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authorStephen Hemminger <shemminger@linux-foundation.org>2007-03-22 12:17:05 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2007-04-25 22:27:21 -0700
commit075aa573b74a732aeff487ab77d3fbd627c10856 (patch)
treeba787170f860875318a13e4c934dc02a0304a18f
parentb407621c35ed5f9a0734e57472e9539117963768 (diff)
[NETEM]: Optimize tfifo
In most cases, the next packet will be sent after the last one. So optimize that case. Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/sched/sch_netem.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 4ac6df0a5b3..7e9e658d4d9 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -479,22 +479,28 @@ static int netem_change(struct Qdisc *sch, struct rtattr *opt)
*/
struct fifo_sched_data {
u32 limit;
+ psched_time_t oldest;
};
static int tfifo_enqueue(struct sk_buff *nskb, struct Qdisc *sch)
{
struct fifo_sched_data *q = qdisc_priv(sch);
struct sk_buff_head *list = &sch->q;
- const struct netem_skb_cb *ncb
- = (const struct netem_skb_cb *)nskb->cb;
+ psched_time_t tnext = ((struct netem_skb_cb *)nskb->cb)->time_to_send;
struct sk_buff *skb;
if (likely(skb_queue_len(list) < q->limit)) {
+ /* Optimize for add at tail */
+ if (likely(skb_queue_empty(list) || !PSCHED_TLESS(tnext, q->oldest))) {
+ q->oldest = tnext;
+ return qdisc_enqueue_tail(nskb, sch);
+ }
+
skb_queue_reverse_walk(list, skb) {
const struct netem_skb_cb *cb
= (const struct netem_skb_cb *)skb->cb;
- if (!PSCHED_TLESS(ncb->time_to_send, cb->time_to_send))
+ if (!PSCHED_TLESS(tnext, cb->time_to_send))
break;
}
@@ -507,7 +513,7 @@ static int tfifo_enqueue(struct sk_buff *nskb, struct Qdisc *sch)
return NET_XMIT_SUCCESS;
}
- return qdisc_drop(nskb, sch);
+ return qdisc_reshape_fail(nskb, sch);
}
static int tfifo_init(struct Qdisc *sch, struct rtattr *opt)
@@ -523,6 +529,7 @@ static int tfifo_init(struct Qdisc *sch, struct rtattr *opt)
} else
q->limit = max_t(u32, sch->dev->tx_queue_len, 1);
+ PSCHED_SET_PASTPERFECT(q->oldest);
return 0;
}