2 * net/sched/sch_generic.c Generic packet scheduler routines.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 * Jamal Hadi Salim, <hadi@cyberus.ca> 990601
14 #include <linux/bitops.h>
15 #include <linux/module.h>
16 #include <linux/types.h>
17 #include <linux/kernel.h>
18 #include <linux/sched.h>
19 #include <linux/string.h>
20 #include <linux/errno.h>
21 #include <linux/netdevice.h>
22 #include <linux/skbuff.h>
23 #include <linux/rtnetlink.h>
24 #include <linux/init.h>
25 #include <linux/rcupdate.h>
26 #include <linux/list.h>
27 #include <linux/slab.h>
28 #include <net/pkt_sched.h>
31 /* Main transmission queue. */
33 /* Modifications to data participating in scheduling must be protected with
34 * qdisc_lock(qdisc) spinlock.
36 * The idea is the following:
37 * - enqueue, dequeue are serialized via qdisc root lock
38 * - ingress filtering is also serialized via qdisc root lock
39 * - updates to tree and tree walking are only done under the rtnl mutex.
42 static inline int dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q)
47 q->q.qlen++; /* it's still part of the queue */
53 static inline struct sk_buff *dequeue_skb(struct Qdisc *q)
55 struct sk_buff *skb = q->gso_skb;
58 struct net_device *dev = qdisc_dev(q);
59 struct netdev_queue *txq;
61 /* check the reason of requeuing without tx lock first */
62 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
63 if (!netif_xmit_frozen_or_stopped(txq)) {
75 static inline int handle_dev_cpu_collision(struct sk_buff *skb,
76 struct netdev_queue *dev_queue,
81 if (unlikely(dev_queue->xmit_lock_owner == smp_processor_id())) {
83 * Same CPU holding the lock. It may be a transient
84 * configuration error, when hard_start_xmit() recurses. We
85 * detect it by checking xmit owner and drop the packet when
86 * deadloop is detected. Return OK to try the next skb.
89 net_warn_ratelimited("Dead loop on netdevice %s, fix it urgently!\n",
90 dev_queue->dev->name);
94 * Another cpu is holding lock, requeue & delay xmits for
97 __this_cpu_inc(softnet_data.cpu_collision);
98 ret = dev_requeue_skb(skb, q);
105 * Transmit one skb, and handle the return status as required. Holding the
106 * __QDISC_STATE_RUNNING bit guarantees that only one CPU can execute this
109 * Returns to the caller:
110 * 0 - queue is empty or throttled.
111 * >0 - queue is not empty.
113 int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
114 struct net_device *dev, struct netdev_queue *txq,
115 spinlock_t *root_lock)
117 int ret = NETDEV_TX_BUSY;
119 /* And release qdisc */
120 spin_unlock(root_lock);
122 HARD_TX_LOCK(dev, txq, smp_processor_id());
123 if (!netif_xmit_frozen_or_stopped(txq))
124 ret = dev_hard_start_xmit(skb, dev, txq);
126 HARD_TX_UNLOCK(dev, txq);
128 spin_lock(root_lock);
130 if (dev_xmit_complete(ret)) {
131 /* Driver sent out skb successfully or skb was consumed */
133 } else if (ret == NETDEV_TX_LOCKED) {
134 /* Driver try lock failed */
135 ret = handle_dev_cpu_collision(skb, txq, q);
137 /* Driver returned NETDEV_TX_BUSY - requeue skb */
138 if (unlikely(ret != NETDEV_TX_BUSY))
139 net_warn_ratelimited("BUG %s code %d qlen %d\n",
140 dev->name, ret, q->q.qlen);
142 ret = dev_requeue_skb(skb, q);
145 if (ret && netif_xmit_frozen_or_stopped(txq))
152 * NOTE: Called under qdisc_lock(q) with locally disabled BH.
154 * __QDISC_STATE_RUNNING guarantees only one CPU can process
155 * this qdisc at a time. qdisc_lock(q) serializes queue accesses for
158 * netif_tx_lock serializes accesses to device driver.
160 * qdisc_lock(q) and netif_tx_lock are mutually exclusive,
161 * if one is grabbed, another must be free.
163 * Note, that this procedure can be called by a watchdog timer
165 * Returns to the caller:
166 * 0 - queue is empty or throttled.
167 * >0 - queue is not empty.
170 static inline int qdisc_restart(struct Qdisc *q)
172 struct netdev_queue *txq;
173 struct net_device *dev;
174 spinlock_t *root_lock;
178 skb = dequeue_skb(q);
181 WARN_ON_ONCE(skb_dst_is_noref(skb));
182 root_lock = qdisc_lock(q);
184 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
186 return sch_direct_xmit(skb, q, dev, txq, root_lock);
189 void __qdisc_run(struct Qdisc *q)
191 int quota = weight_p;
193 while (qdisc_restart(q)) {
195 * Ordered by possible occurrence: Postpone processing if
196 * 1. we've exceeded packet quota
197 * 2. another process needs the CPU;
199 if (--quota <= 0 || need_resched()) {
208 unsigned long dev_trans_start(struct net_device *dev)
210 unsigned long val, res = dev->trans_start;
213 for (i = 0; i < dev->num_tx_queues; i++) {
214 val = netdev_get_tx_queue(dev, i)->trans_start;
215 if (val && time_after(val, res))
218 dev->trans_start = res;
221 EXPORT_SYMBOL(dev_trans_start);
223 static void dev_watchdog(unsigned long arg)
225 struct net_device *dev = (struct net_device *)arg;
228 if (!qdisc_tx_is_noop(dev)) {
229 if (netif_device_present(dev) &&
230 netif_running(dev) &&
231 netif_carrier_ok(dev)) {
232 int some_queue_timedout = 0;
234 unsigned long trans_start;
236 for (i = 0; i < dev->num_tx_queues; i++) {
237 struct netdev_queue *txq;
239 txq = netdev_get_tx_queue(dev, i);
241 * old device drivers set dev->trans_start
243 trans_start = txq->trans_start ? : dev->trans_start;
244 if (netif_xmit_stopped(txq) &&
245 time_after(jiffies, (trans_start +
246 dev->watchdog_timeo))) {
247 some_queue_timedout = 1;
248 txq->trans_timeout++;
253 if (some_queue_timedout) {
254 WARN_ONCE(1, KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit queue %u timed out\n",
255 dev->name, netdev_drivername(dev), i);
256 dev->netdev_ops->ndo_tx_timeout(dev);
258 if (!mod_timer(&dev->watchdog_timer,
259 round_jiffies(jiffies +
260 dev->watchdog_timeo)))
264 netif_tx_unlock(dev);
269 void __netdev_watchdog_up(struct net_device *dev)
271 if (dev->netdev_ops->ndo_tx_timeout) {
272 if (dev->watchdog_timeo <= 0)
273 dev->watchdog_timeo = 5*HZ;
274 if (!mod_timer(&dev->watchdog_timer,
275 round_jiffies(jiffies + dev->watchdog_timeo)))
280 static void dev_watchdog_up(struct net_device *dev)
282 __netdev_watchdog_up(dev);
285 static void dev_watchdog_down(struct net_device *dev)
287 netif_tx_lock_bh(dev);
288 if (del_timer(&dev->watchdog_timer))
290 netif_tx_unlock_bh(dev);
294 * netif_carrier_on - set carrier
295 * @dev: network device
297 * Device has detected that carrier.
299 void netif_carrier_on(struct net_device *dev)
301 if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
302 if (dev->reg_state == NETREG_UNINITIALIZED)
304 linkwatch_fire_event(dev);
305 if (netif_running(dev))
306 __netdev_watchdog_up(dev);
309 EXPORT_SYMBOL(netif_carrier_on);
312 * netif_carrier_off - clear carrier
313 * @dev: network device
315 * Device has detected loss of carrier.
317 void netif_carrier_off(struct net_device *dev)
319 if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
320 if (dev->reg_state == NETREG_UNINITIALIZED)
322 linkwatch_fire_event(dev);
325 EXPORT_SYMBOL(netif_carrier_off);
328 * netif_notify_peers - notify network peers about existence of @dev
329 * @dev: network device
331 * Generate traffic such that interested network peers are aware of
332 * @dev, such as by generating a gratuitous ARP. This may be used when
333 * a device wants to inform the rest of the network about some sort of
334 * reconfiguration such as a failover event or virtual machine
337 void netif_notify_peers(struct net_device *dev)
340 call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
343 EXPORT_SYMBOL(netif_notify_peers);
345 /* "NOOP" scheduler: the best scheduler, recommended for all interfaces
346 under all circumstances. It is difficult to invent anything faster or
350 static int noop_enqueue(struct sk_buff *skb, struct Qdisc * qdisc)
356 static struct sk_buff *noop_dequeue(struct Qdisc * qdisc)
361 struct Qdisc_ops noop_qdisc_ops __read_mostly = {
364 .enqueue = noop_enqueue,
365 .dequeue = noop_dequeue,
366 .peek = noop_dequeue,
367 .owner = THIS_MODULE,
370 static struct netdev_queue noop_netdev_queue = {
371 .qdisc = &noop_qdisc,
372 .qdisc_sleeping = &noop_qdisc,
375 struct Qdisc noop_qdisc = {
376 .enqueue = noop_enqueue,
377 .dequeue = noop_dequeue,
378 .flags = TCQ_F_BUILTIN,
379 .ops = &noop_qdisc_ops,
380 .list = LIST_HEAD_INIT(noop_qdisc.list),
381 .q.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock),
382 .dev_queue = &noop_netdev_queue,
383 .busylock = __SPIN_LOCK_UNLOCKED(noop_qdisc.busylock),
385 EXPORT_SYMBOL(noop_qdisc);
387 static struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
390 .enqueue = noop_enqueue,
391 .dequeue = noop_dequeue,
392 .peek = noop_dequeue,
393 .owner = THIS_MODULE,
396 static struct Qdisc noqueue_qdisc;
397 static struct netdev_queue noqueue_netdev_queue = {
398 .qdisc = &noqueue_qdisc,
399 .qdisc_sleeping = &noqueue_qdisc,
402 static struct Qdisc noqueue_qdisc = {
404 .dequeue = noop_dequeue,
405 .flags = TCQ_F_BUILTIN,
406 .ops = &noqueue_qdisc_ops,
407 .list = LIST_HEAD_INIT(noqueue_qdisc.list),
408 .q.lock = __SPIN_LOCK_UNLOCKED(noqueue_qdisc.q.lock),
409 .dev_queue = &noqueue_netdev_queue,
410 .busylock = __SPIN_LOCK_UNLOCKED(noqueue_qdisc.busylock),
414 static const u8 prio2band[TC_PRIO_MAX + 1] = {
415 1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1
418 /* 3-band FIFO queue: old style, but should be a bit faster than
419 generic prio+fifo combination.
422 #define PFIFO_FAST_BANDS 3
425 * Private data for a pfifo_fast scheduler containing:
426 * - queues for the three band
427 * - bitmap indicating which of the bands contain skbs
429 struct pfifo_fast_priv {
431 struct sk_buff_head q[PFIFO_FAST_BANDS];
435 * Convert a bitmap to the first band number where an skb is queued, where:
436 * bitmap=0 means there are no skbs on any band.
437 * bitmap=1 means there is an skb on band 0.
438 * bitmap=7 means there are skbs on all 3 bands, etc.
440 static const int bitmap2band[] = {-1, 0, 1, 0, 2, 0, 1, 0};
442 static inline struct sk_buff_head *band2list(struct pfifo_fast_priv *priv,
445 return priv->q + band;
448 static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc)
450 if (skb_queue_len(&qdisc->q) < qdisc_dev(qdisc)->tx_queue_len) {
451 int band = prio2band[skb->priority & TC_PRIO_MAX];
452 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
453 struct sk_buff_head *list = band2list(priv, band);
455 priv->bitmap |= (1 << band);
457 return __qdisc_enqueue_tail(skb, qdisc, list);
460 return qdisc_drop(skb, qdisc);
463 static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc)
465 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
466 int band = bitmap2band[priv->bitmap];
468 if (likely(band >= 0)) {
469 struct sk_buff_head *list = band2list(priv, band);
470 struct sk_buff *skb = __qdisc_dequeue_head(qdisc, list);
473 if (skb_queue_empty(list))
474 priv->bitmap &= ~(1 << band);
482 static struct sk_buff *pfifo_fast_peek(struct Qdisc *qdisc)
484 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
485 int band = bitmap2band[priv->bitmap];
488 struct sk_buff_head *list = band2list(priv, band);
490 return skb_peek(list);
496 static void pfifo_fast_reset(struct Qdisc *qdisc)
499 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
501 for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
502 __qdisc_reset_queue(qdisc, band2list(priv, prio));
505 qdisc->qstats.backlog = 0;
509 static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)
511 struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS };
513 memcpy(&opt.priomap, prio2band, TC_PRIO_MAX + 1);
514 if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
515 goto nla_put_failure;
522 static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt)
525 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
527 for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
528 skb_queue_head_init(band2list(priv, prio));
530 /* Can by-pass the queue discipline */
531 qdisc->flags |= TCQ_F_CAN_BYPASS;
535 struct Qdisc_ops pfifo_fast_ops __read_mostly = {
537 .priv_size = sizeof(struct pfifo_fast_priv),
538 .enqueue = pfifo_fast_enqueue,
539 .dequeue = pfifo_fast_dequeue,
540 .peek = pfifo_fast_peek,
541 .init = pfifo_fast_init,
542 .reset = pfifo_fast_reset,
543 .dump = pfifo_fast_dump,
544 .owner = THIS_MODULE,
546 EXPORT_SYMBOL(pfifo_fast_ops);
548 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
549 struct Qdisc_ops *ops)
553 unsigned int size = QDISC_ALIGN(sizeof(*sch)) + ops->priv_size;
556 p = kzalloc_node(size, GFP_KERNEL,
557 netdev_queue_numa_node_read(dev_queue));
561 sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p);
562 /* if we got non aligned memory, ask more and do alignment ourself */
565 p = kzalloc_node(size + QDISC_ALIGNTO - 1, GFP_KERNEL,
566 netdev_queue_numa_node_read(dev_queue));
569 sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p);
570 sch->padded = (char *) sch - (char *) p;
572 INIT_LIST_HEAD(&sch->list);
573 skb_queue_head_init(&sch->q);
574 spin_lock_init(&sch->busylock);
576 sch->enqueue = ops->enqueue;
577 sch->dequeue = ops->dequeue;
578 sch->dev_queue = dev_queue;
579 dev_hold(qdisc_dev(sch));
580 atomic_set(&sch->refcnt, 1);
587 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
588 struct Qdisc_ops *ops, unsigned int parentid)
592 sch = qdisc_alloc(dev_queue, ops);
595 sch->parent = parentid;
597 if (!ops->init || ops->init(sch, NULL) == 0)
604 EXPORT_SYMBOL(qdisc_create_dflt);
606 /* Under qdisc_lock(qdisc) and BH! */
608 void qdisc_reset(struct Qdisc *qdisc)
610 const struct Qdisc_ops *ops = qdisc->ops;
615 if (qdisc->gso_skb) {
616 kfree_skb(qdisc->gso_skb);
617 qdisc->gso_skb = NULL;
621 EXPORT_SYMBOL(qdisc_reset);
623 static void qdisc_rcu_free(struct rcu_head *head)
625 struct Qdisc *qdisc = container_of(head, struct Qdisc, rcu_head);
627 kfree((char *) qdisc - qdisc->padded);
630 void qdisc_destroy(struct Qdisc *qdisc)
632 const struct Qdisc_ops *ops = qdisc->ops;
634 if (qdisc->flags & TCQ_F_BUILTIN ||
635 !atomic_dec_and_test(&qdisc->refcnt))
638 #ifdef CONFIG_NET_SCHED
639 qdisc_list_del(qdisc);
641 qdisc_put_stab(rtnl_dereference(qdisc->stab));
643 gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est);
649 module_put(ops->owner);
650 dev_put(qdisc_dev(qdisc));
652 kfree_skb(qdisc->gso_skb);
654 * gen_estimator est_timer() might access qdisc->q.lock,
655 * wait a RCU grace period before freeing qdisc.
657 call_rcu(&qdisc->rcu_head, qdisc_rcu_free);
659 EXPORT_SYMBOL(qdisc_destroy);
661 /* Attach toplevel qdisc to device queue. */
662 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
665 struct Qdisc *oqdisc = dev_queue->qdisc_sleeping;
666 spinlock_t *root_lock;
668 root_lock = qdisc_lock(oqdisc);
669 spin_lock_bh(root_lock);
671 /* Prune old scheduler */
672 if (oqdisc && atomic_read(&oqdisc->refcnt) <= 1)
675 /* ... and graft new one */
678 dev_queue->qdisc_sleeping = qdisc;
679 rcu_assign_pointer(dev_queue->qdisc, &noop_qdisc);
681 spin_unlock_bh(root_lock);
685 EXPORT_SYMBOL(dev_graft_qdisc);
687 static void attach_one_default_qdisc(struct net_device *dev,
688 struct netdev_queue *dev_queue,
691 struct Qdisc *qdisc = &noqueue_qdisc;
693 if (dev->tx_queue_len) {
694 qdisc = qdisc_create_dflt(dev_queue,
695 &pfifo_fast_ops, TC_H_ROOT);
697 netdev_info(dev, "activation failed\n");
701 dev_queue->qdisc_sleeping = qdisc;
704 static void attach_default_qdiscs(struct net_device *dev)
706 struct netdev_queue *txq;
709 txq = netdev_get_tx_queue(dev, 0);
711 if (!netif_is_multiqueue(dev) || dev->tx_queue_len == 0) {
712 netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL);
713 dev->qdisc = txq->qdisc_sleeping;
714 atomic_inc(&dev->qdisc->refcnt);
716 qdisc = qdisc_create_dflt(txq, &mq_qdisc_ops, TC_H_ROOT);
718 qdisc->ops->attach(qdisc);
724 static void transition_one_qdisc(struct net_device *dev,
725 struct netdev_queue *dev_queue,
726 void *_need_watchdog)
728 struct Qdisc *new_qdisc = dev_queue->qdisc_sleeping;
729 int *need_watchdog_p = _need_watchdog;
731 if (!(new_qdisc->flags & TCQ_F_BUILTIN))
732 clear_bit(__QDISC_STATE_DEACTIVATED, &new_qdisc->state);
734 rcu_assign_pointer(dev_queue->qdisc, new_qdisc);
735 if (need_watchdog_p && new_qdisc != &noqueue_qdisc) {
736 dev_queue->trans_start = 0;
737 *need_watchdog_p = 1;
741 void dev_activate(struct net_device *dev)
745 /* No queueing discipline is attached to device;
746 create default one i.e. pfifo_fast for devices,
747 which need queueing and noqueue_qdisc for
751 if (dev->qdisc == &noop_qdisc)
752 attach_default_qdiscs(dev);
754 if (!netif_carrier_ok(dev))
755 /* Delay activation until next carrier-on event */
759 netdev_for_each_tx_queue(dev, transition_one_qdisc, &need_watchdog);
760 if (dev_ingress_queue(dev))
761 transition_one_qdisc(dev, dev_ingress_queue(dev), NULL);
764 dev->trans_start = jiffies;
765 dev_watchdog_up(dev);
768 EXPORT_SYMBOL(dev_activate);
770 static void dev_deactivate_queue(struct net_device *dev,
771 struct netdev_queue *dev_queue,
772 void *_qdisc_default)
774 struct Qdisc *qdisc_default = _qdisc_default;
777 qdisc = dev_queue->qdisc;
779 spin_lock_bh(qdisc_lock(qdisc));
781 if (!(qdisc->flags & TCQ_F_BUILTIN))
782 set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state);
784 rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
787 spin_unlock_bh(qdisc_lock(qdisc));
791 static bool some_qdisc_is_busy(struct net_device *dev)
795 for (i = 0; i < dev->num_tx_queues; i++) {
796 struct netdev_queue *dev_queue;
797 spinlock_t *root_lock;
801 dev_queue = netdev_get_tx_queue(dev, i);
802 q = dev_queue->qdisc_sleeping;
803 root_lock = qdisc_lock(q);
805 spin_lock_bh(root_lock);
807 val = (qdisc_is_running(q) ||
808 test_bit(__QDISC_STATE_SCHED, &q->state));
810 spin_unlock_bh(root_lock);
819 * dev_deactivate_many - deactivate transmissions on several devices
820 * @head: list of devices to deactivate
822 * This function returns only when all outstanding transmissions
823 * have completed, unless all devices are in dismantle phase.
825 void dev_deactivate_many(struct list_head *head)
827 struct net_device *dev;
828 bool sync_needed = false;
830 list_for_each_entry(dev, head, unreg_list) {
831 netdev_for_each_tx_queue(dev, dev_deactivate_queue,
833 if (dev_ingress_queue(dev))
834 dev_deactivate_queue(dev, dev_ingress_queue(dev),
837 dev_watchdog_down(dev);
838 sync_needed |= !dev->dismantle;
841 /* Wait for outstanding qdisc-less dev_queue_xmit calls.
842 * This is avoided if all devices are in dismantle phase :
843 * Caller will call synchronize_net() for us
848 /* Wait for outstanding qdisc_run calls. */
849 list_for_each_entry(dev, head, unreg_list)
850 while (some_qdisc_is_busy(dev))
854 void dev_deactivate(struct net_device *dev)
858 list_add(&dev->unreg_list, &single);
859 dev_deactivate_many(&single);
862 EXPORT_SYMBOL(dev_deactivate);
864 static void dev_init_scheduler_queue(struct net_device *dev,
865 struct netdev_queue *dev_queue,
868 struct Qdisc *qdisc = _qdisc;
870 dev_queue->qdisc = qdisc;
871 dev_queue->qdisc_sleeping = qdisc;
874 void dev_init_scheduler(struct net_device *dev)
876 dev->qdisc = &noop_qdisc;
877 netdev_for_each_tx_queue(dev, dev_init_scheduler_queue, &noop_qdisc);
878 if (dev_ingress_queue(dev))
879 dev_init_scheduler_queue(dev, dev_ingress_queue(dev), &noop_qdisc);
881 setup_timer(&dev->watchdog_timer, dev_watchdog, (unsigned long)dev);
884 static void shutdown_scheduler_queue(struct net_device *dev,
885 struct netdev_queue *dev_queue,
886 void *_qdisc_default)
888 struct Qdisc *qdisc = dev_queue->qdisc_sleeping;
889 struct Qdisc *qdisc_default = _qdisc_default;
892 rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
893 dev_queue->qdisc_sleeping = qdisc_default;
895 qdisc_destroy(qdisc);
899 void dev_shutdown(struct net_device *dev)
901 netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc);
902 if (dev_ingress_queue(dev))
903 shutdown_scheduler_queue(dev, dev_ingress_queue(dev), &noop_qdisc);
904 qdisc_destroy(dev->qdisc);
905 dev->qdisc = &noop_qdisc;
907 WARN_ON(timer_pending(&dev->watchdog_timer));