diff options
| -rw-r--r-- | net/sched/sch_netem.c | 202 |
1 files changed, 81 insertions, 121 deletions
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index a92c1b3dab83..06a5cebad342 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -67,7 +67,11 @@ */ struct netem_sched_data { + /* internal t(ime)fifo qdisc uses sch->q and sch->limit */ + + /* optional qdisc for classful handling (NULL at netem init) */ struct Qdisc *qdisc; + struct qdisc_watchdog watchdog; psched_tdiff_t latency; @@ -117,7 +121,9 @@ struct netem_sched_data { }; -/* Time stamp put into socket buffer control block */ +/* Time stamp put into socket buffer control block + * Only valid when skbs are in our internal t(ime)fifo queue. + */ struct netem_skb_cb { psched_time_t time_to_send; }; @@ -324,6 +330,31 @@ static psched_time_t packet_len_2_sched_time(unsigned int len, struct netem_sche return PSCHED_NS2TICKS(ticks); } +static int tfifo_enqueue(struct sk_buff *nskb, struct Qdisc *sch) +{ + struct sk_buff_head *list = &sch->q; + psched_time_t tnext = netem_skb_cb(nskb)->time_to_send; + struct sk_buff *skb; + + if (likely(skb_queue_len(list) < sch->limit)) { + skb = skb_peek_tail(list); + /* Optimize for add at tail */ + if (likely(!skb || tnext >= netem_skb_cb(skb)->time_to_send)) + return qdisc_enqueue_tail(nskb, sch); + + skb_queue_reverse_walk(list, skb) { + if (tnext >= netem_skb_cb(skb)->time_to_send) + break; + } + + __skb_queue_after(list, skb, nskb); + sch->qstats.backlog += qdisc_pkt_len(nskb); + return NET_XMIT_SUCCESS; + } + + return qdisc_reshape_fail(nskb, sch); +} + /* * Insert one skb into qdisc. * Note: parent depends on return value to account for queue length. @@ -399,7 +430,7 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch) now = psched_get_time(); if (q->rate) { - struct sk_buff_head *list = &q->qdisc->q; + struct sk_buff_head *list = &sch->q; delay += packet_len_2_sched_time(skb->len, q); @@ -417,7 +448,7 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch) cb->time_to_send = now + delay; ++q->counter; - ret = qdisc_enqueue(skb, q->qdisc); + ret = tfifo_enqueue(skb, sch); } else { /* * Do re-ordering by putting one out of N packets at the front @@ -426,7 +457,7 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch) cb->time_to_send = psched_get_time(); q->counter = 0; - __skb_queue_head(&q->qdisc->q, skb); + __skb_queue_head(&sch->q, skb); q->qdisc->qstats.backlog += qdisc_pkt_len(skb); q->qdisc->qstats.requeues++; ret = NET_XMIT_SUCCESS; @@ -439,19 +470,20 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch) } } - sch->q.qlen++; return NET_XMIT_SUCCESS; } static unsigned int netem_drop(struct Qdisc *sch) { struct netem_sched_data *q = qdisc_priv(sch); - unsigned int len = 0; + unsigned int len; - if (q->qdisc->ops->drop && (len = q->qdisc->ops->drop(q->qdisc)) != 0) { - sch->q.qlen--; + len = qdisc_queue_drop(sch); + if (!len && q->qdisc && q->qdisc->ops->drop) + len = q->qdisc->ops->drop(q->qdisc); + if (len) sch->qstats.drops++; - } + return len; } @@ -463,16 +495,16 @@ static struct sk_buff *netem_dequeue(struct Qdisc *sch) if (qdisc_is_throttled(sch)) return NULL; - skb = q->qdisc->ops->peek(q->qdisc); +tfifo_dequeue: + skb = qdisc_peek_head(sch); if (skb) { const struct netem_skb_cb *cb = netem_skb_cb(skb); - psched_time_t now = psched_get_time(); /* if more time remaining? */ - if (cb->time_to_send <= now) { - skb = qdisc_dequeue_peeked(q->qdisc); + if (cb->time_to_send <= psched_get_time()) { + skb = qdisc_dequeue_tail(sch); if (unlikely(!skb)) - return NULL; + goto qdisc_dequeue; #ifdef CONFIG_NET_CLS_ACT /* @@ -483,15 +515,37 @@ static struct sk_buff *netem_dequeue(struct Qdisc *sch) skb->tstamp.tv64 = 0; #endif - sch->q.qlen--; + if (q->qdisc) { + int err = qdisc_enqueue(skb, q->qdisc); + + if (unlikely(err != NET_XMIT_SUCCESS)) { + if (net_xmit_drop_count(err)) { + sch->qstats.drops++; + qdisc_tree_decrease_qlen(sch, 1); + } + } + goto tfifo_dequeue; + } +deliver: qdisc_unthrottled(sch); qdisc_bstats_update(sch, skb); return skb; } + if (q->qdisc) { + skb = q->qdisc->ops->dequeue(q->qdisc); + if (skb) + goto deliver; + } qdisc_watchdog_schedule(&q->watchdog, cb->time_to_send); } +qdisc_dequeue: + if (q->qdisc) { + skb = q->qdisc->ops->dequeue(q->qdisc); + if (skb) + goto deliver; + } return NULL; } @@ -499,8 +553,9 @@ static void netem_reset(struct Qdisc *sch) { struct netem_sched_data *q = qdisc_priv(sch); - qdisc_reset(q->qdisc); - sch->q.qlen = 0; + qdisc_reset_queue(sch); + if (q->qdisc) + qdisc_reset(q->qdisc); qdisc_watchdog_cancel(&q->watchdog); } @@ -690,11 +745,7 @@ static int netem_change(struct Qdisc *sch, struct nlattr *opt) if (ret < 0) return ret; - ret = fifo_set_limit(q->qdisc, qopt->limit); - if (ret) { - pr_info("netem: can't set fifo limit\n"); - return ret; - } + sch->limit = qopt->limit; q->latency = qopt->latency; q->jitter = qopt->jitter; @@ -735,88 +786,6 @@ static int netem_change(struct Qdisc *sch, struct nlattr *opt) return ret; } -/* - * Special case version of FIFO queue for use by netem. - * It queues in order based on timestamps in skb's - */ -struct fifo_sched_data { - u32 limit; - psched_time_t oldest; -}; - -static int tfifo_enqueue(struct sk_buff *nskb, struct Qdisc *sch) -{ - struct fifo_sched_data *q = qdisc_priv(sch); - struct sk_buff_head *list = &sch->q; - psched_time_t tnext = netem_skb_cb(nskb)->time_to_send; - struct sk_buff *skb; - - if (likely(skb_queue_len(list) < q->limit)) { - /* Optimize for add at tail */ - if (likely(skb_queue_empty(list) || tnext >= q->oldest)) { - q->oldest = tnext; - return qdisc_enqueue_tail(nskb, sch); - } - - skb_queue_reverse_walk(list, skb) { - const struct netem_skb_cb *cb = netem_skb_cb(skb); - - if (tnext >= cb->time_to_send) - break; - } - - __skb_queue_after(list, skb, nskb); - - sch->qstats.backlog += qdisc_pkt_len(nskb); - - return NET_XMIT_SUCCESS; - } - - return qdisc_reshape_fail(nskb, sch); -} - -static int tfifo_init(struct Qdisc *sch, struct nlattr *opt) -{ - struct fifo_sched_data *q = qdisc_priv(sch); - - if (opt) { - struct tc_fifo_qopt *ctl = nla_data(opt); - if (nla_len(opt) < sizeof(*ctl)) - return -EINVAL; - - q->limit = ctl->limit; - } else - q->limit = max_t(u32, qdisc_dev(sch)->tx_queue_len, 1); - - q->oldest = PSCHED_PASTPERFECT; - return 0; -} - -static int tfifo_dump(struct Qdisc *sch, struct sk_buff *skb) -{ - struct fifo_sched_data *q = qdisc_priv(sch); - struct tc_fifo_qopt opt = { .limit = q->limit }; - - NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); - return skb->len; - -nla_put_failure: - return -1; -} - -static struct Qdisc_ops tfifo_qdisc_ops __read_mostly = { - .id = "tfifo", - .priv_size = sizeof(struct fifo_sched_data), - .enqueue = tfifo_enqueue, - .dequeue = qdisc_dequeue_head, - .peek = qdisc_peek_head, - .drop = qdisc_queue_drop, - .init = tfifo_init, - .reset = qdisc_reset_queue, - .change = tfifo_init, - .dump = tfifo_dump, -}; - static int netem_init(struct Qdisc *sch, struct nlattr *opt) { struct netem_sched_data *q = qdisc_priv(sch); @@ -828,18 +797,9 @@ static int netem_init(struct Qdisc *sch, struct nlattr *opt) qdisc_watchdog_init(&q->watchdog, sch); q->loss_model = CLG_RANDOM; - q->qdisc = qdisc_create_dflt(sch->dev_queue, &tfifo_qdisc_ops, - TC_H_MAKE(sch->handle, 1)); - if (!q->qdisc) { - pr_notice("netem: qdisc create tfifo qdisc failed\n"); - return -ENOMEM; - } - ret = netem_change(sch, opt); - if (ret) { + if (ret) pr_info("netem: change failed\n"); - qdisc_destroy(q->qdisc); - } return ret; } @@ -848,7 +808,8 @@ static void netem_destroy(struct Qdisc *sch) struct netem_sched_data *q = qdisc_priv(sch); qdisc_watchdog_cancel(&q->watchdog); - qdisc_destroy(q->qdisc); + if (q->qdisc) + qdisc_destroy(q->qdisc); dist_free(q->delay_dist); } @@ -952,7 +913,7 @@ static int netem_dump_class(struct Qdisc *sch, unsigned long cl, { struct netem_sched_data *q = qdisc_priv(sch); - if (cl != 1) /* only one class */ + if (cl != 1 || !q->qdisc) /* only one class */ return -ENOENT; tcm->tcm_handle |= TC_H_MIN(1); @@ -966,14 +927,13 @@ static int netem_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, { struct netem_sched_data *q = qdisc_priv(sch); - if (new == NULL) - new = &noop_qdisc; - sch_tree_lock(sch); *old = q->qdisc; q->qdisc = new; - qdisc_tree_decrease_qlen(*old, (*old)->q.qlen); - qdisc_reset(*old); + if (*old) { + qdisc_tree_decrease_qlen(*old, (*old)->q.qlen); + qdisc_reset(*old); + } sch_tree_unlock(sch); return 0; |