diff options
| author | Cong Wang <xiyou.wangcong@gmail.com> | 2020-05-26 21:35:26 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-05-27 15:05:49 -0700 |
| commit | 70f50965338a12e17454c31ad5ece27069719358 (patch) | |
| tree | 6fbefb496398d793022646a147b760964106addb /net/sched | |
| parent | f5a7833e83628f18c1ee94e6ffcb1d232f029be9 (diff) | |
| download | linux-70f50965338a12e17454c31ad5ece27069719358.tar.bz2 | |
net_sched: avoid resetting active qdisc for multiple times
Except for sch_mq and sch_mqprio, each dev queue points to the
same root qdisc, so when we reset the dev queues with
netdev_for_each_tx_queue() we end up resetting the same instance
of the root qdisc for multiple times.
Avoid this by checking the __QDISC_STATE_DEACTIVATED bit in
each iteration, so for sch_mq/sch_mqprio, we still reset all
of them like before, for the rest, we only reset it once.
Reported-by: Václav Zindulka <vaclav.zindulka@tlapnet.cz>
Tested-by: Václav Zindulka <vaclav.zindulka@tlapnet.cz>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched')
| -rw-r--r-- | net/sched/sch_generic.c | 37 |
1 files changed, 23 insertions, 14 deletions
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index a4271e47f220..d13e27467470 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -1128,6 +1128,28 @@ void dev_activate(struct net_device *dev) } EXPORT_SYMBOL(dev_activate); +static void qdisc_deactivate(struct Qdisc *qdisc) +{ + bool nolock = qdisc->flags & TCQ_F_NOLOCK; + + if (qdisc->flags & TCQ_F_BUILTIN) + return; + if (test_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state)) + return; + + if (nolock) + spin_lock_bh(&qdisc->seqlock); + spin_lock_bh(qdisc_lock(qdisc)); + + set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state); + + qdisc_reset(qdisc); + + spin_unlock_bh(qdisc_lock(qdisc)); + if (nolock) + spin_unlock_bh(&qdisc->seqlock); +} + static void dev_deactivate_queue(struct net_device *dev, struct netdev_queue *dev_queue, void *_qdisc_default) @@ -1137,21 +1159,8 @@ static void dev_deactivate_queue(struct net_device *dev, qdisc = rtnl_dereference(dev_queue->qdisc); if (qdisc) { - bool nolock = qdisc->flags & TCQ_F_NOLOCK; - - if (nolock) - spin_lock_bh(&qdisc->seqlock); - spin_lock_bh(qdisc_lock(qdisc)); - - if (!(qdisc->flags & TCQ_F_BUILTIN)) - set_bit(__QDISC_STATE_DEACTIVATED, &qdisc->state); - + qdisc_deactivate(qdisc); rcu_assign_pointer(dev_queue->qdisc, qdisc_default); - qdisc_reset(qdisc); - - spin_unlock_bh(qdisc_lock(qdisc)); - if (nolock) - spin_unlock_bh(&qdisc->seqlock); } } |