Re: [RFC] sched: CHOKe packet scheduler (v0.2)

Eric Dumazet
2011-01-05T20:06:12Z

Le mercredi 05 janvier 2011 à 11:21 -0800, Stephen Hemminger a écrit :
> This implements the CHOKe packet scheduler based on the existing
> Linux RED scheduler based on the algorithm described in the paper.
>

> +
> +static int choke_enqueue(struct sk_buff *skb, struct Qdisc *sch)
> +{
> + struct choke_sched_data *q = qdisc_priv(sch);
> + struct red_parms *p = &q->parms;
> +
> + p->qavg = red_calc_qavg(p, skb_queue_len(&sch->q));
> + if (red_is_idling(p))
> + red_end_of_idle_period(p);
> +
> + if (p->qavg <= p->qth_min)
> + p->qcount = -1;
> + else {
> + struct sk_buff *oskb;
> +
> + /* Draw a packet at random from queue */
> + oskb = skb_peek_random(&sch->q);
> +
> + /* Both packets from same flow?
> + * Assumes skb_get_rxhash already set hash on oskb->rxhash
> + * prior to queuing

but this is not true... if at that time, p->qavg was <= p->qth_min.
Packet was directly enqueued.

Just use :

if (skb_get_rxhash(oskb) == skb_get_rxhash(skb))

Since skb_get_rxhash(skb) doesnt recompute rxhash if already set.

Hmm... I am now wondering if this actually works on egress at all
(can we use rxhash here I mean)

> + */
> + if (oskb->rxhash == skb_get_rxhash(skb)) {
> + /* Drop both packets */
> + __skb_unlink(oskb, &sch->q);
> + qdisc_drop(oskb, sch);
> + goto congestion_drop;
> + }