[NETEM]: use PSCHED_LESS
Convert netem to use PSCHED_LESS and warn if requeue fails.
With some of the psched clock sources, the subtraction doesn't
work always work right without wrapping.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index bb9bf8d..d871fe7 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -185,10 +185,13 @@
|| q->counter < q->gap /* inside last reordering gap */
|| q->reorder < get_crandom(&q->reorder_cor)) {
psched_time_t now;
+ psched_tdiff_t delay;
+
+ delay = tabledist(q->latency, q->jitter,
+ &q->delay_cor, q->delay_dist);
+
PSCHED_GET_TIME(now);
- PSCHED_TADD2(now, tabledist(q->latency, q->jitter,
- &q->delay_cor, q->delay_dist),
- cb->time_to_send);
+ PSCHED_TADD2(now, delay, cb->time_to_send);
++q->counter;
ret = q->qdisc->enqueue(skb, q->qdisc);
} else {
@@ -248,24 +251,31 @@
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) {
+
+ 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 {
+ psched_tdiff_t delay = PSCHED_TDIFF(cb->time_to_send, now);
+
+ if (q->qdisc->ops->requeue(skb, q->qdisc) != NET_XMIT_SUCCESS) {
+ sch->qstats.drops++;
+
+ /* After this qlen is confused */
+ printk(KERN_ERR "netem: queue discpline %s could not requeue\n",
+ q->qdisc->ops->id);
+
+ sch->q.qlen--;
+ }
+
+ mod_timer(&q->timer, jiffies + PSCHED_US2JIFFIE(delay));
+ sch->flags |= TCQ_F_THROTTLED;
}
-
- mod_timer(&q->timer, jiffies + delay);
- sch->flags |= TCQ_F_THROTTLED;
-
- if (q->qdisc->ops->requeue(skb, q->qdisc) != 0)
- sch->qstats.drops++;
}
return NULL;