Change the Default Memory Limit of WSL2

I was running a Go program in WSL2, and it stalled at 12GB of memory usage (my machine has 24GB total). No error, no panic, just silence.

~ Run go test ./
=== RUN   TestDBMetaphysicsProblem
--- PASS: TestDBMetaphysicsProblem (10.94s)
=== RUN   TestDBSequentialOP
FAIL	github.com/therainisme/mlsm	182.824s

Turns out WSL2 caps memory at half of your Windows memory by default. Source: https://learn.microsoft.com/en-us/windows/wsl/wsl-config#main-wsl-settings

Configure the Memory Limit

Create a .wslconfig file in your user directory (usually C:\users\YourUsername) with the following content:

[wsl2]
memory=16GB

After saving, restart WSL2 with wsl --shutdown. Then run free inside WSL2 to verify:

~ free
               total        used        free      shared  buff/cache   available
Mem:        16381032      909836    14426152         980     1045044    15175252
Swap:        4194304       87336     4106968

Memory is now 16GB. The Go program that eats memory can finally finish running.