示例#1
0
文件: sch_fq.c 项目: AK101111/linux
static struct sk_buff *fq_dequeue(struct Qdisc *sch)
{
	struct fq_sched_data *q = qdisc_priv(sch);
	u64 now = ktime_get_ns();
	struct fq_flow_head *head;
	struct sk_buff *skb;
	struct fq_flow *f;
	u32 rate;

	skb = fq_dequeue_head(sch, &q->internal);
	if (skb)
		goto out;
	fq_check_throttled(q, now);
begin:
	head = &q->new_flows;
	if (!head->first) {
		head = &q->old_flows;
		if (!head->first) {
			if (q->time_next_delayed_flow != ~0ULL)
				qdisc_watchdog_schedule_ns(&q->watchdog,
							   q->time_next_delayed_flow);
			return NULL;
		}
	}
	f = head->first;

	if (f->credit <= 0) {
		f->credit += q->quantum;
		head->first = f->next;
		fq_flow_add_tail(&q->old_flows, f);
		goto begin;
	}

	skb = f->head;
	if (unlikely(skb && now < f->time_next_packet &&
		     !skb_is_tcp_pure_ack(skb))) {
		head->first = f->next;
		fq_flow_set_throttled(q, f);
		goto begin;
	}

	skb = fq_dequeue_head(sch, f);
	if (!skb) {
		head->first = f->next;
		/* force a pass through old_flows to prevent starvation */
		if ((head == &q->new_flows) && q->old_flows.first) {
			fq_flow_add_tail(&q->old_flows, f);
		} else {
			fq_flow_set_detached(f);
			q->inactive_flows++;
		}
		goto begin;
	}
	prefetch(&skb->end);
	f->credit -= qdisc_pkt_len(skb);

	if (f->credit > 0 || !q->rate_enable)
		goto out;

	/* Do not pace locally generated ack packets */
	if (skb_is_tcp_pure_ack(skb))
		goto out;

	rate = q->flow_max_rate;
	if (skb->sk)
		rate = min(skb->sk->sk_pacing_rate, rate);

	if (rate != ~0U) {
		u32 plen = max(qdisc_pkt_len(skb), q->quantum);
		u64 len = (u64)plen * NSEC_PER_SEC;

		if (likely(rate))
			do_div(len, rate);
		/* Since socket rate can change later,
		 * clamp the delay to 1 second.
		 * Really, providers of too big packets should be fixed !
		 */
		if (unlikely(len > NSEC_PER_SEC)) {
			len = NSEC_PER_SEC;
			q->stat_pkts_too_long++;
		}

		f->time_next_packet = now + len;
	}
out:
	qdisc_bstats_update(sch, skb);
	return skb;
}
示例#2
0
static struct sk_buff *fq_dequeue(struct Qdisc *sch)
{
	struct fq_sched_data *q = qdisc_priv(sch);
	u64 now = ktime_to_ns(ktime_get());
	struct fq_flow_head *head;
	struct sk_buff *skb;
	struct fq_flow *f;
	u32 rate;

	skb = fq_dequeue_head(sch, &q->internal);
	if (skb)
		goto out;
	fq_check_throttled(q, now);
begin:
	head = &q->new_flows;
	if (!head->first) {
		head = &q->old_flows;
		if (!head->first) {
			if (q->time_next_delayed_flow != ~0ULL)
				qdisc_watchdog_schedule_ns(&q->watchdog,
							   q->time_next_delayed_flow);
			return NULL;
		}
	}
	f = head->first;

	if (f->credit <= 0) {
		f->credit += q->quantum;
		head->first = f->next;
		fq_flow_add_tail(&q->old_flows, f);
		goto begin;
	}

	if (unlikely(f->head && now < f->time_next_packet)) {
		head->first = f->next;
		fq_flow_set_throttled(q, f);
		goto begin;
	}

	skb = fq_dequeue_head(sch, f);
	if (!skb) {
		head->first = f->next;
		/* force a pass through old_flows to prevent starvation */
		if ((head == &q->new_flows) && q->old_flows.first) {
			fq_flow_add_tail(&q->old_flows, f);
		} else {
			fq_flow_set_detached(f);
			f->age = jiffies;
			q->inactive_flows++;
		}
		goto begin;
	}
	prefetch(&skb->end);
	f->time_next_packet = now;
	f->credit -= qdisc_pkt_len(skb);

	if (f->credit > 0 || !q->rate_enable)
		goto out;

	rate = q->flow_max_rate;
	if (skb->sk && skb->sk->sk_state != TCP_TIME_WAIT)
		rate = min(skb->sk->sk_pacing_rate, rate);

	if (rate != ~0U) {
		u32 plen = max(qdisc_pkt_len(skb), q->quantum);
		u64 len = (u64)plen * NSEC_PER_SEC;

		if (likely(rate))
			do_div(len, rate);
		/* Since socket rate can change later,
		 * clamp the delay to 125 ms.
		 * TODO: maybe segment the too big skb, as in commit
		 * e43ac79a4bc ("sch_tbf: segment too big GSO packets")
		 */
		if (unlikely(len > 125 * NSEC_PER_MSEC)) {
			len = 125 * NSEC_PER_MSEC;
			q->stat_pkts_too_long++;
		}

		f->time_next_packet = now + len;
	}
out:
	qdisc_bstats_update(sch, skb);
	qdisc_unthrottled(sch);
	return skb;
}
示例#3
0
文件: sch_fq.c 项目: AK101111/linux
static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q)
{
	struct rb_node **p, *parent;
	struct sock *sk = skb->sk;
	struct rb_root *root;
	struct fq_flow *f;

	/* warning: no starvation prevention... */
	if (unlikely((skb->priority & TC_PRIO_MAX) == TC_PRIO_CONTROL))
		return &q->internal;

	/* SYNACK messages are attached to a TCP_NEW_SYN_RECV request socket
	 * or a listener (SYNCOOKIE mode)
	 * 1) request sockets are not full blown,
	 *    they do not contain sk_pacing_rate
	 * 2) They are not part of a 'flow' yet
	 * 3) We do not want to rate limit them (eg SYNFLOOD attack),
	 *    especially if the listener set SO_MAX_PACING_RATE
	 * 4) We pretend they are orphaned
	 */
	if (!sk || sk_listener(sk)) {
		unsigned long hash = skb_get_hash(skb) & q->orphan_mask;

		/* By forcing low order bit to 1, we make sure to not
		 * collide with a local flow (socket pointers are word aligned)
		 */
		sk = (struct sock *)((hash << 1) | 1UL);
		skb_orphan(skb);
	}

	root = &q->fq_root[hash_32((u32)(long)sk, q->fq_trees_log)];

	if (q->flows >= (2U << q->fq_trees_log) &&
	    q->inactive_flows > q->flows/2)
		fq_gc(q, root, sk);

	p = &root->rb_node;
	parent = NULL;
	while (*p) {
		parent = *p;

		f = container_of(parent, struct fq_flow, fq_node);
		if (f->sk == sk) {
			/* socket might have been reallocated, so check
			 * if its sk_hash is the same.
			 * It not, we need to refill credit with
			 * initial quantum
			 */
			if (unlikely(skb->sk &&
				     f->socket_hash != sk->sk_hash)) {
				f->credit = q->initial_quantum;
				f->socket_hash = sk->sk_hash;
				f->time_next_packet = 0ULL;
			}
			return f;
		}
		if (f->sk > sk)
			p = &parent->rb_right;
		else
			p = &parent->rb_left;
	}

	f = kmem_cache_zalloc(fq_flow_cachep, GFP_ATOMIC | __GFP_NOWARN);
	if (unlikely(!f)) {
		q->stat_allocation_errors++;
		return &q->internal;
	}
	fq_flow_set_detached(f);
	f->sk = sk;
	if (skb->sk)
		f->socket_hash = sk->sk_hash;
	f->credit = q->initial_quantum;

	rb_link_node(&f->fq_node, parent, p);
	rb_insert_color(&f->fq_node, root);

	q->flows++;
	q->inactive_flows++;
	return f;
}
示例#4
0
static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q)
{
	struct rb_node **p, *parent;
	struct sock *sk = skb->sk;
	struct rb_root *root;
	struct fq_flow *f;
	int band;

	/* warning: no starvation prevention... */
	band = prio2band[skb->priority & TC_PRIO_MAX];
	if (unlikely(band == 0))
		return &q->internal;

	if (unlikely(!sk)) {
		/* By forcing low order bit to 1, we make sure to not
		 * collide with a local flow (socket pointers are word aligned)
		 */
		sk = (struct sock *)(skb_get_rxhash(skb) | 1L);
	}

	root = &q->fq_root[hash_32((u32)(long)sk, q->fq_trees_log)];

	if (q->flows >= (2U << q->fq_trees_log) &&
	    q->inactive_flows > q->flows/2)
		fq_gc(q, root, sk);

	p = &root->rb_node;
	parent = NULL;
	while (*p) {
		parent = *p;

		f = container_of(parent, struct fq_flow, fq_node);
		if (f->sk == sk) {
			/* socket might have been reallocated, so check
			 * if its sk_hash is the same.
			 * It not, we need to refill credit with
			 * initial quantum
			 */
			if (unlikely(skb->sk &&
				     f->socket_hash != sk->sk_hash)) {
				f->credit = q->initial_quantum;
				f->socket_hash = sk->sk_hash;
			}
			return f;
		}
		if (f->sk > sk)
			p = &parent->rb_right;
		else
			p = &parent->rb_left;
	}

	f = kmem_cache_zalloc(fq_flow_cachep, GFP_ATOMIC | __GFP_NOWARN);
	if (unlikely(!f)) {
		q->stat_allocation_errors++;
		return &q->internal;
	}
	fq_flow_set_detached(f);
	f->sk = sk;
	if (skb->sk)
		f->socket_hash = sk->sk_hash;
	f->credit = q->initial_quantum;

	rb_link_node(&f->fq_node, parent, p);
	rb_insert_color(&f->fq_node, root);

	q->flows++;
	q->inactive_flows++;
	return f;
}