Support more than 64 cores

If you want to use more than 64 cores in WSL2 (e.g. if you have AMD Threadripper 7980x), you can follow the steps:

Build computecore.dll for WSL2

1. Generate project

    mkdir build
    cd build
    cmake ..
   

2. Open build/Project.sln and generate a x64 release build.

3. Launch task manager, kill wslservice.exe process.

4. Copy the generated build/Release/computecore.dll to C:\Program Files\WSL\.

5. Launch any WSL2 distribution, type nproc or lscpu, you should see all cores.

Change hypervisor scheduler type

Now you can see all cpus in WSL2, but actually, you might still can't use all of them. For example, if you run:

make -j`nproc`

from task manager, you might still see only 50% cpus are working. That because the default hyperV scheduler is Root, all tasks are still not scheduled cross all cpu groups. You can run the following command from powershell console to check your current hyperV scheduler:

Get-WinEvent -FilterHashTable @{ProviderName="Microsoft-Windows-Hyper-V-Hypervisor"; ID=2} -MaxEvents 1

If it outputs Hypervisor scheduler type is 0x4, it means you are using Root scheduler. You need run the following command to change the scheduler type to Core:

bcdedit /set hypervisorschedulertype Core

Restart machine to take the settings effect. Note, if you enable bitlocker, you might need input the bitlocker key after restarting. So please save your bitlocker key before restarting.

Now, you can use full cores really!