test/sysperf/syscall2.c

   1 /*
   2  * syscall2.c
   3  *
   4  * All-threads getuid timing test.
   5  */
   6
   7 #include <sys/types.h>
   8 #include <sys/errno.h>
   9 #include <sys/mman.h>
  10 #include <time.h>
  11 #include <stdio.h>
  12
  13 #include <machine/atomic.h>
  14
  15 #include "blib.h"
  16
  17 extern int getuid_test(void);
  18
  19 int
  20 main(void)
  21 {
  22         struct timespec ts, ts2;
  23         int error;
  24         long long count = 0;
  25         long long max;
  26         int j;
  27         int cpuno;
  28         int ncpu;
  29         int *done;
  30         size_t ncpu_size;
  31
  32         done = mmap(NULL, 4096, PROT_READ|PROT_WRITE,
  33                      MAP_SHARED|MAP_ANON, -1, 0);
  34
  35         /*
  36          * How many cpu threads are there?
  37          */
  38         ncpu = 0;
  39         ncpu_size = sizeof(ncpu);
  40         if (sysctlbyname("hw.ncpu", &ncpu, &ncpu_size, NULL, 0) < 0) {
  41                 perror("sysctl hw.ncpu");
  42                 exit(1);
  43         }
  44         printf("timing standard getuid() syscall, %d threads\n", ncpu);
  45         printf("if using powerd, run several times\n");
  46         *done = 0;
  47
  48         /*
  49          * Approximate timing run length
  50          */
  51         start_timing();
  52         while (stop_timing(0, NULL) == 0) {
  53                 for (j = 0; j < 100; ++j)
  54                         getuid();
  55                 count += 100;
  56         }
  57         max = count;
  58
  59         /*
  60          * Run same length on all threads.
  61          */
  62         for (cpuno = 0; cpuno < ncpu; ++cpuno) {
  63                 if (fork() == 0) {
  64                         /*
  65                          * Give scheduler time to move threads around
  66                          */
  67                         start_timing();
  68                         while (stop_timing(0, NULL) == 0) {
  69                                 for (j = 0; j < 100; ++j)
  70                                         getuid();
  71                         }
  72
  73                         /*
  74                          * Actual timing test is here.
  75                          */
  76                         start_timing();
  77                         for (count = 0; count < max; count += 100) {
  78                                 for (j = 0; j < 100; ++j)
  79                                         getuid();
  80                         }
  81                         stop_timing(count, "getuid() sysmsg");
  82
  83                         /*
  84                          * Don't unbusy the cpu until the other threads are
  85                          * done.
  86                          */
  87                         atomic_add_int(done, 1);
  88                         while (*done < ncpu)    /* wait for other threads */
  89                                 getuid();
  90                         exit(0);
  91                 }
  92         }
  93         while (wait3(NULL, 0, NULL) > 0 || errno == EINTR)
  94                 ;
  95         return 0;
  96 }