1. A computer program product for optimizing a memory nest for a workload by an operating system, the computer program product comprising: a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising: determining a cache/memory footprint of each work unit of the workload; assigning a time slice to each work unit of the workload based on the cache/memory footprint of the work unit; and executing the workload, on a processor, by providing each work unit access to the processor for the time slice assigned to the work unit.