[Cake] [PATCH 0/3] Add Common Applications Kept Enhanced (sch_cake) qdisc
Dave Taht
dave.taht at gmail.com
Wed Nov 22 13:03:11 EST 2017
at what commit it worked properly?
On Wed, Nov 22, 2017 at 3:02 AM, Sebastian Moeller <moeller0 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at 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 at lists.bufferbloat.net
>> https://lists.bufferbloat.net/listinfo/cake
>
--
Dave Täht
CEO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-669-226-2619
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