[Cake] [PATCH iproute2-next v7] Add support for cake qdisc

Toke Høiland-Jørgensen toke at toke.dk
Sat Apr 28 11:27:51 EDT 2018


Stephen Hemminger <stephen at networkplumber.org> writes:

> On Fri, 27 Apr 2018 21:57:20 +0200
> Toke Høiland-Jørgensen <toke at toke.dk> wrote:
>
>> sch_cake is intended to squeeze the most bandwidth and 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 a cable ISP uplink:
>> 
>> tc qdisc add dev eth0 cake bandwidth 20Mbit nat docsis ack-filter
>> 
>> To shape a cable download link (ifb and tc-mirred setup elided)
>> 
>> tc qdisc add dev ifb0 cake bandwidth 200mbit nat docsis ingress wash besteffort
>> 
>> 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 novel "triple-isolate" mode (the default) which balances per-host
>>   and per-flow FQ even through NAT.
>> * An deficit based shaper, that can also be used in an unlimited mode.
>> * 8 way set associative hashing to reduce flow collisions to a minimum.
>> * A reasonable interpretation of various diffserv latency/loss tradeoffs.
>> * Support for zeroing diffserv markings for entering and exiting traffic.
>> * Support for interacting well with Docsis 3.0 shaper framing.
>> * Support for DSL framing types and shapers.
>> * Support for ack filtering.
>> * Extensive statistics for measuring, loss, ecn markings, latency variation.
>> 
>> Various versions baking 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 simpler configuration.
>> 
>> Cake's principal author is Jonathan Morton, with contributions from
>> Kevin Darbyshire-Bryant, Toke Høiland-Jørgensen, Sebastian Moeller,
>> Ryan Mounce, Guido Sarducci, Dean Scarff, Nils Andreas Svee, Dave Täht,
>> and Loganaden Velvindron.
>> 
>> Testing from Pete Heist, Georgios Amanakis, and the many other members of
>> the cake at lists.bufferbloat.net mailing list.
>> 
>> Signed-off-by: Dave Taht <dave.taht at gmail.com>
>> Signed-off-by: Toke Høiland-Jørgensen <toke at toke.dk>
>> ---
>> Changelog:
>> v7:
>>   - Move the target/interval presets to a table and check that only
>>     one is passed.
>> 
>> v6:
>>   - Identical to v5 because apparently I don't git so well... :/
>> 
>> v5:
>>   - Print the SPLIT_GSO flag
>>   - Switch to print_u64() for JSON output
>>   - Fix a format string for mpu option output
>> 
>> v4:
>>   - Switch stats parsing to use nested netlink attributes
>>   - Tweaks to JSON stats output keys
>> 
>> v3:
>>   - Remove accidentally included test flag
>> 
>> v2:
>>   - Updated netlink config ABI
>>   - Remove diffserv-llt mode
>>   - Various tweaks and clean-ups of stats output
>>  man/man8/tc-cake.8 | 632 ++++++++++++++++++++++++++++++++++++++
>>  man/man8/tc.8      |   1 +
>>  tc/Makefile        |   1 +
>>  tc/q_cake.c        | 748 +++++++++++++++++++++++++++++++++++++++++++++
>>  4 files changed, 1382 insertions(+)
>>  create mode 100644 man/man8/tc-cake.8
>>  create mode 100644 tc/q_cake.c
>
> Looks good to me, when cake makes it into net-next.

Awesome, thanks!

-Toke


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