There is provided mechanisms for scheduling a task from a plurality of tasks to a processor core of a cluster of processor cores. The processor cores share caches. A method is performed by a controller. The method comprises determining group-wise task relationships between the plurality of tasks based on duration of cache misses resulting from running groups of the plurality of tasks on processorcores sharing the same cache. The method comprises scheduling the task to one of the processor cores based on the group-wise task relationships of the task.