This source file includes following definitions.
- ilog2
- find_pagesizes
- default_huge_page_size
- show
- read_sysfs
- read_free
- test_mmap
- test_shmget
- sanity_checks
- main
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15 #define _GNU_SOURCE 1
16 #include <sys/mman.h>
17 #include <stdlib.h>
18 #include <stdio.h>
19 #include <sys/ipc.h>
20 #include <sys/shm.h>
21 #include <sys/stat.h>
22 #include <glob.h>
23 #include <assert.h>
24 #include <unistd.h>
25 #include <stdarg.h>
26 #include <string.h>
27
28 #define err(x) perror(x), exit(1)
29
30 #define MAP_HUGE_2MB (21 << MAP_HUGE_SHIFT)
31 #define MAP_HUGE_1GB (30 << MAP_HUGE_SHIFT)
32 #define MAP_HUGE_SHIFT 26
33 #define MAP_HUGE_MASK 0x3f
34 #if !defined(MAP_HUGETLB)
35 #define MAP_HUGETLB 0x40000
36 #endif
37
38 #define SHM_HUGETLB 04000
39 #define SHM_HUGE_SHIFT 26
40 #define SHM_HUGE_MASK 0x3f
41 #define SHM_HUGE_2MB (21 << SHM_HUGE_SHIFT)
42 #define SHM_HUGE_1GB (30 << SHM_HUGE_SHIFT)
43
44 #define NUM_PAGESIZES 5
45
46 #define NUM_PAGES 4
47
48 #define Dprintf(fmt...)
49
50 unsigned long page_sizes[NUM_PAGESIZES];
51 int num_page_sizes;
52
53 int ilog2(unsigned long v)
54 {
55 int l = 0;
56 while ((1UL << l) < v)
57 l++;
58 return l;
59 }
60
61 void find_pagesizes(void)
62 {
63 glob_t g;
64 int i;
65 glob("/sys/kernel/mm/hugepages/hugepages-*kB", 0, NULL, &g);
66 assert(g.gl_pathc <= NUM_PAGESIZES);
67 for (i = 0; i < g.gl_pathc; i++) {
68 sscanf(g.gl_pathv[i], "/sys/kernel/mm/hugepages/hugepages-%lukB",
69 &page_sizes[i]);
70 page_sizes[i] <<= 10;
71 printf("Found %luMB\n", page_sizes[i] >> 20);
72 }
73 num_page_sizes = g.gl_pathc;
74 globfree(&g);
75 }
76
77 unsigned long default_huge_page_size(void)
78 {
79 unsigned long hps = 0;
80 char *line = NULL;
81 size_t linelen = 0;
82 FILE *f = fopen("/proc/meminfo", "r");
83 if (!f)
84 return 0;
85 while (getline(&line, &linelen, f) > 0) {
86 if (sscanf(line, "Hugepagesize: %lu kB", &hps) == 1) {
87 hps <<= 10;
88 break;
89 }
90 }
91 free(line);
92 return hps;
93 }
94
95 void show(unsigned long ps)
96 {
97 char buf[100];
98 if (ps == getpagesize())
99 return;
100 printf("%luMB: ", ps >> 20);
101 fflush(stdout);
102 snprintf(buf, sizeof buf,
103 "cat /sys/kernel/mm/hugepages/hugepages-%lukB/free_hugepages",
104 ps >> 10);
105 system(buf);
106 }
107
108 unsigned long read_sysfs(int warn, char *fmt, ...)
109 {
110 char *line = NULL;
111 size_t linelen = 0;
112 char buf[100];
113 FILE *f;
114 va_list ap;
115 unsigned long val = 0;
116
117 va_start(ap, fmt);
118 vsnprintf(buf, sizeof buf, fmt, ap);
119 va_end(ap);
120
121 f = fopen(buf, "r");
122 if (!f) {
123 if (warn)
124 printf("missing %s\n", buf);
125 return 0;
126 }
127 if (getline(&line, &linelen, f) > 0) {
128 sscanf(line, "%lu", &val);
129 }
130 fclose(f);
131 free(line);
132 return val;
133 }
134
135 unsigned long read_free(unsigned long ps)
136 {
137 return read_sysfs(ps != getpagesize(),
138 "/sys/kernel/mm/hugepages/hugepages-%lukB/free_hugepages",
139 ps >> 10);
140 }
141
142 void test_mmap(unsigned long size, unsigned flags)
143 {
144 char *map;
145 unsigned long before, after;
146 int err;
147
148 before = read_free(size);
149 map = mmap(NULL, size*NUM_PAGES, PROT_READ|PROT_WRITE,
150 MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB|flags, -1, 0);
151
152 if (map == (char *)-1) err("mmap");
153 memset(map, 0xff, size*NUM_PAGES);
154 after = read_free(size);
155 Dprintf("before %lu after %lu diff %ld size %lu\n",
156 before, after, before - after, size);
157 assert(size == getpagesize() || (before - after) == NUM_PAGES);
158 show(size);
159 err = munmap(map, size);
160 assert(!err);
161 }
162
163 void test_shmget(unsigned long size, unsigned flags)
164 {
165 int id;
166 unsigned long before, after;
167 int err;
168
169 before = read_free(size);
170 id = shmget(IPC_PRIVATE, size * NUM_PAGES, IPC_CREAT|0600|flags);
171 if (id < 0) err("shmget");
172
173 struct shm_info i;
174 if (shmctl(id, SHM_INFO, (void *)&i) < 0) err("shmctl");
175 Dprintf("alloc %lu res %lu\n", i.shm_tot, i.shm_rss);
176
177
178 Dprintf("id %d\n", id);
179 char *map = shmat(id, NULL, 0600);
180 if (map == (char*)-1) err("shmat");
181
182 shmctl(id, IPC_RMID, NULL);
183
184 memset(map, 0xff, size*NUM_PAGES);
185 after = read_free(size);
186
187 Dprintf("before %lu after %lu diff %ld size %lu\n",
188 before, after, before - after, size);
189 assert(size == getpagesize() || (before - after) == NUM_PAGES);
190 show(size);
191 err = shmdt(map);
192 assert(!err);
193 }
194
195 void sanity_checks(void)
196 {
197 int i;
198 unsigned long largest = getpagesize();
199
200 for (i = 0; i < num_page_sizes; i++) {
201 if (page_sizes[i] > largest)
202 largest = page_sizes[i];
203
204 if (read_free(page_sizes[i]) < NUM_PAGES) {
205 printf("Not enough huge pages for page size %lu MB, need %u\n",
206 page_sizes[i] >> 20,
207 NUM_PAGES);
208 exit(0);
209 }
210 }
211
212 if (read_sysfs(0, "/proc/sys/kernel/shmmax") < NUM_PAGES * largest) {
213 printf("Please do echo %lu > /proc/sys/kernel/shmmax", largest * NUM_PAGES);
214 exit(0);
215 }
216
217 #if defined(__x86_64__)
218 if (largest != 1U<<30) {
219 printf("No GB pages available on x86-64\n"
220 "Please boot with hugepagesz=1G hugepages=%d\n", NUM_PAGES);
221 exit(0);
222 }
223 #endif
224 }
225
226 int main(void)
227 {
228 int i;
229 unsigned default_hps = default_huge_page_size();
230
231 find_pagesizes();
232
233 sanity_checks();
234
235 for (i = 0; i < num_page_sizes; i++) {
236 unsigned long ps = page_sizes[i];
237 int arg = ilog2(ps) << MAP_HUGE_SHIFT;
238 printf("Testing %luMB mmap with shift %x\n", ps >> 20, arg);
239 test_mmap(ps, MAP_HUGETLB | arg);
240 }
241 printf("Testing default huge mmap\n");
242 test_mmap(default_hps, SHM_HUGETLB);
243
244 puts("Testing non-huge shmget");
245 test_shmget(getpagesize(), 0);
246
247 for (i = 0; i < num_page_sizes; i++) {
248 unsigned long ps = page_sizes[i];
249 int arg = ilog2(ps) << SHM_HUGE_SHIFT;
250 printf("Testing %luMB shmget with shift %x\n", ps >> 20, arg);
251 test_shmget(ps, SHM_HUGETLB | arg);
252 }
253 puts("default huge shmget");
254 test_shmget(default_hps, SHM_HUGETLB);
255
256 return 0;
257 }