diff options
author | David Woodhouse <dwmw2@shinybook.infradead.org> | 2005-06-02 16:39:11 +0100 |
---|---|---|
committer | David Woodhouse <dwmw2@shinybook.infradead.org> | 2005-06-02 16:39:11 +0100 |
commit | 1c3f45ab2f7f879ea482501c83899505c31f7539 (patch) | |
tree | 672465b3b9b3e2e26a8caf74ed64aa6885c52c13 /net/sched/sch_netem.c | |
parent | 4bcff1b37e7c3aed914d1ce5b45994adc7dbf455 (diff) | |
parent | e0d6d71440a3a35c6fc2dde09f8e8d4d7bd44dda (diff) |
Merge with master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
Diffstat (limited to 'net/sched/sch_netem.c')
-rw-r--r-- | net/sched/sch_netem.c | 209 |
1 files changed, 96 insertions, 113 deletions
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index e0c9fbe73b1..bb9bf8d5003 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -53,7 +53,6 @@ struct netem_sched_data { struct Qdisc *qdisc; - struct sk_buff_head delayed; struct timer_list timer; u32 latency; @@ -63,11 +62,12 @@ struct netem_sched_data { u32 gap; u32 jitter; u32 duplicate; + u32 reorder; struct crndstate { unsigned long last; unsigned long rho; - } delay_cor, loss_cor, dup_cor; + } delay_cor, loss_cor, dup_cor, reorder_cor; struct disttable { u32 size; @@ -137,122 +137,68 @@ static long tabledist(unsigned long mu, long sigma, return x / NETEM_DIST_SCALE + (sigma / NETEM_DIST_SCALE) * t + mu; } -/* Put skb in the private delayed queue. */ -static int netem_delay(struct Qdisc *sch, struct sk_buff *skb) -{ - struct netem_sched_data *q = qdisc_priv(sch); - psched_tdiff_t td; - psched_time_t now; - - PSCHED_GET_TIME(now); - td = tabledist(q->latency, q->jitter, &q->delay_cor, q->delay_dist); - - /* Always queue at tail to keep packets in order */ - if (likely(q->delayed.qlen < q->limit)) { - struct netem_skb_cb *cb = (struct netem_skb_cb *)skb->cb; - - PSCHED_TADD2(now, td, cb->time_to_send); - - pr_debug("netem_delay: skb=%p now=%llu tosend=%llu\n", skb, - now, cb->time_to_send); - - __skb_queue_tail(&q->delayed, skb); - return NET_XMIT_SUCCESS; - } - - pr_debug("netem_delay: queue over limit %d\n", q->limit); - sch->qstats.overlimits++; - kfree_skb(skb); - return NET_XMIT_DROP; -} - /* - * Move a packet that is ready to send from the delay holding - * list to the underlying qdisc. + * Insert one skb into qdisc. + * Note: parent depends on return value to account for queue length. + * NET_XMIT_DROP: queue length didn't change. + * NET_XMIT_SUCCESS: one skb was queued. */ -static int netem_run(struct Qdisc *sch) -{ - struct netem_sched_data *q = qdisc_priv(sch); - struct sk_buff *skb; - psched_time_t now; - - PSCHED_GET_TIME(now); - - skb = skb_peek(&q->delayed); - if (skb) { - const struct netem_skb_cb *cb - = (const struct netem_skb_cb *)skb->cb; - long delay - = PSCHED_US2JIFFIE(PSCHED_TDIFF(cb->time_to_send, now)); - pr_debug("netem_run: skb=%p delay=%ld\n", skb, delay); - - /* if more time remaining? */ - if (delay > 0) { - mod_timer(&q->timer, jiffies + delay); - return 1; - } - - __skb_unlink(skb, &q->delayed); - - if (q->qdisc->enqueue(skb, q->qdisc)) { - sch->q.qlen--; - sch->qstats.drops++; - } - } - - return 0; -} - static int netem_enqueue(struct sk_buff *skb, struct Qdisc *sch) { struct netem_sched_data *q = qdisc_priv(sch); + struct netem_skb_cb *cb = (struct netem_skb_cb *)skb->cb; + struct sk_buff *skb2; int ret; + int count = 1; pr_debug("netem_enqueue skb=%p\n", skb); + /* Random duplication */ + if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor)) + ++count; + /* Random packet drop 0 => none, ~0 => all */ - if (q->loss && q->loss >= get_crandom(&q->loss_cor)) { - pr_debug("netem_enqueue: random loss\n"); + if (q->loss && q->loss >= get_crandom(&q->loss_cor)) + --count; + + if (count == 0) { sch->qstats.drops++; kfree_skb(skb); - return 0; /* lie about loss so TCP doesn't know */ + return NET_XMIT_DROP; } - /* Random duplication */ - if (q->duplicate && q->duplicate >= get_crandom(&q->dup_cor)) { - struct sk_buff *skb2; - - skb2 = skb_clone(skb, GFP_ATOMIC); - if (skb2 && netem_delay(sch, skb2) == NET_XMIT_SUCCESS) { - struct Qdisc *qp; - - /* Since one packet can generate two packets in the - * queue, the parent's qlen accounting gets confused, - * so fix it. - */ - qp = qdisc_lookup(sch->dev, TC_H_MAJ(sch->parent)); - if (qp) - qp->q.qlen++; - - sch->q.qlen++; - sch->bstats.bytes += skb2->len; - sch->bstats.packets++; - } else - sch->qstats.drops++; + /* + * If we need to duplicate packet, then re-insert at top of the + * qdisc tree, since parent queuer expects that only one + * skb will be queued. + */ + if (count > 1 && (skb2 = skb_clone(skb, GFP_ATOMIC)) != NULL) { + struct Qdisc *rootq = sch->dev->qdisc; + u32 dupsave = q->duplicate; /* prevent duplicating a dup... */ + q->duplicate = 0; + + rootq->enqueue(skb2, rootq); + q->duplicate = dupsave; } - /* If doing simple delay then gap == 0 so all packets - * go into the delayed holding queue - * otherwise if doing out of order only "1 out of gap" - * packets will be delayed. - */ - if (q->counter < q->gap) { + if (q->gap == 0 /* not doing reordering */ + || q->counter < q->gap /* inside last reordering gap */ + || q->reorder < get_crandom(&q->reorder_cor)) { + psched_time_t now; + PSCHED_GET_TIME(now); + PSCHED_TADD2(now, tabledist(q->latency, q->jitter, + &q->delay_cor, q->delay_dist), + cb->time_to_send); ++q->counter; ret = q->qdisc->enqueue(skb, q->qdisc); } else { + /* + * Do re-ordering by putting one out of N packets at the front + * of the queue. + */ + PSCHED_GET_TIME(cb->time_to_send); q->counter = 0; - ret = netem_delay(sch, skb); - netem_run(sch); + ret = q->qdisc->ops->requeue(skb, q->qdisc); } if (likely(ret == NET_XMIT_SUCCESS)) { @@ -296,22 +242,33 @@ static struct sk_buff *netem_dequeue(struct Qdisc *sch) { struct netem_sched_data *q = qdisc_priv(sch); struct sk_buff *skb; - int pending; - - pending = netem_run(sch); skb = q->qdisc->dequeue(q->qdisc); if (skb) { - pr_debug("netem_dequeue: return skb=%p\n", skb); - sch->q.qlen--; - sch->flags &= ~TCQ_F_THROTTLED; - } - else if (pending) { - pr_debug("netem_dequeue: throttling\n"); + 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) { + pr_debug("netem_dequeue: return skb=%p\n", skb); + sch->q.qlen--; + sch->flags &= ~TCQ_F_THROTTLED; + return skb; + } + + mod_timer(&q->timer, jiffies + delay); sch->flags |= TCQ_F_THROTTLED; - } - return skb; + if (q->qdisc->ops->requeue(skb, q->qdisc) != 0) + sch->qstats.drops++; + } + + return NULL; } static void netem_watchdog(unsigned long arg) @@ -328,8 +285,6 @@ static void netem_reset(struct Qdisc *sch) struct netem_sched_data *q = qdisc_priv(sch); qdisc_reset(q->qdisc); - skb_queue_purge(&q->delayed); - sch->q.qlen = 0; sch->flags &= ~TCQ_F_THROTTLED; del_timer_sync(&q->timer); @@ -397,6 +352,19 @@ static int get_correlation(struct Qdisc *sch, const struct rtattr *attr) return 0; } +static int get_reorder(struct Qdisc *sch, const struct rtattr *attr) +{ + struct netem_sched_data *q = qdisc_priv(sch); + const struct tc_netem_reorder *r = RTA_DATA(attr); + + if (RTA_PAYLOAD(attr) != sizeof(*r)) + return -EINVAL; + + q->reorder = r->probability; + init_crandom(&q->reorder_cor, r->correlation); + return 0; +} + static int netem_change(struct Qdisc *sch, struct rtattr *opt) { struct netem_sched_data *q = qdisc_priv(sch); @@ -417,9 +385,15 @@ static int netem_change(struct Qdisc *sch, struct rtattr *opt) q->jitter = qopt->jitter; q->limit = qopt->limit; q->gap = qopt->gap; + q->counter = 0; q->loss = qopt->loss; q->duplicate = qopt->duplicate; + /* for compatiablity with earlier versions. + * if gap is set, need to assume 100% probablity + */ + q->reorder = ~0; + /* Handle nested options after initial queue options. * Should have put all options in nested format but too late now. */ @@ -441,6 +415,11 @@ static int netem_change(struct Qdisc *sch, struct rtattr *opt) if (ret) return ret; } + if (tb[TCA_NETEM_REORDER-1]) { + ret = get_reorder(sch, tb[TCA_NETEM_REORDER-1]); + if (ret) + return ret; + } } @@ -455,11 +434,9 @@ static int netem_init(struct Qdisc *sch, struct rtattr *opt) if (!opt) return -EINVAL; - skb_queue_head_init(&q->delayed); init_timer(&q->timer); q->timer.function = netem_watchdog; q->timer.data = (unsigned long) sch; - q->counter = 0; q->qdisc = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops); if (!q->qdisc) { @@ -491,6 +468,7 @@ static int netem_dump(struct Qdisc *sch, struct sk_buff *skb) struct rtattr *rta = (struct rtattr *) b; struct tc_netem_qopt qopt; struct tc_netem_corr cor; + struct tc_netem_reorder reorder; qopt.latency = q->latency; qopt.jitter = q->jitter; @@ -504,6 +482,11 @@ static int netem_dump(struct Qdisc *sch, struct sk_buff *skb) cor.loss_corr = q->loss_cor.rho; cor.dup_corr = q->dup_cor.rho; RTA_PUT(skb, TCA_NETEM_CORR, sizeof(cor), &cor); + + reorder.probability = q->reorder; + reorder.correlation = q->reorder_cor.rho; + RTA_PUT(skb, TCA_NETEM_REORDER, sizeof(reorder), &reorder); + rta->rta_len = skb->tail - b; return skb->len; |