1. A method of accounting for processor time usage in a processor core, comprising: at a periodic interval having a rate equal to a clock cycle of the processor core, determining relative internal resource usage by a plurality of threads executing within said processor core by determining whether or not each thread is in a particular cycle state and determining a number of resources for each thread that is determined to be in the particular cycle state, wherein said relative internal resource usage is an indication of a relative amount of utilization of one or more resources within said processor core as among the plurality of threads; in response to said determining, fractionally updating a plurality of processor core internal resource usage counts each associated with a particular one of the plurality of threads in conformity with the number of resources used by the associated thread as determined by the determining; and apportioning the processor time usage over a timebase cycle to respective threads of the plurality of threads in proportion to the internal resource usage counts, wherein threads of the plurality of threads that use more of the one or more resources are accounted a higher amount of the processor time usage.