Fans of the open-source Haiku OS derived from BeOS can now be happy if running on modern processors there are some major CPU scheduling improvements and support for more than eight processor cores.
For Haiku fans there is a lengthy post on the Haiku blog
about all of the scheduler improvements made in recent months to the operating system with still a decent following.
The main scheduler logic for Haiku has been completed, a spinlock has been removed with more fine-grained locking, IRQs/MSIs are now directed to an arbitrary logical processor, changes to how dynamic priorities are handled, and inter-processor interrupts (IPI) have improved. With this work there's also a new cpufreq module for Intel Sandy Bridge and newer processors while a cpuidle module is available for all processors with support for C-states and invariant TSC.
Another important change made is that Haiku OS can now work on more than eight processor cores and can now work on systems with up to 64 cores, while that limit can be made higher in the future.