__wake_up_sync9
Wake up threads blocked on a waitqueue.
Usage
void __wake_up_sync(wait_queue_head_t * q, unsigned int mode, int nr_exclusive);
Arguments
q
the waitqueue
mode
which threads
nr_exclusive
how many wake-one or wake-many threads to wake up
Overview
The sync wakeup differs that the waker knows that it will schedule away soon, so while the target thread will be woken up, it will not be migrated to another CPU - ie. the two threads are ´synchronized´ with each other. This can prevent needless bouncing between CPUs.
On UP it can prevent extra preemption.
Releases
2 releases since Debian 4.0 (Etch); the text changed 1 time.