Ejemplo n.º 1
0
static unsigned int sfq_drop(struct Qdisc *sch)
{
	struct sfq_sched_data *q = qdisc_priv(sch);
	sfq_index x, d = q->cur_depth;
	struct sk_buff *skb;
	unsigned int len;
	struct sfq_slot *slot;

	/* Queue is full! Find the longest slot and drop tail packet from it */
	if (d > 1) {
		x = q->dep[d].next;
		slot = &q->slots[x];
drop:
		skb = q->headdrop ? slot_dequeue_head(slot) : slot_dequeue_tail(slot);
		len = qdisc_pkt_len(skb);
		slot->backlog -= len;
		sfq_dec(q, x);
		kfree_skb(skb);
		sch->q.qlen--;
		sch->qstats.drops++;
		sch->qstats.backlog -= len;
		return len;
	}

	if (d == 1) {
		/* It is difficult to believe, but ALL THE SLOTS HAVE LENGTH 1. */
		x = q->tail->next;
		slot = &q->slots[x];
		q->tail->next = slot->next;
		q->ht[slot->hash] = SFQ_EMPTY_SLOT;
		goto drop;
	}

	return 0;
}
Ejemplo n.º 2
0
static unsigned int sfq_drop(struct Qdisc *sch)
{
	struct sfq_sched_data *q = qdisc_priv(sch);
	sfq_index x, d = q->cur_depth;
	struct sk_buff *skb;
	unsigned int len;
	struct sfq_slot *slot;

	/*                                                                   */
	if (d > 1) {
		x = q->dep[d].next;
		slot = &q->slots[x];
drop:
		skb = q->headdrop ? slot_dequeue_head(slot) : slot_dequeue_tail(slot);
		len = qdisc_pkt_len(skb);
		slot->backlog -= len;
		sfq_dec(q, x);
		kfree_skb(skb);
		sch->q.qlen--;
		sch->qstats.drops++;
		sch->qstats.backlog -= len;
		return len;
	}

	if (d == 1) {
		/*                                                              */
		x = q->tail->next;
		slot = &q->slots[x];
		q->tail->next = slot->next;
		q->ht[slot->hash] = SFQ_EMPTY_SLOT;
		goto drop;
	}

	return 0;
}
Ejemplo n.º 3
0
static struct sk_buff *
sfq_dequeue(struct Qdisc *sch)
{
	struct sfq_sched_data *q = qdisc_priv(sch);
	struct sk_buff *skb;
	sfq_index a, next_a;
	struct sfq_slot *slot;

	/* No active slots */
	if (q->tail == NULL)
		return NULL;

next_slot:
	a = q->tail->next;
	slot = &q->slots[a];
	if (slot->allot <= 0) {
		q->tail = slot;
		slot->allot += q->scaled_quantum;
		goto next_slot;
	}
	skb = slot_dequeue_head(slot);
	sfq_dec(q, a);
	qdisc_bstats_update(sch, skb);
	sch->q.qlen--;
	sch->qstats.backlog -= qdisc_pkt_len(skb);
	slot->backlog -= qdisc_pkt_len(skb);
	/* Is the slot empty? */
	if (slot->qlen == 0) {
		q->ht[slot->hash] = SFQ_EMPTY_SLOT;
		next_a = slot->next;
		if (a == next_a) {
			q->tail = NULL; /* no more active slots */
			return skb;
		}
		q->tail->next = next_a;
	} else {
		slot->allot -= SFQ_ALLOT_SIZE(qdisc_pkt_len(skb));
	}
	return skb;
}
Ejemplo n.º 4
0
/*
 * When q->perturbation is changed, we rehash all queued skbs
 * to avoid OOO (Out Of Order) effects.
 * We dont use sfq_dequeue()/sfq_enqueue() because we dont want to change
 * counters.
 */
static void sfq_rehash(struct Qdisc *sch)
{
	struct sfq_sched_data *q = qdisc_priv(sch);
	struct sk_buff *skb;
	int i;
	struct sfq_slot *slot;
	struct sk_buff_head list;
	int dropped = 0;

	__skb_queue_head_init(&list);

	for (i = 0; i < q->maxflows; i++) {
		slot = &q->slots[i];
		if (!slot->qlen)
			continue;
		while (slot->qlen) {
			skb = slot_dequeue_head(slot);
			sfq_dec(q, i);
			__skb_queue_tail(&list, skb);
		}
		slot->backlog = 0;
		red_set_vars(&slot->vars);
		q->ht[slot->hash] = SFQ_EMPTY_SLOT;
	}
	q->tail = NULL;

	while ((skb = __skb_dequeue(&list)) != NULL) {
		unsigned int hash = sfq_hash(q, skb);
		sfq_index x = q->ht[hash];

		slot = &q->slots[x];
		if (x == SFQ_EMPTY_SLOT) {
			x = q->dep[0].next; /* get a free slot */
			if (x >= SFQ_MAX_FLOWS) {
drop:				sch->qstats.backlog -= qdisc_pkt_len(skb);
				kfree_skb(skb);
				dropped++;
				continue;
			}
			q->ht[hash] = x;
			slot = &q->slots[x];
			slot->hash = hash;
		}
		if (slot->qlen >= q->maxdepth)
			goto drop;
		slot_queue_add(slot, skb);
		if (q->red_parms)
			slot->vars.qavg = red_calc_qavg(q->red_parms,
							&slot->vars,
							slot->backlog);
		slot->backlog += qdisc_pkt_len(skb);
		sfq_inc(q, x);
		if (slot->qlen == 1) {		/* The flow is new */
			if (q->tail == NULL) {	/* It is the first flow */
				slot->next = x;
			} else {
				slot->next = q->tail->next;
				q->tail->next = x;
			}
			q->tail = slot;
			slot->allot = q->scaled_quantum;
		}
	}
	sch->q.qlen -= dropped;
	qdisc_tree_decrease_qlen(sch, dropped);
}
Ejemplo n.º 5
0
static int
sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
	struct sfq_sched_data *q = qdisc_priv(sch);
	unsigned int hash;
	sfq_index x, qlen;
	struct sfq_slot *slot;
	int uninitialized_var(ret);
	struct sk_buff *head;
	int delta;

	hash = sfq_classify(skb, sch, &ret);
	if (hash == 0) {
		if (ret & __NET_XMIT_BYPASS)
			sch->qstats.drops++;
		kfree_skb(skb);
		return ret;
	}
	hash--;

	x = q->ht[hash];
	slot = &q->slots[x];
	if (x == SFQ_EMPTY_SLOT) {
		x = q->dep[0].next; /* get a free slot */
		if (x >= SFQ_MAX_FLOWS)
			return qdisc_drop(skb, sch);
		q->ht[hash] = x;
		slot = &q->slots[x];
		slot->hash = hash;
		slot->backlog = 0; /* should already be 0 anyway... */
		red_set_vars(&slot->vars);
		goto enqueue;
	}
	if (q->red_parms) {
		slot->vars.qavg = red_calc_qavg_no_idle_time(q->red_parms,
							&slot->vars,
							slot->backlog);
		switch (red_action(q->red_parms,
				   &slot->vars,
				   slot->vars.qavg)) {
		case RED_DONT_MARK:
			break;

		case RED_PROB_MARK:
			sch->qstats.overlimits++;
			if (sfq_prob_mark(q)) {
				/* We know we have at least one packet in queue */
				if (sfq_headdrop(q) &&
				    INET_ECN_set_ce(slot->skblist_next)) {
					q->stats.prob_mark_head++;
					break;
				}
				if (INET_ECN_set_ce(skb)) {
					q->stats.prob_mark++;
					break;
				}
			}
			q->stats.prob_drop++;
			goto congestion_drop;

		case RED_HARD_MARK:
			sch->qstats.overlimits++;
			if (sfq_hard_mark(q)) {
				/* We know we have at least one packet in queue */
				if (sfq_headdrop(q) &&
				    INET_ECN_set_ce(slot->skblist_next)) {
					q->stats.forced_mark_head++;
					break;
				}
				if (INET_ECN_set_ce(skb)) {
					q->stats.forced_mark++;
					break;
				}
			}
			q->stats.forced_drop++;
			goto congestion_drop;
		}
	}

	if (slot->qlen >= q->maxdepth) {
congestion_drop:
		if (!sfq_headdrop(q))
			return qdisc_drop(skb, sch);

		/* We know we have at least one packet in queue */
		head = slot_dequeue_head(slot);
		delta = qdisc_pkt_len(head) - qdisc_pkt_len(skb);
		sch->qstats.backlog -= delta;
		slot->backlog -= delta;
		qdisc_drop(head, sch);

		slot_queue_add(slot, skb);
		return NET_XMIT_CN;
	}

enqueue:
	sch->qstats.backlog += qdisc_pkt_len(skb);
	slot->backlog += qdisc_pkt_len(skb);
	slot_queue_add(slot, skb);
	sfq_inc(q, x);
	if (slot->qlen == 1) {		/* The flow is new */
		if (q->tail == NULL) {	/* It is the first flow */
			slot->next = x;
		} else {
			slot->next = q->tail->next;
			q->tail->next = x;
		}
		/* We put this flow at the end of our flow list.
		 * This might sound unfair for a new flow to wait after old ones,
		 * but we could endup servicing new flows only, and freeze old ones.
		 */
		q->tail = slot;
		/* We could use a bigger initial quantum for new flows */
		slot->allot = q->scaled_quantum;
	}
	if (++sch->q.qlen <= q->limit)
		return NET_XMIT_SUCCESS;

	qlen = slot->qlen;
	sfq_drop(sch);
	/* Return Congestion Notification only if we dropped a packet
	 * from this flow.
	 */
	if (qlen != slot->qlen)
		return NET_XMIT_CN;

	/* As we dropped a packet, better let upper stack know this */
	qdisc_tree_decrease_qlen(sch, 1);
	return NET_XMIT_SUCCESS;
}
Ejemplo n.º 6
0
static int
sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
	struct sfq_sched_data *q = qdisc_priv(sch);
	unsigned int hash;
	sfq_index x, qlen;
	struct sfq_slot *slot;
	int uninitialized_var(ret);
	struct sk_buff *head;
	int delta;

	hash = sfq_classify(skb, sch, &ret);
	if (hash == 0) {
		if (ret & __NET_XMIT_BYPASS)
			sch->qstats.drops++;
		kfree_skb(skb);
		return ret;
	}
	hash--;

	x = q->ht[hash];
	slot = &q->slots[x];
	if (x == SFQ_EMPTY_SLOT) {
		x = q->dep[0].next; /*                 */
		if (x >= SFQ_MAX_FLOWS)
			return qdisc_drop(skb, sch);
		q->ht[hash] = x;
		slot = &q->slots[x];
		slot->hash = hash;
		slot->backlog = 0; /*                               */
		red_set_vars(&slot->vars);
		goto enqueue;
	}
	if (q->red_parms) {
		slot->vars.qavg = red_calc_qavg_no_idle_time(q->red_parms,
							&slot->vars,
							slot->backlog);
		switch (red_action(q->red_parms,
				   &slot->vars,
				   slot->vars.qavg)) {
		case RED_DONT_MARK:
			break;

		case RED_PROB_MARK:
			sch->qstats.overlimits++;
			if (sfq_prob_mark(q)) {
				/*                                              */
				if (sfq_headdrop(q) &&
				    INET_ECN_set_ce(slot->skblist_next)) {
					q->stats.prob_mark_head++;
					break;
				}
				if (INET_ECN_set_ce(skb)) {
					q->stats.prob_mark++;
					break;
				}
			}
			q->stats.prob_drop++;
			goto congestion_drop;

		case RED_HARD_MARK:
			sch->qstats.overlimits++;
			if (sfq_hard_mark(q)) {
				/*                                              */
				if (sfq_headdrop(q) &&
				    INET_ECN_set_ce(slot->skblist_next)) {
					q->stats.forced_mark_head++;
					break;
				}
				if (INET_ECN_set_ce(skb)) {
					q->stats.forced_mark++;
					break;
				}
			}
			q->stats.forced_drop++;
			goto congestion_drop;
		}
	}

	if (slot->qlen >= q->maxdepth) {
congestion_drop:
		if (!sfq_headdrop(q))
			return qdisc_drop(skb, sch);

		/*                                              */
		head = slot_dequeue_head(slot);
		delta = qdisc_pkt_len(head) - qdisc_pkt_len(skb);
		sch->qstats.backlog -= delta;
		slot->backlog -= delta;
		qdisc_drop(head, sch);

		slot_queue_add(slot, skb);
		return NET_XMIT_CN;
	}

enqueue:
	sch->qstats.backlog += qdisc_pkt_len(skb);
	slot->backlog += qdisc_pkt_len(skb);
	slot_queue_add(slot, skb);
	sfq_inc(q, x);
	if (slot->qlen == 1) {		/*                 */
		if (q->tail == NULL) {	/*                      */
			slot->next = x;
		} else {
			slot->next = q->tail->next;
			q->tail->next = x;
		}
		/*                                              
                                                                   
                                                                      
   */
		q->tail = slot;
		/*                                                     */
		slot->allot = q->scaled_quantum;
	}
	if (++sch->q.qlen <= q->limit)
		return NET_XMIT_SUCCESS;

	qlen = slot->qlen;
	sfq_drop(sch);
	/*                                                           
                   
  */
	if (qlen != slot->qlen)
		return NET_XMIT_CN;

	/*                                                          */
	qdisc_tree_decrease_qlen(sch, 1);
	return NET_XMIT_SUCCESS;
}