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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#include "../kselftest.h"
20
21#define MAP_SIZE 1048576
22
23struct map_list {
24 void *map;
25 struct map_list *next;
26};
27
28int read_memory_info(unsigned long *memfree, unsigned long *hugepagesize)
29{
30 char buffer[256] = {0};
31 char *cmd = "cat /proc/meminfo | grep -i memfree | grep -o '[0-9]*'";
32 FILE *cmdfile = popen(cmd, "r");
33
34 if (!(fgets(buffer, sizeof(buffer), cmdfile))) {
35 perror("Failed to read meminfo\n");
36 return -1;
37 }
38
39 pclose(cmdfile);
40
41 *memfree = atoll(buffer);
42 cmd = "cat /proc/meminfo | grep -i hugepagesize | grep -o '[0-9]*'";
43 cmdfile = popen(cmd, "r");
44
45 if (!(fgets(buffer, sizeof(buffer), cmdfile))) {
46 perror("Failed to read meminfo\n");
47 return -1;
48 }
49
50 pclose(cmdfile);
51 *hugepagesize = atoll(buffer);
52
53 return 0;
54}
55
56int prereq(void)
57{
58 char allowed;
59 int fd;
60
61 fd = open("/proc/sys/vm/compact_unevictable_allowed",
62 O_RDONLY | O_NONBLOCK);
63 if (fd < 0) {
64 perror("Failed to open\n"
65 "/proc/sys/vm/compact_unevictable_allowed\n");
66 return -1;
67 }
68
69 if (read(fd, &allowed, sizeof(char)) != sizeof(char)) {
70 perror("Failed to read from\n"
71 "/proc/sys/vm/compact_unevictable_allowed\n");
72 close(fd);
73 return -1;
74 }
75
76 close(fd);
77 if (allowed == '1')
78 return 0;
79
80 return -1;
81}
82
83int check_compaction(unsigned long mem_free, unsigned int hugepage_size)
84{
85 int fd;
86 int compaction_index = 0;
87 char initial_nr_hugepages[10] = {0};
88 char nr_hugepages[10] = {0};
89
90 /* We want to test with 80% of available memory. Else, OOM killer comes
91 in to play */
92 mem_free = mem_free * 0.8;
93
94 fd = open("/proc/sys/vm/nr_hugepages", O_RDWR | O_NONBLOCK);
95 if (fd < 0) {
96 perror("Failed to open /proc/sys/vm/nr_hugepages");
97 return -1;
98 }
99
100 if (read(fd, initial_nr_hugepages, sizeof(initial_nr_hugepages)) <= 0) {
101 perror("Failed to read from /proc/sys/vm/nr_hugepages");
102 goto close_fd;
103 }
104
105 /* Start with the initial condition of 0 huge pages*/
106 if (write(fd, "0", sizeof(char)) != sizeof(char)) {
107 perror("Failed to write 0 to /proc/sys/vm/nr_hugepages\n");
108 goto close_fd;
109 }
110
111 lseek(fd, 0, SEEK_SET);
112
113 /* Request a large number of huge pages. The Kernel will allocate
114 as much as it can */
115 if (write(fd, "100000", (6*sizeof(char))) != (6*sizeof(char))) {
116 perror("Failed to write 100000 to /proc/sys/vm/nr_hugepages\n");
117 goto close_fd;
118 }
119
120 lseek(fd, 0, SEEK_SET);
121
122 if (read(fd, nr_hugepages, sizeof(nr_hugepages)) <= 0) {
123 perror("Failed to re-read from /proc/sys/vm/nr_hugepages\n");
124 goto close_fd;
125 }
126
127 /* We should have been able to request at least 1/3 rd of the memory in
128 huge pages */
129 compaction_index = mem_free/(atoi(nr_hugepages) * hugepage_size);
130
131 if (compaction_index > 3) {
132 printf("No of huge pages allocated = %d\n",
133 (atoi(nr_hugepages)));
134 fprintf(stderr, "ERROR: Less that 1/%d of memory is available\n"
135 "as huge pages\n", compaction_index);
136 goto close_fd;
137 }
138
139 printf("No of huge pages allocated = %d\n",
140 (atoi(nr_hugepages)));
141
142 lseek(fd, 0, SEEK_SET);
143
144 if (write(fd, initial_nr_hugepages, strlen(initial_nr_hugepages))
145 != strlen(initial_nr_hugepages)) {
146 perror("Failed to write value to /proc/sys/vm/nr_hugepages\n");
147 goto close_fd;
148 }
149
150 close(fd);
151 return 0;
152
153 close_fd:
154 close(fd);
155 printf("Not OK. Compaction test failed.");
156 return -1;
157}
158
159
160int main(int argc, char **argv)
161{
162 struct rlimit lim;
163 struct map_list *list, *entry;
164 size_t page_size, i;
165 void *map = NULL;
166 unsigned long mem_free = 0;
167 unsigned long hugepage_size = 0;
168 unsigned long mem_fragmentable = 0;
169
170 if (prereq() != 0) {
171 printf("Either the sysctl compact_unevictable_allowed is not\n"
172 "set to 1 or couldn't read the proc file.\n"
173 "Skipping the test\n");
174 return KSFT_SKIP;
175 }
176
177 lim.rlim_cur = RLIM_INFINITY;
178 lim.rlim_max = RLIM_INFINITY;
179 if (setrlimit(RLIMIT_MEMLOCK, &lim)) {
180 perror("Failed to set rlimit:\n");
181 return -1;
182 }
183
184 page_size = getpagesize();
185
186 list = NULL;
187
188 if (read_memory_info(&mem_free, &hugepage_size) != 0) {
189 printf("ERROR: Cannot read meminfo\n");
190 return -1;
191 }
192
193 mem_fragmentable = mem_free * 0.8 / 1024;
194
195 while (mem_fragmentable > 0) {
196 map = mmap(NULL, MAP_SIZE, PROT_READ | PROT_WRITE,
197 MAP_ANONYMOUS | MAP_PRIVATE | MAP_LOCKED, -1, 0);
198 if (map == MAP_FAILED)
199 break;
200
201 entry = malloc(sizeof(struct map_list));
202 if (!entry) {
203 munmap(map, MAP_SIZE);
204 break;
205 }
206 entry->map = map;
207 entry->next = list;
208 list = entry;
209
210 /* Write something (in this case the address of the map) to
211 * ensure that KSM can't merge the mapped pages
212 */
213 for (i = 0; i < MAP_SIZE; i += page_size)
214 *(unsigned long *)(map + i) = (unsigned long)map + i;
215
216 mem_fragmentable--;
217 }
218
219 for (entry = list; entry != NULL; entry = entry->next) {
220 munmap(entry->map, MAP_SIZE);
221 if (!entry->next)
222 break;
223 entry = entry->next;
224 }
225
226 if (check_compaction(mem_free, hugepage_size) == 0)
227 return 0;
228
229 return -1;
230}