Microsoft's WSL2 Transitions To Linux 6.6 LTS Kernel

The kernel powering Microsoft's Windows Subsystem for Linux 2 (WSL2) has long been using the Linux 5.15 LTS kernel while finally it's now upgraded past that aging long-term support kernel and onto the current Linux 6.6 LTS series.

WSL2's kernel hadn't upgraded to Linux 6.1 LTS but has now jumped ahead off Linux 5.15 to use the much more recent 6.6 LTS series. The linux-msft-wsl-6.6.36.3 kernel was released on Monday as the first WSL2 kernel using Linux 6.6.36 as its base. Besides upgrading the kernel version, there are x86_64/ARM64 kernel configuration changes including loadable modules support.

In the jump from Linux 5.15 to 6.6 LTS also means carrying less out-of-tree patches thanks to all the upstreaming work over the past three years. Patches around page reporting, vPCI, memory reclaim, vSock, and other features are now upstream in the kernel and don't need to be maintained separately by Microsoft's kernel downstream.

Downloads and more details on this new Linux 6.6 based kernel now deploying to WSL2 users can be found via the WSL2-Linux-Kernel GitHub repository. With that said, it sounds like a good opportunity for running some new Microsoft WSL2 Linux benchmarks as time allows in the coming weeks.