#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_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 */