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 get_delta_usec;
  21         __u64 put_delta_usec;
  22         __u64 addr;
  23         __u64 size;
  24         __u32 nr_pages_per_call;
  25         __u32 flags;
  26 };
  27
  28 int main(int argc, char **argv)
  29 {
  30         struct gup_benchmark gup;
  31         unsigned long size = 128 * MB;
  32         int i, fd, opt, nr_pages = 1, thp = -1, repeats = 1, write = 0;
  33         char *p;
  34
  35         while ((opt = getopt(argc, argv, "m:r:n:tT")) != -1) {
  36                 switch (opt) {
  37                 case 'm':
  38                         size = atoi(optarg) * MB;
  39                         break;
  40                 case 'r':
  41                         repeats = atoi(optarg);
  42                         break;
  43                 case 'n':
  44                         nr_pages = atoi(optarg);
  45                         break;
  46                 case 't':
  47                         thp = 1;
  48                         break;
  49                 case 'T':
  50                         thp = 0;
  51                         break;
  52                 case 'w':
  53                         write = 1;
  54                 default:
  55                         return -1;
  56                 }
  57         }
  58
  59         gup.nr_pages_per_call = nr_pages;
  60         gup.flags = write;
  61
  62         fd = open("/sys/kernel/debug/gup_benchmark", O_RDWR);
  63         if (fd == -1)
  64                 perror("open"), exit(1);
  65
  66         p = mmap(NULL, size, PROT_READ | PROT_WRITE,
  67                         MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
  68         if (p == MAP_FAILED)
  69                 perror("mmap"), exit(1);
  70         gup.addr = (unsigned long)p;
  71
  72         if (thp == 1)
  73                 madvise(p, size, MADV_HUGEPAGE);
  74         else if (thp == 0)
  75                 madvise(p, size, MADV_NOHUGEPAGE);
  76
  77         for (; (unsigned long)p < gup.addr + size; p += PAGE_SIZE)
  78                 p[0] = 0;
  79
  80         for (i = 0; i < repeats; i++) {
  81                 gup.size = size;
  82                 if (ioctl(fd, GUP_FAST_BENCHMARK, &gup))
  83                         perror("ioctl"), exit(1);
  84
  85                 printf("Time: get:%lld put:%lld us", gup.get_delta_usec,
  86                         gup.put_delta_usec);
  87                 if (gup.size != size)
  88                         printf(", truncated (size: %lld)", gup.size);
  89                 printf("\n");
  90         }
  91
  92         return 0;
  93 }