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Commit | Line | Data |
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9cfe06f8 SR |
1 | #include <linux/module.h> |
2 | #include <linux/kthread.h> | |
3 | ||
4 | /* | |
5 | * Any file that uses trace points, must include the header. | |
6 | * But only one file, must include the header by defining | |
7 | * CREATE_TRACE_POINTS first. This will make the C code that | |
8 | * creates the handles for the trace points. | |
9 | */ | |
10 | #define CREATE_TRACE_POINTS | |
11 | #include "trace-events-sample.h" | |
12 | ||
4e20e3a6 SRRH |
13 | static const char *random_strings[] = { |
14 | "Mother Goose", | |
15 | "Snoopy", | |
16 | "Gandalf", | |
17 | "Frodo", | |
18 | "One ring to rule them all" | |
19 | }; | |
9cfe06f8 SR |
20 | |
21 | static void simple_thread_func(int cnt) | |
22 | { | |
4e20e3a6 SRRH |
23 | int array[6]; |
24 | int len = cnt % 5; | |
25 | int i; | |
26 | ||
9cfe06f8 SR |
27 | set_current_state(TASK_INTERRUPTIBLE); |
28 | schedule_timeout(HZ); | |
4e20e3a6 SRRH |
29 | |
30 | for (i = 0; i < len; i++) | |
31 | array[i] = i + 1; | |
32 | array[i] = 0; | |
33 | ||
c4c7eb29 | 34 | /* Silly tracepoints */ |
4e20e3a6 | 35 | trace_foo_bar("hello", cnt, array, random_strings[len], |
0c98d344 | 36 | ¤t->cpus_allowed); |
c4c7eb29 | 37 | |
7496946a SRRH |
38 | trace_foo_with_template_simple("HELLO", cnt); |
39 | ||
c4c7eb29 | 40 | trace_foo_bar_with_cond("Some times print", cnt); |
7496946a SRRH |
41 | |
42 | trace_foo_with_template_cond("prints other times", cnt); | |
43 | ||
44 | trace_foo_with_template_print("I have to be different", cnt); | |
9cfe06f8 SR |
45 | } |
46 | ||
47 | static int simple_thread(void *arg) | |
48 | { | |
49 | int cnt = 0; | |
50 | ||
51 | while (!kthread_should_stop()) | |
52 | simple_thread_func(cnt++); | |
53 | ||
54 | return 0; | |
55 | } | |
56 | ||
57 | static struct task_struct *simple_tsk; | |
6adc13f8 SRRH |
58 | static struct task_struct *simple_tsk_fn; |
59 | ||
60 | static void simple_thread_func_fn(int cnt) | |
61 | { | |
62 | set_current_state(TASK_INTERRUPTIBLE); | |
63 | schedule_timeout(HZ); | |
64 | ||
65 | /* More silly tracepoints */ | |
66 | trace_foo_bar_with_fn("Look at me", cnt); | |
7496946a | 67 | trace_foo_with_template_fn("Look at me too", cnt); |
6adc13f8 SRRH |
68 | } |
69 | ||
70 | static int simple_thread_fn(void *arg) | |
71 | { | |
72 | int cnt = 0; | |
73 | ||
74 | while (!kthread_should_stop()) | |
75 | simple_thread_func_fn(cnt++); | |
76 | ||
77 | return 0; | |
78 | } | |
79 | ||
80 | static DEFINE_MUTEX(thread_mutex); | |
5f369a7f | 81 | static bool simple_thread_cnt; |
6adc13f8 | 82 | |
8cf868af | 83 | int foo_bar_reg(void) |
6adc13f8 | 84 | { |
5f369a7f SRV |
85 | mutex_lock(&thread_mutex); |
86 | if (simple_thread_cnt++) | |
87 | goto out; | |
88 | ||
6adc13f8 SRRH |
89 | pr_info("Starting thread for foo_bar_fn\n"); |
90 | /* | |
91 | * We shouldn't be able to start a trace when the module is | |
92 | * unloading (there's other locks to prevent that). But | |
93 | * for consistency sake, we still take the thread_mutex. | |
94 | */ | |
6adc13f8 | 95 | simple_tsk_fn = kthread_run(simple_thread_fn, NULL, "event-sample-fn"); |
5f369a7f | 96 | out: |
6adc13f8 | 97 | mutex_unlock(&thread_mutex); |
8cf868af | 98 | return 0; |
6adc13f8 SRRH |
99 | } |
100 | ||
101 | void foo_bar_unreg(void) | |
102 | { | |
6adc13f8 | 103 | mutex_lock(&thread_mutex); |
5f369a7f SRV |
104 | if (--simple_thread_cnt) |
105 | goto out; | |
106 | ||
107 | pr_info("Killing thread for foo_bar_fn\n"); | |
6adc13f8 SRRH |
108 | if (simple_tsk_fn) |
109 | kthread_stop(simple_tsk_fn); | |
110 | simple_tsk_fn = NULL; | |
5f369a7f | 111 | out: |
6adc13f8 SRRH |
112 | mutex_unlock(&thread_mutex); |
113 | } | |
9cfe06f8 SR |
114 | |
115 | static int __init trace_event_init(void) | |
116 | { | |
117 | simple_tsk = kthread_run(simple_thread, NULL, "event-sample"); | |
118 | if (IS_ERR(simple_tsk)) | |
119 | return -1; | |
120 | ||
121 | return 0; | |
122 | } | |
123 | ||
124 | static void __exit trace_event_exit(void) | |
125 | { | |
126 | kthread_stop(simple_tsk); | |
6adc13f8 SRRH |
127 | mutex_lock(&thread_mutex); |
128 | if (simple_tsk_fn) | |
129 | kthread_stop(simple_tsk_fn); | |
130 | simple_tsk_fn = NULL; | |
131 | mutex_unlock(&thread_mutex); | |
9cfe06f8 SR |
132 | } |
133 | ||
134 | module_init(trace_event_init); | |
135 | module_exit(trace_event_exit); | |
136 | ||
137 | MODULE_AUTHOR("Steven Rostedt"); | |
138 | MODULE_DESCRIPTION("trace-events-sample"); | |
139 | MODULE_LICENSE("GPL"); |