1 files changed, 36 insertions, 88 deletions

diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 5c0f0c209a4c..48360f7eec5d 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;