[Bloat] WSL2 + fq_codel

[Dave Taht]

On Sat, Feb 25, 2023 at 12:54 PM Stephen Hemminger
<stephen at networkplumber.org> wrote:
>
> On Sat, 25 Feb 2023 15:37:02 -0500
> Michael Richardson via Bloat <bloat at lists.bufferbloat.net> wrote:
>
> > Dave Taht via Bloat <bloat at lists.bufferbloat.net> wrote:
> >     > I so want to believe... I so want to believe... can anyone confirm?
> >
> >     > https://raw.githubusercontent.com/microsoft/WSL2-Linux-Kernel/linux-msft-wsl-5.15.y/Microsoft/config-wsl
> >
> > But, AFAIK, WSL isn't a kernel.  It's an implementation of the Linux ABI on
> > top of Windows service(s).  If you told me that they build some of it from
> > actual Linux kernel sources, I'd believe you.  (Rather like User-Mode-Linux)
> >
> > If you told me that they have a kernel that they build for when they actually
> > spin up an actual VM (such as to run containers) that would also be unsurprising.
> >
> >     > ...
> >
> >     > CONFIG_NET_SCH_DEFAULT=y
> >     > CONFIG_DEFAULT_FQ_CODEL=y
> >     > # CONFIG_DEFAULT_PFIFO_FAST is not set
> >     > CONFIG_DEFAULT_NET_SCH="fq_codel"
> >
> > It would be nice if the billion windows desktops started doing
> > something better, but I don't think it will help observed latency.
> > The real question is what the default schedule for the default Azure Linux VM
> > is.
> >
>
> I think WSL2 is actually a full Linux VM running in Hyper-V.

Yes, it is. But it is kind of unknown how the underlying network
interface is behaving in this case, as well as what the actual default
qdisc is, and this not just a random gist. It was VERY exciting to see
that gist go by...

are there no windows users on this list? :/ We long ago should have
pursued at least flent, and a TCP_INFO equivalent sampling method for
windows. The closest thing we have for windows is the rust-based:
https://github.com/Zoxc/crusader

-- 
A pithy note on VOQs vs SQM: https://blog.cerowrt.org/post/juniper/
Dave Täht CEO, TekLibre, LLC