test/sysperf/mutex4.c

   1 /*
   2  * mutex4.c
   3  *
   4  * $DragonFly: src/test/sysperf/mutex4.c,v 1.1 2008/05/09 15:49:42 dillon Exp $
   5  */
   6
   7 #include "blib.h"
   8
   9 #include <sys/types.h>
  10 #include <machine/atomic.h>
  11 #include <machine/cpufunc.h>
  12
  13 struct globaldata {
  14         int gd_cpumask;
  15         int gd_spinlocks;
  16 };
  17
  18 int *mtx;
  19 struct globaldata gd;
  20
  21 typedef struct globaldata *globaldata_t;
  22
  23 void
  24 rd_lock_contested(void)
  25 {
  26 }
  27
  28 static __inline void
  29 rd_lock(void)
  30 {
  31         atomic_set_int(mtx, 1);
  32         *mtx = 2;
  33         *mtx = 3;
  34 }
  35
  36 static __inline void
  37 rd_unlock(void)
  38 {
  39 }
  40
  41 int
  42 main(int ac, char **av)
  43 {
  44     long long count = 0;
  45     long long max;
  46     int j;
  47     int *counter;
  48     pid_t pid;
  49
  50     printf("Test simple locked bus cycle mutex latency\n");
  51     printf("auto-forks two processes for the test with shared memory\n");
  52     printf("This test is only useful on a SMP box\n");
  53
  54     start_timing();
  55     mtx = mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANON, -1, 0);
  56     counter = mtx + 64;
  57     gd.gd_cpumask = 0x00000001;
  58     gd.gd_spinlocks = 0;
  59     while (stop_timing(0, NULL) == 0) {
  60         for (j = 0; j < 100; ++j) {
  61             rd_lock();
  62             rd_unlock();
  63         }
  64         count += 100;
  65     }
  66     max = count;
  67     *mtx = 0;
  68
  69     start_timing();
  70     for (count = 0; count < max; count += 100) {
  71         for (j = 0; j < 100; ++j) {
  72             rd_lock();
  73             rd_unlock();        /* release */
  74         }
  75     }
  76     stop_timing(count, "complex_mtx(uncontested/1cpu)");
  77
  78     if ((pid = fork()) == 0) {
  79         for (;;) {
  80             for (j = 0; j < 100; ++j) {
  81                 rd_lock();
  82                 rd_unlock();    /* release */
  83                 ++counter[128];
  84             }
  85         }
  86     } else {
  87         gd.gd_cpumask = 0x00000002;
  88         gd.gd_spinlocks = 0;
  89         start_timing();
  90         for (count = 0; count < max; count += 100) {
  91             for (j = 0; j < 100; ++j) {
  92                 rd_lock();
  93                 rd_unlock();    /* release */
  94                 ++counter[64];
  95             }
  96         }
  97         stop_timing(count, "complex_mtx");
  98         printf("proc1=%d proc2=%d\n", counter[64], counter[128]);
  99         kill(pid, 9);
 100     }
 101     return(0);
 102 }
 103