git.itanic.dy.fi Git - membench/blob - membench.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <sys/time.h>
   4
   5 #define lsize sizeof(unsigned long)
   6
   7 long long usec_diff(const struct timeval *a, const struct timeval *b)
   8 {
   9         long long usec_a, usec_b;
  10         usec_a = a->tv_sec * 1000000 + a->tv_usec;
  11         usec_b = b->tv_sec * 1000000 + b->tv_usec;
  12         return usec_b - usec_a;
  13 }
  14
  15 int main(int argc, char *argv[])
  16 {
  17         int iterations, j, k, count, size, mask, latcount;
  18         unsigned long *buf, i, tmp = 0;
  19         struct timeval start, end;
  20
  21         printf("Benchmark sequential access bandwidth "
  22                 "and random access latency\n\n");
  23
  24         if (argc > 1)
  25                 iterations = atoi(argv[1]);
  26         else
  27                 iterations = 24;
  28
  29         if (argc > 2)
  30                 count = atoi(argv[2]);
  31         else
  32                 count = 1024;
  33         latcount = count / 10;
  34
  35         printf("Doing %d runs with buffer size goin up to %dk\n",
  36                iterations, 1 << (iterations - 10));
  37         printf("Running each round %d times\n", count);
  38         printf("Size of unsigned long is %d bits\n\n", (int)lsize * 8);
  39
  40         switch (lsize) {
  41         case 4:
  42                 j = 12;
  43                 break;
  44         case 8:
  45                 j = 10;
  46                 break;
  47         default:
  48                 printf("WTF?\n");
  49                 exit(1);
  50         }
  51
  52         printf("          |"
  53                "         Read         |"
  54                "         Write        |\n"
  55                "          |"
  56                "-----------------------"
  57                "-----------------------\n"
  58                "    Size  |"
  59                "    MiB/s         ns  |"
  60                "    MiB/s         ns  |\n"
  61                "----------|"
  62                "-----------------------"
  63                "-----------------------\n"
  64                 );
  65
  66         for (; j < iterations + 1; j++) {
  67                 size = (1 << j) / lsize;
  68                 buf = malloc(size * lsize);
  69                 mask = size - 1;
  70
  71                 if (buf == NULL) {
  72                         printf("Malloc failed\n");
  73                         exit(1);
  74                 }
  75
  76                 /* Touch the pages */
  77                 for (i = 0; i < size; i++)
  78                         buf[i] = i;
  79
  80                 printf("%8dk |", (int)(size * lsize / 1024));
  81
  82                 /* Read bandwidth*/
  83
  84                 fflush(stdout);
  85
  86                 gettimeofday(&start, 0);
  87                 for (k = 0; k < count; k++) {
  88                         buf[0] = tmp;
  89                         for (i = 0; i < size; i++)
  90                                 tmp += buf[i];
  91                 }
  92
  93                 gettimeofday(&end, 0);
  94
  95                 printf("% 9.2f  ", (double)(size * lsize) *
  96                        (1000000 / (1024.0 * 1024.0)) * count /
  97                        (double) usec_diff(&start, &end));
  98
  99                 fflush(stdout);
 100
 101                 /* Read latency */
 102
 103                 gettimeofday(&start, 0);
 104                 for (k = 0; k < latcount; k++) {
 105                         buf[0] = tmp;
 106                         for (i = 0; i < size; i++)
 107                                 tmp += buf[random() & mask];
 108                 }
 109
 110                 gettimeofday(&end, 0);
 111
 112                 printf("% 9.3f  |", usec_diff(&start, &end) * 1000 /
 113                        ((double) (size * latcount )));
 114
 115
 116                 fflush(stdout);
 117
 118                 /* Write bandwidth */
 119
 120                 gettimeofday(&start, 0);
 121                 for (k = 0; k < count; k++)
 122                         for (i = 0; i < size; i++)
 123                                  buf[i] = i;
 124                 gettimeofday(&end, 0);
 125
 126                 printf("% 9.2f  ", (double)(size * lsize) *
 127                        (1000000 / (1024.0 * 1024.0)) * count /
 128                        (double) usec_diff(&start, &end));
 129
 130                 fflush(stdout);
 131
 132                 /* Write latency */
 133
 134                 gettimeofday(&start, 0);
 135                 for (k = 0; k < latcount; k++)
 136                         for (i = 0; i < size; i++)
 137                                 buf[random() % mask] = i;
 138                 gettimeofday(&end, 0);
 139
 140                 printf("% 9.3f  |", usec_diff(&start, &end) * 1000 /
 141                        ((double) (size * latcount )));
 142
 143                 printf("\n");
 144
 145                 free(buf);
 146         }
 147         return 0;
 148 }