Adaptive partition schedulers are a relatively new type of partition scheduler, which in turn is a kind of scheduling algorithm, pioneered with the most recent version of the QNX operating system. Adaptive partitioning, or AP, allows the real-time system designer to request that a percentage of processing resources be reserved for a particular partition. The operating system's priority-driven pre-emptive scheduler will behave in the same way that a non-AP system would until the system is overloaded. During overload, the AP scheduler enforces hard limits on total run-time for the subsystems within a partition, as dictated by the allocated percentage of processor bandwidth for the particular partition.