- wait_event_freezable(wq, condition);
- the waitqueue to wait on
- a C expression for the event to wait for
The process is put to sleep (TASK_INTERRUPTIBLE -- so as not to contribute to system load) until the condition evaluates to true. The condition is checked each time the waitqueue wq is woken up.
wake_up has to be called after changing any variable that could change the result of the wait condition.