[PATCH] netem --

[Stephen Hemminger <shemminger@xxxxxxxx>]

The netem scheduler needs to limit its delayed packet queue to prevent
a application burst from chewing up too much memory.

Signed-off-by: Stephen Hemminger <shemminger@xxxxxxxx>

diff -Nru a/net/sched/sch_netem.c b/net/sched/sch_netem.c
--- a/net/sched/sch_netem.c     2004-07-13 13:02:58 -07:00
+++ b/net/sched/sch_netem.c     2004-07-13 13:02:58 -07:00
@@ -643,11 +643,17 @@
        PSCHED_TADD2(now, delay, cb->time_to_send);
        
        /* Always queue at tail to keep packets in order */
-       __skb_queue_tail(&q->delayed, skb);
-       sch->q.qlen++;
-       sch->stats.bytes += skb->len;
-       sch->stats.packets++;
-       return 0;
+       if (likely(q->delayed.qlen < q->limit)) {
+               __skb_queue_tail(&q->delayed, skb);
+               sch->q.qlen++;
+               sch->stats.bytes += skb->len;
+               sch->stats.packets++;
+               return 0;
+       }
+
+       sch->stats.drops++;
+       kfree_skb(skb);
+       return NET_XMIT_DROP;
 }
 
 /* Requeue packets but don't change time stamp */