31d375f5 |
1 | /* test-tsc-sync.c |
2 | * |
3 | * Test TSC sync |
4 | */ |
5 | |
6 | |
7 | #include <linux/module.h> |
8 | #include <linux/timer.h> |
9 | #include <asm/timex.h> |
10 | #include <linux/jiffies.h> |
11 | |
12 | static DEFINE_PER_CPU(cycles_t, count) = 0; |
13 | |
14 | static struct timer_list test_timer; |
15 | |
16 | /* IPI called on each CPU. */ |
17 | static void test_each(void *info) |
18 | { |
19 | __get_cpu_var(count) = get_cycles(); |
20 | } |
21 | |
22 | static void do_test_timer(unsigned long data) |
23 | { |
24 | int cpu; |
25 | |
26 | /* Increment the counters */ |
27 | on_each_cpu(test_each, NULL, 0, 1); |
28 | /* Read all the counters */ |
29 | printk("Counters read from CPU %d\n", smp_processor_id()); |
30 | for_each_online_cpu(cpu) { |
31 | printk("Read : CPU %d, count %llu\n", cpu, |
32 | per_cpu(count, cpu)); |
33 | } |
34 | del_timer(&test_timer); |
35 | test_timer.expires = jiffies + 1000; |
36 | add_timer(&test_timer); |
37 | } |
38 | |
39 | static int __init test_init(void) |
40 | { |
41 | /* initialize the timer that will increment the counter */ |
42 | init_timer(&test_timer); |
43 | test_timer.function = do_test_timer; |
44 | test_timer.expires = jiffies + 1; |
45 | add_timer(&test_timer); |
46 | |
47 | return 0; |
48 | } |
49 | |
50 | static void __exit test_exit(void) |
51 | { |
52 | del_timer_sync(&test_timer); |
53 | } |
54 | |
55 | module_init(test_init); |
56 | module_exit(test_exit); |
57 | |
58 | MODULE_LICENSE("GPL"); |
59 | MODULE_AUTHOR("Mathieu Desnoyers"); |
60 | MODULE_DESCRIPTION("sync tsc test"); |
61 | |