[Bloat] CAKE in openwrt high CPU

[Mikael Abrahamsson]

On Mon, 31 Aug 2020, Toke Høiland-Jørgensen wrote:

> Hmm, you say CAKE and FQ-Codel - so you're not enabling the shaper (that
> would be FQ-CoDel+HTB)? An exact config might be useful (or just the
> output of tc -s qdisc).

Yeah, I guess I'm also using HTB to get the 900 megabit/s SQM is looking 
for.

If I only use FQ_CODEL to get interface speeds my performance is fine.

> If you are indeed not shaping, maybe you're hitting the issue fixed by this commit?
>
> https://github.com/dtaht/sch_cake/commit/3152477235c934022049fcddc063c45d37ec10e6n

I enabled it just now to get the config.

qdisc cake 8030: dev eth0 root refcnt 9 bandwidth 900Mbit besteffort 
triple-isolate nonat nowash no-ack-filter split-gso rtt 100.0ms raw 
overhead 0
  Sent 4346128 bytes 11681 pkt (dropped 0, overlimits 1004 requeues 17)
  backlog 0b 0p requeues 17
  memory used: 33328b of 15140Kb
  capacity estimate: 900Mbit
  min/max network layer size:           42 /    1514
  min/max overhead-adjusted size:       42 /    1514
  average network hdr offset:           14

                   Tin 0
   thresh        900Mbit
   target          5.0ms
   interval      100.0ms
   pk_delay         18us
   av_delay          6us
   sp_delay          4us
   backlog            0b
   pkts            11681
   bytes         4346128
   way_inds           30
   way_miss          735
   way_cols            0
   drops               0
   marks               0
   ack_drop            0
   sp_flows            3
   bk_flows            1
   un_flows            0
   max_len         22710
   quantum          1514

qdisc ingress ffff: dev eth0 parent ffff:fff1 ----------------
  Sent 4716199 bytes 10592 pkt (dropped 0, overlimits 0 requeues 0)
  backlog 0b 0p requeues 0

...

qdisc cake 8031: dev ifb4eth0 root refcnt 2 bandwidth 900Mbit besteffort 
triple-isolate nonat nowash no-ack-filter split-gso rtt 100.0ms raw 
overhead 0
  Sent 4946683 bytes 10592 pkt (dropped 0, overlimits 492 requeues 0)
  backlog 0b 0p requeues 0
  memory used: 35Kb of 15140Kb
  capacity estimate: 900Mbit
  min/max network layer size:           60 /    1514
  min/max overhead-adjusted size:       60 /    1514
  average network hdr offset:           14

                   Tin 0
   thresh        900Mbit
   target          5.0ms
   interval      100.0ms
   pk_delay         19us
   av_delay          6us
   sp_delay          4us
   backlog            0b
   pkts            10592
   bytes         4946683
   way_inds           33
   way_miss          969
   way_cols            0
   drops               0
   marks               0
   ack_drop            0
   sp_flows            2
   bk_flows            1
   un_flows            0
   max_len         21196
   quantum          1514


-- 
Mikael Abrahamsson    email: swmike at swm.pp.se