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

From: Stephen Hemminger <[email-masked]>
Date: Fri, 27 Apr 2018 18:03:56 -0700

On Fri, 27 Apr 2018 21:57:20 +0200
Toke Høiland-Jørgensen <[email-masked]> 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 [email-masked] mailing list.
> 
> Signed-off-by: Dave Taht <[email-masked]>
> Signed-off-by: Toke Høiland-Jørgensen <[email-masked]>
> ---
> 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.