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1 | #ifndef _LINUX_KTHREAD_H |
2 | #define _LINUX_KTHREAD_H | |
3 | /* Simple interface for creating and stopping kernel threads without mess. */ | |
4 | #include <linux/err.h> | |
5 | #include <linux/sched.h> | |
6 | ||
7 | /** | |
8 | * kthread_create: create a kthread. | |
9 | * @threadfn: the function to run until signal_pending(current). | |
10 | * @data: data ptr for @threadfn. | |
11 | * @namefmt: printf-style name for the thread. | |
12 | * | |
13 | * Description: This helper function creates and names a kernel | |
14 | * thread. The thread will be stopped: use wake_up_process() to start | |
15 | * it. See also kthread_run(), kthread_create_on_cpu(). | |
16 | * | |
17 | * When woken, the thread will run @threadfn() with @data as its | |
18 | * argument. @threadfn can either call do_exit() directly if it is a | |
19 | * standalone thread for which noone will call kthread_stop(), or | |
20 | * return when 'kthread_should_stop()' is true (which means | |
21 | * kthread_stop() has been called). The return value should be zero | |
22 | * or a negative error number: it will be passed to kthread_stop(). | |
23 | * | |
24 | * Returns a task_struct or ERR_PTR(-ENOMEM). | |
25 | */ | |
26 | struct task_struct *kthread_create(int (*threadfn)(void *data), | |
27 | void *data, | |
28 | const char namefmt[], ...); | |
29 | ||
30 | /** | |
31 | * kthread_run: create and wake a thread. | |
32 | * @threadfn: the function to run until signal_pending(current). | |
33 | * @data: data ptr for @threadfn. | |
34 | * @namefmt: printf-style name for the thread. | |
35 | * | |
36 | * Description: Convenient wrapper for kthread_create() followed by | |
37 | * wake_up_process(). Returns the kthread, or ERR_PTR(-ENOMEM). */ | |
38 | #define kthread_run(threadfn, data, namefmt, ...) \ | |
39 | ({ \ | |
40 | struct task_struct *__k \ | |
41 | = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \ | |
42 | if (!IS_ERR(__k)) \ | |
43 | wake_up_process(__k); \ | |
44 | __k; \ | |
45 | }) | |
46 | ||
47 | /** | |
48 | * kthread_bind: bind a just-created kthread to a cpu. | |
49 | * @k: thread created by kthread_create(). | |
50 | * @cpu: cpu (might not be online, must be possible) for @k to run on. | |
51 | * | |
52 | * Description: This function is equivalent to set_cpus_allowed(), | |
53 | * except that @cpu doesn't need to be online, and the thread must be | |
54 | * stopped (ie. just returned from kthread_create(). | |
55 | */ | |
56 | void kthread_bind(struct task_struct *k, unsigned int cpu); | |
57 | ||
58 | /** | |
59 | * kthread_stop: stop a thread created by kthread_create(). | |
60 | * @k: thread created by kthread_create(). | |
61 | * | |
62 | * Sets kthread_should_stop() for @k to return true, wakes it, and | |
63 | * waits for it to exit. Your threadfn() must not call do_exit() | |
64 | * itself if you use this function! This can also be called after | |
65 | * kthread_create() instead of calling wake_up_process(): the thread | |
66 | * will exit without calling threadfn(). | |
67 | * | |
68 | * Returns the result of threadfn(), or -EINTR if wake_up_process() | |
69 | * was never called. */ | |
70 | int kthread_stop(struct task_struct *k); | |
71 | ||
72 | /** | |
73 | * kthread_should_stop: should this kthread return now? | |
74 | * | |
75 | * When someone calls kthread_stop on your kthread, it will be woken | |
76 | * and this will return true. You should then return, and your return | |
77 | * value will be passed through to kthread_stop(). | |
78 | */ | |
79 | int kthread_should_stop(void); | |
80 | ||
81 | #endif /* _LINUX_KTHREAD_H */ |