sched/deadline: Implement cancel_dl_timer() to use in switched_from_dl()

[mirror_ubuntu-bionic-kernel.git] / kernel / sched / sched.h

diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index ec3917c5f898fc41513126fae54e9f3f51771bd7..49b941fe2cc29c74e24a31181b115780ed1c3344 100644 (file)
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1157,6 +1157,11 @@ struct sched_class {
        void (*task_fork) (struct task_struct *p);
        void (*task_dead) (struct task_struct *p);
 
+       /*
+        * The switched_from() call is allowed to drop rq->lock, therefore we
+        * cannot assume the switched_from/switched_to pair is serliazed by
+        * rq->lock. They are however serialized by p->pi_lock.
+        */
        void (*switched_from) (struct rq *this_rq, struct task_struct *task);
        void (*switched_to) (struct rq *this_rq, struct task_struct *task);
        void (*prio_changed) (struct rq *this_rq, struct task_struct *task,