linux/net/sched
Kevin Bracey fb80445c43 net_sched: restore "mpu xxx" handling
commit 56b765b79e ("htb: improved accuracy at high rates") broke
"overhead X", "linklayer atm" and "mpu X" attributes.

"overhead X" and "linklayer atm" have already been fixed. This restores
the "mpu X" handling, as might be used by DOCSIS or Ethernet shaping:

    tc class add ... htb rate X overhead 4 mpu 64

The code being fixed is used by htb, tbf and act_police. Cake has its
own mpu handling. qdisc_calculate_pkt_len still uses the size table
containing values adjusted for mpu by user space.

iproute2 tc has always passed mpu into the kernel via a tc_ratespec
structure, but the kernel never directly acted on it, merely stored it
so that it could be read back by `tc class show`.

Rather, tc would generate length-to-time tables that included the mpu
(and linklayer) in their construction, and the kernel used those tables.

Since v3.7, the tables were no longer used. Along with "mpu", this also
broke "overhead" and "linklayer" which were fixed in 01cb71d2d4
("net_sched: restore "overhead xxx" handling", v3.10) and 8a8e3d84b1
("net_sched: restore "linklayer atm" handling", v3.11).

"overhead" was fixed by simply restoring use of tc_ratespec::overhead -
this had originally been used by the kernel but was initially omitted
from the new non-table-based calculations.

"linklayer" had been handled in the table like "mpu", but the mode was
not originally passed in tc_ratespec. The new implementation was made to
handle it by getting new versions of tc to pass the mode in an extended
tc_ratespec, and for older versions of tc the table contents were analysed
at load time to deduce linklayer.

As "mpu" has always been given to the kernel in tc_ratespec,
accompanying the mpu-based table, we can restore system functionality
with no userspace change by making the kernel act on the tc_ratespec
value.

Fixes: 56b765b79e ("htb: improved accuracy at high rates")
Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: Vimalkumar <j.vimal@gmail.com>
Link: https://lore.kernel.org/r/20220112170210.1014351-1-kevin@bracey.fi
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-01-13 11:06:42 -08:00
..
act_api.c flow_offload: fix suspicious RCU usage when offloading tc action 2021-12-23 11:17:00 +00:00
act_bpf.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_connmark.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_csum.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_ct.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-01-09 17:00:17 -08:00
act_ctinfo.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_gact.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_gate.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_ife.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_ipt.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_meta_mark.c
act_meta_skbprio.c
act_meta_skbtcindex.c
act_mirred.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_mpls.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_nat.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_pedit.c flow_offload: add ops to tc_action_ops for flow action setup 2021-12-19 14:08:48 +00:00
act_police.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_sample.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_simple.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_skbedit.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_skbmod.c flow_offload: fill flags to action structure 2021-12-19 14:08:47 +00:00
act_tunnel_key.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
act_vlan.c flow_offload: allow user to offload tc action to net device 2021-12-19 14:08:48 +00:00
cls_api.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-01-09 17:00:17 -08:00
cls_basic.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_bpf.c bpf: Refactor BPF_PROG_RUN into a function 2021-08-17 00:45:07 +02:00
cls_cgroup.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_flow.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_flower.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-12-23 16:09:58 -08:00
cls_fw.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_matchall.c flow_offload: validate flags of filter and actions 2021-12-19 14:08:48 +00:00
cls_route.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_rsvp6.c
cls_rsvp.c
cls_rsvp.h net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_tcindex.c net_sched: refactor TC action init API 2021-08-02 10:24:38 +01:00
cls_u32.c flow_offload: validate flags of filter and actions 2021-12-19 14:08:48 +00:00
em_canid.c
em_cmp.c
em_ipset.c
em_ipt.c
em_meta.c net: introduce sk_forward_alloc_get() 2021-10-27 18:20:29 -07:00
em_nbyte.c
em_text.c
em_u32.c
ematch.c net: sched: Fix spelling mistakes 2021-05-31 22:44:56 -07:00
Kconfig
Makefile
sch_api.c sch_api: Don't skip qdisc attach on ingress 2022-01-13 12:34:59 +00:00
sch_atm.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_blackhole.c
sch_cake.c sch_cake: revise Diffserv docs 2022-01-07 08:41:29 -08:00
sch_cbq.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_cbs.c
sch_choke.c net: sched: validate stab values 2021-03-10 15:47:52 -08:00
sch_codel.c
sch_drr.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_dsmark.c net/sched: store the last executed chain also for clsact egress 2021-07-29 22:17:37 +01:00
sch_etf.c
sch_ets.c net/sched: sch_ets: don't remove idle classes from the round-robin list 2021-12-13 12:30:23 +00:00
sch_fifo.c net_sched: fix NULL deref in fifo_set_limit() 2021-10-01 14:59:10 -07:00
sch_fq_codel.c fq_codel: generalise ce_threshold marking for subset of traffic 2021-10-20 15:24:36 -07:00
sch_fq_pie.c net/sched: fq_pie: prevent dismantle issue 2021-12-09 08:01:00 -08:00
sch_fq.c
sch_frag.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-12-31 14:35:40 +00:00
sch_generic.c net_sched: restore "mpu xxx" handling 2022-01-13 11:06:42 -08:00
sch_gred.c net: sched: gred: dynamically allocate tc_gred_qopt_offload 2021-10-27 12:06:52 -07:00
sch_hfsc.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_hhf.c
sch_htb.c sch_htb: Add extack messages for EOPNOTSUPP errors 2021-10-28 14:34:03 +01:00
sch_ingress.c
sch_mq.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_mqprio.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_multiq.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_netem.c net: sched: sch_netem: Refactor code in 4-state loss generator 2021-11-15 13:23:23 +00:00
sch_pie.c
sch_plug.c
sch_prio.c net: sched: Remove Qdisc::running sequence counter 2021-10-18 12:54:41 +01:00
sch_qfq.c sch_qfq: prevent shift-out-of-bounds in qfq_init_qdisc 2022-01-04 12:36:51 +00:00
sch_red.c net: sched: validate stab values 2021-03-10 15:47:52 -08:00
sch_sfb.c net/sched: store the last executed chain also for clsact egress 2021-07-29 22:17:37 +01:00
sch_sfq.c net/sched: store the last executed chain also for clsact egress 2021-07-29 22:17:37 +01:00
sch_skbprio.c
sch_taprio.c net/sched: sch_taprio: fix undefined behavior in ktime_mono_to_any 2021-11-09 19:16:23 -08:00
sch_tbf.c net: sch_tbf: Add a graft command 2021-10-19 12:24:51 +01:00
sch_teql.c net: sched: sch_teql: fix null-pointer dereference 2021-04-08 14:14:42 -07:00