1. A method of setting priorities of threads of time-sensitive tasks and time-insensitive tasks, said method comprising: (a) assigning priorities to the threads of said time-sensitive tasks according to criteria defined by system profile tasks; (b) using a system responsiveness cell (SRC) value to indicate a percentage of time processor resources should be applied to the threads of said time-sensitive tasks or to the threads of said time-insensitive tasks; (c) dynamically adjusting the priorities of the threads of said time-sensitive tasks according to the priorities of said system profile tasks even if the threads are in different tasks; further comprising: (d) mapping the time-sensitive tasks to the system profile tasks, wherein the time-sensitive tasks comprise a multimedia task; wherein dynamically adjusting the priorities of the threads of said time-sensitive tasks according to the priorities of said system profile tasks comprises, during a first time period, assigning priorities of the threads of said time-sensitive tasks to a first priority level, and, during a second time period, assigning priorities of the threads of said time-sensitive tasks to a second priority level, wherein the second priority level has a lower priority than the first priority level, and a cycle time comprises the first and second time period, and the SRC value indicates the percentage of the cycle time that the first time period or the second time period makes up.