X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Flinux%2Fkthread.h;h=ebdd41fd1082dfd77c7096e84ac9ec491ed82f8c;hb=9464c7cf61b9433057924c36e6e02f303a00e768;hp=1c65e7a9f186cceee83a1e5e199db44b4260daf2;hpb=41689045f6a3cbe0550e1d34e9cc20d2e8c432ba;p=linux-2.6.git diff --git a/include/linux/kthread.h b/include/linux/kthread.h index 1c65e7a9f..ebdd41fd1 100644 --- a/include/linux/kthread.h +++ b/include/linux/kthread.h @@ -4,19 +4,37 @@ #include #include +/** + * kthread_create: create a kthread. + * @threadfn: the function to run until signal_pending(current). + * @data: data ptr for @threadfn. + * @namefmt: printf-style name for the thread. + * + * Description: This helper function creates and names a kernel + * thread. The thread will be stopped: use wake_up_process() to start + * it. See also kthread_run(), kthread_create_on_cpu(). + * + * When woken, the thread will run @threadfn() with @data as its + * argument. @threadfn can either call do_exit() directly if it is a + * standalone thread for which noone will call kthread_stop(), or + * return when 'kthread_should_stop()' is true (which means + * kthread_stop() has been called). The return value should be zero + * or a negative error number: it will be passed to kthread_stop(). + * + * Returns a task_struct or ERR_PTR(-ENOMEM). + */ struct task_struct *kthread_create(int (*threadfn)(void *data), void *data, const char namefmt[], ...); /** - * kthread_run - create and wake a thread. + * kthread_run: create and wake a thread. * @threadfn: the function to run until signal_pending(current). * @data: data ptr for @threadfn. * @namefmt: printf-style name for the thread. * * Description: Convenient wrapper for kthread_create() followed by - * wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM). - */ + * wake_up_process(). Returns the kthread, or ERR_PTR(-ENOMEM). */ #define kthread_run(threadfn, data, namefmt, ...) \ ({ \ struct task_struct *__k \ @@ -26,8 +44,50 @@ struct task_struct *kthread_create(int (*threadfn)(void *data), __k; \ }) +/** + * kthread_bind: bind a just-created kthread to a cpu. + * @k: thread created by kthread_create(). + * @cpu: cpu (might not be online, must be possible) for @k to run on. + * + * Description: This function is equivalent to set_cpus_allowed(), + * except that @cpu doesn't need to be online, and the thread must be + * stopped (ie. just returned from kthread_create(). + */ void kthread_bind(struct task_struct *k, unsigned int cpu); + +/** + * kthread_stop: stop a thread created by kthread_create(). + * @k: thread created by kthread_create(). + * + * Sets kthread_should_stop() for @k to return true, wakes it, and + * waits for it to exit. Your threadfn() must not call do_exit() + * itself if you use this function! This can also be called after + * kthread_create() instead of calling wake_up_process(): the thread + * will exit without calling threadfn(). + * + * Returns the result of threadfn(), or -EINTR if wake_up_process() + * was never called. */ int kthread_stop(struct task_struct *k); + +/** + * kthread_stop_sem: stop a thread created by kthread_create(). + * @k: thread created by kthread_create(). + * @s: semaphore that @k waits on while idle. + * + * Does essentially the same thing as kthread_stop() above, but wakes + * @k by calling up(@s). + * + * Returns the result of threadfn(), or -EINTR if wake_up_process() + * was never called. */ +int kthread_stop_sem(struct task_struct *k, struct semaphore *s); + +/** + * kthread_should_stop: should this kthread return now? + * + * When someone calls kthread_stop on your kthread, it will be woken + * and this will return true. You should then return, and your return + * value will be passed through to kthread_stop(). + */ int kthread_should_stop(void); #endif /* _LINUX_KTHREAD_H */