tools/perf/bench/syscall.c

   1 /*
   2  *
   3  * syscall.c
   4  *
   5  * syscall: Benchmark for system call performance
   6  */
   7 #include "../perf.h"
   8 #include "../util/util.h"
   9 #include <subcmd/parse-options.h>
  10 #include "../builtin.h"
  11 #include "bench.h"
  12
  13 #include <stdio.h>
  14 #include <sys/time.h>
  15 #include <sys/syscall.h>
  16 #include <sys/types.h>
  17 #include <unistd.h>
  18 #include <stdlib.h>
  19
  20 #define LOOPS_DEFAULT 10000000
  21 static  int loops = LOOPS_DEFAULT;
  22
  23 static const struct option options[] = {
  24         OPT_INTEGER('l', "loop",        &loops,         "Specify number of loops"),
  25         OPT_END()
  26 };
  27
  28 static const char * const bench_syscall_usage[] = {
  29         "perf bench syscall <options>",
  30         NULL
  31 };
  32
  33 int bench_syscall_basic(int argc, const char **argv)
  34 {
  35         struct timeval start, stop, diff;
  36         unsigned long long result_usec = 0;
  37         int i;
  38
  39         argc = parse_options(argc, argv, options, bench_syscall_usage, 0);
  40
  41         gettimeofday(&start, NULL);
  42
  43         for (i = 0; i < loops; i++)
  44                 getppid();
  45
  46         gettimeofday(&stop, NULL);
  47         timersub(&stop, &start, &diff);
  48
  49         switch (bench_format) {
  50         case BENCH_FORMAT_DEFAULT:
  51                 printf("# Executed %'d getppid() calls\n", loops);
  52
  53                 result_usec = diff.tv_sec * 1000000;
  54                 result_usec += diff.tv_usec;
  55
  56                 printf(" %14s: %lu.%03lu [sec]\n\n", "Total time",
  57                        diff.tv_sec,
  58                        (unsigned long) (diff.tv_usec/1000));
  59
  60                 printf(" %14lf usecs/op\n",
  61                        (double)result_usec / (double)loops);
  62                 printf(" %'14d ops/sec\n",
  63                        (int)((double)loops /
  64                              ((double)result_usec / (double)1000000)));
  65                 break;
  66
  67         case BENCH_FORMAT_SIMPLE:
  68                 printf("%lu.%03lu\n",
  69                        diff.tv_sec,
  70                        (unsigned long) (diff.tv_usec / 1000));
  71                 break;
  72
  73         default:
  74                 /* reaching here is something disaster */
  75                 fprintf(stderr, "Unknown format:%d\n", bench_format);
  76                 exit(1);
  77                 break;
  78         }
  79
  80         return 0;
  81 }