1 files changed, 36 insertions, 88 deletions

diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 5c0f0c2..48360f7 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -53,7 +53,6 @@
 
 struct netem_sched_data {
 	struct Qdisc	*qdisc;
-	struct sk_buff_head delayed;
 	struct timer_list timer;
 
 	u32 latency;
@@ -137,72 +136,6 @@ static long tabledist(unsigned long mu, long sigma,
 	return  x / NETEM_DIST_SCALE + (sigma / NETEM_DIST_SCALE) * t + mu;
 }
 
-/* Put skb in the private delayed queue. */
-static int netem_delay(struct Qdisc *sch, struct sk_buff *skb)
-{
-	struct netem_sched_data *q = qdisc_priv(sch);
-	psched_tdiff_t td;
-	psched_time_t now;
-	
-	PSCHED_GET_TIME(now);
-	td = tabledist(q->latency, q->jitter, &q->delay_cor, q->delay_dist);
-	
-	/* Always queue at tail to keep packets in order */
-	if (likely(q->delayed.qlen < q->limit)) {
-		struct netem_skb_cb *cb = (struct netem_skb_cb *)skb->cb;
-	
-		PSCHED_TADD2(now, td, cb->time_to_send);
-
-		pr_debug("netem_delay: skb=%p now=%llu tosend=%llu\n", skb, 
-			 now, cb->time_to_send);
-	
-		__skb_queue_tail(&q->delayed, skb);
-		return NET_XMIT_SUCCESS;
-	}
-
-	pr_debug("netem_delay: queue over limit %d\n", q->limit);
-	sch->qstats.overlimits++;
-	kfree_skb(skb);
-	return NET_XMIT_DROP;
-}
-
-/*
- *  Move a packet that is ready to send from the delay holding
- *  list to the underlying qdisc.
- */
-static int netem_run(struct Qdisc *sch)
-{
-	struct netem_sched_data *q = qdisc_priv(sch);
-	struct sk_buff *skb;
-	psched_time_t now;
-
-	PSCHED_GET_TIME(now);
-
-	skb = skb_peek(&q->delayed);
-	if (skb) {
-		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_run: skb=%p delay=%ld\n", skb, delay);
-
-		/* if more time remaining? */
-		if (delay > 0) {
-			mod_timer(&q->timer, jiffies + delay);
-			return 1;
-		}
-
-		__skb_unlink(skb, &q->delayed);
-		
-		if (q->qdisc->enqueue(skb, q->qdisc)) {
-			sch->q.qlen--;
-			sch->qstats.drops++;
-		} 
-	}
-
-	return 0;
-}
-
 /*
  * Insert one skb into qdisc.
  * Note: parent depends on return value to account for queue length.
@@ -212,6 +145,7 @@ static int netem_run(struct Qdisc *sch)
 static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 {
 	struct netem_sched_data *q = qdisc_priv(sch);
+	struct netem_skb_cb *cb = (struct netem_skb_cb *)skb->cb;
 	struct sk_buff *skb2;
 	int ret;
 	int count = 1;
@@ -246,18 +180,24 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 		q->duplicate = dupsave;
 	}
 
-	/* If doing simple delay then gap == 0 so all packets
-	 * go into the delayed holding queue
-	 * otherwise if doing out of order only "1 out of gap"
-	 * packets will be delayed.
+	/* 
+	 * Do re-ordering by putting one out of N packets at the front
+	 * of the queue.
+	 * gap == 0 is special case for no-reordering.
 	 */
-	if (q->counter < q->gap) {
+	if (q->gap == 0 || q->counter != q->gap) {
+		psched_time_t now;
+		PSCHED_GET_TIME(now);
+		PSCHED_TADD2(now, 
+			     tabledist(q->latency, q->jitter, &q->delay_cor, q->delay_dist),
+			     cb->time_to_send);
+		
 		++q->counter;
 		ret = q->qdisc->enqueue(skb, q->qdisc);
 	} else {
 		q->counter = 0;
-		ret = netem_delay(sch, skb);
-		netem_run(sch);
+		PSCHED_GET_TIME(cb->time_to_send);
+		ret = q->qdisc->ops->requeue(skb, q->qdisc);
 	}
 
 	if (likely(ret == NET_XMIT_SUCCESS)) {
@@ -301,22 +241,33 @@ static struct sk_buff *netem_dequeue(struct Qdisc *sch)
 {
 	struct netem_sched_data *q = qdisc_priv(sch);
 	struct sk_buff *skb;
-	int pending;
-
-	pending = netem_run(sch);
 
 	skb = q->qdisc->dequeue(q->qdisc);
 	if (skb) {
-		pr_debug("netem_dequeue: return skb=%p\n", skb);
-		sch->q.qlen--;
-		sch->flags &= ~TCQ_F_THROTTLED;
-	}
-	else if (pending) {
-		pr_debug("netem_dequeue: throttling\n");
+		const struct netem_skb_cb *cb
+			= (const struct netem_skb_cb *)skb->cb;
+		psched_time_t now;
+		long delay;
+
+		/* if more time remaining? */
+		PSCHED_GET_TIME(now);
+		delay = PSCHED_US2JIFFIE(PSCHED_TDIFF(cb->time_to_send, now));
+		pr_debug("netem_run: skb=%p delay=%ld\n", skb, delay);
+		if (delay <= 0) {
+			pr_debug("netem_dequeue: return skb=%p\n", skb);
+			sch->q.qlen--;
+			sch->flags &= ~TCQ_F_THROTTLED;
+			return skb;
+		}
+
+		mod_timer(&q->timer, jiffies + delay);
 		sch->flags |= TCQ_F_THROTTLED;
-	} 
 
-	return skb;
+		if (q->qdisc->ops->requeue(skb, q->qdisc) != 0)
+			sch->qstats.drops++;
+	}
+
+	return NULL;
 }
 
 static void netem_watchdog(unsigned long arg)
@@ -333,8 +284,6 @@ static void netem_reset(struct Qdisc *sch)
 	struct netem_sched_data *q = qdisc_priv(sch);
 
 	qdisc_reset(q->qdisc);
-	skb_queue_purge(&q->delayed);
-
 	sch->q.qlen = 0;
 	sch->flags &= ~TCQ_F_THROTTLED;
 	del_timer_sync(&q->timer);
@@ -460,7 +409,6 @@ static int netem_init(struct Qdisc *sch, struct rtattr *opt)
 	if (!opt)
 		return -EINVAL;
 
-	skb_queue_head_init(&q->delayed);
 	init_timer(&q->timer);
 	q->timer.function = netem_watchdog;
 	q->timer.data = (unsigned long) sch;