/* * net/sched/sch_generic.c Generic packet scheduler routines. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> * Jamal Hadi Salim, <hadi@cyberus.ca> 990601 * - Ingress support */ #include <linux/bitops.h> #include <linux/module.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/sched.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/netdevice.h> #include <linux/skbuff.h> #include <linux/rtnetlink.h> #include <linux/init.h> #include <linux/rcupdate.h> #include <linux/list.h> #include <linux/slab.h> #include <net/pkt_sched.h> #include <net/dst.h> /* Main transmission queue. */ /* Modifications to data participating in scheduling must be protected with * qdisc_lock(qdisc) spinlock. * * The idea is the following: * - enqueue, dequeue are serialized via qdisc root lock * - ingress filtering is also serialized via qdisc root lock * - updates to tree and tree walking are only done under the rtnl mutex. */ static inline int dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q) { skb_dst_force(skb); q->gso_skb = skb; q->qstats.requeues++; q->q.qlen++; /* it's still part of the queue */ __netif_schedule(q); return 0; } static inline struct sk_buff *dequeue_skb(struct Qdisc *q) { struct sk_buff *skb = q->gso_skb; if (unlikely(skb)) { struct net_device *dev = qdisc_dev(q); struct netdev_queue *txq; /* check the reason of requeuing without tx lock first */ txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); if (!netif_tx_queue_frozen_or_stopped(txq)) { q->gso_skb = NULL; q->q.qlen--; } else skb = NULL; } else { skb = q->dequeue(q); } return skb; } static inline int handle_dev_cpu_collision(struct sk_buff *skb, struct netdev_queue *dev_queue, struct Qdisc *q) { int ret; if (unlikely(dev_queue->xmit_lock_owner == smp_processor_id())) { /* * Same CPU holding the lock. It may be a transient * configuration error, when hard_start_xmit() recurses. We * detect it by checking xmit owner and drop the packet when * deadloop is detected. Return OK to try the next skb. */ kfree_skb(skb); if (net_ratelimit()) pr_warning("Dead loop on netdevice %s, fix it urgently!\n", dev_queue->dev->name); ret = qdisc_qlen(q); } else { /* * Another cpu is holding lock, requeue & delay xmits for * some time. */ __this_cpu_inc(softnet_data.cpu_collision); ret = dev_requeue_skb(skb, q); } return ret; } /* * Transmit one skb, and handle the return status as required. Holding the * __QDISC_STATE_RUNNING bit guarantees that only one CPU can execute this * function. * * Returns to the caller: * 0 - queue is empty or throttled. * >0 - queue is not empty. */ int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q, struct net_device *dev, struct netdev_queue *txq, spinlock_t *root_lock) { int ret = NETDEV_TX_BUSY; /* And release qdisc */ spin_unlock(root_lock); HARD_TX_LOCK(dev, txq, smp_processor_id()); if (!netif_tx_queue_frozen_or_stopped(txq)) ret = dev_hard_start_xmit(skb, dev, txq); HARD_TX_UNLOCK(dev, txq); spin_lock(root_lock); if (dev_xmit_complete(ret)) { /* Driver sent out skb successfully or skb was consumed */ ret = qdisc_qlen(q); } else if (ret == NETDEV_TX_LOCKED) { /* Driver try lock failed */ ret = handle_dev_cpu_collision(skb, txq, q); } else { /* Driver returned NETDEV_TX_BUSY - requeue skb */ if (unlikely (ret != NETDEV_TX_BUSY && net_ratelimit())) pr_warning("BUG %s code %d qlen %d\n", dev->name, ret, q->q.qlen); ret = dev_requeue_skb(skb, q); } if (ret && netif_tx_queue_frozen_or_stopped(txq)) ret = 0; return ret; } /* * NOTE: Called under qdisc_lock(q) with locally disabled BH. * * __QDISC_STATE_RUNNING guarantees only one CPU can process * this qdisc at a time. qdisc_lock(q) serializes queue accesses for * this queue. * * netif_tx_lock serializes accesses to device driver. * * qdisc_lock(q) and netif_tx_lock are mutually exclusive, * if one is grabbed, another must be free. * * Note, that this procedure can be called by a watchdog timer * * Returns to the caller: * 0 - queue is empty or throttled. * >0 - queue is not empty. * */ static inline int qdisc_restart(struct Qdisc *q) { struct netdev_queue *txq; struct net_device *dev; spinlock_t *root_lock; struct sk_buff *skb; /* Dequeue packet */ skb = dequeue_skb(q); if (unlikely(!skb)) return 0; WARN_ON_ONCE(skb_dst_is_noref(skb)); root_lock = qdisc_lock(q); dev = qdisc_dev(q); txq = netdev_get_tx_queue(dev, skb_get_queue_mapping(skb)); return sch_direct_xmit(skb, q, dev, txq, root_lock); } void __qdisc_run(struct Qdisc *q) { int quota = weight_p; while (qdisc_restart(q)) { /* * Ordered by possible occurrence: Postpone processing if * 1. we've exceeded packet quota * 2. another process needs the CPU; */ if (--quota <= 0 || need_resched()) { __netif_schedule(q); break; } } qdisc_run_end(q); } unsigned long dev_trans_start(struct net_device *dev) { unsigned long val, res = dev->trans_start; unsigned int i; for (i = 0; i < dev->num_tx_queues; i++) { val = netdev_get_tx_queue(dev, i)->trans_start; if (val && time_after(val, res)) res = val; } dev->trans_start = res; return res; } EXPORT_SYMBOL(dev_trans_start); static void dev_watchdog(unsigned long arg) { struct net_device *dev = (struct net_device *)arg; netif_tx_lock(dev); if (!qdisc_tx_is_noop(dev)) { if (netif_device_present(dev) && netif_running(dev) && netif_carrier_ok(dev)) { int some_queue_timedout = 0; unsigned int i; unsigned long trans_start; for (i = 0; i < dev->num_tx_queues; i++) { struct netdev_queue *txq; txq = netdev_get_tx_queue(dev, i); /* * old device drivers set dev->trans_start */ trans_start = txq->trans_start ? : dev->trans_start; if (netif_tx_queue_stopped(txq) && time_after(jiffies, (trans_start + dev->watchdog_timeo))) { some_queue_timedout = 1; break; } } if (some_queue_timedout) { WARN_ONCE(1, KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit queue %u timed out\n", dev->name, netdev_drivername(dev), i); dev->netdev_ops->ndo_tx_timeout(dev); } if (!mod_timer(&dev->watchdog_timer, round_jiffies(jiffies + dev->watchdog_timeo))) dev_hold(dev); } } netif_tx_unlock(dev); dev_put(dev); } void __netdev_watchdog_up(struct net_device *dev) { if (dev->netdev_ops->ndo_tx_timeout) { if (dev->watchdog_timeo <= 0) dev->watchdog_timeo = 5*HZ; if (!mod_timer(&dev->watchdog_timer, round_jiffies(jiffies + dev->watchdog_timeo))) dev_hold(dev); } } static void dev_watchdog_up(struct net_device *dev) { __netdev_watchdog_up(dev); } static void dev_watchdog_down(struct net_device *dev) { netif_tx_lock_bh(dev); if (del_timer(&dev->watchdog_timer)) dev_put(dev); netif_tx_unlock_bh(dev); } /** * netif_carrier_on - set carrier * @dev: network device * * Device has detected that carrier. */ void netif_carrier_on(struct net_device *dev) { if (test_and_clear_bit(__LINK_STATE_NOCARRIER, &dev->state)) { if (dev->reg_state == NETREG_UNINITIALIZED) return; linkwatch_fire_event(dev); if (netif_running(dev)) __netdev_watchdog_up(dev); } } EXPORT_SYMBOL(netif_carrier_on); /** * netif_carrier_off - clear carrier * @dev: network device * * Device has detected loss of carrier. */ void netif_carrier_off(struct net_device *dev) { if (!test_and_set_bit(__LINK_STATE_NOCARRIER, &dev->state)) { if (dev->reg_state == NETREG_UNINITIALIZED) return; linkwatch_fire_event(dev); } } EXPORT_SYMBOL(netif_carrier_off); /** * netif_notify_peers - notify network peers about existence of @dev * @dev: network device * * Generate traffic such that interested network peers are aware of * @dev, such as by generating a gratuitous ARP. This may be used when * a device wants to inform the rest of the network about some sort of * reconfiguration such as a failover event or virtual machine * migration. */ void netif_notify_peers(struct net_device *dev) { rtnl_lock(); call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev); rtnl_unlock(); } EXPORT_SYMBOL(netif_notify_peers); /* "NOOP" scheduler: the best scheduler, recommended for all interfaces under all circumstances. It is difficult to invent anything faster or cheaper. */ static int noop_enqueue(struct sk_buff *skb, struct Qdisc * qdisc) { kfree_skb(skb); return NET_XMIT_CN; } static struct sk_buff *noop_dequeue(struct Qdisc * qdisc) { return NULL; } struct Qdisc_ops noop_qdisc_ops __read_mostly = { .id = "noop", .priv_size = 0, .enqueue = noop_enqueue, .dequeue = noop_dequeue, .peek = noop_dequeue, .owner = THIS_MODULE, }; static struct netdev_queue noop_netdev_queue = { .qdisc = &noop_qdisc, .qdisc_sleeping = &noop_qdisc, }; struct Qdisc noop_qdisc = { .enqueue = noop_enqueue, .dequeue = noop_dequeue, .flags = TCQ_F_BUILTIN, .ops = &noop_qdisc_ops, .list = LIST_HEAD_INIT(noop_qdisc.list), .q.lock = __SPIN_LOCK_UNLOCKED(noop_qdisc.q.lock), .dev_queue = &noop_netdev_queue, .busylock = __SPIN_LOCK_UNLOCKED(noop_qdisc.busylock), }; EXPORT_SYMBOL(noop_qdisc); static struct Qdisc_ops noqueue_qdisc_ops __read_mostly = { .id = "noqueue", .priv_size = 0, .enqueue = noop_enqueue, .dequeue = noop_dequeue, .peek = noop_dequeue, .owner = THIS_MODULE, }; static struct Qdisc noqueue_qdisc; static struct netdev_queue noqueue_netdev_queue = { .qdisc = &noqueue_qdisc, .qdisc_sleeping = &noqueue_qdisc, }; static struct Qdisc noqueue_qdisc = { .enqueue = NULL, .dequeue = noop_dequeue, .flags = TCQ_F_BUILTIN, .ops = &noqueue_qdisc_ops, .list = LIST_HEAD_INIT(noqueue_qdisc.list), .q.lock = __SPIN_LOCK_UNLOCKED(noqueue_qdisc.q.lock), .dev_queue = &noqueue_netdev_queue, .busylock = __SPIN_LOCK_UNLOCKED(noqueue_qdisc.busylock), }; 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 /* * Private data for a pfifo_fast scheduler containing: * - queues for the three band * - bitmap indicating which of the bands contain skbs */ struct pfifo_fast_priv { u32 bitmap; struct sk_buff_head q[PFIFO_FAST_BANDS]; }; /* * Convert a bitmap to the first band number where an skb is queued, where: * bitmap=0 means there are no skbs on any band. * bitmap=1 means there is an skb on band 0. * bitmap=7 means there are skbs on all 3 bands, etc. */ static const int bitmap2band[] = {-1, 0, 1, 0, 2, 0, 1, 0}; static inline struct sk_buff_head *band2list(struct pfifo_fast_priv *priv, int band) { return priv->q + band; } static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc) { if (skb_queue_len(&qdisc->q) < qdisc_dev(qdisc)->tx_queue_len) { int band = prio2band[skb->priority & TC_PRIO_MAX]; struct pfifo_fast_priv *priv = qdisc_priv(qdisc); struct sk_buff_head *list = band2list(priv, band); priv->bitmap |= (1 << band); qdisc->q.qlen++; return __qdisc_enqueue_tail(skb, qdisc, list); } return qdisc_drop(skb, qdisc); } static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc) { struct pfifo_fast_priv *priv = qdisc_priv(qdisc); int band = bitmap2band[priv->bitmap]; if (likely(band >= 0)) { struct sk_buff_head *list = band2list(priv, band); struct sk_buff *skb = __qdisc_dequeue_head(qdisc, list); qdisc->q.qlen--; if (skb_queue_empty(list)) priv->bitmap &= ~(1 << band); return skb; } return NULL; } static struct sk_buff *pfifo_fast_peek(struct Qdisc *qdisc) { struct pfifo_fast_priv *priv = qdisc_priv(qdisc); int band = bitmap2band[priv->bitmap]; if (band >= 0) { struct sk_buff_head *list = band2list(priv, band); return skb_peek(list); } return NULL; } static void pfifo_fast_reset(struct Qdisc *qdisc) { int prio; struct pfifo_fast_priv *priv = qdisc_priv(qdisc); for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) __qdisc_reset_queue(qdisc, band2list(priv, prio)); priv->bitmap = 0; 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 pfifo_fast_priv *priv = qdisc_priv(qdisc); for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) skb_queue_head_init(band2list(priv, prio)); /* Can by-pass the queue discipline */ qdisc->flags |= TCQ_F_CAN_BYPASS; return 0; } struct Qdisc_ops pfifo_fast_ops __read_mostly = { .id = "pfifo_fast", .priv_size = sizeof(struct pfifo_fast_priv), .enqueue = pfifo_fast_enqueue, .dequeue = pfifo_fast_dequeue, .peek = pfifo_fast_peek, .init = pfifo_fast_init, .reset = pfifo_fast_reset, .dump = pfifo_fast_dump, .owner = THIS_MODULE, }; EXPORT_SYMBOL(pfifo_fast_ops); struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, struct Qdisc_ops *ops) { void *p; struct Qdisc *sch; unsigned int size = QDISC_ALIGN(sizeof(*sch)) + ops->priv_size; int err = -ENOBUFS; p = kzalloc_node(size, GFP_KERNEL, netdev_queue_numa_node_read(dev_queue)); if (!p) goto errout; sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p); /* if we got non aligned memory, ask more and do alignment ourself */ if (sch != p) { kfree(p); p = kzalloc_node(size + QDISC_ALIGNTO - 1, GFP_KERNEL, netdev_queue_numa_node_read(dev_queue)); if (!p) goto errout; sch = (struct Qdisc *) QDISC_ALIGN((unsigned long) p); sch->padded = (char *) sch - (char *) p; } INIT_LIST_HEAD(&sch->list); skb_queue_head_init(&sch->q); spin_lock_init(&sch->busylock); sch->ops = ops; sch->enqueue = ops->enqueue; sch->dequeue = ops->dequeue; sch->dev_queue = dev_queue; dev_hold(qdisc_dev(sch)); atomic_set(&sch->refcnt, 1); return sch; errout: return ERR_PTR(err); } struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue, struct Qdisc_ops *ops, unsigned int parentid) { struct Qdisc *sch; sch = qdisc_alloc(dev_queue, ops); if (IS_ERR(sch)) goto errout; sch->parent = parentid; if (!ops->init || ops->init(sch, NULL) == 0) return sch; qdisc_destroy(sch); errout: return NULL; } EXPORT_SYMBOL(qdisc_create_dflt); /* Under qdisc_lock(qdisc) and BH! */ void qdisc_reset(struct Qdisc *qdisc) { const struct Qdisc_ops *ops = qdisc->ops; if (ops->reset) ops->reset(qdisc); if (qdisc->gso_skb) { kfree_skb(qdisc->gso_skb); qdisc->gso_skb = NULL; qdisc->q.qlen = 0; } } EXPORT_SYMBOL(qdisc_reset); static void qdisc_rcu_free(struct rcu_head *head) { struct Qdisc *qdisc = container_of(head, struct Qdisc, rcu_head); kfree((char *) qdisc - qdisc->padded); } void qdisc_destroy(struct Qdisc *qdisc) { const struct Qdisc_ops *ops = qdisc->ops; if (qdisc->flags & TCQ_F_BUILTIN || !atomic_dec_and_test(&qdisc->refcnt)) return; #ifdef CONFIG_NET_SCHED qdisc_list_del(qdisc); qdisc_put_stab(rtnl_dereference(qdisc->stab)); #endif gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est); if (ops->reset) ops->reset(qdisc); if (ops->destroy) ops->destroy(qdisc); module_put(ops->owner); dev_put(qdisc_dev(qdisc)); kfree_skb(qdisc->gso_skb); /* * gen_estimator est_timer() might access qdisc->q.lock, * wait a RCU grace period before freeing qdisc. */ call_rcu(&qdisc->rcu_head, qdisc_rcu_free); } EXPORT_SYMBOL(qdisc_destroy); /* Attach toplevel qdisc to device queue. */ struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue, struct Qdisc *qdisc) { struct Qdisc *oqdisc = dev_queue->qdisc_sleeping; spinlock_t *root_lock; root_lock = qdisc_lock(oqdisc); spin_lock_bh(root_lock); /* Prune old scheduler */ if (oqdisc && atomic_read(&oqdisc->refcnt) <= 1) qdisc_reset(oqdisc); /* ... and graft new one */ if (qdisc == NULL) qdisc = &noop_qdisc; dev_queue->qdisc_sleeping = qdisc; rcu_assign_pointer(dev_queue->qdisc, &noop_qdisc); spin_unlock_bh(root_lock); return oqdisc; } EXPORT_SYMBOL(dev_graft_qdisc); static void attach_one_default_qdisc(struct net_device *dev, struct netdev_queue *dev_queue, void *_unused) { struct Qdisc *qdisc = &noqueue_qdisc; if (dev->tx_queue_len) { qdisc = qdisc_create_dflt(dev_queue, &pfifo_fast_ops, TC_H_ROOT); if (!qdisc) { netdev_info(dev, "activation failed\n"); return; } } dev_queue->qdisc_sleeping = qdisc; } static void attach_default_qdiscs(struct net_device *dev) { struct netdev_queue *txq; struct Qdisc *qdisc; txq = netdev_get_tx_queue(dev, 0); if (!netif_is_multiqueue(dev) || dev->tx_queue_len == 0) { netdev_for_each_tx_queue(dev, attach_one_default_qdisc, NULL); dev->qdisc = txq->qdisc_sleeping; atomic_inc(&dev->qdisc->refcnt); } else { qdisc = qdisc_create_dflt(txq, &mq_qdisc_ops, TC_H_ROOT); if (qdisc) { qdisc->ops->attach(qdisc); dev->qdisc = qdisc; } } } static void transition_one_qdisc(struct net_device *dev, struct netdev_queue *dev_queue, void *_need_watchdog) { struct Qdisc *new_qdisc = dev_queue->qdisc_sleeping; int *need_watchdog_p = _need_watchdog; if (!(new_qdisc->flags & TCQ_F_BUILTIN)) clear_bit(__QDISC_STATE_DEACTIVATED, &new_qdisc->state); rcu_assign_pointer(dev_queue->qdisc, new_qdisc); if (need_watchdog_p && new_qdisc != &noqueue_qdisc) { dev_queue->trans_start = 0; *need_watchdog_p = 1; } } 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 */ if (dev->qdisc == &noop_qdisc) attach_default_qdiscs(dev); if (!netif_carrier_ok(dev)) /* Delay activation until next carrier-on event */ return; need_watchdog = 0; netdev_for_each_tx_queue(dev, transition_one_qdisc, &need_watchdog); if (dev_ingress_queue(dev)) transition_one_qdisc(dev, dev_ingress_queue(dev), NULL); if (need_watchdog) { dev->trans_start = jiffies; dev_watchdog_up(dev); } } EXPORT_SYMBOL(dev_activate); static void dev_deactivate_queue(struct net_device *dev, struct netdev_queue *dev_queue, void *_qdisc_default) { struct Qdisc *qdisc_default = _qdisc_default; struct Qdisc *qdisc; qdisc = dev_queue->qdisc; if (qdisc) { spin_lock_bh(qdisc_lock(qdisc)); if (!(qdisc->flags & TCQ_F_BUILTIN)) set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state); rcu_assign_pointer(dev_queue->qdisc, qdisc_default); qdisc_reset(qdisc); spin_unlock_bh(qdisc_lock(qdisc)); } } static bool some_qdisc_is_busy(struct net_device *dev) { unsigned int i; for (i = 0; i < dev->num_tx_queues; i++) { struct netdev_queue *dev_queue; spinlock_t *root_lock; struct Qdisc *q; int val; dev_queue = netdev_get_tx_queue(dev, i); q = dev_queue->qdisc_sleeping; root_lock = qdisc_lock(q); spin_lock_bh(root_lock); val = (qdisc_is_running(q) || test_bit(__QDISC_STATE_SCHED, &q->state)); spin_unlock_bh(root_lock); if (val) return true; } return false; } /** * dev_deactivate_many - deactivate transmissions on several devices * @head: list of devices to deactivate * * This function returns only when all outstanding transmissions * have completed, unless all devices are in dismantle phase. */ void dev_deactivate_many(struct list_head *head) { struct net_device *dev; bool sync_needed = false; list_for_each_entry(dev, head, unreg_list) { netdev_for_each_tx_queue(dev, dev_deactivate_queue, &noop_qdisc); if (dev_ingress_queue(dev)) dev_deactivate_queue(dev, dev_ingress_queue(dev), &noop_qdisc); dev_watchdog_down(dev); sync_needed |= !dev->dismantle; } /* Wait for outstanding qdisc-less dev_queue_xmit calls. * This is avoided if all devices are in dismantle phase : * Caller will call synchronize_net() for us */ if (sync_needed) synchronize_net(); /* Wait for outstanding qdisc_run calls. */ list_for_each_entry(dev, head, unreg_list) while (some_qdisc_is_busy(dev)) yield(); } void dev_deactivate(struct net_device *dev) { LIST_HEAD(single); list_add(&dev->unreg_list, &single); dev_deactivate_many(&single); list_del(&single); } EXPORT_SYMBOL(dev_deactivate); static void dev_init_scheduler_queue(struct net_device *dev, struct netdev_queue *dev_queue, void *_qdisc) { struct Qdisc *qdisc = _qdisc; dev_queue->qdisc = qdisc; dev_queue->qdisc_sleeping = qdisc; } void dev_init_scheduler(struct net_device *dev) { dev->qdisc = &noop_qdisc; netdev_for_each_tx_queue(dev, dev_init_scheduler_queue, &noop_qdisc); if (dev_ingress_queue(dev)) dev_init_scheduler_queue(dev, dev_ingress_queue(dev), &noop_qdisc); setup_timer(&dev->watchdog_timer, dev_watchdog, (unsigned long)dev); } static void shutdown_scheduler_queue(struct net_device *dev, struct netdev_queue *dev_queue, void *_qdisc_default) { struct Qdisc *qdisc = dev_queue->qdisc_sleeping; struct Qdisc *qdisc_default = _qdisc_default; if (qdisc) { rcu_assign_pointer(dev_queue->qdisc, qdisc_default); dev_queue->qdisc_sleeping = qdisc_default; qdisc_destroy(qdisc); } } void dev_shutdown(struct net_device *dev) { netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc); if (dev_ingress_queue(dev)) shutdown_scheduler_queue(dev, dev_ingress_queue(dev), &noop_qdisc); qdisc_destroy(dev->qdisc); dev->qdisc = &noop_qdisc; WARN_ON(timer_pending(&dev->watchdog_timer)); }