Commit 7eec4174 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

pkt_sched: fq: fix non TCP flows pacing 



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: default avatarSteinar H. Gunderson <sesse@google.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2b1f18a4

net/core/sock.c

+1 −0
Original line number Diff line number Diff line
@@ -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)

net/sched/sch_fq.c

+9 −11
Original line number Diff line number Diff line
@@ -472,19 +472,15 @@ 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 = min(rate, q->flow_max_rate);

	} else {

	rate = q->flow_max_rate;

		if (rate == ~0U)

			goto out;

	}

	if (rate) {

	if (skb->sk && skb->sk->sk_state != TCP_TIME_WAIT)

		rate = min(skb->sk->sk_pacing_rate, rate);



	if (rate != ~0U) {

		u32 plen = max(qdisc_pkt_len(skb), q->quantum);

		u64 len = (u64)plen * NSEC_PER_SEC;



		if (likely(rate))

			do_div(len, rate);

		/* Since socket rate can change later,

		 * clamp the delay to 125 ms.
@@ -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;

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