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