[Bloat] "BBR" TCP patches submitted to linux kernel

[Dave Täht]

On 9/29/16 6:54 PM, Mario Ferreira wrote:
> On Thu, Sep 29, 2016, 16:43 Dave Täht <dave at taht.net
> <mailto:dave at taht.net>> wrote:
> 
> 
> 
>     On 9/29/16 4:24 AM, Mário Sérgio Fujikawa Ferreira wrote:
>     > Is there a mailing list I can lurk in to follow on the development?
>     >
>     > I'm most interested on a delta to apply to Android 6.x Franco Kernel
>     > (https://github.com/franciscofranco/angler)
> 
>     Android is still shipping linux 3.10? How... quaint.
> 
> 
> That's for Huawei Nexus 6P. Google's flagship till Pixel XL arrives.
> I'll try getting BBR merged to Franco's kernel (officially or maintained
> as a fork)  and add tc-adv with fq_codel/cake.
> 
> Since this is mobile, I'm pretty sure it will present a whole new host
> of "data points". 

yes! (there have been a few studies of this, btw)

The part that we don't really know on the android handsets is how
much buffering there really is between qdisc, driver, and firmware,
which no doubt varies between models - and within a model on the
different wifi and 4G stacks. Odds are - just as we just ripped out on
the ath9k/ath10k - so much intermediate buffering exists as to make
applying the latency managing qdisc on top of marginal effectiveness.

In the case of BBR, well, there is some hope that would regulate
TCP on the uplink, but it will have no effect on the down (neither will
the qdiscs) - and it requires sch_fq to work properly - which
means that you'd have a choice between bbr + sch_fq, or
sch_cake/sch_fq_codel.

In all cases, acquiring more data and backports would be nice.
> 
> I'm swamped right now but I'll have time by november for both FreeBSD
> and Android 6 (7 doesn't have source code released just yet) . I'm no
> expert but I'll help as I can.
> 
>     >  2. ipfw/dummynet AQM with FQ-Codel
>     >   
>      (https://lists.freebsd.org/pipermail/freebsd-ipfw/2016-February/006026.html)
> 
>     I made some comments on this that I'd like people to look at what is
>     really going on in bsd + fq_codel at > 100mbit.
> 
>     https://github.com/opnsense/core/issues/505
> 
> 
> I haven't been involved with the FreeBSD project on recent years but
> I'll try to advocate internally. 
> -- 
> 
> Mario S F Ferreira - Brazil - "I guess this is a signature."
> feature, n: a documented bug | bug, n: an undocumented feature
>