kernel/linux.git/include/net/pkt_sched.h, branch linux-7.0.y

net/sched: don't use dynamic lockdep keys with clsact/ingress/noqueue

2026-02-05T17:32:45+00:00

Currently we are registering one dynamic lockdep key for each allocated qdisc, to avoid false deadlock reports when mirred (or TC eBPF) redirects packets to another device while the root lock is acquired [1]. Since dynamic keys are a limited resource, we can save them at least for qdiscs that are not meant to acquire the root lock in the traffic path, or to carry traffic at all, like: - clsact - ingress - noqueue Don't register dynamic keys for the above schedulers, so that we hit MAX_LOCKDEP_KEYS later in our tests. [1] https://github.com/multipath-tcp/mptcp_net-next/issues/451 Changes in v2: - change ordering of spin_lock_init() vs. lockdep_register_key() (Jakub Kicinski) Signed-off-by: Davide Caratti Link: https://patch.msgid.link/94448f7fa7c4f52d2ce416a4895ec87d456d7417.1770220576.git.dcaratti@redhat.com Signed-off-by: Jakub Kicinski

net_sched: add qdisc_dequeue_drop() helper

2025-11-25T15:10:32+00:00

Some qdisc like cake, codel, fq_codel might drop packets in their dequeue() method. This is currently problematic because dequeue() runs with the qdisc spinlock held. Freeing skbs can be extremely expensive. Add qdisc_dequeue_drop() method and a new TCQ_F_DEQUEUE_DROPS so that these qdiscs can opt-in to defer the skb frees after the socket spinlock is released. TCQ_F_DEQUEUE_DROPS is an attempt to not penalize other qdiscs with an extra cache line miss. Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20251121083256.674562-14-edumazet@google.com Signed-off-by: Paolo Abeni

net/sched: Remove unused typedef psched_tdiff_t

2025-10-28T01:05:54+00:00

Since commit 051d44209842 ("net/sched: Retire CBQ qdisc") this is not used anymore. Signed-off-by: Yue Haibing Link: https://patch.msgid.link/20251024025145.4069583-1-yuehaibing@huawei.com Signed-off-by: Jakub Kicinski

net/sched: Remove unused inline helper qdisc_from_priv()

2025-10-23T02:20:48+00:00

Since commit fb38306ceb9e ("net/sched: Retire ATM qdisc"), this is not used and can be removed. Signed-off-by: Yue Haibing Link: https://patch.msgid.link/20251021114626.3148894-1-yuehaibing@huawei.com Signed-off-by: Jakub Kicinski

net/sched: sch_qfq: Fix null-deref in agg_dequeue

2025-07-10T09:08:35+00:00

To prevent a potential crash in agg_dequeue (net/sched/sch_qfq.c) when cl->qdisc->ops->peek(cl->qdisc) returns NULL, we check the return value before using it, similar to the existing approach in sch_hfsc.c. To avoid code duplication, the following changes are made: 1. Changed qdisc_warn_nonwc(include/net/pkt_sched.h) into a static inline function. 2. Moved qdisc_peek_len from net/sched/sch_hfsc.c to include/net/pkt_sched.h so that sch_qfq can reuse it. 3. Applied qdisc_peek_len in agg_dequeue to avoid crashing. Signed-off-by: Xiang Mei Reviewed-by: Cong Wang Link: https://patch.msgid.link/20250705212143.3982664-1-xmei5@asu.edu Signed-off-by: Paolo Abeni

net/sched: Add helper macros with module names

2024-02-02T18:57:55+00:00

The macros are preparation for adding module aliases en mass in a separate commit. Although it would be tempting to create aliases like cls-foo for name cls_foo, this could not be used because modprobe utilities treat '-' and '_' interchangeably. In the end, the naming follows pattern of proto modules in linux/net.h. Signed-off-by: Michal Koutný Acked-by: Jamal Hadi Salim Reviewed-by: Jiri Pirko Link: https://lore.kernel.org/r/20240201130943.19536-2-mkoutny@suse.com Signed-off-by: Jakub Kicinski

net: sched: Make tc-related drop reason more flexible for remaining qdiscs

2023-12-20T11:50:13+00:00

Incrementing on Daniel's patch[1], make tc-related drop reason more flexible for remaining qdiscs - that is, all qdiscs aside from clsact. In essence, the drop reason will be set by cls_api and act_api in case any error occurred in the data path. With that, we can give the user more detailed information so that they can distinguish between a policy drop or an error drop. [1] https://lore.kernel.org/all/20231009092655.22025-1-daniel@iogearbox.net Signed-off-by: Victor Nogueira Acked-by: Daniel Borkmann Reviewed-by: Simon Horman Signed-off-by: David S. Miller

net: sched: Move drop_reason to struct tc_skb_cb

2023-12-20T11:50:13+00:00

Move drop_reason from struct tcf_result to skb cb - more specifically to struct tc_skb_cb. With that, we'll be able to also set the drop reason for the remaining qdiscs (aside from clsact) that do not have access to tcf_result when time comes to set the skb drop reason. Signed-off-by: Victor Nogueira Acked-by: Daniel Borkmann Reviewed-by: Simon Horman Signed-off-by: David S. Miller

net_sched: constify qdisc_priv()

2023-10-01T12:20:36+00:00

In order to propagate const qualifiers, we change qdisc_priv() to accept a possibly const argument. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net/sched: make psched_mtu() RTNL-less safe

2023-07-12T22:59:33+00:00

Eric Dumazet says[1]: ------- Speaking of psched_mtu(), I see that net/sched/sch_pie.c is using it without holding RTNL, so dev->mtu can be changed underneath. KCSAN could issue a warning. ------- Annotate dev->mtu with READ_ONCE() so KCSAN don't issue a warning. [1] https://lore.kernel.org/all/CANn89iJoJO5VtaJ-2=_d2aOQhb0Xw8iBT_Cxqp2HyuS-zj6azw@mail.gmail.com/ v1 -> v2: Fix commit message Fixes: d4b36210c2e6 ("net: pkt_sched: PIE AQM scheme") Suggested-by: Eric Dumazet Signed-off-by: Pedro Tammela Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20230711021634.561598-1-pctammela@mojatatu.com Signed-off-by: Jakub Kicinski