Commit 2c08a4f8 authored by Vladimir Oltean's avatar Vladimir Oltean Committed by Jakub Kicinski
Browse files

net/sched: taprio: replace safety precautions with comments 



The WARN_ON_ONCE() checks introduced in commit 13511704 ("net:
taprio offload: enforce qdisc to netdev queue mapping") take a small
toll on performance, but otherwise, the conditions are never expected to
happen. Replace them with comments, such that the information is still
conveyed to developers.

Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 026de64d

net/sched/sch_taprio.c

+9 −15
Original line number Diff line number Diff line
@@ -432,6 +432,9 @@ static int taprio_enqueue_one(struct sk_buff *skb, struct Qdisc *sch, 
	return qdisc_enqueue(skb, 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 int taprio_enqueue(struct sk_buff *skb, struct Qdisc *sch,

			  struct sk_buff **to_free)

{
@@ -439,11 +442,6 @@ static int taprio_enqueue(struct sk_buff *skb, struct Qdisc *sch, 
	struct Qdisc *child;

	int queue;



	if (unlikely(FULL_OFFLOAD_IS_ENABLED(q->flags))) {

		WARN_ONCE(1, "Trying to enqueue skb into the root of a taprio qdisc configured with full offload\n");

		return qdisc_drop(skb, sch, to_free);

	}



	queue = skb_get_queue_mapping(skb);



	child = q->qdiscs[queue];
@@ -489,6 +487,9 @@ 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);
@@ -498,11 +499,6 @@ static struct sk_buff *taprio_peek(struct Qdisc *sch) 
	u32 gate_mask;

	int i;



	if (unlikely(FULL_OFFLOAD_IS_ENABLED(q->flags))) {

		WARN_ONCE(1, "Trying to peek into the root of a taprio qdisc configured with full offload\n");

		return NULL;

	}



	rcu_read_lock();

	entry = rcu_dereference(q->current_entry);

	gate_mask = entry ? entry->gate_mask : TAPRIO_ALL_GATES_OPEN;
@@ -545,6 +541,9 @@ static void taprio_set_budget(struct taprio_sched *q, struct sched_entry *entry) 
			     atomic64_read(&q->picos_per_byte)));

}



/* 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_dequeue(struct Qdisc *sch)

{

	struct taprio_sched *q = qdisc_priv(sch);
@@ -554,11 +553,6 @@ static struct sk_buff *taprio_dequeue(struct Qdisc *sch) 
	u32 gate_mask;

	int i;



	if (unlikely(FULL_OFFLOAD_IS_ENABLED(q->flags))) {

		WARN_ONCE(1, "Trying to dequeue from the root of a taprio qdisc configured with full offload\n");

		return NULL;

	}



	rcu_read_lock();

	entry = rcu_dereference(q->current_entry);

	/* if there's no entry, it means that the schedule didn't