#ifndef _LINUX_KTHREAD_H #define _LINUX_KTHREAD_H /* Simple interface for creating and stopping kernel threads without mess. */ #include <linux/err.h> #include <linux/sched.h> /** * 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. * @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). */ #define kthread_run(threadfn, data, namefmt, ...) \ ({ \ struct task_struct *__k \ = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \ if (!IS_ERR(__k)) \ wake_up_process(__k); \ __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 */