diff --git a/include/linux/sched.h b/include/linux/sched.h index 30ad7e836bc0..5ff7d268c814 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1004,6 +1004,7 @@ struct task_struct { raw_spinlock_t pi_lock; struct wake_q_node wake_q; + struct wake_q_head *wake_q_head; #ifdef CONFIG_RT_MUTEXES /* PI waiters blocked on a rt_mutex held by this task: */ diff --git a/include/linux/sched/wake_q.h b/include/linux/sched/wake_q.h index 26a2013ac39c..1e05e5669713 100644 --- a/include/linux/sched/wake_q.h +++ b/include/linux/sched/wake_q.h @@ -38,6 +38,7 @@ struct wake_q_head { struct wake_q_node *first; struct wake_q_node **lastp; + int count; }; #define WAKE_Q_TAIL ((struct wake_q_node *) 0x01) @@ -49,6 +50,7 @@ static inline void wake_q_init(struct wake_q_head *head) { head->first = WAKE_Q_TAIL; head->lastp = &head->first; + head->count = 0; } static inline bool wake_q_empty(struct wake_q_head *head) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 2e83effd24b2..066b206d58f2 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -538,6 +538,7 @@ static bool __wake_q_add(struct wake_q_head *head, struct task_struct *task) */ *head->lastp = node; head->lastp = &node->next; + head->count++; return true; } @@ -594,12 +595,14 @@ void wake_up_q(struct wake_q_head *head) /* Task can safely be re-inserted now: */ node = node->next; task->wake_q.next = NULL; + task->wake_q_head = head; /* * wake_up_process() executes a full barrier, which pairs with * the queueing in wake_q_add() so as not to miss wakeups. */ wake_up_process(task); + task->wake_q_head = NULL; put_task_struct(task); } }