Red Hat Enterprise Linux v.4 based on Linux 2.6 kernel infrastructure

Linux v.4 kernel offers numerous improvements over earlier kernels, including many enhanced algorithms and features:

Generic logical CPU scheduler: Handles multi-core and hyperthreaded CPUs.

Object-based Reverse Mapping VM: Improved performance in memory constrained systems.

Read Copy Update: SMP algorithm optimization for operating system data structures.

Multiple I/O schedulers: Selectable based on the application environment.

Enhanced SMP & NUMA support: Improved performance and scalability for large servers.

Network interrupt mitigation (NAPI): Improved performance for heavy network loads.