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