diff options
Diffstat (limited to 'kernel/sched/wait.c')
| -rw-r--r-- | kernel/sched/wait.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/kernel/sched/wait.c b/kernel/sched/wait.c index 01f5d3020589..183cc6ae68a6 100644 --- a/kernel/sched/wait.c +++ b/kernel/sched/wait.c @@ -37,6 +37,17 @@ void add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue } EXPORT_SYMBOL(add_wait_queue_exclusive); +void add_wait_queue_priority(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry) +{ + unsigned long flags; + + wq_entry->flags |= WQ_FLAG_EXCLUSIVE | WQ_FLAG_PRIORITY; + spin_lock_irqsave(&wq_head->lock, flags); + __add_wait_queue(wq_head, wq_entry); + spin_unlock_irqrestore(&wq_head->lock, flags); +} +EXPORT_SYMBOL_GPL(add_wait_queue_priority); + void remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry) { unsigned long flags; @@ -57,7 +68,11 @@ EXPORT_SYMBOL(remove_wait_queue); /* * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve - * number) then we wake all the non-exclusive tasks and one exclusive task. + * number) then we wake that number of exclusive tasks, and potentially all + * the non-exclusive tasks. Normally, exclusive tasks will be at the end of + * the list and any non-exclusive tasks will be woken first. A priority task + * may be at the head of the list, and can consume the event without any other + * tasks being woken. * * There are circumstances in which we can try to wake a task which has already * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns |