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_tx_queue_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.
90 pr_warning("Dead loop on netdevice %s, fix it urgently!\n",
91 dev_queue->dev->name);
95 * Another cpu is holding lock, requeue & delay xmits for
98 __this_cpu_inc(softnet_data.cpu_collision);
99 ret = dev_requeue_skb(skb, q);
106 * Transmit one skb, and handle the return status as required. Holding the
107 * __QDISC_STATE_RUNNING bit guarantees that only one CPU can execute this
110 * Returns to the caller:
111 * 0 - queue is empty or throttled.
112 * >0 - queue is not empty.
114 int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
115 struct net_device *dev, struct netdev_queue *txq,
116 spinlock_t *root_lock)
118 int ret = NETDEV_TX_BUSY;
120 /* And release qdisc */
121 spin_unlock(root_lock);
123 HARD_TX_LOCK(dev, txq, smp_processor_id());
124 if (!netif_tx_queue_frozen_or_stopped(txq))
125 ret = dev_hard_start_xmit(skb, dev, txq);
127 HARD_TX_UNLOCK(dev, txq);
129 spin_lock(root_lock);
131 if (dev_xmit_complete(ret)) {
132 /* Driver sent out skb successfully or skb was consumed */
134 } else if (ret == NETDEV_TX_LOCKED) {
135 /* Driver try lock failed */
136 ret = handle_dev_cpu_collision(skb, txq, q);
138 /* Driver returned NETDEV_TX_BUSY - requeue skb */
139 if (unlikely (ret != NETDEV_TX_BUSY && net_ratelimit()))
140 pr_warning("BUG %s code %d qlen %d\n",
141 dev->name, ret, q->q.qlen);
143 ret = dev_requeue_skb(skb, q);
146 if (ret && netif_tx_queue_frozen_or_stopped(txq))
153 * NOTE: Called under qdisc_lock(q) with locally disabled BH.
155 * __QDISC_STATE_RUNNING guarantees only one CPU can process
156 * this qdisc at a time. qdisc_lock(q) serializes queue accesses for
159 * netif_tx_lock serializes accesses to device driver.
161 * qdisc_lock(q) and netif_tx_lock are mutually exclusive,
162 * if one is grabbed, another must be free.
164 * Note, that this procedure can be called by a watchdog timer
166 * Returns to the caller:
167 * 0 - queue is empty or throttled.
168 * >0 - queue is not empty.
171 static inline int qdisc_restart(struct Qdisc *q)
173 struct netdev_queue *txq;
174 struct net_device *dev;
175 spinlock_t *root_lock;
179 skb = dequeue_skb(q);
182 WARN_ON_ONCE(skb_dst_is_noref(skb));
183 root_lock = qdisc_lock(q);
185 txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
187 return sch_direct_xmit(skb, q, dev, txq, root_lock);
190 void __qdisc_run(struct Qdisc *q)
192 int quota = weight_p;
195 while (qdisc_restart(q)) {
198 * Ordered by possible occurrence: Postpone processing if
199 * 1. we've exceeded packet quota
200 * 2. another process needs the CPU;
202 if (work >= quota || need_resched()) {
211 unsigned long dev_trans_start(struct net_device *dev)
213 unsigned long val, res = dev->trans_start;
216 for (i = 0; i < dev->num_tx_queues; i++) {
217 val = netdev_get_tx_queue(dev, i)->trans_start;
218 if (val && time_after(val, res))
221 dev->trans_start = res;
224 EXPORT_SYMBOL(dev_trans_start);
226 static void dev_watchdog(unsigned long arg)
228 struct net_device *dev = (struct net_device *)arg;
231 if (!qdisc_tx_is_noop(dev)) {
232 if (netif_device_present(dev) &&
233 netif_running(dev) &&
234 netif_carrier_ok(dev)) {
235 int some_queue_timedout = 0;
237 unsigned long trans_start;
239 for (i = 0; i < dev->num_tx_queues; i++) {
240 struct netdev_queue *txq;
242 txq = netdev_get_tx_queue(dev, i);
244 * old device drivers set dev->trans_start
246 trans_start = txq->trans_start ? : dev->trans_start;
247 if (netif_tx_queue_stopped(txq) &&
248 time_after(jiffies, (trans_start +
249 dev->watchdog_timeo))) {
250 some_queue_timedout = 1;
255 if (some_queue_timedout) {
256 WARN_ONCE(1, KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit queue %u timed out\n",
257 dev->name, netdev_drivername(dev), i);
258 dev->netdev_ops->ndo_tx_timeout(dev);
260 if (!mod_timer(&dev->watchdog_timer,
261 round_jiffies(jiffies +
262 dev->watchdog_timeo)))
266 netif_tx_unlock(dev);
271 void __netdev_watchdog_up(struct net_device *dev)
273 if (dev->netdev_ops->ndo_tx_timeout) {
274 if (dev->watchdog_timeo <= 0)
275 dev->watchdog_timeo = 5*HZ;
276 if (!mod_timer(&dev->watchdog_timer,
277 round_jiffies(jiffies + dev->watchdog_timeo)))
282 static void dev_watchdog_up(struct net_device *dev)
284 __netdev_watchdog_up(dev);
287 static void dev_watchdog_down(struct net_device *dev)
289 netif_tx_lock_bh(dev);
290 if (del_timer(&dev->watchdog_timer))
292 netif_tx_unlock_bh(dev);
296 * netif_carrier_on - set carrier
297 * @dev: network device
299 * Device has detected that carrier.
301 void netif_carrier_on(struct net_device *dev)
303 if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
304 if (dev->reg_state == NETREG_UNINITIALIZED)
306 linkwatch_fire_event(dev);
307 if (netif_running(dev))
308 __netdev_watchdog_up(dev);
311 EXPORT_SYMBOL(netif_carrier_on);
314 * netif_carrier_off - clear carrier
315 * @dev: network device
317 * Device has detected loss of carrier.
319 void netif_carrier_off(struct net_device *dev)
321 if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) {
322 if (dev->reg_state == NETREG_UNINITIALIZED)
324 linkwatch_fire_event(dev);
327 EXPORT_SYMBOL(netif_carrier_off);
330 * netif_notify_peers - notify network peers about existence of @dev
331 * @dev: network device
333 * Generate traffic such that interested network peers are aware of
334 * @dev, such as by generating a gratuitous ARP. This may be used when
335 * a device wants to inform the rest of the network about some sort of
336 * reconfiguration such as a failover event or virtual machine
339 void netif_notify_peers(struct net_device *dev)
342 call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
345 EXPORT_SYMBOL(netif_notify_peers);
347 /* "NOOP" scheduler: the best scheduler, recommended for all interfaces
348 under all circumstances. It is difficult to invent anything faster or
352 static int noop_enqueue(struct sk_buff *skb, struct Qdisc * qdisc)
358 static struct sk_buff *noop_dequeue(struct Qdisc * qdisc)
363 struct Qdisc_ops noop_qdisc_ops __read_mostly = {
366 .enqueue = noop_enqueue,
367 .dequeue = noop_dequeue,
368 .peek = noop_dequeue,
369 .owner = THIS_MODULE,
372 static struct netdev_queue noop_netdev_queue = {
373 .qdisc = &noop_qdisc,
374 .qdisc_sleeping = &noop_qdisc,
377 struct Qdisc noop_qdisc = {
378 .enqueue = noop_enqueue,
379 .dequeue = noop_dequeue,
380 .flags = TCQ_F_BUILTIN,
381 .ops = &noop_qdisc_ops,
382 .list = LIST_HEAD_INIT(noop_qdisc.list),
383 .q.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock),
384 .dev_queue = &noop_netdev_queue,
385 .busylock = __SPIN_LOCK_UNLOCKED(noop_qdisc.busylock),
387 EXPORT_SYMBOL(noop_qdisc);
389 static struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
392 .enqueue = noop_enqueue,
393 .dequeue = noop_dequeue,
394 .peek = noop_dequeue,
395 .owner = THIS_MODULE,
398 static struct Qdisc noqueue_qdisc;
399 static struct netdev_queue noqueue_netdev_queue = {
400 .qdisc = &noqueue_qdisc,
401 .qdisc_sleeping = &noqueue_qdisc,
404 static struct Qdisc noqueue_qdisc = {
406 .dequeue = noop_dequeue,
407 .flags = TCQ_F_BUILTIN,
408 .ops = &noqueue_qdisc_ops,
409 .list = LIST_HEAD_INIT(noqueue_qdisc.list),
410 .q.lock = __SPIN_LOCK_UNLOCKED(noqueue_qdisc.q.lock),
411 .dev_queue = &noqueue_netdev_queue,
412 .busylock = __SPIN_LOCK_UNLOCKED(noqueue_qdisc.busylock),
416 static const u8 prio2band[TC_PRIO_MAX + 1] = {
417 1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1
420 /* 3-band FIFO queue: old style, but should be a bit faster than
421 generic prio+fifo combination.
424 #define PFIFO_FAST_BANDS 3
427 * Private data for a pfifo_fast scheduler containing:
428 * - queues for the three band
429 * - bitmap indicating which of the bands contain skbs
431 struct pfifo_fast_priv {
433 struct sk_buff_head q[PFIFO_FAST_BANDS];
437 * Convert a bitmap to the first band number where an skb is queued, where:
438 * bitmap=0 means there are no skbs on any band.
439 * bitmap=1 means there is an skb on band 0.
440 * bitmap=7 means there are skbs on all 3 bands, etc.
442 static const int bitmap2band[] = {-1, 0, 1, 0, 2, 0, 1, 0};
444 static inline struct sk_buff_head *band2list(struct pfifo_fast_priv *priv,
447 return priv->q + band;
450 static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc)
452 if (skb_queue_len(&qdisc->q) < qdisc_dev(qdisc)->tx_queue_len) {
453 int band = prio2band[skb->priority & TC_PRIO_MAX];
454 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
455 struct sk_buff_head *list = band2list(priv, band);
457 priv->bitmap |= (1 << band);
459 return __qdisc_enqueue_tail(skb, qdisc, list);
462 return qdisc_drop(skb, qdisc);
465 static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc)
467 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
468 int band = bitmap2band[priv->bitmap];
470 if (likely(band >= 0)) {
471 struct sk_buff_head *list = band2list(priv, band);
472 struct sk_buff *skb = __qdisc_dequeue_head(qdisc, list);
475 if (skb_queue_empty(list))
476 priv->bitmap &= ~(1 << band);
484 static struct sk_buff *pfifo_fast_peek(struct Qdisc *qdisc)
486 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
487 int band = bitmap2band[priv->bitmap];
490 struct sk_buff_head *list = band2list(priv, band);
492 return skb_peek(list);
498 static void pfifo_fast_reset(struct Qdisc *qdisc)
501 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
503 for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
504 __qdisc_reset_queue(qdisc, band2list(priv, prio));
507 qdisc->qstats.backlog = 0;
511 static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)
513 struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS };
515 memcpy(&opt.priomap, prio2band, TC_PRIO_MAX + 1);
516 NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
523 static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt)
526 struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
528 for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
529 skb_queue_head_init(band2list(priv, prio));
531 /* Can by-pass the queue discipline */
532 qdisc->flags |= TCQ_F_CAN_BYPASS;
536 struct Qdisc_ops pfifo_fast_ops __read_mostly = {
538 .priv_size = sizeof(struct pfifo_fast_priv),
539 .enqueue = pfifo_fast_enqueue,
540 .dequeue = pfifo_fast_dequeue,
541 .peek = pfifo_fast_peek,
542 .init = pfifo_fast_init,
543 .reset = pfifo_fast_reset,
544 .dump = pfifo_fast_dump,
545 .owner = THIS_MODULE,
547 EXPORT_SYMBOL(pfifo_fast_ops);
549 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
550 struct Qdisc_ops *ops)
554 unsigned int size = QDISC_ALIGN(sizeof(*sch)) + ops->priv_size;
557 p = kzalloc_node(size, GFP_KERNEL,
558 netdev_queue_numa_node_read(dev_queue));
562 sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p);
563 /* if we got non aligned memory, ask more and do alignment ourself */
566 p = kzalloc_node(size + QDISC_ALIGNTO - 1, GFP_KERNEL,
567 netdev_queue_numa_node_read(dev_queue));
570 sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p);
571 sch->padded = (char *) sch - (char *) p;
573 INIT_LIST_HEAD(&sch->list);
574 skb_queue_head_init(&sch->q);
575 spin_lock_init(&sch->busylock);
577 sch->enqueue = ops->enqueue;
578 sch->dequeue = ops->dequeue;
579 sch->dev_queue = dev_queue;
580 dev_hold(qdisc_dev(sch));
581 atomic_set(&sch->refcnt, 1);
588 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
589 struct Qdisc_ops *ops, unsigned int parentid)
593 sch = qdisc_alloc(dev_queue, ops);
596 sch->parent = parentid;
598 if (!ops->init || ops->init(sch, NULL) == 0)
605 EXPORT_SYMBOL(qdisc_create_dflt);
607 /* Under qdisc_lock(qdisc) and BH! */
609 void qdisc_reset(struct Qdisc *qdisc)
611 const struct Qdisc_ops *ops = qdisc->ops;
616 if (qdisc->gso_skb) {
617 kfree_skb(qdisc->gso_skb);
618 qdisc->gso_skb = NULL;
622 EXPORT_SYMBOL(qdisc_reset);
624 static void qdisc_rcu_free(struct rcu_head *head)
626 struct Qdisc *qdisc = container_of(head, struct Qdisc, rcu_head);
628 kfree((char *) qdisc - qdisc->padded);
631 void qdisc_destroy(struct Qdisc *qdisc)
633 const struct Qdisc_ops *ops = qdisc->ops;
635 if (qdisc->flags & TCQ_F_BUILTIN ||
636 !atomic_dec_and_test(&qdisc->refcnt))
639 #ifdef CONFIG_NET_SCHED
640 qdisc_list_del(qdisc);
642 qdisc_put_stab(rtnl_dereference(qdisc->stab));
644 gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est);
650 module_put(ops->owner);
651 dev_put(qdisc_dev(qdisc));
653 kfree_skb(qdisc->gso_skb);
655 * gen_estimator est_timer() might access qdisc->q.lock,
656 * wait a RCU grace period before freeing qdisc.
658 call_rcu(&qdisc->rcu_head, qdisc_rcu_free);
660 EXPORT_SYMBOL(qdisc_destroy);
662 /* Attach toplevel qdisc to device queue. */
663 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
666 struct Qdisc *oqdisc = dev_queue->qdisc_sleeping;
667 spinlock_t *root_lock;
669 root_lock = qdisc_lock(oqdisc);
670 spin_lock_bh(root_lock);
672 /* Prune old scheduler */
673 if (oqdisc && atomic_read(&oqdisc->refcnt) <= 1)
676 /* ... and graft new one */
679 dev_queue->qdisc_sleeping = qdisc;
680 rcu_assign_pointer(dev_queue->qdisc, &noop_qdisc);
682 spin_unlock_bh(root_lock);
686 EXPORT_SYMBOL(dev_graft_qdisc);
688 static void attach_one_default_qdisc(struct net_device *dev,
689 struct netdev_queue *dev_queue,
692 struct Qdisc *qdisc = &noqueue_qdisc;
694 if (dev->tx_queue_len) {
695 qdisc = qdisc_create_dflt(dev_queue,
696 &pfifo_fast_ops, TC_H_ROOT);
698 netdev_info(dev, "activation failed\n");
702 dev_queue->qdisc_sleeping = qdisc;
705 static void attach_default_qdiscs(struct net_device *dev)
707 struct netdev_queue *txq;
710 txq = netdev_get_tx_queue(dev, 0);
712 if (!netif_is_multiqueue(dev) || dev->tx_queue_len == 0) {
713 netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL);
714 dev->qdisc = txq->qdisc_sleeping;
715 atomic_inc(&dev->qdisc->refcnt);
717 qdisc = qdisc_create_dflt(txq, &mq_qdisc_ops, TC_H_ROOT);
719 qdisc->ops->attach(qdisc);
725 static void transition_one_qdisc(struct net_device *dev,
726 struct netdev_queue *dev_queue,
727 void *_need_watchdog)
729 struct Qdisc *new_qdisc = dev_queue->qdisc_sleeping;
730 int *need_watchdog_p = _need_watchdog;
732 if (!(new_qdisc->flags & TCQ_F_BUILTIN))
733 clear_bit(__QDISC_STATE_DEACTIVATED, &new_qdisc->state);
735 rcu_assign_pointer(dev_queue->qdisc, new_qdisc);
736 if (need_watchdog_p && new_qdisc != &noqueue_qdisc) {
737 dev_queue->trans_start = 0;
738 *need_watchdog_p = 1;
742 void dev_activate(struct net_device *dev)
746 /* No queueing discipline is attached to device;
747 create default one i.e. pfifo_fast for devices,
748 which need queueing and noqueue_qdisc for
752 if (dev->qdisc == &noop_qdisc)
753 attach_default_qdiscs(dev);
755 if (!netif_carrier_ok(dev))
756 /* Delay activation until next carrier-on event */
760 netdev_for_each_tx_queue(dev, transition_one_qdisc, &need_watchdog);
761 if (dev_ingress_queue(dev))
762 transition_one_qdisc(dev, dev_ingress_queue(dev), NULL);
765 dev->trans_start = jiffies;
766 dev_watchdog_up(dev);
769 EXPORT_SYMBOL(dev_activate);
771 static void dev_deactivate_queue(struct net_device *dev,
772 struct netdev_queue *dev_queue,
773 void *_qdisc_default)
775 struct Qdisc *qdisc_default = _qdisc_default;
778 qdisc = dev_queue->qdisc;
780 spin_lock_bh(qdisc_lock(qdisc));
782 if (!(qdisc->flags & TCQ_F_BUILTIN))
783 set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state);
785 rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
788 spin_unlock_bh(qdisc_lock(qdisc));
792 static bool some_qdisc_is_busy(struct net_device *dev)
796 for (i = 0; i < dev->num_tx_queues; i++) {
797 struct netdev_queue *dev_queue;
798 spinlock_t *root_lock;
802 dev_queue = netdev_get_tx_queue(dev, i);
803 q = dev_queue->qdisc_sleeping;
804 root_lock = qdisc_lock(q);
806 spin_lock_bh(root_lock);
808 val = (qdisc_is_running(q) ||
809 test_bit(__QDISC_STATE_SCHED, &q->state));
811 spin_unlock_bh(root_lock);
820 * dev_deactivate_many - deactivate transmissions on several devices
821 * @head: list of devices to deactivate
823 * This function returns only when all outstanding transmissions
824 * have completed, unless all devices are in dismantle phase.
826 void dev_deactivate_many(struct list_head *head)
828 struct net_device *dev;
829 bool sync_needed = false;
831 list_for_each_entry(dev, head, unreg_list) {
832 netdev_for_each_tx_queue(dev, dev_deactivate_queue,
834 if (dev_ingress_queue(dev))
835 dev_deactivate_queue(dev, dev_ingress_queue(dev),
838 dev_watchdog_down(dev);
839 sync_needed |= !dev->dismantle;
842 /* Wait for outstanding qdisc-less dev_queue_xmit calls.
843 * This is avoided if all devices are in dismantle phase :
844 * Caller will call synchronize_net() for us
849 /* Wait for outstanding qdisc_run calls. */
850 list_for_each_entry(dev, head, unreg_list)
851 while (some_qdisc_is_busy(dev))
855 void dev_deactivate(struct net_device *dev)
859 list_add(&dev->unreg_list, &single);
860 dev_deactivate_many(&single);
863 EXPORT_SYMBOL(dev_deactivate);
865 static void dev_init_scheduler_queue(struct net_device *dev,
866 struct netdev_queue *dev_queue,
869 struct Qdisc *qdisc = _qdisc;
871 dev_queue->qdisc = qdisc;
872 dev_queue->qdisc_sleeping = qdisc;
875 void dev_init_scheduler(struct net_device *dev)
877 dev->qdisc = &noop_qdisc;
878 netdev_for_each_tx_queue(dev, dev_init_scheduler_queue, &noop_qdisc);
879 if (dev_ingress_queue(dev))
880 dev_init_scheduler_queue(dev, dev_ingress_queue(dev), &noop_qdisc);
882 setup_timer(&dev->watchdog_timer, dev_watchdog, (unsigned long)dev);
885 static void shutdown_scheduler_queue(struct net_device *dev,
886 struct netdev_queue *dev_queue,
887 void *_qdisc_default)
889 struct Qdisc *qdisc = dev_queue->qdisc_sleeping;
890 struct Qdisc *qdisc_default = _qdisc_default;
893 rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
894 dev_queue->qdisc_sleeping = qdisc_default;
896 qdisc_destroy(qdisc);
900 void dev_shutdown(struct net_device *dev)
902 netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc);
903 if (dev_ingress_queue(dev))
904 shutdown_scheduler_queue(dev, dev_ingress_queue(dev), &noop_qdisc);
905 qdisc_destroy(dev->qdisc);
906 dev->qdisc = &noop_qdisc;
908 WARN_ON(timer_pending(&dev->watchdog_timer));