WSLg aka the killer feature of Windows 11

One of the great things about Windows 11 was the inclusion of the Windows Subsystem for Linux or WSL. It wasn’t available at launch but it started with v1 a simple ELF loader and an implementation of the Linux kernel on the NTOS kernel. Being a re-implementation of Linux it was great for what did work, however many things did not. Compared to other Unix subsystems for NT over the years however WSLv1 was the best no question.

Not being enough however, Microsoft took a page out of the old WinOS/2 days and stubbed a Linux kernel to run under Hyper-V, allowing it to run far more applications, and for me giving the ability to use applications that alter memory space, and allowing i386/x32 applications to run. You could happily export your X-11 display to a Windows based X server, and get applications that way. But this isn’t 1993 so it was very limiting.

Enter WSLg

The big change is the ability to use RDP to hook both Wayland and Pulse Audio bringing Linux ‘desktop’ X11 applications to the Windows desktop. Also added in is virtual GPU capabilities allowing accelerated 3D, along with CUDA applications to run (although with a performance penalty.

The downshot for me, is that my existing Debian 10 install was not picking this up, and was somehow picking up a VMware

VMware llvmpipe

I have no idea how or why it was picking this up. While I did have the VMware Player installed, the newer versions backend through Hyper-V.

I did find this article, which gave me a path to get where I wanted, although the transition of an existing v2 instance didn’t work for me. Maybe Debian 10 is too weird. I don’t know.

Not sure where how to proceed I backed up my home directory and un-installed VMware Player and purged my existing Debian 10. I installed that Ubuntu Community Preview which promises to include all the new and exciting features.

$ glxinfo -B
name of display: :0
display: :0  screen: 0
direct rendering: Yes
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: Microsoft Corporation (0xffffffff)
    Device: D3D12 (NVIDIA GeForce RTX 2070) (0xffffffff)
    Version: 21.0.3
    Accelerated: yes
    Video memory: 40710MB
    Unified memory: no
    Preferred profile: core (0x1)
    Max core profile version: 3.3
    Max compat profile version: 3.1
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.0
OpenGL vendor string: Microsoft Corporation
OpenGL renderer string: D3D12 (NVIDIA GeForce RTX 2070)
OpenGL core profile version string: 3.3 (Core Profile) Mesa 21.0.3
OpenGL core profile shading language version string: 3.30
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile

OpenGL version string: 3.1 Mesa 21.0.3
OpenGL shading language version string: 1.40
OpenGL context flags: (none)

OpenGL ES profile version string: OpenGL ES 3.0 Mesa 21.0.3
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.00

Now this is looking MUCH better.

224FPS! FurMark

Now compare this to a native version of FuMark:

500 FPS

So it’s a 50% haircut. Ouch.

Gaming however using steam (yes steam runs!) reveals some other deeper issues. The mouse tracking is WAY off. So for FPS stuff you’ll spend a lot of time staring at the ceiling or the floors. The next issue is there is no mouselock, so things that rely on being able to move the mouse far beyond a screen length is impossible to play. To be fair it’s a preview, and so far I have to admit Windows 11 feels more like a technical preview. Also I don’t know what the deal is or anything about profiling it but KOTOR2 is insanely slow. Although at least with 3d acceleration running it’s not 1 frame every 5 seconds.

So I was building a Windows 2019 server

As I got a ‘totally legit’ serial code in my box of cereal.

After the install I thought it’d be fun to install the Linux Subsystem.

While following the powershell instructions here, I thought the list of quick links of distros to download was interesting:

That’s right ARM Linux userland! I still have high hopes for Windows on ARM (I have 2 Windows RT devices now!!) although I’m not holding my breath.

Maybe there will be some ARM boards that are suitable for the desktop that aren’t over 1k USD.. That’d be nice.

Interesting trivia is that the Linux Subsystem started it’s life on ARM as a way to run Android binaries on Windows Phone. And true to everything Microsoft does, it got to the point where it could start to run things (albeit poorly) and was summarily killed. Although it’s found life despite the original false start as a general ‘text mode’ subsystem for Windows.

However running Linux binaries on Windows currently just shows that NTOS isn’t as efficient as the Linux kernel when it comes to emulating the Linux ABI. Although this was the original ‘dream’ of the microkernel, and a POSIX subsystem for NT was always part of the original design, although it really was more of a checkbox for GSA contracts, and outside of being able to use pax & vi it really was handicapped by not having BSD extensions, and especially by not having any access to the TCP/IP stack.


I should add these notes from the future past for the future me, when messing around with Windows Server 2019 build 1809 when they finally brought the Linux Subsystem into the fold. Unpacking the distribution and running the ‘setup’ sets it up DIRECTLY into that directory. So put it where you want it.

When you mess that up, you have to use the wslconfig program!

Of note is:

wslconfig /list /all
Lists all distributions, including ones that aren’t currently usable. They may be in the process of installing, uninstalling, or are in a broken state.

wslconfig /unregister <DistributionName>
Unregisters the distribution from WSL so it can be reinstalled or cleaned up.

This way you can now clean up your mess, and get Linux installed right.