200-sched_esfq.patch

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+	n = q->dep[x].next;
+	p = q->dep[x].prev;
+	q->dep[p].next = n;
+	q->dep[n].prev = p;
+	d = q->qs[x].qlen;
+	if (q->max_depth < d)
+		q->max_depth = d;
+
+	esfq_link(q, x);
+}
+
+static unsigned int esfq_drop(struct Qdisc *sch)
+{
+	struct esfq_sched_data *q = qdisc_priv(sch);
+	esfq_index d = q->max_depth;
+	struct sk_buff *skb;
+	unsigned int len;
+
+	/* Queue is full! Find the longest slot and
+	   drop a packet from it */
+
+	if (d > 1) {
+		esfq_index x = q->dep[d+q->depth].next;
+		skb = q->qs[x].prev;
+		len = skb->len;
+		__skb_unlink(skb, &q->qs[x]);
+		kfree_skb(skb);
+		esfq_dec(q, x);
+		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. */
+		d = q->next[q->tail];
+		q->next[q->tail] = q->next[d];
+		q->allot[q->next[d]] += q->quantum;
+		skb = q->qs[d].prev;
+		len = skb->len;
+		__skb_unlink(skb, &q->qs[d]);
+		kfree_skb(skb);
+		esfq_dec(q, d);
+		sch->q.qlen--;
+		q->ht[q->hash[d]] = q->depth;
+		sch->qstats.drops++;
+		sch->qstats.backlog -= len;
+		return len;
+	}
+
+	return 0;
+}
+
+static int
+esfq_enqueue(struct sk_buff *skb, struct Qdisc* sch)
+{
+	struct esfq_sched_data *q = qdisc_priv(sch);
+	unsigned hash = esfq_hash(q, skb);
+	unsigned depth = q->depth;
+	esfq_index x;
+
+	x = q->ht[hash];
+	if (x == depth) {
+		q->ht[hash] = x = q->dep[depth].next;
+		q->hash[x] = hash;
+	}
+	sch->qstats.backlog += skb->len;
+	__skb_queue_tail(&q->qs[x], skb);
+	esfq_inc(q, x);
+	if (q->qs[x].qlen == 1) {		/* The flow is new */
+		if (q->tail == depth) {	/* It is the first flow */
+			q->tail = x;
+			q->next[x] = x;
+			q->allot[x] = q->quantum;
+		} else {
+			q->next[x] = q->next[q->tail];
+			q->next[q->tail] = x;
+			q->tail = x;
+		}
+	}
+	if (++sch->q.qlen < q->limit-1) {
+		sch->bstats.bytes += skb->len;
+		sch->bstats.packets++;
+		return 0;
+	}
+
+	esfq_drop(sch);
+	return NET_XMIT_CN;
+}
+
+static int
+esfq_requeue(struct sk_buff *skb, struct Qdisc* sch)
+{
+	struct esfq_sched_data *q = qdisc_priv(sch);
+	unsigned hash = esfq_hash(q, skb);
+	unsigned depth = q->depth;
+	esfq_index x;
+
+	x = q->ht[hash];
+	if (x == depth) {
+		q->ht[hash] = x = q->dep[depth].next;
+		q->hash[x] = hash;
+	}
+	sch->qstats.backlog += skb->len;
+	__skb_queue_head(&q->qs[x], skb);
+	esfq_inc(q, x);
+	if (q->qs[x].qlen == 1) {		/* The flow is new */
+		if (q->tail == depth) {	/* It is the first flow */
+			q->tail = x;
+			q->next[x] = x;
+			q->allot[x] = q->quantum;
+		} else {
+			q->next[x] = q->next[q->tail];
+			q->next[q->tail] = x;
+			q->tail = x;
+		}
+	}
+	if (++sch->q.qlen < q->limit - 1) {
+		sch->qstats.requeues++;
+		return 0;
+	}
+
+	sch->qstats.drops++;
+	esfq_drop(sch);
+	return NET_XMIT_CN;
+}
+
+
+
+
+static struct sk_buff *
+esfq_dequeue(struct Qdisc* sch)
+{
+	struct esfq_sched_data *q = qdisc_priv(sch);
+	struct sk_buff *skb;
+	unsigned depth = q->depth;
+	esfq_index a, old_a;
+
+	/* No active slots */
+	if (q->tail == depth)
+		return NULL;
+	
+	a = old_a = q->next[q->tail];
+	
+	/* Grab packet */
+	skb = __skb_dequeue(&q->qs[a]);
+	esfq_dec(q, a);
+	sch->q.qlen--;
+	sch->qstats.backlog -= skb->len;
+	
+	/* Is the slot empty? */
+	if (q->qs[a].qlen == 0) {
+		q->ht[q->hash[a]] = depth;
+		a = q->next[a];
+		if (a == old_a) {
+			q->tail = depth;
+			return skb;
+		}
+		q->next[q->tail] = a;
+		q->allot[a] += q->quantum;
+	} else if ((q->allot[a] -= skb->len) <= 0) {
+		q->tail = a;
+		a = q->next[a];
+		q->allot[a] += q->quantum;
+	}
+	
+	return skb;
+}
+
+static void
+esfq_reset(struct Qdisc* sch)
+{
+	struct sk_buff *skb;
+
+	while ((skb = esfq_dequeue(sch)) != NULL)
+		kfree_skb(skb);
+}
+
+static void esfq_perturbation(unsigned long arg)
+{
+	struct Qdisc *sch = (struct Qdisc*)arg;
+	struct esfq_sched_data *q = qdisc_priv(sch);
+
+	q->perturbation = net_random()&0x1F;
+
+	if (q->perturb_period) {
+		q->perturb_timer.expires = jiffies + q->perturb_period;
+		add_timer(&q->perturb_timer);
+	}
+}
+
+static int esfq_change(struct Qdisc *sch, struct rtattr *opt)
+{
+	struct esfq_sched_data *q = qdisc_priv(sch);
+	struct tc_esfq_qopt *ctl = RTA_DATA(opt);
+	int old_perturb = q->perturb_period;
+	
+	if (opt->rta_len < RTA_LENGTH(sizeof(*ctl)))
+		return -EINVAL;
+	
+	sch_tree_lock(sch);
+	q->quantum = ctl->quantum ? : psched_mtu(sch->dev);
+	q->perturb_period = ctl->perturb_period*HZ;
+//	q->hash_divisor = ctl->divisor;
+//	q->tail = q->limit = q->depth = ctl->flows;
+	
+	if (ctl->limit)
+		q->limit = min_t(u32, ctl->limit, q->depth);
+	
+	if (ctl->hash_kind) {
+		q->hash_kind = ctl->hash_kind;
+		if (q->hash_kind != TCA_SFQ_HASH_CLASSIC)
+			q->perturb_period = 0;
+	}
+	
+	// is sch_tree_lock enough to do this ?
+	while (sch->q.qlen >= q->limit-1)
+		esfq_drop(sch);
+	
+	if (old_perturb)
+		del_timer(&q->perturb_timer);
+	if (q->perturb_period) {
+		q->perturb_timer.expires = jiffies + q->perturb_period;
+		add_timer(&q->perturb_timer);
+	} else {
+		q->perturbation = 0;
+	}
+	sch_tree_unlock(sch);
+	return 0;
+}
+
+static int esfq_init(struct Qdisc *sch, struct rtattr *opt)
+{
+	struct esfq_sched_data *q = qdisc_priv(sch);
+	struct tc_esfq_qopt *ctl;
+	esfq_index p = ~0U/2;
+	int i;
+	
+	if (opt && opt->rta_len < RTA_LENGTH(sizeof(*ctl)))
+		return -EINVAL;
+
+	init_timer(&q->perturb_timer);
+	q->perturb_timer.data = (unsigned long)sch;
+	q->perturb_timer.function = esfq_perturbation;
+	q->perturbation = 0;
+	q->hash_kind = TCA_SFQ_HASH_CLASSIC;
+	q->max_depth = 0;
+	q->dyn_min = ~0U; /* maximum value for this type */
+	q->dyn_max = 0;  /* dyn_min/dyn_max will be set properly upon first packet */
+	if (opt == NULL) {
+		q->quantum = psched_mtu(sch->dev);
+		q->perturb_period = 0;
+		q->hash_divisor = 1024;
+		q->tail = q->limit = q->depth = 128;
+		
+	} else {
+		ctl = RTA_DATA(opt);
+		q->quantum = ctl->quantum ? : psched_mtu(sch->dev);
+		q->perturb_period = ctl->perturb_period*HZ;
+		q->hash_divisor = ctl->divisor ? : 1024;
+		q->tail = q->limit = q->depth = ctl->flows ? : 128;
+		
+		if ( q->depth > p - 1 )
+			return -EINVAL;
+		
+		if (ctl->limit)
+			q->limit = min_t(u32, ctl->limit, q->depth);
+		
+		if (ctl->hash_kind) {
+			q->hash_kind = ctl->hash_kind;
+		}
+		
+		if (q->perturb_period) {
+			q->perturb_timer.expires = jiffies + q->perturb_period;
+			add_timer(&q->perturb_timer);
+		}
+	}
+	
+	q->ht = kmalloc(q->hash_divisor*sizeof(esfq_index), GFP_KERNEL);
+	if (!q->ht)
+		goto err_case;
+		
+	q->dep = kmalloc((1+q->depth*2)*sizeof(struct esfq_head), GFP_KERNEL);
+	if (!q->dep)
+		goto err_case;
+	q->next = kmalloc(q->depth*sizeof(esfq_index), GFP_KERNEL);
+	if (!q->next)
+		goto err_case;
+	
+	q->allot = kmalloc(q->depth*sizeof(short), GFP_KERNEL);
+	if (!q->allot)
+		goto err_case;
+	q->hash = kmalloc(q->depth*sizeof(unsigned short), GFP_KERNEL);
+	if (!q->hash)
+		goto err_case;
+	q->qs = kmalloc(q->depth*sizeof(struct sk_buff_head), GFP_KERNEL);
+	if (!q->qs)
+		goto err_case;
+	
+	for (i=0; i< q->hash_divisor; i++)
+		q->ht[i] = q->depth;
+	for (i=0; i<q->depth; i++) {
+		skb_queue_head_init(&q->qs[i]);
+		q->dep[i+q->depth].next = i+q->depth;
+		q->dep[i+q->depth].prev = i+q->depth;
+	}
+	
+	for (i=0; i<q->depth; i++)
+		esfq_link(q, i);
+	return 0;
+err_case:
+	del_timer(&q->perturb_timer);
+	if (q->ht)
+		kfree(q->ht);
+	if (q->dep)
+		kfree(q->dep);
+	if (q->next)
+		kfree(q->next);
+	if (q->allot)
+		kfree(q->allot);
+	if (q->hash)
+		kfree(q->hash);
+	if (q->qs)
+		kfree(q->qs);
+	return -ENOBUFS;
+}
+
+static void esfq_destroy(struct Qdisc *sch)
+{
+	struct esfq_sched_data *q = qdisc_priv(sch);
+	del_timer(&q->perturb_timer);
+	if(q->ht)
+		kfree(q->ht);
+	if(q->dep)
+		kfree(q->dep);
+	if(q->next)
+		kfree(q->next);
+	if(q->allot)
+		kfree(q->allot);
+	if(q->hash)
+		kfree(q->hash);
+	if(q->qs)
+		kfree(q->qs);
+}
+
+static int esfq_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+	struct esfq_sched_data *q = qdisc_priv(sch);
+	unsigned char	 *b = skb->tail;
+	struct tc_esfq_qopt opt;
+
+	opt.quantum = q->quantum;
+	opt.perturb_period = q->perturb_period/HZ;
+
+	opt.limit = q->limit;
+	opt.divisor = q->hash_divisor;
+	opt.flows = q->depth;
+	opt.hash_kind = q->hash_kind;
+
+	RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
+
+	return skb->len;
+
+rtattr_failure:
+	skb_trim(skb, b - skb->data);
+	return -1;
+}
+
+static struct Qdisc_ops esfq_qdisc_ops =
+{
+	.next		=	NULL,
+	.cl_ops		=	NULL,
+	.id		=	"esfq",
+	.priv_size	=	sizeof(struct esfq_sched_data),
+	.enqueue	=	esfq_enqueue,
+	.dequeue	=	esfq_dequeue,
+	.requeue	=	esfq_requeue,
+	.drop		=	esfq_drop,
+	.init		=	esfq_init,
+	.reset		=	esfq_reset,
+	.destroy	=	esfq_destroy,
+	.change		=	NULL, /* esfq_change - needs more work */
+	.dump		=	esfq_dump,
+	.owner		=	THIS_MODULE,
+};
+
+static int __init esfq_module_init(void)
+{
+	return register_qdisc(&esfq_qdisc_ops);
+}
+static void __exit esfq_module_exit(void) 
+{
+	unregister_qdisc(&esfq_qdisc_ops);
+}
+module_init(esfq_module_init)
+module_exit(esfq_module_exit)
+MODULE_LICENSE("GPL");