1. A symmetric multiprocessing system comprising: first and second central processing units; a first adaptive partition processing scheduler associated with the first central processing unit to selectively allocate the first central processing unit to run multiple process threads of one or more adaptive partitions based on a comparison between merit function values of the one or more adaptive partitions, each of the one or more adaptive partitions comprising said multiple process threads, where the merit function values for a particular partition, p, of the one or more adaptive partitions is based, at least in part, on whether the adaptive partition has available budget on the first central processing unit; and a second adaptive partition processing scheduler associated with the second central processing unit to selectively allocate the second central processing unit to run process threads of the one or more adaptive partitions based on a comparison between merit function values of the one or more adaptive partitions, where the merit function values for a particular partition, p, of the one or more adaptive partitions is based, at least in part, on whether the adaptive partition has available budget on the second central processing unit, where the merit function values for a particular partition, p, of the one or more adaptive partitions associated with the first adaptive partition scheduler is based, at least in part, on whether the adaptive partition has available global budget among the first central processing unit and the second central processing unit, and where a budget assigned to and used by a partition of the one or more adaptive partitions is based on a number of ticks occurring during an averaging window, and where the adaptive partition has available global budget on the first central processing unit when a number of ticks used globally by the adaptive partition during a current averaging window is less than or equal to a number of ticks assigned as the available global budget to the adaptive partition.