wsl2-kernel-zswap

WSL2 kernel with zswap.

Tested on:

• Ubuntu 22.04 with kernel 5.15.153.1-microsoft-standard-WSL2 (kernel 5.x)
• Ubuntu with kernel 6.x-microsoft-standard-WSL2 (kernel 6.x)

Building

Quick Start (review script first recommended)

# Download and review the script first
curl -O https://raw.githubusercontent.com/dhanar10/wsl2-kernel-zswap/main/build.sh
less build.sh

# After reviewing, run it
bash build.sh

One-liner (use at your own risk)

curl https://raw.githubusercontent.com/dhanar10/wsl2-kernel-zswap/main/build.sh | bash

The script automatically detects your kernel version and:

• For kernel 5.x: builds the kernel with CONFIG_FRONTSWAP support
• For kernel 6.x: builds the kernel without CONFIG_FRONTSWAP (removed in 6.x) and generates a modules.vhdx file containing kernel modules

Installation

Kernel 5.x

After building, copy arch/x86/boot/bzImage to your Windows C: drive and configure .wslconfig:

[wsl2]
kernel=C:\\bzImage

Then restart WSL: wsl --shutdown

Kernel 6.x

After building:

1. Copy arch/x86/boot/bzImage to /mnt/c/bzImage
2. Copy modules.vhdx to /mnt/c/modules.vhdx
3. Configure .wslconfig in your Windows user directory:

   [wsl2]
   kernel=C:\\bzImage
   kernelModules=C:\\modules.vhdx
   

4. Restart WSL: wsl --shutdown

Verifying zswap

After restarting WSL, verify zswap is enabled:

cat /sys/module/zswap/parameters/enabled
# Should output: Y

cat /sys/module/zswap/parameters/compressor
# Should output: zstd