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