diff options
Diffstat (limited to 'net/sched')
| -rw-r--r-- | net/sched/sch_netem.c | 122 |
1 files changed, 109 insertions, 13 deletions
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index bb9bf8d..cdc8d28 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -25,6 +25,8 @@ #include <net/pkt_sched.h> +#define VERSION "1.1" + /* Network Emulation Queuing algorithm. ==================================== @@ -185,10 +187,13 @@ static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch) || q->counter < q->gap /* inside last reordering gap */ || q->reorder < get_crandom(&q->reorder_cor)) { psched_time_t now; + psched_tdiff_t delay; + + delay = tabledist(q->latency, q->jitter, + &q->delay_cor, q->delay_dist); + PSCHED_GET_TIME(now); - PSCHED_TADD2(now, tabledist(q->latency, q->jitter, - &q->delay_cor, q->delay_dist), - cb->time_to_send); + PSCHED_TADD2(now, delay, cb->time_to_send); ++q->counter; ret = q->qdisc->enqueue(skb, q->qdisc); } else { @@ -248,24 +253,31 @@ static struct sk_buff *netem_dequeue(struct Qdisc *sch) const struct netem_skb_cb *cb = (const struct netem_skb_cb *)skb->cb; psched_time_t now; - long delay; /* if more time remaining? */ PSCHED_GET_TIME(now); - delay = PSCHED_US2JIFFIE(PSCHED_TDIFF(cb->time_to_send, now)); - pr_debug("netem_run: skb=%p delay=%ld\n", skb, delay); - if (delay <= 0) { + + if (PSCHED_TLESS(cb->time_to_send, now)) { pr_debug("netem_dequeue: return skb=%p\n", skb); sch->q.qlen--; sch->flags &= ~TCQ_F_THROTTLED; return skb; - } + } else { + psched_tdiff_t delay = PSCHED_TDIFF(cb->time_to_send, now); + + if (q->qdisc->ops->requeue(skb, q->qdisc) != NET_XMIT_SUCCESS) { + sch->qstats.drops++; - mod_timer(&q->timer, jiffies + delay); - sch->flags |= TCQ_F_THROTTLED; + /* After this qlen is confused */ + printk(KERN_ERR "netem: queue discpline %s could not requeue\n", + q->qdisc->ops->id); - if (q->qdisc->ops->requeue(skb, q->qdisc) != 0) - sch->qstats.drops++; + sch->q.qlen--; + } + + mod_timer(&q->timer, jiffies + PSCHED_US2JIFFIE(delay)); + sch->flags |= TCQ_F_THROTTLED; + } } return NULL; @@ -290,11 +302,16 @@ static void netem_reset(struct Qdisc *sch) del_timer_sync(&q->timer); } +/* Pass size change message down to embedded FIFO */ static int set_fifo_limit(struct Qdisc *q, int limit) { struct rtattr *rta; int ret = -ENOMEM; + /* Hack to avoid sending change message to non-FIFO */ + if (strncmp(q->ops->id + 1, "fifo", 4) != 0) + return 0; + rta = kmalloc(RTA_LENGTH(sizeof(struct tc_fifo_qopt)), GFP_KERNEL); if (rta) { rta->rta_type = RTM_NEWQDISC; @@ -426,6 +443,84 @@ static int netem_change(struct Qdisc *sch, struct rtattr *opt) return 0; } +/* + * 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; +}; + +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; + const struct netem_skb_cb *ncb + = (const struct netem_skb_cb *)nskb->cb; + struct sk_buff *skb; + + if (likely(skb_queue_len(list) < q->limit)) { + skb_queue_reverse_walk(list, skb) { + const struct netem_skb_cb *cb + = (const struct netem_skb_cb *)skb->cb; + + if (PSCHED_TLESS(cb->time_to_send, ncb->time_to_send)) + break; + } + + __skb_queue_after(list, skb, nskb); + + sch->qstats.backlog += nskb->len; + sch->bstats.bytes += nskb->len; + sch->bstats.packets++; + + return NET_XMIT_SUCCESS; + } + + return qdisc_drop(nskb, sch); +} + +static int tfifo_init(struct Qdisc *sch, struct rtattr *opt) +{ + struct fifo_sched_data *q = qdisc_priv(sch); + + if (opt) { + struct tc_fifo_qopt *ctl = RTA_DATA(opt); + if (RTA_PAYLOAD(opt) < sizeof(*ctl)) + return -EINVAL; + + q->limit = ctl->limit; + } else + q->limit = max_t(u32, sch->dev->tx_queue_len, 1); + + 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 }; + + RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); + return skb->len; + +rtattr_failure: + return -1; +} + +static struct Qdisc_ops tfifo_qdisc_ops = { + .id = "tfifo", + .priv_size = sizeof(struct fifo_sched_data), + .enqueue = tfifo_enqueue, + .dequeue = qdisc_dequeue_head, + .requeue = qdisc_requeue, + .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 rtattr *opt) { struct netem_sched_data *q = qdisc_priv(sch); @@ -438,7 +533,7 @@ static int netem_init(struct Qdisc *sch, struct rtattr *opt) q->timer.function = netem_watchdog; q->timer.data = (unsigned long) sch; - q->qdisc = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops); + q->qdisc = qdisc_create_dflt(sch->dev, &tfifo_qdisc_ops); if (!q->qdisc) { pr_debug("netem: qdisc create failed\n"); return -ENOMEM; @@ -601,6 +696,7 @@ static struct Qdisc_ops netem_qdisc_ops = { static int __init netem_module_init(void) { + pr_info("netem: version " VERSION "\n"); return register_qdisc(&netem_qdisc_ops); } static void __exit netem_module_exit(void) |