Commit a9312ae8 authored by David S. Miller's avatar David S. Miller
Browse files

pkt_sched: Add 'deactivated' state. 



This new state lets dev_deactivate() mark a qdisc as having been
deactivated.

dev_queue_xmit() and ing_filter() check for this bit and do not
try to process the qdisc if the bit is set.

dev_deactivate() polls the qdisc after setting the bit, waiting
for both __QDISC_STATE_RUNNING and __QDISC_STATE_SCHED to clear.

This isn't perfect yet, but subsequent changesets will make it so.
This part is just one piece of the puzzle.

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 08013fa3

include/net/sch_generic.h

+1 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ enum qdisc_state_t 
{

	__QDISC_STATE_RUNNING,

	__QDISC_STATE_SCHED,

	__QDISC_STATE_DEACTIVATED,

};



struct qdisc_size_table {

net/core/dev.c

+8 −1
Original line number Diff line number Diff line
@@ -1800,6 +1800,12 @@ gso: 


		spin_lock(root_lock);



		if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {

			spin_unlock(root_lock);

			rc = NET_XMIT_DROP;

			goto out_kfree_skb;

		}



		rc = qdisc_enqueue_root(skb, q);

		qdisc_run(q);
@@ -2084,6 +2090,7 @@ static int ing_filter(struct sk_buff *skb) 
	q = rxq->qdisc;

	if (q != &noop_qdisc) {

		spin_lock(qdisc_lock(q));

		if (likely(!test_bit(__QDISC_STATE_DEACTIVATED, &q->state)))

			result = qdisc_enqueue_root(skb, q);

		spin_unlock(qdisc_lock(q));

	}

net/sched/sch_generic.c

+6 −0
Original line number Diff line number Diff line
@@ -597,6 +597,9 @@ static void transition_one_qdisc(struct net_device *dev, 
	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)

		*need_watchdog_p = 1;
@@ -640,6 +643,9 @@ static void dev_deactivate_queue(struct net_device *dev, 
	if (qdisc) {

		spin_lock_bh(qdisc_lock(qdisc));



		if (!(qdisc->flags & TCQ_F_BUILTIN))

			set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state);



		dev_queue->qdisc = qdisc_default;

		qdisc_reset(qdisc);

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