From f38c39d6ce8226519455a6dfe91c2ad84f363f6f Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Mon, 20 Mar 2006 19:20:44 -0800 Subject: [PATCH] [PKT_SCHED]: Convert sch_red to a classful qdisc Convert sch_red to a classful qdisc. All qdiscs that maintain accurate backlog counters are eligible as child qdiscs. When a queue limit larger than zero is given, a bfifo qdisc is used for backwards compatibility. Current versions of tc enforce a limit larger than zero, other users can avoid creating the default qdisc by using zero. Signed-off-by: Patrick McHardy Acked-by: Jamal Hadi Salim Signed-off-by: David S. Miller --- net/sched/sch_red.c | 179 ++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 163 insertions(+), 16 deletions(-) diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c index dccfa44c2d..2be563cba7 100644 --- a/net/sched/sch_red.c +++ b/net/sched/sch_red.c @@ -44,6 +44,7 @@ struct red_sched_data unsigned char flags; struct red_parms parms; struct red_stats stats; + struct Qdisc *qdisc; }; static inline int red_use_ecn(struct red_sched_data *q) @@ -59,8 +60,10 @@ static inline int red_use_harddrop(struct red_sched_data *q) static int red_enqueue(struct sk_buff *skb, struct Qdisc* sch) { struct red_sched_data *q = qdisc_priv(sch); + struct Qdisc *child = q->qdisc; + int ret; - q->parms.qavg = red_calc_qavg(&q->parms, sch->qstats.backlog); + q->parms.qavg = red_calc_qavg(&q->parms, child->qstats.backlog); if (red_is_idling(&q->parms)) red_end_of_idle_period(&q->parms); @@ -91,11 +94,16 @@ static int red_enqueue(struct sk_buff *skb, struct Qdisc* sch) break; } - if (sch->qstats.backlog + skb->len <= q->limit) - return qdisc_enqueue_tail(skb, sch); - - q->stats.pdrop++; - return qdisc_drop(skb, sch); + ret = child->enqueue(skb, child); + if (likely(ret == NET_XMIT_SUCCESS)) { + sch->bstats.bytes += skb->len; + sch->bstats.packets++; + sch->q.qlen++; + } else { + q->stats.pdrop++; + sch->qstats.drops++; + } + return ret; congestion_drop: qdisc_drop(skb, sch); @@ -105,21 +113,30 @@ congestion_drop: static int red_requeue(struct sk_buff *skb, struct Qdisc* sch) { struct red_sched_data *q = qdisc_priv(sch); + struct Qdisc *child = q->qdisc; + int ret; if (red_is_idling(&q->parms)) red_end_of_idle_period(&q->parms); - return qdisc_requeue(skb, sch); + ret = child->ops->requeue(skb, child); + if (likely(ret == NET_XMIT_SUCCESS)) { + sch->qstats.requeues++; + sch->q.qlen++; + } + return ret; } static struct sk_buff * red_dequeue(struct Qdisc* sch) { struct sk_buff *skb; struct red_sched_data *q = qdisc_priv(sch); + struct Qdisc *child = q->qdisc; - skb = qdisc_dequeue_head(sch); - - if (skb == NULL && !red_is_idling(&q->parms)) + skb = child->dequeue(child); + if (skb) + sch->q.qlen--; + else if (!red_is_idling(&q->parms)) red_start_of_idle_period(&q->parms); return skb; @@ -127,14 +144,14 @@ static struct sk_buff * red_dequeue(struct Qdisc* sch) static unsigned int red_drop(struct Qdisc* sch) { - struct sk_buff *skb; struct red_sched_data *q = qdisc_priv(sch); + struct Qdisc *child = q->qdisc; + unsigned int len; - skb = qdisc_dequeue_tail(sch); - if (skb) { - unsigned int len = skb->len; + if (child->ops->drop && (len = child->ops->drop(child)) > 0) { q->stats.other++; - qdisc_drop(skb, sch); + sch->qstats.drops++; + sch->q.qlen--; return len; } @@ -148,15 +165,48 @@ static void red_reset(struct Qdisc* sch) { struct red_sched_data *q = qdisc_priv(sch); - qdisc_reset_queue(sch); + qdisc_reset(q->qdisc); + sch->q.qlen = 0; red_restart(&q->parms); } +static void red_destroy(struct Qdisc *sch) +{ + struct red_sched_data *q = qdisc_priv(sch); + qdisc_destroy(q->qdisc); +} + +static struct Qdisc *red_create_dflt(struct net_device *dev, u32 limit) +{ + struct Qdisc *q = qdisc_create_dflt(dev, &bfifo_qdisc_ops); + struct rtattr *rta; + int ret; + + if (q) { + rta = kmalloc(RTA_LENGTH(sizeof(struct tc_fifo_qopt)), + GFP_KERNEL); + if (rta) { + rta->rta_type = RTM_NEWQDISC; + rta->rta_len = RTA_LENGTH(sizeof(struct tc_fifo_qopt)); + ((struct tc_fifo_qopt *)RTA_DATA(rta))->limit = limit; + + ret = q->ops->change(q, rta); + kfree(rta); + + if (ret == 0) + return q; + } + qdisc_destroy(q); + } + return NULL; +} + static int red_change(struct Qdisc *sch, struct rtattr *opt) { struct red_sched_data *q = qdisc_priv(sch); struct rtattr *tb[TCA_RED_MAX]; struct tc_red_qopt *ctl; + struct Qdisc *child = NULL; if (opt == NULL || rtattr_parse_nested(tb, TCA_RED_MAX, opt)) return -EINVAL; @@ -169,9 +219,17 @@ static int red_change(struct Qdisc *sch, struct rtattr *opt) ctl = RTA_DATA(tb[TCA_RED_PARMS-1]); + if (ctl->limit > 0) { + child = red_create_dflt(sch->dev, ctl->limit); + if (child == NULL) + return -ENOMEM; + } + sch_tree_lock(sch); q->flags = ctl->flags; q->limit = ctl->limit; + if (child) + qdisc_destroy(xchg(&q->qdisc, child)); red_set_parms(&q->parms, ctl->qth_min, ctl->qth_max, ctl->Wlog, ctl->Plog, ctl->Scell_log, @@ -186,6 +244,9 @@ static int red_change(struct Qdisc *sch, struct rtattr *opt) static int red_init(struct Qdisc* sch, struct rtattr *opt) { + struct red_sched_data *q = qdisc_priv(sch); + + q->qdisc = &noop_qdisc; return red_change(sch, opt); } @@ -224,15 +285,101 @@ static int red_dump_stats(struct Qdisc *sch, struct gnet_dump *d) return gnet_stats_copy_app(d, &st, sizeof(st)); } +static int red_dump_class(struct Qdisc *sch, unsigned long cl, + struct sk_buff *skb, struct tcmsg *tcm) +{ + struct red_sched_data *q = qdisc_priv(sch); + + if (cl != 1) + return -ENOENT; + tcm->tcm_handle |= TC_H_MIN(1); + tcm->tcm_info = q->qdisc->handle; + return 0; +} + +static int red_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, + struct Qdisc **old) +{ + struct red_sched_data *q = qdisc_priv(sch); + + if (new == NULL) + new = &noop_qdisc; + + sch_tree_lock(sch); + *old = xchg(&q->qdisc, new); + qdisc_reset(*old); + sch->q.qlen = 0; + sch_tree_unlock(sch); + return 0; +} + +static struct Qdisc *red_leaf(struct Qdisc *sch, unsigned long arg) +{ + struct red_sched_data *q = qdisc_priv(sch); + return q->qdisc; +} + +static unsigned long red_get(struct Qdisc *sch, u32 classid) +{ + return 1; +} + +static void red_put(struct Qdisc *sch, unsigned long arg) +{ + return; +} + +static int red_change_class(struct Qdisc *sch, u32 classid, u32 parentid, + struct rtattr **tca, unsigned long *arg) +{ + return -ENOSYS; +} + +static int red_delete(struct Qdisc *sch, unsigned long cl) +{ + return -ENOSYS; +} + +static void red_walk(struct Qdisc *sch, struct qdisc_walker *walker) +{ + if (!walker->stop) { + if (walker->count >= walker->skip) + if (walker->fn(sch, 1, walker) < 0) { + walker->stop = 1; + return; + } + walker->count++; + } +} + +static struct tcf_proto **red_find_tcf(struct Qdisc *sch, unsigned long cl) +{ + return NULL; +} + +static struct Qdisc_class_ops red_class_ops = { + .graft = red_graft, + .leaf = red_leaf, + .get = red_get, + .put = red_put, + .change = red_change_class, + .delete = red_delete, + .walk = red_walk, + .tcf_chain = red_find_tcf, + .dump = red_dump_class, +}; + static struct Qdisc_ops red_qdisc_ops = { .id = "red", .priv_size = sizeof(struct red_sched_data), + .cl_ops = &red_class_ops, .enqueue = red_enqueue, .dequeue = red_dequeue, .requeue = red_requeue, .drop = red_drop, .init = red_init, .reset = red_reset, + .destroy = red_destroy, .change = red_change, .dump = red_dump, .dump_stats = red_dump_stats, -- 2.39.5