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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 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}
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}