02e6c126 |
1 | /* test-cmpxchg.c |
2 | * |
3 | * Test time spent in a LTTng instrumentation probe. |
4 | */ |
5 | |
6 | |
7 | #include <linux/init.h> |
8 | #include <linux/module.h> |
9 | #include <linux/ltt-core.h> |
10 | #include <asm/system.h> |
11 | |
12 | #define NR_LOOPS 2000 |
13 | |
14 | static volatile int test_val = 100; |
15 | |
16 | static void do_test(void) |
17 | { |
18 | int val; |
19 | |
20 | val = test_val; |
21 | |
22 | ret = cmpxchg(&test_val, val, 101); |
23 | } |
24 | |
25 | static int ltt_test_init(void) |
26 | { |
27 | unsigned int i; |
28 | cycles_t time1, time2, time; |
29 | cycles_t max_time = 0, min_time = 18446744073709551615ULL; /* (2^64)-1 */ |
30 | cycles_t tot_time = 0; |
31 | unsigned long flags; |
32 | printk(KERN_ALERT "test init\n"); |
33 | |
34 | local_irq_save(flags); |
35 | for(i=0; i<NR_LOOPS; i++) { |
36 | time1 = get_cycles(); |
37 | do_test(); |
38 | time2 = get_cycles(); |
39 | time = time2 - time1; |
40 | max_time = max(max_time, time); |
41 | min_time = min(min_time, time); |
42 | tot_time += time; |
43 | } |
44 | local_irq_restore(flags); |
45 | |
46 | printk(KERN_ALERT "test results : time per probe\n"); |
47 | printk(KERN_ALERT "number of loops : %d\n", NR_LOOPS); |
48 | printk(KERN_ALERT "total time : %llu\n", tot_time); |
49 | printk(KERN_ALERT "min : %llu\n", min_time); |
50 | printk(KERN_ALERT "max : %llu\n", max_time); |
51 | |
52 | printk(KERN_ALERT "test end\n"); |
53 | |
54 | return -EAGAIN; /* Fail will directly unload the module */ |
55 | } |
56 | |
57 | static void ltt_test_exit(void) |
58 | { |
59 | printk(KERN_ALERT "test exit\n"); |
60 | } |
61 | |
62 | module_init(ltt_test_init) |
63 | module_exit(ltt_test_exit) |
64 | |
65 | MODULE_LICENSE("GPL"); |
66 | MODULE_AUTHOR("Mathieu Desnoyers"); |
67 | MODULE_DESCRIPTION("Linux Trace Toolkit Test"); |
68 | |