Hi. Following LDD3, I am dealing with wait queues, on a 2.6.10. My loop is like: while(enough()){ prepare_to_wait(&queue_head, &queue_entry, TASK_INTERRUPTIBLE); atomic_set(&flag, 0); if (!atomic_read(&flag, 0)) schedule(); finish_wait(&queue_head, &queue_entry); } My intention is to wake up the process at each loop by issuing CTRL^D. Here is what happens: the first time the process yields the processor, it actually sleeps and I have to give it a CTRL^D in order to put it again in running state; unfortunately, in the following loops, although it calls the schedule() function, it magically regains the processor putting hisself in a running state (since it runs, I guess the state is a running one). In a few words, the while loop has thousands of iterations, but CTRL^D is needed only during the first one. Thank you all