tools/testing/selftests/vm/gup_benchmark.c

   1 #include <fcntl.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <unistd.h>
   5
   6 #include <sys/ioctl.h>
   7 #include <sys/mman.h>
   8 #include <sys/prctl.h>
   9 #include <sys/stat.h>
  10 #include <sys/types.h>
  11
  12 #include <linux/types.h>
  13
  14 #define MB (1UL << 20)
  15 #define PAGE_SIZE sysconf(_SC_PAGESIZE)
  16
  17 #define GUP_FAST_BENCHMARK      _IOWR('g', 1, struct gup_benchmark)
  18
  19 struct gup_benchmark {
  20         __u64 delta_usec;
  21         __u64 addr;
  22         __u64 size;
  23         __u32 nr_pages_per_call;
  24         __u32 flags;
  25 };
  26
  27 int main(int argc, char **argv)
  28 {
  29         struct gup_benchmark gup;
  30         unsigned long size = 128 * MB;
  31         int i, fd, opt, nr_pages = 1, thp = -1, repeats = 1, write = 0;
  32         char *p;
  33
  34         while ((opt = getopt(argc, argv, "m:r:n:tT")) != -1) {
  35                 switch (opt) {
  36                 case 'm':
  37                         size = atoi(optarg) * MB;
  38                         break;
  39                 case 'r':
  40                         repeats = atoi(optarg);
  41                         break;
  42                 case 'n':
  43                         nr_pages = atoi(optarg);
  44                         break;
  45                 case 't':
  46                         thp = 1;
  47                         break;
  48                 case 'T':
  49                         thp = 0;
  50                         break;
  51                 case 'w':
  52                         write = 1;
  53                 default:
  54                         return -1;
  55                 }
  56         }
  57
  58         gup.nr_pages_per_call = nr_pages;
  59         gup.flags = write;
  60
  61         fd = open("/sys/kernel/debug/gup_benchmark", O_RDWR);
  62         if (fd == -1)
  63                 perror("open"), exit(1);
  64
  65         p = mmap(NULL, size, PROT_READ | PROT_WRITE,
  66                         MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
  67         if (p == MAP_FAILED)
  68                 perror("mmap"), exit(1);
  69         gup.addr = (unsigned long)p;
  70
  71         if (thp == 1)
  72                 madvise(p, size, MADV_HUGEPAGE);
  73         else if (thp == 0)
  74                 madvise(p, size, MADV_NOHUGEPAGE);
  75
  76         for (; (unsigned long)p < gup.addr + size; p += PAGE_SIZE)
  77                 p[0] = 0;
  78
  79         for (i = 0; i < repeats; i++) {
  80                 gup.size = size;
  81                 if (ioctl(fd, GUP_FAST_BENCHMARK, &gup))
  82                         perror("ioctl"), exit(1);
  83
  84                 printf("Time: %lld us", gup.delta_usec);
  85                 if (gup.size != size)
  86                         printf(", truncated (size: %lld)", gup.size);
  87                 printf("\n");
  88         }
  89
  90         return 0;
  91 }