Commit a0c80b80 authored by David S. Miller's avatar David S. Miller
Browse files

pkt_sched: Make default qdisc nonshared-multiqueue safe. 



Instead of 'pfifo_fast' we have just plain 'fifo_fast'.
No priority queues, just a straight FIFO.

This is necessary in order to legally have a seperate
qdisc per queue in multi-TX-queue setups, and thus get
full parallelization.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 93245dd6

net/sched/sch_generic.c

+22 −77
Original line number Diff line number Diff line
@@ -349,99 +349,44 @@ static struct Qdisc noqueue_qdisc = { 
};





static const u8 prio2band[TC_PRIO_MAX+1] =

	{ 1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1 };



/* 3-band FIFO queue: old style, but should be a bit faster than

   generic prio+fifo combination.

 */



#define PFIFO_FAST_BANDS 3



static inline struct sk_buff_head *prio2list(struct sk_buff *skb,

					     struct Qdisc *qdisc)

{

	struct sk_buff_head *list = qdisc_priv(qdisc);

	return list + prio2band[skb->priority & TC_PRIO_MAX];

}



static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc* qdisc)

static int fifo_fast_enqueue(struct sk_buff *skb, struct Qdisc* qdisc)

{

	struct sk_buff_head *list = prio2list(skb, qdisc);

	struct sk_buff_head *list = &qdisc->q;



	if (skb_queue_len(list) < qdisc_dev(qdisc)->tx_queue_len) {

		qdisc->q.qlen++;

	if (skb_queue_len(list) < qdisc_dev(qdisc)->tx_queue_len)

		return __qdisc_enqueue_tail(skb, qdisc, list);

	}



	return qdisc_drop(skb, qdisc);

}



static struct sk_buff *pfifo_fast_dequeue(struct Qdisc* qdisc)

static struct sk_buff *fifo_fast_dequeue(struct Qdisc* qdisc)

{

	int prio;

	struct sk_buff_head *list = qdisc_priv(qdisc);

	struct sk_buff_head *list = &qdisc->q;



	for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {

		if (!skb_queue_empty(list + prio)) {

			qdisc->q.qlen--;

			return __qdisc_dequeue_head(qdisc, list + prio);

		}

	}

	if (!skb_queue_empty(list))

		return __qdisc_dequeue_head(qdisc, list);



	return NULL;

}



static int pfifo_fast_requeue(struct sk_buff *skb, struct Qdisc* qdisc)

static int fifo_fast_requeue(struct sk_buff *skb, struct Qdisc* qdisc)

{

	qdisc->q.qlen++;

	return __qdisc_requeue(skb, qdisc, prio2list(skb, qdisc));

	return __qdisc_requeue(skb, qdisc, &qdisc->q);

}



static void pfifo_fast_reset(struct Qdisc* qdisc)

static void fifo_fast_reset(struct Qdisc* qdisc)

{

	int prio;

	struct sk_buff_head *list = qdisc_priv(qdisc);



	for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)

		__qdisc_reset_queue(qdisc, list + prio);



	__qdisc_reset_queue(qdisc, &qdisc->q);

	qdisc->qstats.backlog = 0;

	qdisc->q.qlen = 0;

}



static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)

{

	struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS };



	memcpy(&opt.priomap, prio2band, TC_PRIO_MAX+1);

	NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);

	return skb->len;



nla_put_failure:

	return -1;

}



static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt)

{

	int prio;

	struct sk_buff_head *list = qdisc_priv(qdisc);



	for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)

		skb_queue_head_init(list + prio);



	return 0;

}



static struct Qdisc_ops pfifo_fast_ops __read_mostly = {

	.id		=	"pfifo_fast",

	.priv_size	=	PFIFO_FAST_BANDS * sizeof(struct sk_buff_head),

	.enqueue	=	pfifo_fast_enqueue,

	.dequeue	=	pfifo_fast_dequeue,

	.requeue	=	pfifo_fast_requeue,

	.init		=	pfifo_fast_init,

	.reset		=	pfifo_fast_reset,

	.dump		=	pfifo_fast_dump,

static struct Qdisc_ops fifo_fast_ops __read_mostly = {

	.id		=	"fifo_fast",

	.priv_size	=	0,

	.enqueue	=	fifo_fast_enqueue,

	.dequeue	=	fifo_fast_dequeue,

	.requeue	=	fifo_fast_requeue,

	.reset		=	fifo_fast_reset,

	.owner		=	THIS_MODULE,

};
@@ -570,7 +515,7 @@ static void attach_one_default_qdisc(struct net_device *dev, 


	if (dev->tx_queue_len) {

		qdisc = qdisc_create_dflt(dev, dev_queue,

					  &pfifo_fast_ops, TC_H_ROOT);

					  &fifo_fast_ops, TC_H_ROOT);

		if (!qdisc) {

			printk(KERN_INFO "%s: activation failed\n", dev->name);

			return;
@@ -601,9 +546,9 @@ void dev_activate(struct net_device *dev) 
	int need_watchdog;



	/* No queueing discipline is attached to device;

	   create default one i.e. pfifo_fast for devices,

	   which need queueing and noqueue_qdisc for

	   virtual interfaces

	 * create default one i.e. fifo_fast for devices,

	 * which need queueing and noqueue_qdisc for

	 * virtual interfaces.

	 */



	if (dev_all_qdisc_sleeping_noop(dev))

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