How to join a thread in Linux kernel?

Question

The main question is: How we can wait for a thread in Linux kernel to complete? I have seen a few post concerned about proper way of handling threads in Linux kernel but i\'

Answer 1

kthread_stop() is a kernel's way for wait thread to end.

Aside from waiting, kthread_stop() also sets should_stop flag for waited thread and wake up it, if needed. It is usefull for threads which repeat some actions infinitely.

As for single-shot tasks, it is usually simpler to use works for them, instead of kthreads.

EDIT: Note: kthread_stop() can be called only when kthread(task_struct) structure is not freed.

Either thread function should return only after it found kthread_should_stop() return true, or get_task_struct() should be called before start thread (and put_task_struct() should be called after kthread_stop()).