1. A computer implemented method for managing thread performance in a computing environment, the method comprising: assigning a thread performance counter to threads being created in the computing environment, the thread performance counter measuring a number of cache misses for a corresponding thread; calculating a self-thread value S as a change in the thread performance counter of a given thread during a predetermined period; calculating an other-thread value O as a sum of changes in all the thread performance counters during the predetermined period minus S; calculating a first estimation adjustment value associated with a first probability that a second set of cache misses for the corresponding thread replaces a cache area currently occupied by the corresponding thread; estimating a cache occupancy for the given thread based on a previous occupancy E for the following: the given thread, S, O, and the first estimation adjustment value; and assigning computing environment resources to the given thread based on the estimated cache occupancy.