linux 2.6.16.38 w/ vs2.0.3-rc1

[linux-2.6.git] / include / linux / kthread.h

diff --git a/include/linux/kthread.h b/include/linux/kthread.h
index 1c65e7a..ebdd41f 100644 (file)
--- a/include/linux/kthread.h
+++ b/include/linux/kthread.h
@@ -4,19 +4,37 @@
 #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.
+ * 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 */