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 <linux/if_vlan.h>
29 #include <net/sch_generic.h>
30 #include <net/pkt_sched.h>
33 /* Qdisc to use by default */
34 const struct Qdisc_ops
*default_qdisc_ops
= &pfifo_fast_ops
;
35 EXPORT_SYMBOL(default_qdisc_ops
);
37 /* Main transmission queue. */
39 /* Modifications to data participating in scheduling must be protected with
40 * qdisc_lock(qdisc) spinlock.
42 * The idea is the following:
43 * - enqueue, dequeue are serialized via qdisc root lock
44 * - ingress filtering is also serialized via qdisc root lock
45 * - updates to tree and tree walking are only done under the rtnl mutex.
48 static inline int dev_requeue_skb(struct sk_buff
*skb
, struct Qdisc
*q
)
53 q
->q
.qlen
++; /* it's still part of the queue */
59 static struct sk_buff
*try_bulk_dequeue_skb(struct Qdisc
*q
,
60 struct sk_buff
*head_skb
,
63 struct sk_buff
*skb
, *tail_skb
= head_skb
;
65 while (bytelimit
> 0) {
66 /* For now, don't bulk dequeue GSO (or GSO segmented) pkts */
67 if (tail_skb
->next
|| skb_is_gso(tail_skb
))
74 bytelimit
-= skb
->len
; /* covers GSO len */
75 skb
= validate_xmit_skb(skb
, qdisc_dev(q
));
79 /* "skb" can be a skb list after validate call above
80 * (GSO segmented), but it is okay to append it to
81 * current tail_skb->next, because next round will exit
82 * in-case "tail_skb->next" is a skb list.
91 /* Note that dequeue_skb can possibly return a SKB list (via skb->next).
92 * A requeued skb (via q->gso_skb) can also be a SKB list.
94 static inline struct sk_buff
*dequeue_skb(struct Qdisc
*q
)
96 struct sk_buff
*skb
= q
->gso_skb
;
97 const struct netdev_queue
*txq
= q
->dev_queue
;
100 /* check the reason of requeuing without tx lock first */
101 txq
= skb_get_tx_queue(txq
->dev
, skb
);
102 if (!netif_xmit_frozen_or_stopped(txq
)) {
108 if (!(q
->flags
& TCQ_F_ONETXQUEUE
) ||
109 !netif_xmit_frozen_or_stopped(txq
)) {
110 int bytelimit
= qdisc_avail_bulklimit(txq
);
114 bytelimit
-= skb
->len
;
115 skb
= validate_xmit_skb(skb
, qdisc_dev(q
));
117 if (skb
&& qdisc_may_bulk(q
))
118 skb
= try_bulk_dequeue_skb(q
, skb
, bytelimit
);
125 static inline int handle_dev_cpu_collision(struct sk_buff
*skb
,
126 struct netdev_queue
*dev_queue
,
131 if (unlikely(dev_queue
->xmit_lock_owner
== smp_processor_id())) {
133 * Same CPU holding the lock. It may be a transient
134 * configuration error, when hard_start_xmit() recurses. We
135 * detect it by checking xmit owner and drop the packet when
136 * deadloop is detected. Return OK to try the next skb.
139 net_warn_ratelimited("Dead loop on netdevice %s, fix it urgently!\n",
140 dev_queue
->dev
->name
);
144 * Another cpu is holding lock, requeue & delay xmits for
147 __this_cpu_inc(softnet_data
.cpu_collision
);
148 ret
= dev_requeue_skb(skb
, q
);
155 * Transmit possibly several skbs, and handle the return status as
156 * required. Holding the __QDISC___STATE_RUNNING bit guarantees that
157 * only one CPU can execute this function.
159 * Returns to the caller:
160 * 0 - queue is empty or throttled.
161 * >0 - queue is not empty.
163 int sch_direct_xmit(struct sk_buff
*skb
, struct Qdisc
*q
,
164 struct net_device
*dev
, struct netdev_queue
*txq
,
165 spinlock_t
*root_lock
)
167 int ret
= NETDEV_TX_BUSY
;
169 /* And release qdisc */
170 spin_unlock(root_lock
);
172 HARD_TX_LOCK(dev
, txq
, smp_processor_id());
173 if (!netif_xmit_frozen_or_stopped(txq
))
174 skb
= dev_hard_start_xmit(skb
, dev
, txq
, &ret
);
176 HARD_TX_UNLOCK(dev
, txq
);
178 spin_lock(root_lock
);
180 if (dev_xmit_complete(ret
)) {
181 /* Driver sent out skb successfully or skb was consumed */
183 } else if (ret
== NETDEV_TX_LOCKED
) {
184 /* Driver try lock failed */
185 ret
= handle_dev_cpu_collision(skb
, txq
, q
);
187 /* Driver returned NETDEV_TX_BUSY - requeue skb */
188 if (unlikely(ret
!= NETDEV_TX_BUSY
))
189 net_warn_ratelimited("BUG %s code %d qlen %d\n",
190 dev
->name
, ret
, q
->q
.qlen
);
192 ret
= dev_requeue_skb(skb
, q
);
195 if (ret
&& netif_xmit_frozen_or_stopped(txq
))
202 * NOTE: Called under qdisc_lock(q) with locally disabled BH.
204 * __QDISC___STATE_RUNNING guarantees only one CPU can process
205 * this qdisc at a time. qdisc_lock(q) serializes queue accesses for
208 * netif_tx_lock serializes accesses to device driver.
210 * qdisc_lock(q) and netif_tx_lock are mutually exclusive,
211 * if one is grabbed, another must be free.
213 * Note, that this procedure can be called by a watchdog timer
215 * Returns to the caller:
216 * 0 - queue is empty or throttled.
217 * >0 - queue is not empty.
220 static inline int qdisc_restart(struct Qdisc
*q
)
222 struct netdev_queue
*txq
;
223 struct net_device
*dev
;
224 spinlock_t
*root_lock
;
228 skb
= dequeue_skb(q
);
232 WARN_ON_ONCE(skb_dst_is_noref(skb
));
234 root_lock
= qdisc_lock(q
);
236 txq
= skb_get_tx_queue(dev
, skb
);
238 return sch_direct_xmit(skb
, q
, dev
, txq
, root_lock
);
241 void __qdisc_run(struct Qdisc
*q
)
243 int quota
= weight_p
;
245 while (qdisc_restart(q
)) {
247 * Ordered by possible occurrence: Postpone processing if
248 * 1. we've exceeded packet quota
249 * 2. another process needs the CPU;
251 if (--quota
<= 0 || need_resched()) {
260 unsigned long dev_trans_start(struct net_device
*dev
)
262 unsigned long val
, res
;
265 if (is_vlan_dev(dev
))
266 dev
= vlan_dev_real_dev(dev
);
267 res
= dev
->trans_start
;
268 for (i
= 0; i
< dev
->num_tx_queues
; i
++) {
269 val
= netdev_get_tx_queue(dev
, i
)->trans_start
;
270 if (val
&& time_after(val
, res
))
273 dev
->trans_start
= res
;
277 EXPORT_SYMBOL(dev_trans_start
);
279 static void dev_watchdog(unsigned long arg
)
281 struct net_device
*dev
= (struct net_device
*)arg
;
284 if (!qdisc_tx_is_noop(dev
)) {
285 if (netif_device_present(dev
) &&
286 netif_running(dev
) &&
287 netif_carrier_ok(dev
)) {
288 int some_queue_timedout
= 0;
290 unsigned long trans_start
;
292 for (i
= 0; i
< dev
->num_tx_queues
; i
++) {
293 struct netdev_queue
*txq
;
295 txq
= netdev_get_tx_queue(dev
, i
);
297 * old device drivers set dev->trans_start
299 trans_start
= txq
->trans_start
? : dev
->trans_start
;
300 if (netif_xmit_stopped(txq
) &&
301 time_after(jiffies
, (trans_start
+
302 dev
->watchdog_timeo
))) {
303 some_queue_timedout
= 1;
304 txq
->trans_timeout
++;
309 if (some_queue_timedout
) {
310 WARN_ONCE(1, KERN_INFO
"NETDEV WATCHDOG: %s (%s): transmit queue %u timed out\n",
311 dev
->name
, netdev_drivername(dev
), i
);
312 dev
->netdev_ops
->ndo_tx_timeout(dev
);
314 if (!mod_timer(&dev
->watchdog_timer
,
315 round_jiffies(jiffies
+
316 dev
->watchdog_timeo
)))
320 netif_tx_unlock(dev
);
325 void __netdev_watchdog_up(struct net_device
*dev
)
327 if (dev
->netdev_ops
->ndo_tx_timeout
) {
328 if (dev
->watchdog_timeo
<= 0)
329 dev
->watchdog_timeo
= 5*HZ
;
330 if (!mod_timer(&dev
->watchdog_timer
,
331 round_jiffies(jiffies
+ dev
->watchdog_timeo
)))
336 static void dev_watchdog_up(struct net_device
*dev
)
338 __netdev_watchdog_up(dev
);
341 static void dev_watchdog_down(struct net_device
*dev
)
343 netif_tx_lock_bh(dev
);
344 if (del_timer(&dev
->watchdog_timer
))
346 netif_tx_unlock_bh(dev
);
350 * netif_carrier_on - set carrier
351 * @dev: network device
353 * Device has detected that carrier.
355 void netif_carrier_on(struct net_device
*dev
)
357 if (test_and_clear_bit(__LINK_STATE_NOCARRIER
, &dev
->state
)) {
358 if (dev
->reg_state
== NETREG_UNINITIALIZED
)
360 atomic_inc(&dev
->carrier_changes
);
361 linkwatch_fire_event(dev
);
362 if (netif_running(dev
))
363 __netdev_watchdog_up(dev
);
366 EXPORT_SYMBOL(netif_carrier_on
);
369 * netif_carrier_off - clear carrier
370 * @dev: network device
372 * Device has detected loss of carrier.
374 void netif_carrier_off(struct net_device
*dev
)
376 if (!test_and_set_bit(__LINK_STATE_NOCARRIER
, &dev
->state
)) {
377 if (dev
->reg_state
== NETREG_UNINITIALIZED
)
379 atomic_inc(&dev
->carrier_changes
);
380 linkwatch_fire_event(dev
);
383 EXPORT_SYMBOL(netif_carrier_off
);
385 /* "NOOP" scheduler: the best scheduler, recommended for all interfaces
386 under all circumstances. It is difficult to invent anything faster or
390 static int noop_enqueue(struct sk_buff
*skb
, struct Qdisc
*qdisc
)
396 static struct sk_buff
*noop_dequeue(struct Qdisc
*qdisc
)
401 struct Qdisc_ops noop_qdisc_ops __read_mostly
= {
404 .enqueue
= noop_enqueue
,
405 .dequeue
= noop_dequeue
,
406 .peek
= noop_dequeue
,
407 .owner
= THIS_MODULE
,
410 static struct netdev_queue noop_netdev_queue
= {
411 .qdisc
= &noop_qdisc
,
412 .qdisc_sleeping
= &noop_qdisc
,
415 struct Qdisc noop_qdisc
= {
416 .enqueue
= noop_enqueue
,
417 .dequeue
= noop_dequeue
,
418 .flags
= TCQ_F_BUILTIN
,
419 .ops
= &noop_qdisc_ops
,
420 .list
= LIST_HEAD_INIT(noop_qdisc
.list
),
421 .q
.lock
= __SPIN_LOCK_UNLOCKED(noop_qdisc
.q
.lock
),
422 .dev_queue
= &noop_netdev_queue
,
423 .busylock
= __SPIN_LOCK_UNLOCKED(noop_qdisc
.busylock
),
425 EXPORT_SYMBOL(noop_qdisc
);
427 static struct Qdisc_ops noqueue_qdisc_ops __read_mostly
= {
430 .enqueue
= noop_enqueue
,
431 .dequeue
= noop_dequeue
,
432 .peek
= noop_dequeue
,
433 .owner
= THIS_MODULE
,
436 static struct Qdisc noqueue_qdisc
;
437 static struct netdev_queue noqueue_netdev_queue
= {
438 .qdisc
= &noqueue_qdisc
,
439 .qdisc_sleeping
= &noqueue_qdisc
,
442 static struct Qdisc noqueue_qdisc
= {
444 .dequeue
= noop_dequeue
,
445 .flags
= TCQ_F_BUILTIN
,
446 .ops
= &noqueue_qdisc_ops
,
447 .list
= LIST_HEAD_INIT(noqueue_qdisc
.list
),
448 .q
.lock
= __SPIN_LOCK_UNLOCKED(noqueue_qdisc
.q
.lock
),
449 .dev_queue
= &noqueue_netdev_queue
,
450 .busylock
= __SPIN_LOCK_UNLOCKED(noqueue_qdisc
.busylock
),
454 static const u8 prio2band
[TC_PRIO_MAX
+ 1] = {
455 1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1
458 /* 3-band FIFO queue: old style, but should be a bit faster than
459 generic prio+fifo combination.
462 #define PFIFO_FAST_BANDS 3
465 * Private data for a pfifo_fast scheduler containing:
466 * - queues for the three band
467 * - bitmap indicating which of the bands contain skbs
469 struct pfifo_fast_priv
{
471 struct sk_buff_head q
[PFIFO_FAST_BANDS
];
475 * Convert a bitmap to the first band number where an skb is queued, where:
476 * bitmap=0 means there are no skbs on any band.
477 * bitmap=1 means there is an skb on band 0.
478 * bitmap=7 means there are skbs on all 3 bands, etc.
480 static const int bitmap2band
[] = {-1, 0, 1, 0, 2, 0, 1, 0};
482 static inline struct sk_buff_head
*band2list(struct pfifo_fast_priv
*priv
,
485 return priv
->q
+ band
;
488 static int pfifo_fast_enqueue(struct sk_buff
*skb
, struct Qdisc
*qdisc
)
490 if (skb_queue_len(&qdisc
->q
) < qdisc_dev(qdisc
)->tx_queue_len
) {
491 int band
= prio2band
[skb
->priority
& TC_PRIO_MAX
];
492 struct pfifo_fast_priv
*priv
= qdisc_priv(qdisc
);
493 struct sk_buff_head
*list
= band2list(priv
, band
);
495 priv
->bitmap
|= (1 << band
);
497 return __qdisc_enqueue_tail(skb
, qdisc
, list
);
500 return qdisc_drop(skb
, qdisc
);
503 static struct sk_buff
*pfifo_fast_dequeue(struct Qdisc
*qdisc
)
505 struct pfifo_fast_priv
*priv
= qdisc_priv(qdisc
);
506 int band
= bitmap2band
[priv
->bitmap
];
508 if (likely(band
>= 0)) {
509 struct sk_buff_head
*list
= band2list(priv
, band
);
510 struct sk_buff
*skb
= __qdisc_dequeue_head(qdisc
, list
);
513 if (skb_queue_empty(list
))
514 priv
->bitmap
&= ~(1 << band
);
522 static struct sk_buff
*pfifo_fast_peek(struct Qdisc
*qdisc
)
524 struct pfifo_fast_priv
*priv
= qdisc_priv(qdisc
);
525 int band
= bitmap2band
[priv
->bitmap
];
528 struct sk_buff_head
*list
= band2list(priv
, band
);
530 return skb_peek(list
);
536 static void pfifo_fast_reset(struct Qdisc
*qdisc
)
539 struct pfifo_fast_priv
*priv
= qdisc_priv(qdisc
);
541 for (prio
= 0; prio
< PFIFO_FAST_BANDS
; prio
++)
542 __qdisc_reset_queue(qdisc
, band2list(priv
, prio
));
545 qdisc
->qstats
.backlog
= 0;
549 static int pfifo_fast_dump(struct Qdisc
*qdisc
, struct sk_buff
*skb
)
551 struct tc_prio_qopt opt
= { .bands
= PFIFO_FAST_BANDS
};
553 memcpy(&opt
.priomap
, prio2band
, TC_PRIO_MAX
+ 1);
554 if (nla_put(skb
, TCA_OPTIONS
, sizeof(opt
), &opt
))
555 goto nla_put_failure
;
562 static int pfifo_fast_init(struct Qdisc
*qdisc
, struct nlattr
*opt
)
565 struct pfifo_fast_priv
*priv
= qdisc_priv(qdisc
);
567 for (prio
= 0; prio
< PFIFO_FAST_BANDS
; prio
++)
568 __skb_queue_head_init(band2list(priv
, prio
));
570 /* Can by-pass the queue discipline */
571 qdisc
->flags
|= TCQ_F_CAN_BYPASS
;
575 struct Qdisc_ops pfifo_fast_ops __read_mostly
= {
577 .priv_size
= sizeof(struct pfifo_fast_priv
),
578 .enqueue
= pfifo_fast_enqueue
,
579 .dequeue
= pfifo_fast_dequeue
,
580 .peek
= pfifo_fast_peek
,
581 .init
= pfifo_fast_init
,
582 .reset
= pfifo_fast_reset
,
583 .dump
= pfifo_fast_dump
,
584 .owner
= THIS_MODULE
,
587 static struct lock_class_key qdisc_tx_busylock
;
589 struct Qdisc
*qdisc_alloc(struct netdev_queue
*dev_queue
,
590 const struct Qdisc_ops
*ops
)
594 unsigned int size
= QDISC_ALIGN(sizeof(*sch
)) + ops
->priv_size
;
596 struct net_device
*dev
= dev_queue
->dev
;
598 p
= kzalloc_node(size
, GFP_KERNEL
,
599 netdev_queue_numa_node_read(dev_queue
));
603 sch
= (struct Qdisc
*) QDISC_ALIGN((unsigned long) p
);
604 /* if we got non aligned memory, ask more and do alignment ourself */
607 p
= kzalloc_node(size
+ QDISC_ALIGNTO
- 1, GFP_KERNEL
,
608 netdev_queue_numa_node_read(dev_queue
));
611 sch
= (struct Qdisc
*) QDISC_ALIGN((unsigned long) p
);
612 sch
->padded
= (char *) sch
- (char *) p
;
614 INIT_LIST_HEAD(&sch
->list
);
615 skb_queue_head_init(&sch
->q
);
617 spin_lock_init(&sch
->busylock
);
618 lockdep_set_class(&sch
->busylock
,
619 dev
->qdisc_tx_busylock
?: &qdisc_tx_busylock
);
622 sch
->enqueue
= ops
->enqueue
;
623 sch
->dequeue
= ops
->dequeue
;
624 sch
->dev_queue
= dev_queue
;
626 atomic_set(&sch
->refcnt
, 1);
633 struct Qdisc
*qdisc_create_dflt(struct netdev_queue
*dev_queue
,
634 const struct Qdisc_ops
*ops
,
635 unsigned int parentid
)
639 if (!try_module_get(ops
->owner
))
642 sch
= qdisc_alloc(dev_queue
, ops
);
645 sch
->parent
= parentid
;
647 if (!ops
->init
|| ops
->init(sch
, NULL
) == 0)
654 EXPORT_SYMBOL(qdisc_create_dflt
);
656 /* Under qdisc_lock(qdisc) and BH! */
658 void qdisc_reset(struct Qdisc
*qdisc
)
660 const struct Qdisc_ops
*ops
= qdisc
->ops
;
665 if (qdisc
->gso_skb
) {
666 kfree_skb_list(qdisc
->gso_skb
);
667 qdisc
->gso_skb
= NULL
;
671 EXPORT_SYMBOL(qdisc_reset
);
673 static void qdisc_rcu_free(struct rcu_head
*head
)
675 struct Qdisc
*qdisc
= container_of(head
, struct Qdisc
, rcu_head
);
677 if (qdisc_is_percpu_stats(qdisc
))
678 free_percpu(qdisc
->cpu_bstats
);
680 kfree((char *) qdisc
- qdisc
->padded
);
683 void qdisc_destroy(struct Qdisc
*qdisc
)
685 const struct Qdisc_ops
*ops
= qdisc
->ops
;
687 if (qdisc
->flags
& TCQ_F_BUILTIN
||
688 !atomic_dec_and_test(&qdisc
->refcnt
))
691 #ifdef CONFIG_NET_SCHED
692 qdisc_list_del(qdisc
);
694 qdisc_put_stab(rtnl_dereference(qdisc
->stab
));
696 gen_kill_estimator(&qdisc
->bstats
, &qdisc
->rate_est
);
702 module_put(ops
->owner
);
703 dev_put(qdisc_dev(qdisc
));
705 kfree_skb_list(qdisc
->gso_skb
);
707 * gen_estimator est_timer() might access qdisc->q.lock,
708 * wait a RCU grace period before freeing qdisc.
710 call_rcu(&qdisc
->rcu_head
, qdisc_rcu_free
);
712 EXPORT_SYMBOL(qdisc_destroy
);
714 /* Attach toplevel qdisc to device queue. */
715 struct Qdisc
*dev_graft_qdisc(struct netdev_queue
*dev_queue
,
718 struct Qdisc
*oqdisc
= dev_queue
->qdisc_sleeping
;
719 spinlock_t
*root_lock
;
721 root_lock
= qdisc_lock(oqdisc
);
722 spin_lock_bh(root_lock
);
724 /* Prune old scheduler */
725 if (oqdisc
&& atomic_read(&oqdisc
->refcnt
) <= 1)
728 /* ... and graft new one */
731 dev_queue
->qdisc_sleeping
= qdisc
;
732 rcu_assign_pointer(dev_queue
->qdisc
, &noop_qdisc
);
734 spin_unlock_bh(root_lock
);
738 EXPORT_SYMBOL(dev_graft_qdisc
);
740 static void attach_one_default_qdisc(struct net_device
*dev
,
741 struct netdev_queue
*dev_queue
,
744 struct Qdisc
*qdisc
= &noqueue_qdisc
;
746 if (dev
->tx_queue_len
) {
747 qdisc
= qdisc_create_dflt(dev_queue
,
748 default_qdisc_ops
, TC_H_ROOT
);
750 netdev_info(dev
, "activation failed\n");
753 if (!netif_is_multiqueue(dev
))
754 qdisc
->flags
|= TCQ_F_ONETXQUEUE
;
756 dev_queue
->qdisc_sleeping
= qdisc
;
759 static void attach_default_qdiscs(struct net_device
*dev
)
761 struct netdev_queue
*txq
;
764 txq
= netdev_get_tx_queue(dev
, 0);
766 if (!netif_is_multiqueue(dev
) || dev
->tx_queue_len
== 0) {
767 netdev_for_each_tx_queue(dev
, attach_one_default_qdisc
, NULL
);
768 dev
->qdisc
= txq
->qdisc_sleeping
;
769 atomic_inc(&dev
->qdisc
->refcnt
);
771 qdisc
= qdisc_create_dflt(txq
, &mq_qdisc_ops
, TC_H_ROOT
);
774 qdisc
->ops
->attach(qdisc
);
779 static void transition_one_qdisc(struct net_device
*dev
,
780 struct netdev_queue
*dev_queue
,
781 void *_need_watchdog
)
783 struct Qdisc
*new_qdisc
= dev_queue
->qdisc_sleeping
;
784 int *need_watchdog_p
= _need_watchdog
;
786 if (!(new_qdisc
->flags
& TCQ_F_BUILTIN
))
787 clear_bit(__QDISC_STATE_DEACTIVATED
, &new_qdisc
->state
);
789 rcu_assign_pointer(dev_queue
->qdisc
, new_qdisc
);
790 if (need_watchdog_p
&& new_qdisc
!= &noqueue_qdisc
) {
791 dev_queue
->trans_start
= 0;
792 *need_watchdog_p
= 1;
796 void dev_activate(struct net_device
*dev
)
800 /* No queueing discipline is attached to device;
801 * create default one for devices, which need queueing
802 * and noqueue_qdisc for virtual interfaces
805 if (dev
->qdisc
== &noop_qdisc
)
806 attach_default_qdiscs(dev
);
808 if (!netif_carrier_ok(dev
))
809 /* Delay activation until next carrier-on event */
813 netdev_for_each_tx_queue(dev
, transition_one_qdisc
, &need_watchdog
);
814 if (dev_ingress_queue(dev
))
815 transition_one_qdisc(dev
, dev_ingress_queue(dev
), NULL
);
818 dev
->trans_start
= jiffies
;
819 dev_watchdog_up(dev
);
822 EXPORT_SYMBOL(dev_activate
);
824 static void dev_deactivate_queue(struct net_device
*dev
,
825 struct netdev_queue
*dev_queue
,
826 void *_qdisc_default
)
828 struct Qdisc
*qdisc_default
= _qdisc_default
;
831 qdisc
= rtnl_dereference(dev_queue
->qdisc
);
833 spin_lock_bh(qdisc_lock(qdisc
));
835 if (!(qdisc
->flags
& TCQ_F_BUILTIN
))
836 set_bit(__QDISC_STATE_DEACTIVATED
, &qdisc
->state
);
838 rcu_assign_pointer(dev_queue
->qdisc
, qdisc_default
);
841 spin_unlock_bh(qdisc_lock(qdisc
));
845 static bool some_qdisc_is_busy(struct net_device
*dev
)
849 for (i
= 0; i
< dev
->num_tx_queues
; i
++) {
850 struct netdev_queue
*dev_queue
;
851 spinlock_t
*root_lock
;
855 dev_queue
= netdev_get_tx_queue(dev
, i
);
856 q
= dev_queue
->qdisc_sleeping
;
857 root_lock
= qdisc_lock(q
);
859 spin_lock_bh(root_lock
);
861 val
= (qdisc_is_running(q
) ||
862 test_bit(__QDISC_STATE_SCHED
, &q
->state
));
864 spin_unlock_bh(root_lock
);
873 * dev_deactivate_many - deactivate transmissions on several devices
874 * @head: list of devices to deactivate
876 * This function returns only when all outstanding transmissions
877 * have completed, unless all devices are in dismantle phase.
879 void dev_deactivate_many(struct list_head
*head
)
881 struct net_device
*dev
;
882 bool sync_needed
= false;
884 list_for_each_entry(dev
, head
, close_list
) {
885 netdev_for_each_tx_queue(dev
, dev_deactivate_queue
,
887 if (dev_ingress_queue(dev
))
888 dev_deactivate_queue(dev
, dev_ingress_queue(dev
),
891 dev_watchdog_down(dev
);
892 sync_needed
|= !dev
->dismantle
;
895 /* Wait for outstanding qdisc-less dev_queue_xmit calls.
896 * This is avoided if all devices are in dismantle phase :
897 * Caller will call synchronize_net() for us
902 /* Wait for outstanding qdisc_run calls. */
903 list_for_each_entry(dev
, head
, close_list
)
904 while (some_qdisc_is_busy(dev
))
908 void dev_deactivate(struct net_device
*dev
)
912 list_add(&dev
->close_list
, &single
);
913 dev_deactivate_many(&single
);
916 EXPORT_SYMBOL(dev_deactivate
);
918 static void dev_init_scheduler_queue(struct net_device
*dev
,
919 struct netdev_queue
*dev_queue
,
922 struct Qdisc
*qdisc
= _qdisc
;
924 rcu_assign_pointer(dev_queue
->qdisc
, qdisc
);
925 dev_queue
->qdisc_sleeping
= qdisc
;
928 void dev_init_scheduler(struct net_device
*dev
)
930 dev
->qdisc
= &noop_qdisc
;
931 netdev_for_each_tx_queue(dev
, dev_init_scheduler_queue
, &noop_qdisc
);
932 if (dev_ingress_queue(dev
))
933 dev_init_scheduler_queue(dev
, dev_ingress_queue(dev
), &noop_qdisc
);
935 setup_timer(&dev
->watchdog_timer
, dev_watchdog
, (unsigned long)dev
);
938 static void shutdown_scheduler_queue(struct net_device
*dev
,
939 struct netdev_queue
*dev_queue
,
940 void *_qdisc_default
)
942 struct Qdisc
*qdisc
= dev_queue
->qdisc_sleeping
;
943 struct Qdisc
*qdisc_default
= _qdisc_default
;
946 rcu_assign_pointer(dev_queue
->qdisc
, qdisc_default
);
947 dev_queue
->qdisc_sleeping
= qdisc_default
;
949 qdisc_destroy(qdisc
);
953 void dev_shutdown(struct net_device
*dev
)
955 netdev_for_each_tx_queue(dev
, shutdown_scheduler_queue
, &noop_qdisc
);
956 if (dev_ingress_queue(dev
))
957 shutdown_scheduler_queue(dev
, dev_ingress_queue(dev
), &noop_qdisc
);
958 qdisc_destroy(dev
->qdisc
);
959 dev
->qdisc
= &noop_qdisc
;
961 WARN_ON(timer_pending(&dev
->watchdog_timer
));
964 void psched_ratecfg_precompute(struct psched_ratecfg
*r
,
965 const struct tc_ratespec
*conf
,
968 memset(r
, 0, sizeof(*r
));
969 r
->overhead
= conf
->overhead
;
970 r
->rate_bytes_ps
= max_t(u64
, conf
->rate
, rate64
);
971 r
->linklayer
= (conf
->linklayer
& TC_LINKLAYER_MASK
);
974 * The deal here is to replace a divide by a reciprocal one
975 * in fast path (a reciprocal divide is a multiply and a shift)
977 * Normal formula would be :
978 * time_in_ns = (NSEC_PER_SEC * len) / rate_bps
980 * We compute mult/shift to use instead :
981 * time_in_ns = (len * mult) >> shift;
983 * We try to get the highest possible mult value for accuracy,
984 * but have to make sure no overflows will ever happen.
986 if (r
->rate_bytes_ps
> 0) {
987 u64 factor
= NSEC_PER_SEC
;
990 r
->mult
= div64_u64(factor
, r
->rate_bytes_ps
);
991 if (r
->mult
& (1U << 31) || factor
& (1ULL << 63))
998 EXPORT_SYMBOL(psched_ratecfg_precompute
);