diff options
| -rw-r--r-- | include/net/sch_generic.h | 3 | ||||
| -rw-r--r-- | net/core/dev.c | 29 | ||||
| -rw-r--r-- | net/sched/sch_generic.c | 1 |
3 files changed, 28 insertions, 5 deletions
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index b3591e4a..b35301b 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -80,7 +80,8 @@ struct Qdisc { struct gnet_stats_basic_packed bstats; unsigned long __state; struct gnet_stats_queue qstats; - struct rcu_head rcu_head; + struct rcu_head rcu_head; + spinlock_t busylock; }; static inline bool qdisc_is_running(struct Qdisc *qdisc) diff --git a/net/core/dev.c b/net/core/dev.c index 2733226..ffca5c10 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2040,8 +2040,18 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q, struct netdev_queue *txq) { spinlock_t *root_lock = qdisc_lock(q); + bool contended = qdisc_is_running(q); int rc; + /* + * Heuristic to force contended enqueues to serialize on a + * separate lock before trying to get qdisc main lock. + * This permits __QDISC_STATE_RUNNING owner to get the lock more often + * and dequeue packets faster. + */ + if (unlikely(contended)) + spin_lock(&q->busylock); + spin_lock(root_lock); if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) { kfree_skb(skb); @@ -2056,19 +2066,30 @@ static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q, if (!(dev->priv_flags & IFF_XMIT_DST_RELEASE)) skb_dst_force(skb); __qdisc_update_bstats(q, skb->len); - if (sch_direct_xmit(skb, q, dev, txq, root_lock)) + if (sch_direct_xmit(skb, q, dev, txq, root_lock)) { + if (unlikely(contended)) { + spin_unlock(&q->busylock); + contended = false; + } __qdisc_run(q); - else + } else qdisc_run_end(q); rc = NET_XMIT_SUCCESS; } else { skb_dst_force(skb); rc = qdisc_enqueue_root(skb, q); - qdisc_run(q); + if (qdisc_run_begin(q)) { + if (unlikely(contended)) { + spin_unlock(&q->busylock); + contended = false; + } + __qdisc_run(q); + } } spin_unlock(root_lock); - + if (unlikely(contended)) + spin_unlock(&q->busylock); return rc; } diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 37b86ea..d20fcd2 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -561,6 +561,7 @@ struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, INIT_LIST_HEAD(&sch->list); skb_queue_head_init(&sch->q); + spin_lock_init(&sch->busylock); sch->ops = ops; sch->enqueue = ops->enqueue; sch->dequeue = ops->dequeue; |
