diff options
| author | Stephen Hemminger <shemminger@linux-foundation.org> | 2007-03-22 20:17:42 +0100 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-04-26 07:27:22 +0200 |
| commit | 11274e5a43266d531140530adebead6903380caf (patch) | |
| tree | 38c365a3835c9e5973fb1941a31dde8cc4856724 /net/sched/sch_netem.c | |
| parent | [NETEM]: Optimize tfifo (diff) | |
| download | linux-11274e5a43266d531140530adebead6903380caf.tar.xz linux-11274e5a43266d531140530adebead6903380caf.zip | |
[NETEM]: avoid excessive requeues
The netem code would call getnstimeofday() and dequeue/requeue after
every packet, even if it was waiting. Avoid this overhead by using
the throttled flag.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/sch_netem.c')
| -rw-r--r-- | net/sched/sch_netem.c | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index 7e9e658d4d93..fb49e9e7ace0 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -273,6 +273,10 @@ static struct sk_buff *netem_dequeue(struct Qdisc *sch) struct netem_sched_data *q = qdisc_priv(sch); struct sk_buff *skb; + smp_mb(); + if (sch->flags & TCQ_F_THROTTLED) + return NULL; + skb = q->qdisc->dequeue(q->qdisc); if (skb) { const struct netem_skb_cb *cb @@ -285,18 +289,17 @@ static struct sk_buff *netem_dequeue(struct Qdisc *sch) 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 { - qdisc_watchdog_schedule(&q->watchdog, cb->time_to_send); - - 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); - } } + + if (unlikely(q->qdisc->ops->requeue(skb, q->qdisc) != NET_XMIT_SUCCESS)) { + qdisc_tree_decrease_qlen(q->qdisc, 1); + sch->qstats.drops++; + printk(KERN_ERR "netem: %s could not requeue\n", + q->qdisc->ops->id); + } + + qdisc_watchdog_schedule(&q->watchdog, cb->time_to_send); } return NULL; |