diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-06-21 23:16:50 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-06-25 12:19:35 -0400 |
| commit | 008830bc321c0fc22c0db8d5b0b56f854ed90a5c (patch) | |
| tree | 99d4bfa6d32a42e48b598223a5443eb3443ca532 | |
| parent | 520ac30f45519b0a82dd92117c181d1d6144677b (diff) | |
| download | linux-008830bc321c0fc22c0db8d5b0b56f854ed90a5c.tar.bz2 | |
net_sched: fq_codel: cache skb->truesize into skb->cb
Now we defer skb drops, it makes sense to keep a copy
of skb->truesize in struct codel_skb_cb to avoid one
cache line miss per dropped skb in fq_codel_drop(),
to reduce latencies a bit further.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/codel_qdisc.h | 1 | ||||
| -rw-r--r-- | net/sched/sch_fq_codel.c | 7 |
2 files changed, 5 insertions, 3 deletions
diff --git a/include/net/codel_qdisc.h b/include/net/codel_qdisc.h index 8144d9cd2908..098630f83a55 100644 --- a/include/net/codel_qdisc.h +++ b/include/net/codel_qdisc.h @@ -52,6 +52,7 @@ /* Qdiscs using codel plugin must use codel_skb_cb in their own cb[] */ struct codel_skb_cb { codel_time_t enqueue_time; + unsigned int mem_usage; }; static struct codel_skb_cb *get_codel_cb(const struct sk_buff *skb) diff --git a/net/sched/sch_fq_codel.c b/net/sched/sch_fq_codel.c index f715195459c9..a5ea0e9b6be4 100644 --- a/net/sched/sch_fq_codel.c +++ b/net/sched/sch_fq_codel.c @@ -172,7 +172,7 @@ static unsigned int fq_codel_drop(struct Qdisc *sch, unsigned int max_packets, do { skb = dequeue_head(flow); len += qdisc_pkt_len(skb); - mem += skb->truesize; + mem += get_codel_cb(skb)->mem_usage; __qdisc_drop(skb, to_free); } while (++i < max_packets && len < threshold); @@ -216,7 +216,8 @@ static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch, flow->deficit = q->quantum; flow->dropped = 0; } - q->memory_usage += skb->truesize; + get_codel_cb(skb)->mem_usage = skb->truesize; + q->memory_usage += get_codel_cb(skb)->mem_usage; memory_limited = q->memory_usage > q->memory_limit; if (++sch->q.qlen <= sch->limit && !memory_limited) return NET_XMIT_SUCCESS; @@ -267,7 +268,7 @@ static struct sk_buff *dequeue_func(struct codel_vars *vars, void *ctx) if (flow->head) { skb = dequeue_head(flow); q->backlogs[flow - q->flows] -= qdisc_pkt_len(skb); - q->memory_usage -= skb->truesize; + q->memory_usage -= get_codel_cb(skb)->mem_usage; sch->q.qlen--; sch->qstats.backlog -= qdisc_pkt_len(skb); } |