1__WAKE_UP_SYNC_KEY(9)            Driver Basics           __WAKE_UP_SYNC_KEY(9)
2
3
4

NAME

6       __wake_up_sync_key - wake up threads blocked on a waitqueue.
7

SYNOPSIS

9       void __wake_up_sync_key(wait_queue_head_t * q, unsigned int mode,
10                               int nr_exclusive, void * key);
11

ARGUMENTS

13       q
14           the waitqueue
15
16       mode
17           which threads
18
19       nr_exclusive
20           how many wake-one or wake-many threads to wake up
21
22       key
23           opaque value to be passed to wakeup targets
24

DESCRIPTION

26       The sync wakeup differs that the waker knows that it will schedule away
27       soon, so while the target thread will be woken up, it will not be
28       migrated to another CPU - ie. the two threads are 'synchronized' with
29       each other. This can prevent needless bouncing between CPUs.
30
31       On UP it can prevent extra preemption.
32
33       It may be assumed that this function implies a write memory barrier
34       before changing the task state if and only if any tasks are woken up.
35

37Kernel Hackers Manual 3.10         June 2019             __WAKE_UP_SYNC_KEY(9)
Impressum