1 /*
2 * Stress test for transparent huge pages, memory compaction and migration.
3 *
4 * Authors: Konstantin Khlebnikov <koct9i@gmail.com>
5 *
6 * This is free and unencumbered software released into the public domain.
7 */
8
9 #include <stdlib.h>
10 #include <stdio.h>
11 #include <stdint.h>
12 #include <err.h>
13 #include <time.h>
14 #include <unistd.h>
15 #include <fcntl.h>
16 #include <string.h>
17 #include <sys/mman.h>
18
19 #define PAGE_SHIFT 12
20 #define HPAGE_SHIFT 21
21
22 #define PAGE_SIZE (1 << PAGE_SHIFT)
23 #define HPAGE_SIZE (1 << HPAGE_SHIFT)
24
25 #define PAGEMAP_PRESENT(ent) (((ent) & (1ull << 63)) != 0)
26 #define PAGEMAP_PFN(ent) ((ent) & ((1ull << 55) - 1))
27
28 int pagemap_fd;
29
allocate_transhuge(void * ptr)30 int64_t allocate_transhuge(void *ptr)
31 {
32 uint64_t ent[2];
33
34 /* drop pmd */
35 if (mmap(ptr, HPAGE_SIZE, PROT_READ | PROT_WRITE,
36 MAP_FIXED | MAP_ANONYMOUS |
37 MAP_NORESERVE | MAP_PRIVATE, -1, 0) != ptr)
38 errx(2, "mmap transhuge");
39
40 if (madvise(ptr, HPAGE_SIZE, MADV_HUGEPAGE))
41 err(2, "MADV_HUGEPAGE");
42
43 /* allocate transparent huge page */
44 *(volatile void **)ptr = ptr;
45
46 if (pread(pagemap_fd, ent, sizeof(ent),
47 (uintptr_t)ptr >> (PAGE_SHIFT - 3)) != sizeof(ent))
48 err(2, "read pagemap");
49
50 if (PAGEMAP_PRESENT(ent[0]) && PAGEMAP_PRESENT(ent[1]) &&
51 PAGEMAP_PFN(ent[0]) + 1 == PAGEMAP_PFN(ent[1]) &&
52 !(PAGEMAP_PFN(ent[0]) & ((1 << (HPAGE_SHIFT - PAGE_SHIFT)) - 1)))
53 return PAGEMAP_PFN(ent[0]);
54
55 return -1;
56 }
57
main(int argc,char ** argv)58 int main(int argc, char **argv)
59 {
60 size_t ram, len;
61 void *ptr, *p;
62 struct timespec a, b;
63 double s;
64 uint8_t *map;
65 size_t map_len;
66
67 ram = sysconf(_SC_PHYS_PAGES);
68 if (ram > SIZE_MAX / sysconf(_SC_PAGESIZE) / 4)
69 ram = SIZE_MAX / 4;
70 else
71 ram *= sysconf(_SC_PAGESIZE);
72
73 if (argc == 1)
74 len = ram;
75 else if (!strcmp(argv[1], "-h"))
76 errx(1, "usage: %s [size in MiB]", argv[0]);
77 else
78 len = atoll(argv[1]) << 20;
79
80 warnx("allocate %zd transhuge pages, using %zd MiB virtual memory"
81 " and %zd MiB of ram", len >> HPAGE_SHIFT, len >> 20,
82 len >> (20 + HPAGE_SHIFT - PAGE_SHIFT - 1));
83
84 pagemap_fd = open("/proc/self/pagemap", O_RDONLY);
85 if (pagemap_fd < 0)
86 err(2, "open pagemap");
87
88 len -= len % HPAGE_SIZE;
89 ptr = mmap(NULL, len + HPAGE_SIZE, PROT_READ | PROT_WRITE,
90 MAP_ANONYMOUS | MAP_NORESERVE | MAP_PRIVATE, -1, 0);
91 if (ptr == MAP_FAILED)
92 err(2, "initial mmap");
93 ptr += HPAGE_SIZE - (uintptr_t)ptr % HPAGE_SIZE;
94
95 if (madvise(ptr, len, MADV_HUGEPAGE))
96 err(2, "MADV_HUGEPAGE");
97
98 map_len = ram >> (HPAGE_SHIFT - 1);
99 map = malloc(map_len);
100 if (!map)
101 errx(2, "map malloc");
102
103 while (1) {
104 int nr_succeed = 0, nr_failed = 0, nr_pages = 0;
105
106 memset(map, 0, map_len);
107
108 clock_gettime(CLOCK_MONOTONIC, &a);
109 for (p = ptr; p < ptr + len; p += HPAGE_SIZE) {
110 int64_t pfn;
111
112 pfn = allocate_transhuge(p);
113
114 if (pfn < 0) {
115 nr_failed++;
116 } else {
117 size_t idx = pfn >> (HPAGE_SHIFT - PAGE_SHIFT);
118
119 nr_succeed++;
120 if (idx >= map_len) {
121 map = realloc(map, idx + 1);
122 if (!map)
123 errx(2, "map realloc");
124 memset(map + map_len, 0, idx + 1 - map_len);
125 map_len = idx + 1;
126 }
127 if (!map[idx])
128 nr_pages++;
129 map[idx] = 1;
130 }
131
132 /* split transhuge page, keep last page */
133 if (madvise(p, HPAGE_SIZE - PAGE_SIZE, MADV_DONTNEED))
134 err(2, "MADV_DONTNEED");
135 }
136 clock_gettime(CLOCK_MONOTONIC, &b);
137 s = b.tv_sec - a.tv_sec + (b.tv_nsec - a.tv_nsec) / 1000000000.;
138
139 warnx("%.3f s/loop, %.3f ms/page, %10.3f MiB/s\t"
140 "%4d succeed, %4d failed, %4d different pages",
141 s, s * 1000 / (len >> HPAGE_SHIFT), len / s / (1 << 20),
142 nr_succeed, nr_failed, nr_pages);
143 }
144 }
145
