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