net/sched: taprio: avoid calling child->ops->dequeue(child) twice

Simplify taprio_dequeue_from_txq() by noticing that we can goto one call
earlier than the previous skb_found label. This is possible because
we've unified the treatment of the child->ops->dequeue(child) return
call, we always try other TXQs now, instead of abandoning the root
dequeue completely if we failed in the peek() case.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index 272a8b7c0f9f311ef2ee57ebe6812d3ab7b2d060..a3770d599a8457eeb48b5d588c03e1bc86a56dd6 100644 (file)
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -528,12 +528,8 @@ static struct sk_buff *taprio_dequeue_from_txq(struct Qdisc *sch, int txq,
        if (unlikely(!child))
                return NULL;
 
-       if (TXTIME_ASSIST_IS_ENABLED(q->flags)) {
-               skb = child->ops->dequeue(child);
-               if (!skb)
-                       return NULL;
-               goto skb_found;
-       }
+       if (TXTIME_ASSIST_IS_ENABLED(q->flags))
+               goto skip_peek_checks;
 
        skb = child->ops->peek(child);
        if (!skb)
@@ -560,11 +556,11 @@ static struct sk_buff *taprio_dequeue_from_txq(struct Qdisc *sch, int txq,
            atomic_sub_return(len, &entry->budget) < 0)
                return NULL;
 
+skip_peek_checks:
        skb = child->ops->dequeue(child);
        if (unlikely(!skb))
                return NULL;
 
-skb_found:
        qdisc_bstats_update(sch, skb);
        qdisc_qstats_backlog_dec(sch, skb);
        sch->q.qlen--;