Revert "rbtree: empty nodes have no color"

This reverts commit 24207a7f8c5646f2dd220b90aaeff583cdae11e6.

Conflicts:
	include/linux/rbtree.h
Revert "fs/ext4: use rbtree postorder iteration helper instead of opencoding"

This reverts commit 1746d6bef1c33d65b80f27941bcb35a26de598aa.
Revert "rbtree: fix incorrect rbtree node insertion in fs/proc/proc_sysctl.c"

This reverts commit 9c435e3724e73a2bf7e09706bc4bd99d3af4f0d6.
Revert "rbtree: move some implementation details from rbtree.h to rbtree.c"

This reverts commit 1327e1fbdb4c9504425b0a5aaad36fb876e9c493.

Conflicts:
	include/linux/rbtree.h
Revert "sched: window-stats: Fix overflow bug"

This reverts commit a3e2c918f64673f37097bff759de885189903a5f.
Revert "sched: Calculate max_possible_freq based on current policy->max"

This reverts commit d83ee34bd03c46ec8c9ad6bba6fe0116edc234fc.
derp fix
Revert "sched: Disable wakeup hints for foreground tasks by default"

This reverts commit ec711c7f3ac5638a0445de63cb8d892ffbcb1b40.
Revert "sched: Call the notify_on_migrate notifier chain for wakeups as well"

This reverts commit a0db9b801b569f7e1a1fe23eaa053fccd9946d5b.

Conflicts:
	include/linux/sched/sysctl.h
	kernel/sched/core.c
	kernel/sysctl.c
Revert "sched: Make scheduler aware of cpu frequency state"

This reverts commit f3d19a9e536f51e9ee539b4a657625cf70039479.
derp fix