Adaptive, efficient, parallel execution of parallel programs

Abstract

Future multicore processors will be heterogeneous, be increasingly less reliable, and operate in dynamically changing operating conditions. Such environments will result in a constantly varying pool of hardware resources which can greatly complicate the task of efficiently exposing a program's parallelism onto these resources. Coupled with this uncertainty is the diverse set of efficiency metrics that users may desire. This paper proposes Varuna, a system that dynamically, continuously, rapidly and transparently adapts a program's parallelism to best match the instantaneous capabilities of the hardware resources while satisfying different efficiency metrics. Varuna is applicable to both multithreaded and task-based programs and can be seamlessly inserted between the program and the operating system without needing to change the source code of either.