On Sat, 25 Apr 2015 19:17:13 +0200, Mustafa Hussain said:

what the function deactivate_task() exactly do ? thanks in advance.

void deactivate_task(struct rq *rq, struct task_struct *p, int flags) { if (task_contributes_to_load(p)) rq->nr_uninterruptible++; dequeue_task(rq, p, flags); } Which part do you not understand?