1 /*
2 * mutex2.c
3 *
4 * $DragonFly: src/test/sysperf/mutex2.c,v 1.2 2006/04/22 22:32:52 dillon Exp $
5 */
6
7 #include "blib.h"
8
9 int *mtx;
10
11 int
main(int ac,char ** av)12 main(int ac, char **av)
13 {
14 long long count = 0;
15 long long max;
16 int j;
17 int *counter;
18 pid_t pid;
19
20 printf("Test simple locked bus cycle mutex latency\n");
21 printf("auto-forks two processes for the test with shared memory\n");
22 printf("This test is only useful on a SMP box\n");
23
24 start_timing();
25 mtx = mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANON, -1, 0);
26 counter = mtx + 64;
27 while (stop_timing(0, NULL) == 0) {
28 for (j = 0; j < 100; ++j) {
29 get_mtx(1);
30 rel_mtx();
31 }
32 count += 100;
33 }
34 max = count;
35 *mtx = 0;
36
37 start_timing();
38 for (count = 0; count < max; count += 100) {
39 for (j = 0; j < 100; ++j) {
40 get_mtx(1);
41 rel_mtx(); /* release */
42 ++counter[64];
43 }
44 }
45 stop_timing(count, "complex_mtx(uncontested/1cpu)");
46
47 if ((pid = fork()) == 0) {
48 for (;;) {
49 for (j = 0; j < 100; ++j) {
50 get_mtx(2);
51 rel_mtx(); /* release */
52 ++counter[128];
53 }
54 }
55 } else {
56 start_timing();
57 for (count = 0; count < max; count += 100) {
58 for (j = 0; j < 100; ++j) {
59 get_mtx(1);
60 rel_mtx(); /* release */
61 ++counter[64];
62 }
63 }
64 stop_timing(count, "complex_mtx");
65 printf("proc1=%d proc2=%d\n", counter[64], counter[128]);
66 kill(pid, 9);
67 }
68 return(0);
69 }
70
71