Google's Ghost Look Very Appealing For Kernel Scheduling From User-Space & eBPF Programs

Google for quite some time now has been working on "Ghost" as a means of controlling the Linux kernel scheduler from user-space and/or eBPF programs. Ghost provides an extensive API so developers can alter the kernel's scheduler behavior from user-space or eBPF and fine-tune the scheduling behavior based on system preferences.

Google engineer Barret Rhoden presented today at the LPC 2022 Dublin event on the latest Ghost kernel scheduling happenings. Multiple "agents" of user-space programs or eBPF programs can run on the same system for influencing the kernel scheduling behavior.

Google Ghost

Among the future work mentioned for Ghost is potentially implementing Linux's existing CFS algorithm within eBPF and other new capabilities. Those wanting to learn more about Ghost can see the LPC 2022 video recording below.

There is also Rhoden's PDF slide deck for those wanting to learn more. Google's Ghost code is currently developed on GitHub via the ghost-kernel and ghost-userspace repositories.

It will be interesting to see what comes of Ghost and the possibility of the kernel element being mainlined in the future. It was just last week AMD engineers proposed user-space hinting for better task placement by the Linux kernel scheduler while it would seem Ghost could be optimized as well for carrying out that work too with a capable user-space agent taking into account AMD's split-LLC architecture.

Also during the eBPF and networking track today was an update on the HID-BPF effort. That slide deck can be found here.