Class scheduler for increasing the probability of processor access by time-sensitive processes

Abstract

A method and apparatus for enabling a general purpose operating system to maximize the probability of time-sensitive threads, e.g., multimedia threads, gaining access to CPU resources quickly enough to meet the demands of time-sensitive tasks while allowing time-insensitive threads to meet the demands of time-insensitive tasks, is disclosed. The priorities of time-sensitive threads in an operating system are adjusted so that the time-sensitive threads have a high probability of gaining access to CPU resources quickly enough to meet the demands of time-sensitive tasks while allowing time-insensitive threads to meet the demands of time-insensitive tasks. A system responsiveness cell (SRC) value is used to determine how quickly the operating system needs to respond to time-sensitive threads and time-insensitive threads. Priorities of threads are dynamically changed according to the relative CPU resource access requirements of system profile tasks. Criteria for mapping time-sensitive tasks are contained in system profile tasks. Priorities of cross-process groups of time-sensitive threads related to specific instances of tasks are adjusted according to the criteria in the system profile tasks. System profile tasks are stored in a system profile which may vary by machine. Priorities of system profile tasks are the regrouped priorities used by the operating system.