[Cerowrt-devel] [Bloat] Comcast upped service levels -> WNDR3800 can't cope...

[Dave Taht]

On Sep 2, 2014 6:41 AM, "Jonathan Morton" <chromatix99 at gmail.com> wrote:
>
>
> On 1 Sep, 2014, at 9:32 pm, Dave Taht wrote:
>
> >>> It would be cool to be able to program the ethernet hardware itself to
> >>> return completion interrupts at a given transmit rate (so you could
> >>> program the hardware to be any bandwidth not just 10/100/1000). Some
> >>> hardware so far as I know supports this with a "pacing" feature.
> >>
> >> Is there a summary of hardware features like this anywhere?  It'd be
nice to see what us GEM and RTL proles are missing out on.  :-)
> >
> > I'd like one.
>
> Is there at least a list of drivers (both wired and wireless) which are
BQL enabled?  If GEM is not in that list, it might explain why the PCI bus
gets jammed solid on my PowerBook.

A fairly current list (and the means to generate a more current one) is at:

https://www.bufferbloat.net/projects/codel/wiki/Best_practices_for_benchmarking_Codel_and_FQ_Codel

>
> > There are certain 3rd party firmwares like octeon's
> > where it seems possible to add more features to the firmware
> > co-processor, in particular.
>
> Octeon is basically a powerful, multi-core MIPS64 SoC that happens to
have Ethernet hardware attached, and is available in NIC form.  These
"NICs" look like miniature motherboards in PCIe-card format, complete with
mini-SIMM slots.  Utter overkill for normal applications; they're meant to
do encryption on the fly, and were originally introduced as Ethernet-less
coprocessor cards for that purpose.  At least they represent a good example
of what high-end MIPS is like these days.
>
> The original Bigfoot KillerNIC was along those lines, too, but slightly
less overdone.  It still managed to cost $250+, and Newegg still lists a
price in that general range despite being permanently out of stock.  As
well as running Linux on the card itself, the drivers apparently replaced
large parts of the Windows network stack in the quest for efficiency and
low latency.  Results varied; Anandtech suggested that the biggest
improvements probably came on cheaper PCs, whose owners wouldn't be able to
justify such a high-priced NIC - and that was in 2007.
>
> I can't tell what the newer products under the Killer brand (taken over
by Qualcomm/Atheros) really are, but they are sufficiently reduced in cost,
size and complexity to be integrated into "gamer" PC motherboards and
laptops, and they respond to being driven like standard (newish) Atheros
hardware.  In particular, it's unclear whether they do most of their
special sauce in software (so Windows-specific) or firmware.

It is also the chip in the Edgerouter line of products and a few others.

>
> Comments I hear sometimes seem to imply that *some* Atheros hardware runs
internal firmware.  Whether that is strictly wireless hardware, or whether
it extends into Ethernet, I can't yet tell.  Since it's widely deployed, it
would theoretically be a good platform for experimentation - but in
practice?

The ath10k has a cpu and firmware. The ath9k does not.

>
> > tc qdisc add dev eth0 cake bandwidth 50mbit diffservmap std
>
> Or even having the "diffservmap std" part be in the defaults.  I try not
to spend too much mental effort understanding diffserv - it's widely
misunderstood, and most end-user applications ignore it.  Supporting the
basic eight precedences, and maybe some userspace effort to introduce
marking, should be enough.

The various ietf wgs seem to think AFxx is a useful concept.

>
> I like the name, though.  :-)

It is partially a reference to a scene in the 2010 sequel to 2001.

>
>  - Jonathan Morton
>
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