1 /* 2 * Stress test for transparent huge pages, memory compaction and migration. 3 * 4 * Authors: Konstantin Khlebnikov <koct9i (at) 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 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 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
