test/sysperf/loop2.c

   1 /*
   2  * loop2.c
   3  *
   4  * Used as a helper to test AST delivery.  Loops in user mode for a few
   5  * seconds.  This one forks and runs the loop in two processes.
   6  *
   7  * $DragonFly: src/test/sysperf/loop2.c,v 1.1 2003/08/12 02:29:44 dillon Exp $
   8  */
   9
  10 #include "blib.h"
  11
  12 #define LOOP 100000000
  13
  14 static void nop() { }
  15
  16 int
  17 main(int ac, char **av)
  18 {
  19     int i;
  20     pid_t pid;
  21
  22     printf("SMP contention, userland-only loop, duel-forks.  Run just one\n");
  23
  24     start_timing();
  25     if (fork() == 0) {
  26         for (i = 0; i < LOOP; ++i)
  27             nop();
  28         _exit(1);
  29     } else {
  30         for (i = 0; i < LOOP; ++i)
  31             nop();
  32         while (wait(NULL) > 0);
  33         stop_timing(LOOP, "loop2/2xfork");
  34     }
  35     return(0);
  36 }
  37