Sri Jayaramappa | bd67d5c | 2015-04-23 14:21:41 -0400 | [diff] [blame] | 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 | |
| 20 | struct map_list { |
| 21 | void *map; |
| 22 | struct map_list *next; |
| 23 | }; |
| 24 | |
| 25 | int 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 | |
| 53 | int 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 | |
| 80 | int 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)) { |
Yannick Brosseau | ee65735 | 2016-06-20 08:07:21 -0700 | [diff] [blame^] | 104 | perror("Failed to write 0 to /proc/sys/vm/nr_hugepages\n"); |
Sri Jayaramappa | bd67d5c | 2015-04-23 14:21:41 -0400 | [diff] [blame] | 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))) { |
Yannick Brosseau | ee65735 | 2016-06-20 08:07:21 -0700 | [diff] [blame^] | 113 | perror("Failed to write 100000 to /proc/sys/vm/nr_hugepages\n"); |
Sri Jayaramappa | bd67d5c | 2015-04-23 14:21:41 -0400 | [diff] [blame] | 114 | goto close_fd; |
| 115 | } |
| 116 | |
| 117 | lseek(fd, 0, SEEK_SET); |
| 118 | |
| 119 | if (read(fd, nr_hugepages, sizeof(nr_hugepages)) <= 0) { |
Yannick Brosseau | ee65735 | 2016-06-20 08:07:21 -0700 | [diff] [blame^] | 120 | perror("Failed to re-read from /proc/sys/vm/nr_hugepages\n"); |
Sri Jayaramappa | bd67d5c | 2015-04-23 14:21:41 -0400 | [diff] [blame] | 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 | |
Yannick Brosseau | ee65735 | 2016-06-20 08:07:21 -0700 | [diff] [blame^] | 139 | if (write(fd, initial_nr_hugepages, strlen(initial_nr_hugepages)) |
Sri Jayaramappa | bd67d5c | 2015-04-23 14:21:41 -0400 | [diff] [blame] | 140 | != strlen(initial_nr_hugepages)) { |
Yannick Brosseau | ee65735 | 2016-06-20 08:07:21 -0700 | [diff] [blame^] | 141 | perror("Failed to write value to /proc/sys/vm/nr_hugepages\n"); |
Sri Jayaramappa | bd67d5c | 2015-04-23 14:21:41 -0400 | [diff] [blame] | 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 | |
| 155 | int 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 | } |