"With a truckload of help from William Lee Irwin III (who wrote the main architecture) I posted a pluggable CPU scheduler framework that would allow you to build into the kernel as many of multiple CPU schedulers as you like and choose at boot time which one to run. I planned to extend that to runtime selection as well. This is much like the modular pluggable I/O scheduler framework that Linux kernel currently has. It was flat out refused by both Linus and Ingo (who is the CPU scheduler maintainer) as leading to specialisation of CPU schedulers and they both preferred there to be one CPU scheduler that was good at everything. I guess you can say the CPU scheduler is a steamroller that we as desktop users use to crack nuts with, and they didn't want us to build a nutcracker into the kernel."

o_o