LXR linux/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
  21static  int loops = LOOPS_DEFAULT;
  22
  23static const struct option options[] = {
  24        OPT_INTEGER('l', "loop",        &loops,         "Specify number of loops"),
  25        OPT_END()
  26};
  27
  28static const char * const bench_syscall_usage[] = {
  29        "perf bench syscall <options>",
  30        NULL
  31};
  32
  33int 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                       (unsigned long) 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                       (unsigned long) 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}
  82