I'm running e7d0c41ecc2e372a81741a30894f556afec24315 from Linus' tree today, and I'm seeing abysmal scheduler performance. Running make -j4 ends up with all the tasks on CPU 3 most of the time (on my 4-logical-thread laptop). taskset -c 0 whatever puts whatever on CPU 0, but plain while true; do true; done puts the infinite loop on CPU 3 right along with the make -j4 tasks.
This is on Fedora 26, and I don't think I'm doing anything weird. systemd has enabled the cpu controller, but it doesn't seem to have configured anything or created any non-root cgroups. Just a heads up. I haven't tried to diagnose it at all.
