diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 04e84c07c94f..909aff2db2b3 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -75,13 +75,14 @@ struct Qdisc { /* * For performance sake on SMP, we put highly modified fields at the end */ - struct Qdisc *next_sched ____cacheline_aligned_in_smp; - struct sk_buff *gso_skb; - unsigned long state; + struct sk_buff *gso_skb ____cacheline_aligned_in_smp; struct sk_buff_head q; struct gnet_stats_basic_packed bstats; seqcount_t running; struct gnet_stats_queue qstats; + unsigned long state; + struct Qdisc *next_sched; + struct sk_buff *skb_bad_txq; struct rcu_head rcu_head; int padded; atomic_t refcnt; diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index ff86606954f2..e95b67cd5718 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -77,6 +77,34 @@ static void try_bulk_dequeue_skb(struct Qdisc *q, skb->next = NULL; } +/* This variant of try_bulk_dequeue_skb() makes sure + * all skbs in the chain are for the same txq + */ +static void try_bulk_dequeue_skb_slow(struct Qdisc *q, + struct sk_buff *skb, + int *packets) +{ + int mapping = skb_get_queue_mapping(skb); + struct sk_buff *nskb; + int cnt = 0; + + do { + nskb = q->dequeue(q); + if (!nskb) + break; + if (unlikely(skb_get_queue_mapping(nskb) != mapping)) { + q->skb_bad_txq = nskb; + qdisc_qstats_backlog_inc(q, nskb); + q->q.qlen++; + break; + } + skb->next = nskb; + skb = nskb; + } while (++cnt < 8); + (*packets) += cnt; + skb->next = NULL; +} + /* Note that dequeue_skb can possibly return a SKB list (via skb->next). * A requeued skb (via q->gso_skb) can also be a SKB list. */ @@ -87,8 +115,9 @@ static struct sk_buff *dequeue_skb(struct Qdisc *q, bool *validate, const struct netdev_queue *txq = q->dev_queue; *packets = 1; - *validate = true; if (unlikely(skb)) { + /* skb in gso_skb were already validated */ + *validate = false; /* check the reason of requeuing without tx lock first */ txq = skb_get_tx_queue(txq->dev, skb); if (!netif_xmit_frozen_or_stopped(txq)) { @@ -97,15 +126,30 @@ static struct sk_buff *dequeue_skb(struct Qdisc *q, bool *validate, q->q.qlen--; } else skb = NULL; - /* skb in gso_skb were already validated */ - *validate = false; - } else { - if (!(q->flags & TCQ_F_ONETXQUEUE) || - !netif_xmit_frozen_or_stopped(txq)) { - skb = q->dequeue(q); - if (skb && qdisc_may_bulk(q)) - try_bulk_dequeue_skb(q, skb, txq, packets); + return skb; + } + *validate = true; + skb = q->skb_bad_txq; + if (unlikely(skb)) { + /* check the reason of requeuing without tx lock first */ + txq = skb_get_tx_queue(txq->dev, skb); + if (!netif_xmit_frozen_or_stopped(txq)) { + q->skb_bad_txq = NULL; + qdisc_qstats_backlog_dec(q, skb); + q->q.qlen--; + goto bulk; } + return NULL; + } + if (!(q->flags & TCQ_F_ONETXQUEUE) || + !netif_xmit_frozen_or_stopped(txq)) + skb = q->dequeue(q); + if (skb) { +bulk: + if (qdisc_may_bulk(q)) + try_bulk_dequeue_skb(q, skb, txq, packets); + else + try_bulk_dequeue_skb_slow(q, skb, packets); } return skb; } @@ -624,11 +668,14 @@ void qdisc_reset(struct Qdisc *qdisc) if (ops->reset) ops->reset(qdisc); + kfree_skb(qdisc->skb_bad_txq); + qdisc->skb_bad_txq = NULL; + if (qdisc->gso_skb) { kfree_skb_list(qdisc->gso_skb); qdisc->gso_skb = NULL; - qdisc->q.qlen = 0; } + qdisc->q.qlen = 0; } EXPORT_SYMBOL(qdisc_reset); @@ -667,6 +714,7 @@ void qdisc_destroy(struct Qdisc *qdisc) dev_put(qdisc_dev(qdisc)); kfree_skb_list(qdisc->gso_skb); + kfree_skb(qdisc->skb_bad_txq); /* * gen_estimator est_timer() might access qdisc->q.lock, * wait a RCU grace period before freeing qdisc.