diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-06-22 08:16:49 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-06-25 18:19:35 +0200 |
| commit | 520ac30f45519b0a82dd92117c181d1d6144677b (patch) | |
| tree | a3189ae1ab3b5be6213716e42ddaec082578e774 /net/sched/sch_codel.c | |
| parent | Merge branch 'liquidio-next' (diff) | |
| download | linux-520ac30f45519b0a82dd92117c181d1d6144677b.tar.xz linux-520ac30f45519b0a82dd92117c181d1d6144677b.zip | |
net_sched: drop packets after root qdisc lock is released
Qdisc performance suffers when packets are dropped at enqueue()
time because drops (kfree_skb()) are done while qdisc lock is held,
delaying a dequeue() draining the queue.
Nominal throughput can be reduced by 50 % when this happens,
at a time we would like the dequeue() to proceed as fast as possible.
Even FQ is vulnerable to this problem, while one of FQ goals was
to provide some flow isolation.
This patch adds a 'struct sk_buff **to_free' parameter to all
qdisc->enqueue(), and in qdisc_drop() helper.
I measured a performance increase of up to 12 %, but this patch
is a prereq so that future batches in enqueue() can fly.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/sch_codel.c')
| -rw-r--r-- | net/sched/sch_codel.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/net/sched/sch_codel.c b/net/sched/sch_codel.c index c5bc424e3b3c..4002df3c7d9f 100644 --- a/net/sched/sch_codel.c +++ b/net/sched/sch_codel.c @@ -82,7 +82,8 @@ static void drop_func(struct sk_buff *skb, void *ctx) { struct Qdisc *sch = ctx; - qdisc_drop(skb, sch); + kfree_skb(skb); + qdisc_qstats_drop(sch); } static struct sk_buff *codel_qdisc_dequeue(struct Qdisc *sch) @@ -107,7 +108,8 @@ static struct sk_buff *codel_qdisc_dequeue(struct Qdisc *sch) return skb; } -static int codel_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch) +static int codel_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, + struct sk_buff **to_free) { struct codel_sched_data *q; @@ -117,7 +119,7 @@ static int codel_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch) } q = qdisc_priv(sch); q->drop_overlimit++; - return qdisc_drop(skb, sch); + return qdisc_drop(skb, sch, to_free); } static const struct nla_policy codel_policy[TCA_CODEL_MAX + 1] = { |