From bc9fec2f87d57bdbff30d296605e24504513f65c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Dave=20T=C3=A4ht?= <dave.taht@bufferbloat.net> Date: Mon, 17 Sep 2012 19:20:22 -0700 Subject: [PATCH 4/7] net: add skb_reduce_truesize support to common qdiscs Reduce skb size under load when queues begin to fill on the commont qdiscs. --- net/sched/sch_codel.c | 2 ++ net/sched/sch_fifo.c | 12 ++++++++---- net/sched/sch_fq_codel.c | 2 ++ 3 files changed, 12 insertions(+), 4 deletions(-) --- a/net/sched/sch_codel.c +++ b/net/sched/sch_codel.c @@ -96,6 +96,8 @@ static int codel_qdisc_enqueue(struct sk struct codel_sched_data *q; if (likely(qdisc_qlen(sch) < sch->limit)) { + if(qdisc_qlen(sch) > 128) + skb = skb_reduce_truesize(skb); codel_set_enqueue_time(skb); return qdisc_enqueue_tail(skb, sch); } --- a/net/sched/sch_fifo.c +++ b/net/sched/sch_fifo.c @@ -29,17 +29,21 @@ static int bfifo_enqueue(struct sk_buff static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc *sch) { - if (likely(skb_queue_len(&sch->q) < sch->limit)) + if (likely(skb_queue_len(&sch->q) < sch->limit)) { + if (skb_queue_len(&sch->q) > 128) + skb = skb_reduce_truesize(skb); return qdisc_enqueue_tail(skb, sch); - + } return qdisc_reshape_fail(skb, sch); } static int pfifo_tail_enqueue(struct sk_buff *skb, struct Qdisc *sch) { - if (likely(skb_queue_len(&sch->q) < sch->limit)) + if (likely(skb_queue_len(&sch->q) < sch->limit)) { + if (skb_queue_len(&sch->q) > 128) + skb = skb_reduce_truesize(skb); return qdisc_enqueue_tail(skb, sch); - + } /* queue full, remove one skb to fulfill the limit */ __qdisc_queue_drop_head(sch, &sch->q); qdisc_qstats_drop(sch); --- a/net/sched/sch_fq_codel.c +++ b/net/sched/sch_fq_codel.c @@ -185,6 +185,8 @@ static int fq_codel_enqueue(struct sk_bu return ret; } idx--; + if (sch->q.qlen > 128) + skb = skb_reduce_truesize(skb); codel_set_enqueue_time(skb); flow = &q->flows[idx];