Re: [PATCH net-next 00/15] net/sched: no longer acquire RTNL in qdisc dumps

Eric Dumazet
2026-04-08T17:09:35Z

On Wed, Apr 8, 2026 at 5:56 AM Eric Dumazet <edumazet@google.com> wrote:
>
> This (large) series bring RTNL avoidance to qdisc dumps.
>
> We first add annotations for data-races, so that most dump methods
> can run in parallel with data path.
>
> Then change mq and mqprio to no longer acquire each children
> qdisc spinlock.
>
> Last patch replaces RTNL with RCU for tc_dump_qdisc() and the
> qdisc ops->dump() methods.
>
> Series was too big, RTNL avoidance for class dumps will be done later.
>
> Eric Dumazet (15):
> net/sched: rename qstats_overlimit_inc() to qstats_cpu_overlimit_inc()
> net/sched: add qstats_cpu_drop_inc() helper
> net/sched: add READ_ONCE() in gnet_stats_add_queue[_cpu]
> net/sched: add qdisc_qlen_inc() and qdisc_qlen_dec()
> net/sched: annotate data-races around sch->qstats.backlog
> net/sched: sch_sfb: annotate data-races in sfb_dump_stats()
> net/sched: sch_red: annotate data-races in red_dump_stats()
> net/sched: sch_fq_codel: remove data-races from fq_codel_dump_stats()
> net/sched: sch_pie: annotate data-races in pie_dump_stats()
> net/sched: sch_fq_pie: annotate data-races in fq_pie_dump_stats()
> net_sched: sch_hhf: annotate data-races in hhf_dump_stats()
> net/sched: sch_choke: annotate data-races in choke_dump_stats()
> net/sched: sch_cake: annotate data-races in cake_dump_stats()
> net/sched: mq: no longer acquire qdisc spinlocks in dump operations
> net/sched: convert tc_dump_qdisc() to RCU

Do not spend too much time on this V1, I will send a V2 tomorrow
addressing some issues.

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