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 unsigned long start_time
= jiffies
;
194 while (qdisc_restart(q
)) {
196 * Postpone processing if
197 * 1. another process needs the CPU;
198 * 2. we've been doing it for too long.
200 if (need_resched() || jiffies
!= start_time
) {
209 unsigned long dev_trans_start(struct net_device
*dev
)
211 unsigned long val
, res
= dev
->trans_start
;
214 for (i
= 0; i
< dev
->num_tx_queues
; i
++) {
215 val
= netdev_get_tx_queue(dev
, i
)->trans_start
;
216 if (val
&& time_after(val
, res
))
219 dev
->trans_start
= res
;
222 EXPORT_SYMBOL(dev_trans_start
);
224 static void dev_watchdog(unsigned long arg
)
226 struct net_device
*dev
= (struct net_device
*)arg
;
229 if (!qdisc_tx_is_noop(dev
)) {
230 if (netif_device_present(dev
) &&
231 netif_running(dev
) &&
232 netif_carrier_ok(dev
)) {
233 int some_queue_timedout
= 0;
235 unsigned long trans_start
;
237 for (i
= 0; i
< dev
->num_tx_queues
; i
++) {
238 struct netdev_queue
*txq
;
240 txq
= netdev_get_tx_queue(dev
, i
);
242 * old device drivers set dev->trans_start
244 trans_start
= txq
->trans_start
? : dev
->trans_start
;
245 if (netif_tx_queue_stopped(txq
) &&
246 time_after(jiffies
, (trans_start
+
247 dev
->watchdog_timeo
))) {
248 some_queue_timedout
= 1;
253 if (some_queue_timedout
) {
255 WARN_ONCE(1, KERN_INFO
"NETDEV WATCHDOG: %s (%s): transmit queue %u timed out\n",
256 dev
->name
, netdev_drivername(dev
, drivername
, 64), i
);
257 dev
->netdev_ops
->ndo_tx_timeout(dev
);
259 if (!mod_timer(&dev
->watchdog_timer
,
260 round_jiffies(jiffies
+
261 dev
->watchdog_timeo
)))
265 netif_tx_unlock(dev
);
270 void __netdev_watchdog_up(struct net_device
*dev
)
272 if (dev
->netdev_ops
->ndo_tx_timeout
) {
273 if (dev
->watchdog_timeo
<= 0)
274 dev
->watchdog_timeo
= 5*HZ
;
275 if (!mod_timer(&dev
->watchdog_timer
,
276 round_jiffies(jiffies
+ dev
->watchdog_timeo
)))
281 static void dev_watchdog_up(struct net_device
*dev
)
283 __netdev_watchdog_up(dev
);
286 static void dev_watchdog_down(struct net_device
*dev
)
288 netif_tx_lock_bh(dev
);
289 if (del_timer(&dev
->watchdog_timer
))
291 netif_tx_unlock_bh(dev
);
295 * netif_carrier_on - set carrier
296 * @dev: network device
298 * Device has detected that carrier.
300 void netif_carrier_on(struct net_device
*dev
)
302 if (test_and_clear_bit(__LINK_STATE_NOCARRIER
, &dev
->state
)) {
303 if (dev
->reg_state
== NETREG_UNINITIALIZED
)
305 linkwatch_fire_event(dev
);
306 if (netif_running(dev
))
307 __netdev_watchdog_up(dev
);
310 EXPORT_SYMBOL(netif_carrier_on
);
313 * netif_carrier_off - clear carrier
314 * @dev: network device
316 * Device has detected loss of carrier.
318 void netif_carrier_off(struct net_device
*dev
)
320 if (!test_and_set_bit(__LINK_STATE_NOCARRIER
, &dev
->state
)) {
321 if (dev
->reg_state
== NETREG_UNINITIALIZED
)
323 linkwatch_fire_event(dev
);
326 EXPORT_SYMBOL(netif_carrier_off
);
329 * netif_notify_peers - notify network peers about existence of @dev
330 * @dev: network device
332 * Generate traffic such that interested network peers are aware of
333 * @dev, such as by generating a gratuitous ARP. This may be used when
334 * a device wants to inform the rest of the network about some sort of
335 * reconfiguration such as a failover event or virtual machine
338 void netif_notify_peers(struct net_device
*dev
)
341 call_netdevice_notifiers(NETDEV_NOTIFY_PEERS
, dev
);
344 EXPORT_SYMBOL(netif_notify_peers
);
346 /* "NOOP" scheduler: the best scheduler, recommended for all interfaces
347 under all circumstances. It is difficult to invent anything faster or
351 static int noop_enqueue(struct sk_buff
*skb
, struct Qdisc
* qdisc
)
357 static struct sk_buff
*noop_dequeue(struct Qdisc
* qdisc
)
362 struct Qdisc_ops noop_qdisc_ops __read_mostly
= {
365 .enqueue
= noop_enqueue
,
366 .dequeue
= noop_dequeue
,
367 .peek
= noop_dequeue
,
368 .owner
= THIS_MODULE
,
371 static struct netdev_queue noop_netdev_queue
= {
372 .qdisc
= &noop_qdisc
,
373 .qdisc_sleeping
= &noop_qdisc
,
376 struct Qdisc noop_qdisc
= {
377 .enqueue
= noop_enqueue
,
378 .dequeue
= noop_dequeue
,
379 .flags
= TCQ_F_BUILTIN
,
380 .ops
= &noop_qdisc_ops
,
381 .list
= LIST_HEAD_INIT(noop_qdisc
.list
),
382 .q
.lock
= __SPIN_LOCK_UNLOCKED(noop_qdisc
.q
.lock
),
383 .dev_queue
= &noop_netdev_queue
,
384 .busylock
= __SPIN_LOCK_UNLOCKED(noop_qdisc
.busylock
),
386 EXPORT_SYMBOL(noop_qdisc
);
388 static struct Qdisc_ops noqueue_qdisc_ops __read_mostly
= {
391 .enqueue
= noop_enqueue
,
392 .dequeue
= noop_dequeue
,
393 .peek
= noop_dequeue
,
394 .owner
= THIS_MODULE
,
397 static struct Qdisc noqueue_qdisc
;
398 static struct netdev_queue noqueue_netdev_queue
= {
399 .qdisc
= &noqueue_qdisc
,
400 .qdisc_sleeping
= &noqueue_qdisc
,
403 static struct Qdisc noqueue_qdisc
= {
405 .dequeue
= noop_dequeue
,
406 .flags
= TCQ_F_BUILTIN
,
407 .ops
= &noqueue_qdisc_ops
,
408 .list
= LIST_HEAD_INIT(noqueue_qdisc
.list
),
409 .q
.lock
= __SPIN_LOCK_UNLOCKED(noqueue_qdisc
.q
.lock
),
410 .dev_queue
= &noqueue_netdev_queue
,
411 .busylock
= __SPIN_LOCK_UNLOCKED(noqueue_qdisc
.busylock
),
415 static const u8 prio2band
[TC_PRIO_MAX
+ 1] = {
416 1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1
419 /* 3-band FIFO queue: old style, but should be a bit faster than
420 generic prio+fifo combination.
423 #define PFIFO_FAST_BANDS 3
426 * Private data for a pfifo_fast scheduler containing:
427 * - queues for the three band
428 * - bitmap indicating which of the bands contain skbs
430 struct pfifo_fast_priv
{
432 struct sk_buff_head q
[PFIFO_FAST_BANDS
];
436 * Convert a bitmap to the first band number where an skb is queued, where:
437 * bitmap=0 means there are no skbs on any band.
438 * bitmap=1 means there is an skb on band 0.
439 * bitmap=7 means there are skbs on all 3 bands, etc.
441 static const int bitmap2band
[] = {-1, 0, 1, 0, 2, 0, 1, 0};
443 static inline struct sk_buff_head
*band2list(struct pfifo_fast_priv
*priv
,
446 return priv
->q
+ band
;
449 static int pfifo_fast_enqueue(struct sk_buff
*skb
, struct Qdisc
*qdisc
)
451 if (skb_queue_len(&qdisc
->q
) < qdisc_dev(qdisc
)->tx_queue_len
) {
452 int band
= prio2band
[skb
->priority
& TC_PRIO_MAX
];
453 struct pfifo_fast_priv
*priv
= qdisc_priv(qdisc
);
454 struct sk_buff_head
*list
= band2list(priv
, band
);
456 priv
->bitmap
|= (1 << band
);
458 return __qdisc_enqueue_tail(skb
, qdisc
, list
);
461 return qdisc_drop(skb
, qdisc
);
464 static struct sk_buff
*pfifo_fast_dequeue(struct Qdisc
*qdisc
)
466 struct pfifo_fast_priv
*priv
= qdisc_priv(qdisc
);
467 int band
= bitmap2band
[priv
->bitmap
];
469 if (likely(band
>= 0)) {
470 struct sk_buff_head
*list
= band2list(priv
, band
);
471 struct sk_buff
*skb
= __qdisc_dequeue_head(qdisc
, list
);
474 if (skb_queue_empty(list
))
475 priv
->bitmap
&= ~(1 << band
);
483 static struct sk_buff
*pfifo_fast_peek(struct Qdisc
*qdisc
)
485 struct pfifo_fast_priv
*priv
= qdisc_priv(qdisc
);
486 int band
= bitmap2band
[priv
->bitmap
];
489 struct sk_buff_head
*list
= band2list(priv
, band
);
491 return skb_peek(list
);
497 static void pfifo_fast_reset(struct Qdisc
*qdisc
)
500 struct pfifo_fast_priv
*priv
= qdisc_priv(qdisc
);
502 for (prio
= 0; prio
< PFIFO_FAST_BANDS
; prio
++)
503 __qdisc_reset_queue(qdisc
, band2list(priv
, prio
));
506 qdisc
->qstats
.backlog
= 0;
510 static int pfifo_fast_dump(struct Qdisc
*qdisc
, struct sk_buff
*skb
)
512 struct tc_prio_qopt opt
= { .bands
= PFIFO_FAST_BANDS
};
514 memcpy(&opt
.priomap
, prio2band
, TC_PRIO_MAX
+ 1);
515 NLA_PUT(skb
, TCA_OPTIONS
, sizeof(opt
), &opt
);
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
));