Commit c0affa19 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'sch-accurate-backlog' 



Cong Wang says:

====================
net_sched: update backlog for hierarchical qdisc's

For hierarchical qdisc like HTB, we currently only update its qlen
but leave its backlog as zero:

    qdisc htb 1: dev eth0 root refcnt 2 r2q 10 default 1 direct_packets_stat 0 ver 3.17
     Sent 172680457356 bytes 222469449 pkt (dropped 0, overlimits 123575834 requeues 0)
     backlog 0b 72p requeues 0

This patchset makes backlog as accurate as qlen.

v3: rebase and fix the n==0 case for qdisc_tree_reduce_backlog()
v2: rebase and update changelog, not code change
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents f12d33f4 bdf17661

include/net/codel.h

+4 −0
Original line number Diff line number Diff line
@@ -162,12 +162,14 @@ struct codel_vars { 
 * struct codel_stats - contains codel shared variables and stats

 * @maxpacket:	largest packet we've seen so far

 * @drop_count:	temp count of dropped packets in dequeue()

 * @drop_len:	bytes of dropped packets in dequeue()

 * ecn_mark:	number of packets we ECN marked instead of dropping

 * ce_mark:	number of packets CE marked because sojourn time was above ce_threshold

 */

struct codel_stats {

	u32		maxpacket;

	u32		drop_count;

	u32		drop_len;

	u32		ecn_mark;

	u32		ce_mark;

};
@@ -308,6 +310,7 @@ static struct sk_buff *codel_dequeue(struct Qdisc *sch, 
								  vars->rec_inv_sqrt);

					goto end;

				}

				stats->drop_len += qdisc_pkt_len(skb);

				qdisc_drop(skb, sch);

				stats->drop_count++;

				skb = dequeue_func(vars, sch);
@@ -330,6 +333,7 @@ static struct sk_buff *codel_dequeue(struct Qdisc *sch, 
		if (params->ecn && INET_ECN_set_ce(skb)) {

			stats->ecn_mark++;

		} else {

			stats->drop_len += qdisc_pkt_len(skb);

			qdisc_drop(skb, sch);

			stats->drop_count++;

include/net/sch_generic.h

+19 −1
Original line number Diff line number Diff line
@@ -396,7 +396,8 @@ struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue, 
			      struct Qdisc *qdisc);

void qdisc_reset(struct Qdisc *qdisc);

void qdisc_destroy(struct Qdisc *qdisc);

void qdisc_tree_decrease_qlen(struct Qdisc *qdisc, unsigned int n);

void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n,

			       unsigned int len);

struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,

			  const struct Qdisc_ops *ops);

struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
@@ -707,6 +708,23 @@ static inline void qdisc_reset_queue(struct Qdisc *sch) 
	sch->qstats.backlog = 0;

}



static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,

					  struct Qdisc **pold)

{

	struct Qdisc *old;



	sch_tree_lock(sch);

	old = *pold;

	*pold = new;

	if (old != NULL) {

		qdisc_tree_reduce_backlog(old, old->q.qlen, old->qstats.backlog);

		qdisc_reset(old);

	}

	sch_tree_unlock(sch);



	return old;

}



static inline unsigned int __qdisc_queue_drop(struct Qdisc *sch,

					      struct sk_buff_head *list)

{

net/sched/sch_api.c

+5 −3
Original line number Diff line number Diff line
@@ -744,14 +744,15 @@ static u32 qdisc_alloc_handle(struct net_device *dev) 
	return 0;

}



void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n)

void qdisc_tree_reduce_backlog(struct Qdisc *sch, unsigned int n,

			       unsigned int len)

{

	const struct Qdisc_class_ops *cops;

	unsigned long cl;

	u32 parentid;

	int drops;



	if (n == 0)

	if (n == 0 && len == 0)

		return;

	drops = max_t(int, n, 0);

	rcu_read_lock();
@@ -774,11 +775,12 @@ void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n) 
			cops->put(sch, cl);

		}

		sch->q.qlen -= n;

		sch->qstats.backlog -= len;

		__qdisc_qstats_drop(sch, drops);

	}

	rcu_read_unlock();

}

EXPORT_SYMBOL(qdisc_tree_decrease_qlen);

EXPORT_SYMBOL(qdisc_tree_reduce_backlog);



static void notify_and_destroy(struct net *net, struct sk_buff *skb,

			       struct nlmsghdr *n, u32 clid,

net/sched/sch_cbq.c

+4 −8
Original line number Diff line number Diff line
@@ -1624,13 +1624,8 @@ static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, 
			new->reshape_fail = cbq_reshape_fail;

#endif

	}

	sch_tree_lock(sch);

	*old = cl->q;

	cl->q = new;

	qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);

	qdisc_reset(*old);

	sch_tree_unlock(sch);



	*old = qdisc_replace(sch, new, &cl->q);

	return 0;

}
@@ -1914,7 +1909,7 @@ static int cbq_delete(struct Qdisc *sch, unsigned long arg) 
{

	struct cbq_sched_data *q = qdisc_priv(sch);

	struct cbq_class *cl = (struct cbq_class *)arg;

	unsigned int qlen;

	unsigned int qlen, backlog;



	if (cl->filters || cl->children || cl == &q->link)

		return -EBUSY;
@@ -1922,8 +1917,9 @@ static int cbq_delete(struct Qdisc *sch, unsigned long arg) 
	sch_tree_lock(sch);



	qlen = cl->q->q.qlen;

	backlog = cl->q->qstats.backlog;

	qdisc_reset(cl->q);

	qdisc_tree_decrease_qlen(cl->q, qlen);

	qdisc_tree_reduce_backlog(cl->q, qlen, backlog);



	if (cl->next_alive)

		cbq_deactivate_class(cl);

net/sched/sch_choke.c

+4 −2
Original line number Diff line number Diff line
@@ -128,8 +128,8 @@ static void choke_drop_by_idx(struct Qdisc *sch, unsigned int idx) 
		choke_zap_tail_holes(q);



	qdisc_qstats_backlog_dec(sch, skb);

	qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(skb));

	qdisc_drop(skb, sch);

	qdisc_tree_decrease_qlen(sch, 1);

	--sch->q.qlen;

}
@@ -456,6 +456,7 @@ static int choke_change(struct Qdisc *sch, struct nlattr *opt) 
		old = q->tab;

		if (old) {

			unsigned int oqlen = sch->q.qlen, tail = 0;

			unsigned dropped = 0;



			while (q->head != q->tail) {

				struct sk_buff *skb = q->tab[q->head];
@@ -467,11 +468,12 @@ static int choke_change(struct Qdisc *sch, struct nlattr *opt) 
					ntab[tail++] = skb;

					continue;

				}

				dropped += qdisc_pkt_len(skb);

				qdisc_qstats_backlog_dec(sch, skb);

				--sch->q.qlen;

				qdisc_drop(skb, sch);

			}

			qdisc_tree_decrease_qlen(sch, oqlen - sch->q.qlen);

			qdisc_tree_reduce_backlog(sch, oqlen - sch->q.qlen, dropped);

			q->head = 0;

			q->tail = tail;

		}

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