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 <[EMAIL PROTECTED]>
---
net/sched/sch_api.c | 3 +++
net/sched/sch_netem.c | 21 ++++++++++++---------
2 files changed, 15 insertions(+), 9 deletions(-)
--- net-2.6.22.orig/net/sched/sch_api.c
+++ net-2.6.22/net/sched/sch_api.c
@@ -298,6 +298,7 @@ static enum hrtimer_restart qdisc_watchd
timer);
wd->qdisc->flags &= ~TCQ_F_THROTTLED;
+ smp_wmb();
netif_schedule(wd->qdisc->dev);
return HRTIMER_NORESTART;
}
@@ -315,6 +316,7 @@ void qdisc_watchdog_schedule(struct qdis
ktime_t time;
wd->qdisc->flags |= TCQ_F_THROTTLED;
+ smp_wmb();
time = ktime_set(0, 0);
time = ktime_add_ns(time, PSCHED_US2NS(expires));
hrtimer_start(&wd->timer, time, HRTIMER_MODE_ABS);
@@ -325,6 +327,7 @@ void qdisc_watchdog_cancel(struct qdisc_
{
hrtimer_cancel(&wd->timer);
wd->qdisc->flags &= ~TCQ_F_THROTTLED;
+ smp_wmb();
}
EXPORT_SYMBOL(qdisc_watchdog_cancel);
--- net-2.6.22.orig/net/sched/sch_netem.c
+++ net-2.6.22/net/sched/sch_netem.c
@@ -272,6 +272,10 @@ static struct sk_buff *netem_dequeue(str
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
@@ -284,18 +288,17 @@ static struct sk_buff *netem_dequeue(str
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;
--
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
