Re: [Cake] [PATCH 0/3] Add Common Applications Kept Enhanced (sch_cake) qdisc

[Dave Taht <dave.taht@gmail.com>]

at what commit it worked properly?

On Wed, Nov 22, 2017 at 3:02 AM, Sebastian Moeller <moeller0@gmx.de> wrote:
> Hi All,
>
> Tl;dr: Automatic accounting of the kernel added dev->hard_header_len seems currently broken at least in the cobalt branch...
>
>
> as far as I can tell overhead accounting is still busted:
>
>
> user@work-horse:~/CODE/sch_cake$ sudo ../tc-adv/tc/tc qdisc delete dev eth0 root; sudo ../tc-adv/tc/tc qdisc replace dev eth0 root cake raw overhead 5; ../tc-adv/tc/tc -s qdisc show dev eth0
> sudo: unable to resolve host work-horse
> sudo: unable to resolve host work-horse
> qdisc cake 8014: root refcnt 6 unlimited diffserv3 triple-isolate rtt 100.0ms noatm overhead 19 via-ethernet total_overhead 19 hard_header_len 14
>  Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
>  backlog 0b 0p requeues 0
>  memory used: 0b of 15140Kb
>  capacity estimate: 0bit
>                  Bulk   Best Effort      Voice
>   thresh          0bit        0bit        0bit
>   target         5.0ms       5.0ms       5.0ms
>   interval     100.0ms     100.0ms      10.0ms
>   pk_delay         0us         0us         0us
>   av_delay         0us         0us         0us
>   sp_delay         0us         0us         0us
>   pkts               0           0           0
>   bytes              0           0           0
>   way_inds           0           0           0
>   way_miss           0           0           0
>   way_cols           0           0           0
>   drops              0           0           0
>   marks              0           0           0
>   ack_drop           0           0           0
>   sp_flows           0           0           0
>   bk_flows           0           0           0
>   un_flows           0           0           0
>   max_len            0           0           0
>
> user@work-horse:~/CODE/sch_cake$ sudo ../tc-adv/tc/tc qdisc delete dev eth0 root; sudo ../tc-adv/tc/tc qdisc replace dev eth0 root cake overhead 5; ../tc-adv/tc/tc -s qdisc show dev eth0
> sudo: unable to resolve host work-horse
> sudo: unable to resolve host work-horse
> qdisc cake 8015: root refcnt 6 unlimited diffserv3 triple-isolate rtt 100.0ms raw total_overhead 14 hard_header_len 14
>  Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
>  backlog 0b 0p requeues 0
>  memory used: 0b of 15140Kb
>  capacity estimate: 0bit
>                  Bulk   Best Effort      Voice
>   thresh          0bit        0bit        0bit
>   target         5.0ms       5.0ms       5.0ms
>   interval     100.0ms     100.0ms      10.0ms
>   pk_delay         0us         0us         0us
>   av_delay         0us         0us         0us
>   sp_delay         0us         0us         0us
>   pkts               0           0           0
>   bytes              0           0           0
>   way_inds           0           0           0
>   way_miss           0           0           0
>   way_cols           0           0           0
>   drops              0           0           0
>   marks              0           0           0
>   ack_drop           0           0           0
>   sp_flows           0           0           0
>   bk_flows           0           0           0
>   un_flows           0           0           0
>   max_len            0           0           0
>
> user@work-horse:~/CODE/sch_cake$
>
>
> The first seems okay, but the second should not have reported "raw" but rather total_overhead 5 hard_header_len 14 if I understand the intention of the overhead keyword correctly. This also affects the keywords like conservative:
>
> user@work-horse:~/CODE/sch_cake$ sudo ../tc-adv/tc/tc qdisc delete dev eth0 root; sudo ../tc-adv/tc/tc qdisc replace dev eth0 root cake conservative; ../tc-adv/tc/tc -s qdisc show dev eth0
> sudo: unable to resolve host work-horse
> sudo: unable to resolve host work-horse
> qdisc cake 8019: root refcnt 6 unlimited diffserv3 triple-isolate rtt 100.0ms atm overhead 14 via-ethernet total_overhead 14 hard_header_len 14
>  Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
>  backlog 0b 0p requeues 0
>  memory used: 0b of 15140Kb
>  capacity estimate: 0bit
>                  Bulk   Best Effort      Voice
>   thresh          0bit        0bit        0bit
>   target         5.0ms       5.0ms       5.0ms
>   interval     100.0ms     100.0ms      10.0ms
>   pk_delay         0us         0us         0us
>   av_delay         0us         0us         0us
>   sp_delay         0us         0us         0us
>   pkts               0           0           0
>   bytes              0           0           0
>   way_inds           0           0           0
>   way_miss           0           0           0
>   way_cols           0           0           0
>   drops              0           0           0
>   marks              0           0           0
>   ack_drop           0           0           0
>   sp_flows           0           0           0
>   bk_flows           0           0           0
>   un_flows           0           0           0
>   max_len            0           0           0
>
> user@work-horse:~/CODE/sch_cake$ sudo ../tc-adv/tc/tc qdisc delete dev eth0 root; sudo ../tc-adv/tc/tc qdisc replace dev eth0 root cake raw conservative; ../tc-adv/tc/tc -s qdisc show dev eth0
> sudo: unable to resolve host work-horse
> sudo: unable to resolve host work-horse
> qdisc cake 801a: root refcnt 6 unlimited diffserv3 triple-isolate rtt 100.0ms atm overhead 62 via-ethernet total_overhead 62 hard_header_len 14
>  Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
>  backlog 0b 0p requeues 0
>  memory used: 0b of 15140Kb
>  capacity estimate: 0bit
>                  Bulk   Best Effort      Voice
>   thresh          0bit        0bit        0bit
>   target         5.0ms       5.0ms       5.0ms
>   interval     100.0ms     100.0ms      10.0ms
>   pk_delay         0us         0us         0us
>   av_delay         0us         0us         0us
>   sp_delay         0us         0us         0us
>   pkts               0           0           0
>   bytes              0           0           0
>   way_inds           0           0           0
>   way_miss           0           0           0
>   way_cols           0           0           0
>   drops              0           0           0
>   marks              0           0           0
>   ack_drop           0           0           0
>   sp_flows           0           0           0
>   bk_flows           0           0           0
>   un_flows           0           0           0
>   max_len            0           0           0
>
> user@work-horse:~/CODE/sch_cake$
>
>
> So in other words currently the automatic accounting for the kernel added hard_header_len seems broken as the raw keyword disables that functionality. I will try to look deeper into that, but I guess with my limited C skills this might do more harm than good...
>
> Best Regards
>         Sebastian
>
>
>> On Nov 22, 2017, at 01:09, Dave Taht <dave.taht@gmail.com> wrote:
>>
>> sch_cake is intended to squeeze the most bandwidth and lowest latency out
>> of even the slowest ISP links and routers, while presenting an API simple
>> enough that even an ISP can configure it.
>>
>> Example of use on an ISP uplink:
>>
>> tc qdisc add dev eth0 cake bandwidth 20Mbit nat docsis ack-filter
>>
>> Cake can also be used in unlimited mode to drive packets at the speed
>> of the underlying link.
>>
>> Cake is filled with:
>>
>> * A hybrid Codel/Blue AQM algorithm, “Cobalt”, tied to an FQ_Codel
>>  derived Flow Queuing system, which autoconfigures based on the bandwidth.
>> * A unique "triple-isolate" mode (the default) which balances per-flow
>>  and per-host flow FQ even through NAT.
>> * An integral deficit based shaper with extensive dsl and docsis support
>>  that can also be used in unlimited mode.
>> * 8 way set associative queuing to reduce flow collisions to a minimum.
>> * A reasonable interpretation of various diffserv latency/loss tradeoffs.
>> * Support for washing diffserv for entering and exiting traffic.
>> * Perfect support for interacting with Docsis 3.0 shapers.
>> * Extensive support for DSL framing types.
>> * (New) Support for ack filtering.
>>  - 20 % better throughput at a 16x1 down/up ratio on the rrul test.
>> * Extensive statistics for measuring loss, ecn markings, latency variation.
>>
>> There are some features still considered experimental, notably the
>> ingress_autorate bandwidth estimator and cobalt itself.
>>
>> Various versions shipping have been available as an out of tree build for
>> kernel versions going back to 3.10, as the embedded router world has been
>> running a few years behind mainline Linux. A stable version has been
>> generally available on lede-17.01 and later.
>>
>> sch_cake replaces a combination of iptables, tc filter, htb and fq_codel in
>> the sqm-scripts, with sane defaults and vastly easier configuration.
>>
>> Cake's principal author is Jonathan Morton, with contributions from
>> Kevin Darbyshire-Bryant, Toke Høiland-Jørgensen, Sebastian Moeller,
>> Ryan Mounce, Dean Scarff, Guido Sarducci, Nils Andreas Svee, Dave Täht, and
>> Loganaden Velvindron.
>>
>> Dave Taht (3):
>>  pkt_sched.h: add support for sch_cake API
>>  Add Common Applications Kept Enhanced (sch_cake) qdisc
>>  Add support for building the new cake qdisc
>>
>> include/net/cobalt.h           |  152 +++
>> include/uapi/linux/pkt_sched.h |   58 +
>> net/sched/Kconfig              |   11 +
>> net/sched/Makefile             |    1 +
>> net/sched/sch_cake.c           | 2551 ++++++++++++++++++++++++++++++++++++++++
>> 5 files changed, 2773 insertions(+)
>> create mode 100644 include/net/cobalt.h
>> create mode 100644 net/sched/sch_cake.c
>>
>> --
>> 2.7.4
>>
>> _______________________________________________
>> Cake mailing list
>> Cake@lists.bufferbloat.net
>> https://lists.bufferbloat.net/listinfo/cake
>



-- 

Dave Täht
CEO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-669-226-2619