static struct sk_buff *netem_dequeue(struct Qdisc *sch)
{
struct netem_sched_data *q = qdisc_priv(sch);
struct sk_buff *skb;
skb = q->qdisc->dequeue(q->qdisc);
if (skb) {
const struct netem_skb_cb *cb
= (const struct netem_skb_cb *)skb->cb;
psched_time_t now;
/* if more time remaining? */
PSCHED_GET_TIME(now);
if (PSCHED_TLESS(cb->time_to_send, now)) {
pr_debug("netem_dequeue: return skb=%p\n", skb);
sch->q.qlen--;
sch->flags &= ~TCQ_F_THROTTLED;
return skb;
} else {
psched_tdiff_t delay = PSCHED_TDIFF(cb->time_to_send, now);
if (q->qdisc->ops->requeue(skb, q->qdisc) != NET_XMIT_SUCCESS) {
qdisc_tree_decrease_qlen(q->qdisc, 1);
sch->qstats.drops++;
printk(KERN_ERR "netem: queue discpline %s could not requeue\n",
q->qdisc->ops->id);
}
mod_timer(&q->timer, jiffies + PSCHED_US2JIFFIE(delay));
sch->flags |= TCQ_F_THROTTLED;
}
}
return NULL;
}
static void netem_watchdog(unsigned long arg)
{
struct Qdisc *sch = (struct Qdisc *)arg;
struct netem_sched_data *q = qdisc_priv(sch);
struct net_device *dev = sch->dev;
struct sk_buff *skb;
psched_time_t now;
pr_debug("netem_watchdog: fired @%lu\n", jiffies);
spin_lock_bh(&dev->queue_lock);
PSCHED_GET_TIME(now);
while ((skb = skb_peek(&q->delayed)) != NULL) {
const struct netem_skb_cb *cb
= (const struct netem_skb_cb *)skb->cb;
long delay
= PSCHED_US2JIFFIE(PSCHED_TDIFF(cb->time_to_send, now));
pr_debug("netem_watchdog: skb %p@%lu %ld\n",
skb, jiffies, delay);
/* if more time remaining? */
if (delay > 0) {
mod_timer(&q->timer, jiffies + delay);
break;
}
__skb_unlink(skb, &q->delayed);
if (q->qdisc->enqueue(skb, q->qdisc)) {
sch->q.qlen--;
sch->qstats.drops++;
}
}
qdisc_run(dev);
spin_unlock_bh(&dev->queue_lock);
}
