Pileus Git - ~andy/linux/blob - tools/perf/bench/sched-pipe.c

   1 /*
   2  *
   3  * builtin-bench-pipe.c
   4  *
   5  * pipe: Benchmark for pipe()
   6  *
   7  * Based on pipe-test-1m.c by Ingo Molnar <mingo@redhat.com>
   8  *  http://people.redhat.com/mingo/cfs-scheduler/tools/pipe-test-1m.c
   9  * Ported to perf by Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
  10  *
  11  */
  12
  13 #include "../perf.h"
  14 #include "../util/util.h"
  15 #include "../util/parse-options.h"
  16 #include "../builtin.h"
  17 #include "bench.h"
  18
  19 #include <unistd.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <signal.h>
  23 #include <sys/wait.h>
  24 #include <linux/unistd.h>
  25 #include <string.h>
  26 #include <errno.h>
  27 #include <assert.h>
  28 #include <sys/time.h>
  29 #include <sys/types.h>
  30
  31 #define LOOPS_DEFAULT 1000000
  32 static int loops = LOOPS_DEFAULT;
  33 static int simple = 0;
  34
  35 static const struct option options[] = {
  36         OPT_INTEGER('l', "loop", &loops,
  37                     "Specify number of loops"),
  38         OPT_BOOLEAN('s', "simple-output", &simple,
  39                     "Do simple output (this maybe useful for"
  40                     "processing by scripts or graph tools like gnuplot)"),
  41         OPT_END()
  42 };
  43
  44 static const char * const bench_sched_pipe_usage[] = {
  45         "perf bench sched pipe <options>",
  46         NULL
  47 };
  48
  49 int bench_sched_pipe(int argc, const char **argv,
  50                      const char *prefix __used)
  51 {
  52         int pipe_1[2], pipe_2[2];
  53         int m = 0, i;
  54         struct timeval start, stop, diff;
  55         unsigned long long result_usec = 0;
  56
  57         /*
  58          * why does "ret" exist?
  59          * discarding returned value of read(), write()
  60          * causes error in building environment for perf
  61          */
  62         int ret, wait_stat;
  63         pid_t pid, retpid;
  64
  65         argc = parse_options(argc, argv, options,
  66                              bench_sched_pipe_usage, 0);
  67
  68         assert(!pipe(pipe_1));
  69         assert(!pipe(pipe_2));
  70
  71         pid = fork();
  72         assert(pid >= 0);
  73
  74         gettimeofday(&start, NULL);
  75
  76         if (!pid) {
  77                 for (i = 0; i < loops; i++) {
  78                         ret = read(pipe_1[0], &m, sizeof(int));
  79                         ret = write(pipe_2[1], &m, sizeof(int));
  80                 }
  81         } else {
  82                 for (i = 0; i < loops; i++) {
  83                         ret = write(pipe_1[1], &m, sizeof(int));
  84                         ret = read(pipe_2[0], &m, sizeof(int));
  85                 }
  86         }
  87
  88         gettimeofday(&stop, NULL);
  89         timersub(&stop, &start, &diff);
  90
  91         if (pid) {
  92                 retpid = waitpid(pid, &wait_stat, 0);
  93                 assert((retpid == pid) && WIFEXITED(wait_stat));
  94                 return 0;
  95         }
  96
  97         if (simple)
  98                 printf("%lu.%03lu\n",
  99                        diff.tv_sec, diff.tv_usec / 1000);
 100         else {
 101                 printf("(executing %d pipe operations between two tasks)\n\n",
 102                         loops);
 103
 104                 result_usec = diff.tv_sec * 1000000;
 105                 result_usec += diff.tv_usec;
 106
 107                 printf("\tTotal time:%lu.%03lu sec\n",
 108                        diff.tv_sec, diff.tv_usec / 1000);
 109                 printf("\t\t%lf usecs/op\n",
 110                        (double)result_usec / (double)loops);
 111                 printf("\t\t%d ops/sec\n",
 112                        (int)((double)loops /
 113                              ((double)result_usec / (double)1000000)));
 114         }
 115
 116         return 0;
 117 }