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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_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}