A method and system is disclosed which can enhance the performance of computer systems by altering the operation of the operating system of those computer systems. The invention provides a system and method for making exception-less system calls, decoupling the invocation and execution of system calls, thus avoiding or reducing the direct and indirect overheads associated with making a conventional exception-based system call. The invention can be employed with single core processor systems and with multi-core processor systems, both affording improved temporal execution locality and the later also providing improved spatial execution locality. The system and method can be employed in a wide range of operating systems.