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
29struct 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
39enum ksm_merge_type {
40	KSM_MERGE_MADVISE,
41	KSM_MERGE_PRCTL,
42	KSM_MERGE_LAST = KSM_MERGE_PRCTL
43};
44
45enum 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
57int debug;
58
59static 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
78static 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
97static 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
126static 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
144static 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
158static 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
200static 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
218static 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
243static 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
268static 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
278static 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
315static 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
331static 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
347static 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
375err_out:
376	printf("Not OK\n");
377	munmap(map_ptr, page_size * page_count);
378	return KSFT_FAIL;
379}
380
381static 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
415err_out:
416	printf("Not OK\n");
417	munmap(map_ptr, page_size * page_count);
418	return KSFT_FAIL;
419}
420
421static 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
459err_out:
460	printf("Not OK\n");
461	munmap(map_ptr, page_size * page_count);
462	return KSFT_FAIL;
463}
464
465static 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
481static int get_first_mem_node(void)
482{
483	return get_next_mem_node(numa_max_node());
484}
485
486static 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
543err_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
550static 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
612err_out:
613	printf("Not OK\n");
614	munmap(map_ptr_orig, len + HPAGE_SIZE);
615	return KSFT_FAIL;
616}
617
618static 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
653err_out:
654	printf("Not OK\n");
655	munmap(map_ptr, map_size);
656	return KSFT_FAIL;
657}
658
659static 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
700err_out:
701	printf("Not OK\n");
702	munmap(map_ptr, map_size);
703	return KSFT_FAIL;
704}
705
706static 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
771err_out:
772	printf("Not OK\n");
773	munmap(map_ptr, page_size * page_count);
774	return KSFT_FAIL;
775}
776
777int 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") == 0)
815				use_zero_pages = 0;
816			else
817				use_zero_pages = 1;
818			break;
819		case 'm':
820			if (strcmp(optarg, "0") == 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