Re: [PATCH v2 net-next] net/sched: add skbprio scheduler

[Nishanth Devarajan <ndev2021@gmail.com>]

On Sun, Jun 24, 2018 at 11:43:07AM -0400, Jamal Hadi Salim wrote:
> On 23/06/18 04:47 PM, Nishanth Devarajan wrote:
> [..]
> 
> >+	/* Drop the packet at the tail of the lowest priority qdisc. */
> >+	lp_qdisc = &q->qdiscs[lp];
> >+	to_drop = __skb_dequeue_tail(lp_qdisc);
> >+	BUG_ON(!to_drop);
> >+	qdisc_qstats_backlog_dec(sch, to_drop);
> >+	qdisc_drop(to_drop, sch, to_free);
> >+
> 
> Maybe also increase overlimit stat here? It will keep track
> of low prio things dropped because you were congested.
> Such a stat helps when debugging or collecting analytics.
> 
> Per Alex's comment, how about:
> 
> -----------
> Skbprio (SKB Priority Queue) is a queueing discipline that
> prioritizes packets according to their skb->priority field.
> Under congestion, already-enqueued lower priority packets
> will be dropped to make space available for higher priority
> packets. Skbprio was conceived as a solution for
> denial-of-service defenses that need to route packets with
> different priorities as a means to overcome DoS attacks
> as described in paper xxxx...
> 
> 
> cheers,
> jamal

Sounds good, will make some changes in v3.

Thanks,
Nishanth