Commit ecc0cc98 authored by Vladimir Oltean's avatar Vladimir Oltean Committed by David S. Miller
Browse files

net/sched: taprio: delete peek() implementation 



There isn't any code in the network stack which calls taprio_peek().
We only see qdisc->ops->peek() being called on child qdiscs of other
classful qdiscs, never from the generic qdisc code. Whereas taprio is
never a child qdisc, it is always root.

This snippet of a comment from qdisc_peek_dequeued() seems to confirm:

	/* we can reuse ->gso_skb because peek isn't called for root qdiscs */

Since I've been known to be wrong many times though, I'm not completely
removing it, but leaving a stub function in place which emits a warning.

Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: default avatarKurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6da13bf9

net/sched/sch_taprio.c

+1 −42
Original line number Diff line number Diff line
@@ -499,50 +499,9 @@ static int taprio_enqueue(struct sk_buff *skb, struct Qdisc *sch, 
	return taprio_enqueue_one(skb, sch, child, to_free);

}



/* Will not be called in the full offload case, since the TX queues are

 * attached to the Qdisc created using qdisc_create_dflt()

 */

static struct sk_buff *taprio_peek(struct Qdisc *sch)

{

	struct taprio_sched *q = qdisc_priv(sch);

	struct net_device *dev = qdisc_dev(sch);

	struct sched_entry *entry;

	struct sk_buff *skb;

	u32 gate_mask;

	int i;



	rcu_read_lock();

	entry = rcu_dereference(q->current_entry);

	gate_mask = entry ? entry->gate_mask : TAPRIO_ALL_GATES_OPEN;

	rcu_read_unlock();



	if (!gate_mask)

		return NULL;



	for (i = 0; i < dev->num_tx_queues; i++) {

		struct Qdisc *child = q->qdiscs[i];

		int prio;

		u8 tc;



		if (unlikely(!child))

			continue;



		skb = child->ops->peek(child);

		if (!skb)

			continue;



		if (TXTIME_ASSIST_IS_ENABLED(q->flags))

			return skb;



		prio = skb->priority;

		tc = netdev_get_prio_tc_map(dev, prio);



		if (!(gate_mask & BIT(tc)))

			continue;



		return skb;

	}



	WARN_ONCE(1, "taprio only supports operating as root qdisc, peek() not implemented");

	return NULL;

}