CFS gave way to EEVDF over 6.6 to 6.12. Most people who tune a scheduler are solving a problem that isn't a scheduling problem, and the cases where it really is are narrower than the tuning guides let on.
Performance per watt stopped being a mobile concern and became the constraint that shapes datacentre architecture. Most software has no idea how much power it draws, and the first team to put a wattmeter in CI will find savings nobody else can see.
Performance and efficiency cores, unified memory, accelerators on-package. The uniform-core model that every piece of scheduling and benchmarking folklore assumes has stopped being true, and the machine that replaces it does more per watt than anything symmetric ever will.
A great deal of software is still designed around a disk that takes ten milliseconds to seek. That disk hasn't been in the critical path of a serious system for years, and the clever architectures built to work around it are now the bottleneck.
