: GPL-2.0
2
3 #include <sys/mman.h>
4 #include <sys/prctl.h>
5 #include <sys/wait.h>
6 #include <stdbool.h>
7 #include <time.h>
8 #include <string.h>
9 #include <numa.h>
10 #include <unistd.h>
11 #include <fcntl.h>
12 #include <stdint.h>
13 #include <err.h>
14
15 #include "../kselftest.h"
16 #include <include/vdso/time64.h>
17 #include "vm_util.h"
18
19 #define KSM_SYSFS_PATH "/sys/kernel/mm/ksm/"
20 #define KSM_FP(s) (KSM_SYSFS_PATH s)
21 #define KSM_SCAN_LIMIT_SEC_DEFAULT 120
22 #define KSM_PAGE_COUNT_DEFAULT 10l
23 #define KSM_PROT_STR_DEFAULT "rw"
24 #define KSM_USE_ZERO_PAGES_DEFAULT false
25 #define KSM_MERGE_ACROSS_NODES_DEFAULT true
26 #define KSM_MERGE_TYPE_DEFAULT 0
27 #define MB (1ul << 20)
28
29 struct ksm_sysfs {
30 unsigned long max_page_sharing;
31 unsigned long merge_across_nodes;
32 unsigned long pages_to_scan;
33 unsigned long run;
34 unsigned long sleep_millisecs;
35 unsigned long stable_node_chains_prune_millisecs;
36 unsigned long use_zero_pages;
37 };
38
39 enum ksm_merge_type {
40 KSM_MERGE_MADVISE,
41 KSM_MERGE_PRCTL,
42 KSM_MERGE_LAST = KSM_MERGE_PRCTL
43 };
44
45 enum ksm_test_name {
46 CHECK_KSM_MERGE,
47 CHECK_KSM_UNMERGE,
48 CHECK_KSM_GET_MERGE_TYPE,
49 CHECK_KSM_ZERO_PAGE_MERGE,
50 CHECK_KSM_NUMA_MERGE,
51 KSM_MERGE_TIME,
52 KSM_MERGE_TIME_HUGE_PAGES,
53 KSM_UNMERGE_TIME,
54 KSM_COW_TIME
55 };
56
57 int debug;
58
59 static int ksm_write_sysfs(const char *file_path, unsigned long val)
60 {
61 FILE *f = fopen(file_path, "w");
62
63 if (!f) {
64 fprintf(stderr, "f %s\n", file_path);
65 perror("fopen");
66 return 1;
67 }
68 if (fprintf(f, "%lu", val) < 0) {
69 perror("fprintf");
70 fclose(f);
71 return 1;
72 }
73 fclose(f);
74
75 return 0;
76 }
77
78 static int ksm_read_sysfs(const char *file_path, unsigned long *val)
79 {
80 FILE *f = fopen(file_path, "r");
81
82 if (!f) {
83 fprintf(stderr, "f %s\n", file_path);
84 perror("fopen");
85 return 1;
86 }
87 if (fscanf(f, "%lu", val) != 1) {
88 perror("fscanf");
89 fclose(f);
90 return 1;
91 }
92 fclose(f);
93
94 return 0;
95 }
96
97 static void ksm_print_sysfs(void)
98 {
99 unsigned long max_page_sharing, pages_sharing, pages_shared;
100 unsigned long full_scans, pages_unshared, pages_volatile;
101 unsigned long stable_node_chains, stable_node_dups;
102 long general_profit;
103
104 if (ksm_read_sysfs(KSM_FP("pages_shared"), &pages_shared) ||
105 ksm_read_sysfs(KSM_FP("pages_sharing"), &pages_sharing) ||
106 ksm_read_sysfs(KSM_FP("max_page_sharing"), &max_page_sharing) ||
107 ksm_read_sysfs(KSM_FP("full_scans"), &full_scans) ||
108 ksm_read_sysfs(KSM_FP("pages_unshared"), &pages_unshared) ||
109 ksm_read_sysfs(KSM_FP("pages_volatile"), &pages_volatile) ||
110 ksm_read_sysfs(KSM_FP("stable_node_chains"), &stable_node_chains) ||
111 ksm_read_sysfs(KSM_FP("stable_node_dups"), &stable_node_dups) ||
112 ksm_read_sysfs(KSM_FP("general_profit"), (unsigned long *)&general_profit))
113 return;
114
115 printf("pages_shared : %lu\n", pages_shared);
116 printf("pages_sharing : %lu\n", pages_sharing);
117 printf("max_page_sharing : %lu\n", max_page_sharing);
118 printf("full_scans : %lu\n", full_scans);
119 printf("pages_unshared : %lu\n", pages_unshared);
120 printf("pages_volatile : %lu\n", pages_volatile);
121 printf("stable_node_chains: %lu\n", stable_node_chains);
122 printf("stable_node_dups : %lu\n", stable_node_dups);
123 printf("general_profit : %ld\n", general_profit);
124 }
125
126 static void ksm_print_procfs(void)
127 {
128 const char *file_name = "/proc/self/ksm_stat";
129 char buffer[512];
130 FILE *f = fopen(file_name, "r");
131
132 if (!f) {
133 fprintf(stderr, "f %s\n", file_name);
134 perror("fopen");
135 return;
136 }
137
138 while (fgets(buffer, sizeof(buffer), f))
139 printf("%s", buffer);
140
141 fclose(f);
142 }
143
144 static int str_to_prot(char *prot_str)
145 {
146 int prot = 0;
147
148 if ((strchr(prot_str, 'r')) != NULL)
149 prot |= PROT_READ;
150 if ((strchr(prot_str, 'w')) != NULL)
151 prot |= PROT_WRITE;
152 if ((strchr(prot_str, 'x')) != NULL)
153 prot |= PROT_EXEC;
154
155 return prot;
156 }
157
158 static void print_help(void)
159 {
160 printf("usage: ksm_tests [-h] <test type> [-a prot] [-p page_count] [-l timeout]\n"
161 "[-z use_zero_pages] [-m merge_across_nodes] [-s size]\n");
162
163 printf("Supported <test type>:\n"
164 " -M (page merging)\n"
165 " -Z (zero pages merging)\n"
166 " -N (merging of pages in different NUMA nodes)\n"
167 " -U (page unmerging)\n"
168 " -P evaluate merging time and speed.\n"
169 " For this test, the size of duplicated memory area (in MiB)\n"
170 " must be provided using -s option\n"
171 " -H evaluate merging time and speed of area allocated mostly with huge pages\n"
172 " For this test, the size of duplicated memory area (in MiB)\n"
173 " must be provided using -s option\n"
174 " -D evaluate unmerging time and speed when disabling KSM.\n"
175 " For this test, the size of duplicated memory area (in MiB)\n"
176 " must be provided using -s option\n"
177 " -C evaluate the time required to break COW of merged pages.\n\n");
178
179 printf(" -a: specify the access protections of pages.\n"
180 " <prot> must be of the form [rwx].\n"
181 " Default: %s\n", KSM_PROT_STR_DEFAULT);
182 printf(" -p: specify the number of pages to test.\n"
183 " Default: %ld\n", KSM_PAGE_COUNT_DEFAULT);
184 printf(" -l: limit the maximum running time (in seconds) for a test.\n"
185 " Default: %d seconds\n", KSM_SCAN_LIMIT_SEC_DEFAULT);
186 printf(" -z: change use_zero_pages tunable\n"
187 " Default: %d\n", KSM_USE_ZERO_PAGES_DEFAULT);
188 printf(" -m: change merge_across_nodes tunable\n"
189 " Default: %d\n", KSM_MERGE_ACROSS_NODES_DEFAULT);
190 printf(" -d: turn debugging output on\n");
191 printf(" -s: the size of duplicated memory area (in MiB)\n");
192 printf(" -t: KSM merge type\n"
193 " Default: 0\n"
194 " 0: madvise merging\n"
195 " 1: prctl merging\n");
196
197 exit(0);
198 }
199
200 static void *allocate_memory(void *ptr, int prot, int mapping, char data, size_t map_size)
201 {
202 void *map_ptr = mmap(ptr, map_size, PROT_WRITE, mapping, -1, 0);
203
204 if (!map_ptr) {
205 perror("mmap");
206 return NULL;
207 }
208 memset(map_ptr, data, map_size);
209 if (mprotect(map_ptr, map_size, prot)) {
210 perror("mprotect");
211 munmap(map_ptr, map_size);
212 return NULL;
213 }
214
215 return map_ptr;
216 }
217
218 static int ksm_do_scan(int scan_count, struct timespec start_time, int timeout)
219 {
220 struct timespec cur_time;
221 unsigned long cur_scan, init_scan;
222
223 if (ksm_read_sysfs(KSM_FP("full_scans"), &init_scan))
224 return 1;
225 cur_scan = init_scan;
226
227 while (cur_scan < init_scan + scan_count) {
228 if (ksm_read_sysfs(KSM_FP("full_scans"), &cur_scan))
229 return 1;
230 if (clock_gettime(CLOCK_MONOTONIC_RAW, &cur_time)) {
231 perror("clock_gettime");
232 return 1;
233 }
234 if ((cur_time.tv_sec - start_time.tv_sec) > timeout) {
235 printf("Scan time limit exceeded\n");
236 return 1;
237 }
238 }
239
240 return 0;
241 }
242
243 static int ksm_merge_pages(int merge_type, void *addr, size_t size,
244 struct timespec start_time, int timeout)
245 {
246 if (merge_type == KSM_MERGE_MADVISE) {
247 if (madvise(addr, size, MADV_MERGEABLE)) {
248 perror("madvise");
249 return 1;
250 }
251 } else if (merge_type == KSM_MERGE_PRCTL) {
252 if (prctl(PR_SET_MEMORY_MERGE, 1, 0, 0, 0)) {
253 perror("prctl");
254 return 1;
255 }
256 }
257
258 if (ksm_write_sysfs(KSM_FP("run"), 1))
259 return 1;
260
261 /* Since merging occurs only after 2 scans, make sure to get at least 2 full scans */
262 if (ksm_do_scan(2, start_time, timeout))
263 return 1;
264
265 return 0;
266 }
267
268 static int ksm_unmerge_pages(void *addr, size_t size,
269 struct timespec start_time, int timeout)
270 {
271 if (madvise(addr, size, MADV_UNMERGEABLE)) {
272 perror("madvise");
273 return 1;
274 }
275 return 0;
276 }
277
278 static bool assert_ksm_pages_count(long dupl_page_count)
279 {
280 unsigned long max_page_sharing, pages_sharing, pages_shared;
281
282 if (ksm_read_sysfs(KSM_FP("pages_shared"), &pages_shared) ||
283 ksm_read_sysfs(KSM_FP("pages_sharing"), &pages_sharing) ||
284 ksm_read_sysfs(KSM_FP("max_page_sharing"), &max_page_sharing))
285 return false;
286
287 if (debug) {
288 ksm_print_sysfs();
289 ksm_print_procfs();
290 }
291
292 /*
293 * Since there must be at least 2 pages for merging and 1 page can be
294 * shared with the limited number of pages (max_page_sharing), sometimes
295 * there are 'leftover' pages that cannot be merged. For example, if there
296 * are 11 pages and max_page_sharing = 10, then only 10 pages will be
297 * merged and the 11th page won't be affected. As a result, when the number
298 * of duplicate pages is divided by max_page_sharing and the remainder is 1,
299 * pages_shared and pages_sharing values will be equal between dupl_page_count
300 * and dupl_page_count - 1.
301 */
302 if (dupl_page_count % max_page_sharing == 1 || dupl_page_count % max_page_sharing == 0) {
303 if (pages_shared == dupl_page_count / max_page_sharing &&
304 pages_sharing == pages_shared * (max_page_sharing - 1))
305 return true;
306 } else {
307 if (pages_shared == (dupl_page_count / max_page_sharing + 1) &&
308 pages_sharing == dupl_page_count - pages_shared)
309 return true;
310 }
311
312 return false;
313 }
314
315 static int ksm_save_def(struct ksm_sysfs *ksm_sysfs)
316 {
317 if (ksm_read_sysfs(KSM_FP("max_page_sharing"), &ksm_sysfs->max_page_sharing) ||
318 numa_available() ? 0 :
319 ksm_read_sysfs(KSM_FP("merge_across_nodes"), &ksm_sysfs->merge_across_nodes) ||
320 ksm_read_sysfs(KSM_FP("sleep_millisecs"), &ksm_sysfs->sleep_millisecs) ||
321 ksm_read_sysfs(KSM_FP("pages_to_scan"), &ksm_sysfs->pages_to_scan) ||
322 ksm_read_sysfs(KSM_FP("run"), &ksm_sysfs->run) ||
323 ksm_read_sysfs(KSM_FP("stable_node_chains_prune_millisecs"),
324 &ksm_sysfs->stable_node_chains_prune_millisecs) ||
325 ksm_read_sysfs(KSM_FP("use_zero_pages"), &ksm_sysfs->use_zero_pages))
326 return 1;
327
328 return 0;
329 }
330
331 static int ksm_restore(struct ksm_sysfs *ksm_sysfs)
332 {
333 if (ksm_write_sysfs(KSM_FP("max_page_sharing"), ksm_sysfs->max_page_sharing) ||
334 numa_available() ? 0 :
335 ksm_write_sysfs(KSM_FP("merge_across_nodes"), ksm_sysfs->merge_across_nodes) ||
336 ksm_write_sysfs(KSM_FP("pages_to_scan"), ksm_sysfs->pages_to_scan) ||
337 ksm_write_sysfs(KSM_FP("run"), ksm_sysfs->run) ||
338 ksm_write_sysfs(KSM_FP("sleep_millisecs"), ksm_sysfs->sleep_millisecs) ||
339 ksm_write_sysfs(KSM_FP("stable_node_chains_prune_millisecs"),
340 ksm_sysfs->stable_node_chains_prune_millisecs) ||
341 ksm_write_sysfs(KSM_FP("use_zero_pages"), ksm_sysfs->use_zero_pages))
342 return 1;
343
344 return 0;
345 }
346
347 static int check_ksm_merge(int merge_type, int mapping, int prot,
348 long page_count, int timeout, size_t page_size)
349 {
350 void *map_ptr;
351 struct timespec start_time;
352
353 if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
354 perror("clock_gettime");
355 return KSFT_FAIL;
356 }
357
358 /* fill pages with the same data and merge them */
359 map_ptr = allocate_memory(NULL, prot, mapping, '*', page_size * page_count);
360 if (!map_ptr)
361 return KSFT_FAIL;
362
363 if (ksm_merge_pages(merge_type, map_ptr, page_size * page_count, start_time, timeout))
364 goto err_out;
365
366 /* verify that the right number of pages are merged */
367 if (assert_ksm_pages_count(page_count)) {
368 printf("OK\n");
369 munmap(map_ptr, page_size * page_count);
370 if (merge_type == KSM_MERGE_PRCTL)
371 prctl(PR_SET_MEMORY_MERGE, 0, 0, 0, 0);
372 return KSFT_PASS;
373 }
374
375 err_out:
376 printf("Not OK\n");
377 munmap(map_ptr, page_size * page_count);
378 return KSFT_FAIL;
379 }
380
381 static int check_ksm_unmerge(int merge_type, int mapping, int prot, int timeout, size_t page_size)
382 {
383 void *map_ptr;
384 struct timespec start_time;
385 int page_count = 2;
386
387 if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
388 perror("clock_gettime");
389 return KSFT_FAIL;
390 }
391
392 /* fill pages with the same data and merge them */
393 map_ptr = allocate_memory(NULL, prot, mapping, '*', page_size * page_count);
394 if (!map_ptr)
395 return KSFT_FAIL;
396
397 if (ksm_merge_pages(merge_type, map_ptr, page_size * page_count, start_time, timeout))
398 goto err_out;
399
400 /* change 1 byte in each of the 2 pages -- KSM must automatically unmerge them */
401 memset(map_ptr, '-', 1);
402 memset(map_ptr + page_size, '+', 1);
403
404 /* get at least 1 scan, so KSM can detect that the pages were modified */
405 if (ksm_do_scan(1, start_time, timeout))
406 goto err_out;
407
408 /* check that unmerging was successful and 0 pages are currently merged */
409 if (assert_ksm_pages_count(0)) {
410 printf("OK\n");
411 munmap(map_ptr, page_size * page_count);
412 return KSFT_PASS;
413 }
414
415 err_out:
416 printf("Not OK\n");
417 munmap(map_ptr, page_size * page_count);
418 return KSFT_FAIL;
419 }
420
421 static int check_ksm_zero_page_merge(int merge_type, int mapping, int prot, long page_count,
422 int timeout, bool use_zero_pages, size_t page_size)
423 {
424 void *map_ptr;
425 struct timespec start_time;
426
427 if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
428 perror("clock_gettime");
429 return KSFT_FAIL;
430 }
431
432 if (ksm_write_sysfs(KSM_FP("use_zero_pages"), use_zero_pages))
433 return KSFT_FAIL;
434
435 /* fill pages with zero and try to merge them */
436 map_ptr = allocate_memory(NULL, prot, mapping, 0, page_size * page_count);
437 if (!map_ptr)
438 return KSFT_FAIL;
439
440 if (ksm_merge_pages(merge_type, map_ptr, page_size * page_count, start_time, timeout))
441 goto err_out;
442
443 /*
444 * verify that the right number of pages are merged:
445 * 1) if use_zero_pages is set to 1, empty pages are merged
446 * with the kernel zero page instead of with each other;
447 * 2) if use_zero_pages is set to 0, empty pages are not treated specially
448 * and merged as usual.
449 */
450 if (use_zero_pages && !assert_ksm_pages_count(0))
451 goto err_out;
452 else if (!use_zero_pages && !assert_ksm_pages_count(page_count))
453 goto err_out;
454
455 printf("OK\n");
456 munmap(map_ptr, page_size * page_count);
457 return KSFT_PASS;
458
459 err_out:
460 printf("Not OK\n");
461 munmap(map_ptr, page_size * page_count);
462 return KSFT_FAIL;
463 }
464
465 static int get_next_mem_node(int node)
466 {
467
468 long node_size;
469 int mem_node = 0;
470 int i, max_node = numa_max_node();
471
472 for (i = node + 1; i <= max_node + node; i++) {
473 mem_node = i % (max_node + 1);
474 node_size = numa_node_size(mem_node, NULL);
475 if (node_size > 0)
476 break;
477 }
478 return mem_node;
479 }
480
481 static int get_first_mem_node(void)
482 {
483 return get_next_mem_node(numa_max_node());
484 }
485
486 static int check_ksm_numa_merge(int merge_type, int mapping, int prot, int timeout,
487 bool merge_across_nodes, size_t page_size)
488 {
489 void *numa1_map_ptr, *numa2_map_ptr;
490 struct timespec start_time;
491 int page_count = 2;
492 int first_node;
493
494 if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
495 perror("clock_gettime");
496 return KSFT_FAIL;
497 }
498
499 if (numa_available() < 0) {
500 perror("NUMA support not enabled");
501 return KSFT_SKIP;
502 }
503 if (numa_num_configured_nodes() <= 1) {
504 printf("At least 2 NUMA nodes must be available\n");
505 return KSFT_SKIP;
506 }
507 if (ksm_write_sysfs(KSM_FP("merge_across_nodes"), merge_across_nodes))
508 return KSFT_FAIL;
509
510 /* allocate 2 pages in 2 different NUMA nodes and fill them with the same data */
511 first_node = get_first_mem_node();
512 numa1_map_ptr = numa_alloc_onnode(page_size, first_node);
513 numa2_map_ptr = numa_alloc_onnode(page_size, get_next_mem_node(first_node));
514 if (!numa1_map_ptr || !numa2_map_ptr) {
515 perror("numa_alloc_onnode");
516 return KSFT_FAIL;
517 }
518
519 memset(numa1_map_ptr, '*', page_size);
520 memset(numa2_map_ptr, '*', page_size);
521
522 /* try to merge the pages */
523 if (ksm_merge_pages(merge_type, numa1_map_ptr, page_size, start_time, timeout) ||
524 ksm_merge_pages(merge_type, numa2_map_ptr, page_size, start_time, timeout))
525 goto err_out;
526
527 /*
528 * verify that the right number of pages are merged:
529 * 1) if merge_across_nodes was enabled, 2 duplicate pages will be merged;
530 * 2) if merge_across_nodes = 0, there must be 0 merged pages, since there is
531 * only 1 unique page in each node and they can't be shared.
532 */
533 if (merge_across_nodes && !assert_ksm_pages_count(page_count))
534 goto err_out;
535 else if (!merge_across_nodes && !assert_ksm_pages_count(0))
536 goto err_out;
537
538 numa_free(numa1_map_ptr, page_size);
539 numa_free(numa2_map_ptr, page_size);
540 printf("OK\n");
541 return KSFT_PASS;
542
543 err_out:
544 numa_free(numa1_map_ptr, page_size);
545 numa_free(numa2_map_ptr, page_size);
546 printf("Not OK\n");
547 return KSFT_FAIL;
548 }
549
550 static int ksm_merge_hugepages_time(int merge_type, int mapping, int prot,
551 int timeout, size_t map_size)
552 {
553 void *map_ptr, *map_ptr_orig;
554 struct timespec start_time, end_time;
555 unsigned long scan_time_ns;
556 int pagemap_fd, n_normal_pages, n_huge_pages;
557
558 map_size *= MB;
559 size_t len = map_size;
560
561 len -= len % HPAGE_SIZE;
562 map_ptr_orig = mmap(NULL, len + HPAGE_SIZE, PROT_READ | PROT_WRITE,
563 MAP_ANONYMOUS | MAP_NORESERVE | MAP_PRIVATE, -1, 0);
564 map_ptr = map_ptr_orig + HPAGE_SIZE - (uintptr_t)map_ptr_orig % HPAGE_SIZE;
565
566 if (map_ptr_orig == MAP_FAILED)
567 err(2, "initial mmap");
568
569 if (madvise(map_ptr, len, MADV_HUGEPAGE))
570 err(2, "MADV_HUGEPAGE");
571
572 pagemap_fd = open("/proc/self/pagemap", O_RDONLY);
573 if (pagemap_fd < 0)
574 err(2, "open pagemap");
575
576 n_normal_pages = 0;
577 n_huge_pages = 0;
578 for (void *p = map_ptr; p < map_ptr + len; p += HPAGE_SIZE) {
579 if (allocate_transhuge(p, pagemap_fd) < 0)
580 n_normal_pages++;
581 else
582 n_huge_pages++;
583 }
584 printf("Number of normal pages: %d\n", n_normal_pages);
585 printf("Number of huge pages: %d\n", n_huge_pages);
586
587 memset(map_ptr, '*', len);
588
589 if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
590 perror("clock_gettime");
591 goto err_out;
592 }
593 if (ksm_merge_pages(merge_type, map_ptr, map_size, start_time, timeout))
594 goto err_out;
595 if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) {
596 perror("clock_gettime");
597 goto err_out;
598 }
599
600 scan_time_ns = (end_time.tv_sec - start_time.tv_sec) * NSEC_PER_SEC +
601 (end_time.tv_nsec - start_time.tv_nsec);
602
603 printf("Total size: %lu MiB\n", map_size / MB);
604 printf("Total time: %ld.%09ld s\n", scan_time_ns / NSEC_PER_SEC,
605 scan_time_ns % NSEC_PER_SEC);
606 printf("Average speed: %.3f MiB/s\n", (map_size / MB) /
607 ((double)scan_time_ns / NSEC_PER_SEC));
608
609 munmap(map_ptr_orig, len + HPAGE_SIZE);
610 return KSFT_PASS;
611
612 err_out:
613 printf("Not OK\n");
614 munmap(map_ptr_orig, len + HPAGE_SIZE);
615 return KSFT_FAIL;
616 }
617
618 static int ksm_merge_time(int merge_type, int mapping, int prot, int timeout, size_t map_size)
619 {
620 void *map_ptr;
621 struct timespec start_time, end_time;
622 unsigned long scan_time_ns;
623
624 map_size *= MB;
625
626 map_ptr = allocate_memory(NULL, prot, mapping, '*', map_size);
627 if (!map_ptr)
628 return KSFT_FAIL;
629
630 if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
631 perror("clock_gettime");
632 goto err_out;
633 }
634 if (ksm_merge_pages(merge_type, map_ptr, map_size, start_time, timeout))
635 goto err_out;
636 if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) {
637 perror("clock_gettime");
638 goto err_out;
639 }
640
641 scan_time_ns = (end_time.tv_sec - start_time.tv_sec) * NSEC_PER_SEC +
642 (end_time.tv_nsec - start_time.tv_nsec);
643
644 printf("Total size: %lu MiB\n", map_size / MB);
645 printf("Total time: %ld.%09ld s\n", scan_time_ns / NSEC_PER_SEC,
646 scan_time_ns % NSEC_PER_SEC);
647 printf("Average speed: %.3f MiB/s\n", (map_size / MB) /
648 ((double)scan_time_ns / NSEC_PER_SEC));
649
650 munmap(map_ptr, map_size);
651 return KSFT_PASS;
652
653 err_out:
654 printf("Not OK\n");
655 munmap(map_ptr, map_size);
656 return KSFT_FAIL;
657 }
658
659 static int ksm_unmerge_time(int merge_type, int mapping, int prot, int timeout, size_t map_size)
660 {
661 void *map_ptr;
662 struct timespec start_time, end_time;
663 unsigned long scan_time_ns;
664
665 map_size *= MB;
666
667 map_ptr = allocate_memory(NULL, prot, mapping, '*', map_size);
668 if (!map_ptr)
669 return KSFT_FAIL;
670 if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
671 perror("clock_gettime");
672 goto err_out;
673 }
674 if (ksm_merge_pages(merge_type, map_ptr, map_size, start_time, timeout))
675 goto err_out;
676
677 if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
678 perror("clock_gettime");
679 goto err_out;
680 }
681 if (ksm_unmerge_pages(map_ptr, map_size, start_time, timeout))
682 goto err_out;
683 if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) {
684 perror("clock_gettime");
685 goto err_out;
686 }
687
688 scan_time_ns = (end_time.tv_sec - start_time.tv_sec) * NSEC_PER_SEC +
689 (end_time.tv_nsec - start_time.tv_nsec);
690
691 printf("Total size: %lu MiB\n", map_size / MB);
692 printf("Total time: %ld.%09ld s\n", scan_time_ns / NSEC_PER_SEC,
693 scan_time_ns % NSEC_PER_SEC);
694 printf("Average speed: %.3f MiB/s\n", (map_size / MB) /
695 ((double)scan_time_ns / NSEC_PER_SEC));
696
697 munmap(map_ptr, map_size);
698 return KSFT_PASS;
699
700 err_out:
701 printf("Not OK\n");
702 munmap(map_ptr, map_size);
703 return KSFT_FAIL;
704 }
705
706 static int ksm_cow_time(int merge_type, int mapping, int prot, int timeout, size_t page_size)
707 {
708 void *map_ptr;
709 struct timespec start_time, end_time;
710 unsigned long cow_time_ns;
711
712 /* page_count must be less than 2*page_size */
713 size_t page_count = 4000;
714
715 map_ptr = allocate_memory(NULL, prot, mapping, '*', page_size * page_count);
716 if (!map_ptr)
717 return KSFT_FAIL;
718
719 if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
720 perror("clock_gettime");
721 return KSFT_FAIL;
722 }
723 for (size_t i = 0; i < page_count - 1; i = i + 2)
724 memset(map_ptr + page_size * i, '-', 1);
725 if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) {
726 perror("clock_gettime");
727 return KSFT_FAIL;
728 }
729
730 cow_time_ns = (end_time.tv_sec - start_time.tv_sec) * NSEC_PER_SEC +
731 (end_time.tv_nsec - start_time.tv_nsec);
732
733 printf("Total size: %lu MiB\n\n", (page_size * page_count) / MB);
734 printf("Not merged pages:\n");
735 printf("Total time: %ld.%09ld s\n", cow_time_ns / NSEC_PER_SEC,
736 cow_time_ns % NSEC_PER_SEC);
737 printf("Average speed: %.3f MiB/s\n\n", ((page_size * (page_count / 2)) / MB) /
738 ((double)cow_time_ns / NSEC_PER_SEC));
739
740 /* Create 2000 pairs of duplicate pages */
741 for (size_t i = 0; i < page_count - 1; i = i + 2) {
742 memset(map_ptr + page_size * i, '+', i / 2 + 1);
743 memset(map_ptr + page_size * (i + 1), '+', i / 2 + 1);
744 }
745 if (ksm_merge_pages(merge_type, map_ptr, page_size * page_count, start_time, timeout))
746 goto err_out;
747
748 if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
749 perror("clock_gettime");
750 goto err_out;
751 }
752 for (size_t i = 0; i < page_count - 1; i = i + 2)
753 memset(map_ptr + page_size * i, '-', 1);
754 if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) {
755 perror("clock_gettime");
756 goto err_out;
757 }
758
759 cow_time_ns = (end_time.tv_sec - start_time.tv_sec) * NSEC_PER_SEC +
760 (end_time.tv_nsec - start_time.tv_nsec);
761
762 printf("Merged pages:\n");
763 printf("Total time: %ld.%09ld s\n", cow_time_ns / NSEC_PER_SEC,
764 cow_time_ns % NSEC_PER_SEC);
765 printf("Average speed: %.3f MiB/s\n", ((page_size * (page_count / 2)) / MB) /
766 ((double)cow_time_ns / NSEC_PER_SEC));
767
768 munmap(map_ptr, page_size * page_count);
769 return KSFT_PASS;
770
771 err_out:
772 printf("Not OK\n");
773 munmap(map_ptr, page_size * page_count);
774 return KSFT_FAIL;
775 }
776
777 int main(int argc, char *argv[])
778 {
779 int ret, opt;
780 int prot = 0;
781 int ksm_scan_limit_sec = KSM_SCAN_LIMIT_SEC_DEFAULT;
782 int merge_type = KSM_MERGE_TYPE_DEFAULT;
783 long page_count = KSM_PAGE_COUNT_DEFAULT;
784 size_t page_size = sysconf(_SC_PAGESIZE);
785 struct ksm_sysfs ksm_sysfs_old;
786 int test_name = CHECK_KSM_MERGE;
787 bool use_zero_pages = KSM_USE_ZERO_PAGES_DEFAULT;
788 bool merge_across_nodes = KSM_MERGE_ACROSS_NODES_DEFAULT;
789 long size_MB = 0;
790
791 while ((opt = getopt(argc, argv, "dha:p:l:z:m:s:t:MUZNPCHD")) != -1) {
792 switch (opt) {
793 case 'a':
794 prot = str_to_prot(optarg);
795 break;
796 case 'p':
797 page_count = atol(optarg);
798 if (page_count <= 0) {
799 printf("The number of pages must be greater than 0\n");
800 return KSFT_FAIL;
801 }
802 break;
803 case 'l':
804 ksm_scan_limit_sec = atoi(optarg);
805 if (ksm_scan_limit_sec <= 0) {
806 printf("Timeout value must be greater than 0\n");
807 return KSFT_FAIL;
808 }
809 break;
810 case 'h':
811 print_help();
812 break;
813 case 'z':
814 if (strcmp(optarg, "") == 0)
815 use_zero_pages = 0;
816 else
817 use_zero_pages = 1;
818 break;
819 case 'm':
820 if (strcmp(optarg, "") == 0)
821 merge_across_nodes = 0;
822 else
823 merge_across_nodes = 1;
824 break;
825 case 'd':
826 debug = 1;
827 break;
828 case 's':
829 size_MB = atoi(optarg);
830 if (size_MB <= 0) {
831 printf("Size must be greater than 0\n");
832 return KSFT_FAIL;
833 }
834 break;
835 case 't':
836 {
837 int tmp = atoi(optarg);
838
839 if (tmp < 0 || tmp > KSM_MERGE_LAST) {
840 printf("Invalid merge type\n");
841 return KSFT_FAIL;
842 }
843 merge_type = tmp;
844 }
845 break;
846 case 'M':
847 break;
848 case 'U':
849 test_name = CHECK_KSM_UNMERGE;
850 break;
851 case 'Z':
852 test_name = CHECK_KSM_ZERO_PAGE_MERGE;
853 break;
854 case 'N':
855 test_name = CHECK_KSM_NUMA_MERGE;
856 break;
857 case 'P':
858 test_name = KSM_MERGE_TIME;
859 break;
860 case 'H':
861 test_name = KSM_MERGE_TIME_HUGE_PAGES;
862 break;
863 case 'D':
864 test_name = KSM_UNMERGE_TIME;
865 break;
866 case 'C':
867 test_name = KSM_COW_TIME;
868 break;
869 default:
870 return KSFT_FAIL;
871 }
872 }
873
874 if (prot == 0)
875 prot = str_to_prot(KSM_PROT_STR_DEFAULT);
876
877 if (access(KSM_SYSFS_PATH, F_OK)) {
878 printf("Config KSM not enabled\n");
879 return KSFT_SKIP;
880 }
881
882 if (ksm_save_def(&ksm_sysfs_old)) {
883 printf("Cannot save default tunables\n");
884 return KSFT_FAIL;
885 }
886
887 if (ksm_write_sysfs(KSM_FP("run"), 2) ||
888 ksm_write_sysfs(KSM_FP("sleep_millisecs"), 0) ||
889 numa_available() ? 0 :
890 ksm_write_sysfs(KSM_FP("merge_across_nodes"), 1) ||
891 ksm_write_sysfs(KSM_FP("pages_to_scan"), page_count))
892 return KSFT_FAIL;
893
894 switch (test_name) {
895 case CHECK_KSM_MERGE:
896 ret = check_ksm_merge(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count,
897 ksm_scan_limit_sec, page_size);
898 break;
899 case CHECK_KSM_UNMERGE:
900 ret = check_ksm_unmerge(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
901 ksm_scan_limit_sec, page_size);
902 break;
903 case CHECK_KSM_ZERO_PAGE_MERGE:
904 ret = check_ksm_zero_page_merge(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
905 page_count, ksm_scan_limit_sec, use_zero_pages,
906 page_size);
907 break;
908 case CHECK_KSM_NUMA_MERGE:
909 ret = check_ksm_numa_merge(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
910 ksm_scan_limit_sec, merge_across_nodes, page_size);
911 break;
912 case KSM_MERGE_TIME:
913 if (size_MB == 0) {
914 printf("Option '-s' is required.\n");
915 return KSFT_FAIL;
916 }
917 ret = ksm_merge_time(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
918 ksm_scan_limit_sec, size_MB);
919 break;
920 case KSM_MERGE_TIME_HUGE_PAGES:
921 if (size_MB == 0) {
922 printf("Option '-s' is required.\n");
923 return KSFT_FAIL;
924 }
925 ret = ksm_merge_hugepages_time(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
926 ksm_scan_limit_sec, size_MB);
927 break;
928 case KSM_UNMERGE_TIME:
929 if (size_MB == 0) {
930 printf("Option '-s' is required.\n");
931 return KSFT_FAIL;
932 }
933 ret = ksm_unmerge_time(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
934 ksm_scan_limit_sec, size_MB);
935 break;
936 case KSM_COW_TIME:
937 ret = ksm_cow_time(merge_type, MAP_PRIVATE | MAP_ANONYMOUS, prot,
938 ksm_scan_limit_sec, page_size);
939 break;
940 }
941
942 if (ksm_restore(&ksm_sysfs_old)) {
943 printf("Cannot restore default tunables\n");
944 return KSFT_FAIL;
945 }
946
947 return ret;
948 }
949
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