tools/testing/selftests/mm/transhuge-stress.c

   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 #include "util.h"
  19
  20 int backing_fd = -1;
  21 int mmap_flags = MAP_ANONYMOUS | MAP_NORESERVE | MAP_PRIVATE;
  22 #define PROT_RW (PROT_READ | PROT_WRITE)
  23
  24 int main(int argc, char **argv)
  25 {
  26         size_t ram, len;
  27         void *ptr, *p;
  28         struct timespec a, b;
  29         int i = 0;
  30         char *name = NULL;
  31         double s;
  32         uint8_t *map;
  33         size_t map_len;
  34         int pagemap_fd;
  35
  36         ram = sysconf(_SC_PHYS_PAGES);
  37         if (ram > SIZE_MAX / sysconf(_SC_PAGESIZE) / 4)
  38                 ram = SIZE_MAX / 4;
  39         else
  40                 ram *= sysconf(_SC_PAGESIZE);
  41         len = ram;
  42
  43         while (++i < argc) {
  44                 if (!strcmp(argv[i], "-h"))
  45                         errx(1, "usage: %s [size in MiB]", argv[0]);
  46                 else if (!strcmp(argv[i], "-f"))
  47                         name = argv[++i];
  48                 else
  49                         len = atoll(argv[i]) << 20;
  50         }
  51
  52         if (name) {
  53                 backing_fd = open(name, O_RDWR);
  54                 if (backing_fd == -1)
  55                         errx(2, "open %s", name);
  56                 mmap_flags = MAP_SHARED;
  57         }
  58
  59         warnx("allocate %zd transhuge pages, using %zd MiB virtual memory"
  60               " and %zd MiB of ram", len >> HPAGE_SHIFT, len >> 20,
  61               ram >> (20 + HPAGE_SHIFT - PAGE_SHIFT - 1));
  62
  63         pagemap_fd = open("/proc/self/pagemap", O_RDONLY);
  64         if (pagemap_fd < 0)
  65                 err(2, "open pagemap");
  66
  67         len -= len % HPAGE_SIZE;
  68         ptr = mmap(NULL, len + HPAGE_SIZE, PROT_RW, mmap_flags, backing_fd, 0);
  69         if (ptr == MAP_FAILED)
  70                 err(2, "initial mmap");
  71         ptr += HPAGE_SIZE - (uintptr_t)ptr % HPAGE_SIZE;
  72
  73         if (madvise(ptr, len, MADV_HUGEPAGE))
  74                 err(2, "MADV_HUGEPAGE");
  75
  76         map_len = ram >> (HPAGE_SHIFT - 1);
  77         map = malloc(map_len);
  78         if (!map)
  79                 errx(2, "map malloc");
  80
  81         while (1) {
  82                 int nr_succeed = 0, nr_failed = 0, nr_pages = 0;
  83
  84                 memset(map, 0, map_len);
  85
  86                 clock_gettime(CLOCK_MONOTONIC, &a);
  87                 for (p = ptr; p < ptr + len; p += HPAGE_SIZE) {
  88                         int64_t pfn;
  89
  90                         pfn = allocate_transhuge(p, pagemap_fd);
  91
  92                         if (pfn < 0) {
  93                                 nr_failed++;
  94                         } else {
  95                                 size_t idx = pfn >> (HPAGE_SHIFT - PAGE_SHIFT);
  96
  97                                 nr_succeed++;
  98                                 if (idx >= map_len) {
  99                                         map = realloc(map, idx + 1);
 100                                         if (!map)
 101                                                 errx(2, "map realloc");
 102                                         memset(map + map_len, 0, idx + 1 - map_len);
 103                                         map_len = idx + 1;
 104                                 }
 105                                 if (!map[idx])
 106                                         nr_pages++;
 107                                 map[idx] = 1;
 108                         }
 109
 110                         /* split transhuge page, keep last page */
 111                         if (madvise(p, HPAGE_SIZE - PAGE_SIZE, MADV_DONTNEED))
 112                                 err(2, "MADV_DONTNEED");
 113                 }
 114                 clock_gettime(CLOCK_MONOTONIC, &b);
 115                 s = b.tv_sec - a.tv_sec + (b.tv_nsec - a.tv_nsec) / 1000000000.;
 116
 117                 warnx("%.3f s/loop, %.3f ms/page, %10.3f MiB/s\t"
 118                       "%4d succeed, %4d failed, %4d different pages",
 119                       s, s * 1000 / (len >> HPAGE_SHIFT), len / s / (1 << 20),
 120                       nr_succeed, nr_failed, nr_pages);
 121         }
 122 }