State-Aware Concurrency Throttling

Reconfiguration of parallel applications has gained traction with the increasing emphasis on energy/performance trade-off. The ability to dynamically change the amount of resources used by an application allows reaction to changes in the environment, in the application behavior or in the user’s requirements. A popular technique consists in changing the number of threads used by the application (Dynamic Concurrency Throttling). Although this provides good control of application performance and power consumption, managing the technique can impose a significant burden on the application programmer, mainly due to state management and redistribution following the addition or removal of a thread. Nevertheless, some common state access patterns have been identified in some popular applications. By leveraging on this knowledge, we will describe how it is possible to simplify the state management procedures following a Concurrency Throttling operation.