Limiting temperature gradients on many-cores by adaptive reallocation of real-time workloads

The advent of many-core processors came with the increase in computational power needed for future applications. However new challenges arrived at the same time, especially for the real-time community. Each core on such a processor is a heat source and uneven usage can lead to hot spots on the processor, affecting its lifetime and reliability. For real-time systems, it is therefore of paramount importance to keep the temperature differences between the individual cores below critical values, in order to prevent premature failure of the system. We argue that this problem can not be solved by traditional approaches, since the growing number of cores makes them intractable. We rather argue to split the problem in the spacial domain and control the temperature on core level. The cores control their temperature by rearranging the load in a predictable manner during runtime. To achieve this, a feedback controller is implemented on each core. We conclude our work with a simulation based evaluation of the proposed approach comparing its performance against a previously presented algorithm.