diff options
| author | Eric Dumazet <edumazet@google.com> | 2026-05-10 12:14:54 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-05-12 04:28:08 +0300 |
| commit | bb19ce4c4333290bd5f4b1ee616ab46625f010f6 (patch) | |
| tree | b1873753122302f3f892d660f502fcf5723f6d22 | |
| parent | 4f07179f4006cbb1ff199c1e6d8a91d0e8a087b6 (diff) | |
| download | linux-bb19ce4c4333290bd5f4b1ee616ab46625f010f6.tar.xz | |
net/sched: mq_prio: no longer acquire qdisc spinlocks in mqprio_dump()
Prepare mqprio_dump() for RTNL avoidance.
Use RCU instead of RTNL, and no longer acquire each children spinlock.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://patch.msgid.link/20260510091455.4039245-8-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/sched/sch_mqprio.c | 37 |
1 files changed, 24 insertions, 13 deletions
diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c index 3b4881c389c5..f9dab76f40eb 100644 --- a/net/sched/sch_mqprio.c +++ b/net/sched/sch_mqprio.c @@ -551,35 +551,46 @@ nla_put_failure: static int mqprio_dump(struct Qdisc *sch, struct sk_buff *skb) { - struct net_device *dev = qdisc_dev(sch); - struct mqprio_sched *priv = qdisc_priv(sch); struct nlattr *nla = (struct nlattr *)skb_tail_pointer(skb); + struct mqprio_sched *priv = qdisc_priv(sch); + struct net_device *dev = qdisc_dev(sch); + struct gnet_stats_queue qstats = { 0 }; + struct gnet_stats_basic_sync bstats; struct tc_mqprio_qopt opt = { 0 }; + const struct Qdisc *qdisc; unsigned int qlen = 0; - struct Qdisc *qdisc; unsigned int ntx; - qlen = 0; - gnet_stats_basic_sync_init(&sch->bstats); - memset(&sch->qstats, 0, sizeof(sch->qstats)); + gnet_stats_basic_sync_init(&bstats); /* MQ supports lockless qdiscs. However, statistics accounting needs * to account for all, none, or a mix of locked and unlocked child * qdiscs. Percpu stats are added to counters in-band and locking * qdisc totals are added at end. */ + rcu_read_lock(); for (ntx = 0; ntx < dev->num_tx_queues; ntx++) { - qdisc = rtnl_dereference(netdev_get_tx_queue(dev, ntx)->qdisc_sleeping); - spin_lock_bh(qdisc_lock(qdisc)); + qdisc = rcu_dereference(netdev_get_tx_queue(dev, ntx)->qdisc_sleeping); - gnet_stats_add_basic(&sch->bstats, qdisc->cpu_bstats, - &qdisc->bstats, false); - gnet_stats_add_queue(&sch->qstats, qdisc->cpu_qstats, + gnet_stats_add_basic(&bstats, qdisc->cpu_bstats, + &qdisc->bstats, true); + gnet_stats_add_queue(&qstats, qdisc->cpu_qstats, &qdisc->qstats); qlen += qdisc_qlen_lockless(qdisc); - - spin_unlock_bh(qdisc_lock(qdisc)); } + rcu_read_unlock(); + + spin_lock_bh(qdisc_lock(sch)); + _bstats_set(&sch->bstats, u64_stats_read(&bstats.bytes), + u64_stats_read(&bstats.packets)); + spin_unlock_bh(qdisc_lock(sch)); + + WRITE_ONCE(sch->qstats.qlen, qstats.qlen); + WRITE_ONCE(sch->qstats.backlog, qstats.backlog); + WRITE_ONCE(sch->qstats.drops, qstats.drops); + WRITE_ONCE(sch->qstats.requeues, qstats.requeues); + WRITE_ONCE(sch->qstats.overlimits, qstats.overlimits); + WRITE_ONCE(sch->q.qlen, qlen); mqprio_qopt_reconstruct(dev, &opt); |