balance_callback

#ifdef CONFIG_SMP
 
/* rq->lock is NOT held, but preemption is disabled */
static void __balance_callback(struct rq *rq)
{
    struct callback_head *head, *next;
    void (*func)(struct rq *rq);
    unsigned long flags;
 
    raw_spin_lock_irqsave(&rq->lock, flags);
    head = rq->balance_callback;
    rq->balance_callback = NULL;
    while (head) {
        func = (void (*)(struct rq *))head->func;
        next = head->next;
        head->next = NULL;
        head = next;
 
        func(rq);
    }
    raw_spin_unlock_irqrestore(&rq->lock, flags);
}
 
static inline void balance_callback(struct rq *rq)
{
    if (unlikely(rq->balance_callback))
        __balance_callback(rq);
}
 
#else
 
static inline void balance_callback(struct rq *rq)
{
}
函数源码
