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pkt_sched: fq: fix non TCP flows pacing

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Steinar reported FQ pacing was not working for UDP flows.

It looks like the initial sk->sk_pacing_rate value of 0 was
a wrong choice. We should init it to ~0U (unlimited)

Then, TCA_FQ_FLOW_DEFAULT_RATE should be removed because it makes
no real sense. The default rate is really unlimited, and we
need to avoid a zero divide.

Reported-by: Steinar H. Gunderson <sesse@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2013-10-08 15:16:00 -07:00
committed by David S. Miller
parent 2b1f18a4d6
commit 7eec4174ff
2 changed files with 10 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
net/core/sock.c
View File

@@ -2319,6 +2319,7 @@ void sock_init_data(struct socket *sock, struct sock *sk)
sk->sk_ll_usec = sysctl_net_busy_read;
#endif
sk->sk_pacing_rate = ~0U;
/*
* Before updating sk_refcnt, we must commit prior changes to memory
* (Documentation/RCU/rculist_nulls.txt for details)

20
net/sched/sch_fq.c
View File

@@ -472,20 +472,16 @@ begin:
if (f->credit > 0 || !q->rate_enable)
goto out;
if (skb->sk && skb->sk->sk_state != TCP_TIME_WAIT) {
rate = skb->sk->sk_pacing_rate ?: q->flow_default_rate;
rate = q->flow_max_rate;
if (skb->sk && skb->sk->sk_state != TCP_TIME_WAIT)
rate = min(skb->sk->sk_pacing_rate, rate);
rate = min(rate, q->flow_max_rate);
} else {
rate = q->flow_max_rate;
if (rate == ~0U)
goto out;
}
if (rate) {
if (rate != ~0U) {
u32 plen = max(qdisc_pkt_len(skb), q->quantum);
u64 len = (u64)plen * NSEC_PER_SEC;
do_div(len, rate);
if (likely(rate))
do_div(len, rate);
/* Since socket rate can change later,
* clamp the delay to 125 ms.
* TODO: maybe segment the too big skb, as in commit
@@ -735,12 +731,14 @@ static int fq_dump(struct Qdisc *sch, struct sk_buff *skb)
if (opts == NULL)
goto nla_put_failure;
/* TCA_FQ_FLOW_DEFAULT_RATE is not used anymore,
* do not bother giving its value
*/
if (nla_put_u32(skb, TCA_FQ_PLIMIT, sch->limit) ||
nla_put_u32(skb, TCA_FQ_FLOW_PLIMIT, q->flow_plimit) ||
nla_put_u32(skb, TCA_FQ_QUANTUM, q->quantum) ||
nla_put_u32(skb, TCA_FQ_INITIAL_QUANTUM, q->initial_quantum) ||
nla_put_u32(skb, TCA_FQ_RATE_ENABLE, q->rate_enable) ||
nla_put_u32(skb, TCA_FQ_FLOW_DEFAULT_RATE, q->flow_default_rate) ||
nla_put_u32(skb, TCA_FQ_FLOW_MAX_RATE, q->flow_max_rate) ||
nla_put_u32(skb, TCA_FQ_BUCKETS_LOG, q->fq_trees_log))
goto nla_put_failure;