On Tue, Mar 30, 2004 at 10:36:14AM +0530, Srivatsa Vaddagiri wrote:

kthread_stop does:

	1. kthread_stop_info.k = k;
        2. wake_up_process(k);

and if ksoftirqd were to do :

	a. while (!kthread_should_stop()) {
        b.         __set_current_state(TASK_INTERRUPTIBLE);
        c.         schedule();
           }


There is a (narrow) possibility here that a) happens _after_ 1) as well as 
b) _after_ 2).

hmm .. I meant a) happening _before_ 1) and b) happening _after_ 2) ..

        a. __set_current_state(TASK_INTERRUPTIBLE);
	b. while (!kthread_should_stop()) {
        c.         schedule();
        d.         __set_current_state(TASK_INTERRUPTIBLE);
           }

        e. __set_current_state(TASK_RUNNING);

In this case, even if b) happens _after_ 1) and c) _after_ 2), 

Again I meant "even if b) happens _before_ 1) and c) _after_ 2) !!

schedule simply returns immediately because task's state would have been set 
to TASK_RUNNING by 2). It goes back to the kthread_should_stop() check and 
exits!

-- 


Thanks and Regards,
Srivatsa Vaddagiri,
Linux Technology Center,
IBM Software Labs,
Bangalore, INDIA - 560017