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1// SPDX-License-Identifier: GPL-2.0
2/*
3 *
4 * A test for the patch "Allow compaction of unevictable pages".
5 * With this patch we should be able to allocate at least 1/4
6 * of RAM in huge pages. Without the patch much less is
7 * allocated.
8 */
9
10#include <stdio.h>
11#include <stdlib.h>
12#include <sys/mman.h>
13#include <sys/resource.h>
14#include <fcntl.h>
15#include <errno.h>
16#include <unistd.h>
17#include <string.h>
18
19#include "../kselftest.h"
20
21#define MAP_SIZE_MB 100
22#define MAP_SIZE (MAP_SIZE_MB * 1024 * 1024)
23
24struct map_list {
25 void *map;
26 struct map_list *next;
27};
28
29int read_memory_info(unsigned long *memfree, unsigned long *hugepagesize)
30{
31 char buffer[256] = {0};
32 char *cmd = "cat /proc/meminfo | grep -i memfree | grep -o '[0-9]*'";
33 FILE *cmdfile = popen(cmd, "r");
34
35 if (!(fgets(buffer, sizeof(buffer), cmdfile))) {
36 perror("Failed to read meminfo\n");
37 return -1;
38 }
39
40 pclose(cmdfile);
41
42 *memfree = atoll(buffer);
43 cmd = "cat /proc/meminfo | grep -i hugepagesize | grep -o '[0-9]*'";
44 cmdfile = popen(cmd, "r");
45
46 if (!(fgets(buffer, sizeof(buffer), cmdfile))) {
47 perror("Failed to read meminfo\n");
48 return -1;
49 }
50
51 pclose(cmdfile);
52 *hugepagesize = atoll(buffer);
53
54 return 0;
55}
56
57int prereq(void)
58{
59 char allowed;
60 int fd;
61
62 fd = open("/proc/sys/vm/compact_unevictable_allowed",
63 O_RDONLY | O_NONBLOCK);
64 if (fd < 0) {
65 perror("Failed to open\n"
66 "/proc/sys/vm/compact_unevictable_allowed\n");
67 return -1;
68 }
69
70 if (read(fd, &allowed, sizeof(char)) != sizeof(char)) {
71 perror("Failed to read from\n"
72 "/proc/sys/vm/compact_unevictable_allowed\n");
73 close(fd);
74 return -1;
75 }
76
77 close(fd);
78 if (allowed == '1')
79 return 0;
80
81 return -1;
82}
83
84int check_compaction(unsigned long mem_free, unsigned int hugepage_size)
85{
86 int fd;
87 int compaction_index = 0;
88 char initial_nr_hugepages[10] = {0};
89 char nr_hugepages[10] = {0};
90
91 /* We want to test with 80% of available memory. Else, OOM killer comes
92 in to play */
93 mem_free = mem_free * 0.8;
94
95 fd = open("/proc/sys/vm/nr_hugepages", O_RDWR | O_NONBLOCK);
96 if (fd < 0) {
97 perror("Failed to open /proc/sys/vm/nr_hugepages");
98 return -1;
99 }
100
101 if (read(fd, initial_nr_hugepages, sizeof(initial_nr_hugepages)) <= 0) {
102 perror("Failed to read from /proc/sys/vm/nr_hugepages");
103 goto close_fd;
104 }
105
106 /* Start with the initial condition of 0 huge pages*/
107 if (write(fd, "0", sizeof(char)) != sizeof(char)) {
108 perror("Failed to write 0 to /proc/sys/vm/nr_hugepages\n");
109 goto close_fd;
110 }
111
112 lseek(fd, 0, SEEK_SET);
113
114 /* Request a large number of huge pages. The Kernel will allocate
115 as much as it can */
116 if (write(fd, "100000", (6*sizeof(char))) != (6*sizeof(char))) {
117 perror("Failed to write 100000 to /proc/sys/vm/nr_hugepages\n");
118 goto close_fd;
119 }
120
121 lseek(fd, 0, SEEK_SET);
122
123 if (read(fd, nr_hugepages, sizeof(nr_hugepages)) <= 0) {
124 perror("Failed to re-read from /proc/sys/vm/nr_hugepages\n");
125 goto close_fd;
126 }
127
128 /* We should have been able to request at least 1/3 rd of the memory in
129 huge pages */
130 compaction_index = mem_free/(atoi(nr_hugepages) * hugepage_size);
131
132 if (compaction_index > 3) {
133 printf("No of huge pages allocated = %d\n",
134 (atoi(nr_hugepages)));
135 fprintf(stderr, "ERROR: Less that 1/%d of memory is available\n"
136 "as huge pages\n", compaction_index);
137 goto close_fd;
138 }
139
140 printf("No of huge pages allocated = %d\n",
141 (atoi(nr_hugepages)));
142
143 lseek(fd, 0, SEEK_SET);
144
145 if (write(fd, initial_nr_hugepages, strlen(initial_nr_hugepages))
146 != strlen(initial_nr_hugepages)) {
147 perror("Failed to write value to /proc/sys/vm/nr_hugepages\n");
148 goto close_fd;
149 }
150
151 close(fd);
152 return 0;
153
154 close_fd:
155 close(fd);
156 printf("Not OK. Compaction test failed.");
157 return -1;
158}
159
160
161int main(int argc, char **argv)
162{
163 struct rlimit lim;
164 struct map_list *list, *entry;
165 size_t page_size, i;
166 void *map = NULL;
167 unsigned long mem_free = 0;
168 unsigned long hugepage_size = 0;
169 long mem_fragmentable_MB = 0;
170
171 if (prereq() != 0) {
172 printf("Either the sysctl compact_unevictable_allowed is not\n"
173 "set to 1 or couldn't read the proc file.\n"
174 "Skipping the test\n");
175 return KSFT_SKIP;
176 }
177
178 lim.rlim_cur = RLIM_INFINITY;
179 lim.rlim_max = RLIM_INFINITY;
180 if (setrlimit(RLIMIT_MEMLOCK, &lim)) {
181 perror("Failed to set rlimit:\n");
182 return -1;
183 }
184
185 page_size = getpagesize();
186
187 list = NULL;
188
189 if (read_memory_info(&mem_free, &hugepage_size) != 0) {
190 printf("ERROR: Cannot read meminfo\n");
191 return -1;
192 }
193
194 mem_fragmentable_MB = mem_free * 0.8 / 1024;
195
196 while (mem_fragmentable_MB > 0) {
197 map = mmap(NULL, MAP_SIZE, PROT_READ | PROT_WRITE,
198 MAP_ANONYMOUS | MAP_PRIVATE | MAP_LOCKED, -1, 0);
199 if (map == MAP_FAILED)
200 break;
201
202 entry = malloc(sizeof(struct map_list));
203 if (!entry) {
204 munmap(map, MAP_SIZE);
205 break;
206 }
207 entry->map = map;
208 entry->next = list;
209 list = entry;
210
211 /* Write something (in this case the address of the map) to
212 * ensure that KSM can't merge the mapped pages
213 */
214 for (i = 0; i < MAP_SIZE; i += page_size)
215 *(unsigned long *)(map + i) = (unsigned long)map + i;
216
217 mem_fragmentable_MB -= MAP_SIZE_MB;
218 }
219
220 for (entry = list; entry != NULL; entry = entry->next) {
221 munmap(entry->map, MAP_SIZE);
222 if (!entry->next)
223 break;
224 entry = entry->next;
225 }
226
227 if (check_compaction(mem_free, hugepage_size) == 0)
228 return 0;
229
230 return -1;
231}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 *
4 * A test for the patch "Allow compaction of unevictable pages".
5 * With this patch we should be able to allocate at least 1/4
6 * of RAM in huge pages. Without the patch much less is
7 * allocated.
8 */
9
10#include <stdio.h>
11#include <stdlib.h>
12#include <sys/mman.h>
13#include <sys/resource.h>
14#include <fcntl.h>
15#include <errno.h>
16#include <unistd.h>
17#include <string.h>
18
19#define MAP_SIZE 1048576
20
21struct map_list {
22 void *map;
23 struct map_list *next;
24};
25
26int read_memory_info(unsigned long *memfree, unsigned long *hugepagesize)
27{
28 char buffer[256] = {0};
29 char *cmd = "cat /proc/meminfo | grep -i memfree | grep -o '[0-9]*'";
30 FILE *cmdfile = popen(cmd, "r");
31
32 if (!(fgets(buffer, sizeof(buffer), cmdfile))) {
33 perror("Failed to read meminfo\n");
34 return -1;
35 }
36
37 pclose(cmdfile);
38
39 *memfree = atoll(buffer);
40 cmd = "cat /proc/meminfo | grep -i hugepagesize | grep -o '[0-9]*'";
41 cmdfile = popen(cmd, "r");
42
43 if (!(fgets(buffer, sizeof(buffer), cmdfile))) {
44 perror("Failed to read meminfo\n");
45 return -1;
46 }
47
48 pclose(cmdfile);
49 *hugepagesize = atoll(buffer);
50
51 return 0;
52}
53
54int prereq(void)
55{
56 char allowed;
57 int fd;
58
59 fd = open("/proc/sys/vm/compact_unevictable_allowed",
60 O_RDONLY | O_NONBLOCK);
61 if (fd < 0) {
62 perror("Failed to open\n"
63 "/proc/sys/vm/compact_unevictable_allowed\n");
64 return -1;
65 }
66
67 if (read(fd, &allowed, sizeof(char)) != sizeof(char)) {
68 perror("Failed to read from\n"
69 "/proc/sys/vm/compact_unevictable_allowed\n");
70 close(fd);
71 return -1;
72 }
73
74 close(fd);
75 if (allowed == '1')
76 return 0;
77
78 return -1;
79}
80
81int check_compaction(unsigned long mem_free, unsigned int hugepage_size)
82{
83 int fd;
84 int compaction_index = 0;
85 char initial_nr_hugepages[10] = {0};
86 char nr_hugepages[10] = {0};
87
88 /* We want to test with 80% of available memory. Else, OOM killer comes
89 in to play */
90 mem_free = mem_free * 0.8;
91
92 fd = open("/proc/sys/vm/nr_hugepages", O_RDWR | O_NONBLOCK);
93 if (fd < 0) {
94 perror("Failed to open /proc/sys/vm/nr_hugepages");
95 return -1;
96 }
97
98 if (read(fd, initial_nr_hugepages, sizeof(initial_nr_hugepages)) <= 0) {
99 perror("Failed to read from /proc/sys/vm/nr_hugepages");
100 goto close_fd;
101 }
102
103 /* Start with the initial condition of 0 huge pages*/
104 if (write(fd, "0", sizeof(char)) != sizeof(char)) {
105 perror("Failed to write 0 to /proc/sys/vm/nr_hugepages\n");
106 goto close_fd;
107 }
108
109 lseek(fd, 0, SEEK_SET);
110
111 /* Request a large number of huge pages. The Kernel will allocate
112 as much as it can */
113 if (write(fd, "100000", (6*sizeof(char))) != (6*sizeof(char))) {
114 perror("Failed to write 100000 to /proc/sys/vm/nr_hugepages\n");
115 goto close_fd;
116 }
117
118 lseek(fd, 0, SEEK_SET);
119
120 if (read(fd, nr_hugepages, sizeof(nr_hugepages)) <= 0) {
121 perror("Failed to re-read from /proc/sys/vm/nr_hugepages\n");
122 goto close_fd;
123 }
124
125 /* We should have been able to request at least 1/3 rd of the memory in
126 huge pages */
127 compaction_index = mem_free/(atoi(nr_hugepages) * hugepage_size);
128
129 if (compaction_index > 3) {
130 printf("No of huge pages allocated = %d\n",
131 (atoi(nr_hugepages)));
132 fprintf(stderr, "ERROR: Less that 1/%d of memory is available\n"
133 "as huge pages\n", compaction_index);
134 goto close_fd;
135 }
136
137 printf("No of huge pages allocated = %d\n",
138 (atoi(nr_hugepages)));
139
140 lseek(fd, 0, SEEK_SET);
141
142 if (write(fd, initial_nr_hugepages, strlen(initial_nr_hugepages))
143 != strlen(initial_nr_hugepages)) {
144 perror("Failed to write value to /proc/sys/vm/nr_hugepages\n");
145 goto close_fd;
146 }
147
148 close(fd);
149 return 0;
150
151 close_fd:
152 close(fd);
153 printf("Not OK. Compaction test failed.");
154 return -1;
155}
156
157
158int main(int argc, char **argv)
159{
160 struct rlimit lim;
161 struct map_list *list, *entry;
162 size_t page_size, i;
163 void *map = NULL;
164 unsigned long mem_free = 0;
165 unsigned long hugepage_size = 0;
166 unsigned long mem_fragmentable = 0;
167
168 if (prereq() != 0) {
169 printf("Either the sysctl compact_unevictable_allowed is not\n"
170 "set to 1 or couldn't read the proc file.\n"
171 "Skipping the test\n");
172 return 0;
173 }
174
175 lim.rlim_cur = RLIM_INFINITY;
176 lim.rlim_max = RLIM_INFINITY;
177 if (setrlimit(RLIMIT_MEMLOCK, &lim)) {
178 perror("Failed to set rlimit:\n");
179 return -1;
180 }
181
182 page_size = getpagesize();
183
184 list = NULL;
185
186 if (read_memory_info(&mem_free, &hugepage_size) != 0) {
187 printf("ERROR: Cannot read meminfo\n");
188 return -1;
189 }
190
191 mem_fragmentable = mem_free * 0.8 / 1024;
192
193 while (mem_fragmentable > 0) {
194 map = mmap(NULL, MAP_SIZE, PROT_READ | PROT_WRITE,
195 MAP_ANONYMOUS | MAP_PRIVATE | MAP_LOCKED, -1, 0);
196 if (map == MAP_FAILED)
197 break;
198
199 entry = malloc(sizeof(struct map_list));
200 if (!entry) {
201 munmap(map, MAP_SIZE);
202 break;
203 }
204 entry->map = map;
205 entry->next = list;
206 list = entry;
207
208 /* Write something (in this case the address of the map) to
209 * ensure that KSM can't merge the mapped pages
210 */
211 for (i = 0; i < MAP_SIZE; i += page_size)
212 *(unsigned long *)(map + i) = (unsigned long)map + i;
213
214 mem_fragmentable--;
215 }
216
217 for (entry = list; entry != NULL; entry = entry->next) {
218 munmap(entry->map, MAP_SIZE);
219 if (!entry->next)
220 break;
221 entry = entry->next;
222 }
223
224 if (check_compaction(mem_free, hugepage_size) == 0)
225 return 0;
226
227 return -1;
228}