Tapping into the fountain of CPUs: On operating system support for programmable devices

The constant race for faster and more powerful CPUs is drawing to a close. No longer is it feasible to significantly increase the speed of the CPU without paying a crushing penalty in power consumption and production costs. Instead of increasing single thread performance, the industry is turning to multiple CPU threads or cores (such as SMT and CMP) and heterogeneous CPU architectures (such as the Cell Broadband Engine). While this is a step in the right direction, in every modern PC there is a wealth of untapped compute resources. The NIC has a CPU; the disk controller is programmable; some high-end graphics adaptersare already more powerful than host CPUs. Some of these CPUs can perform some functions more efficiently than the host CPUs. Our operating systems and programming abstractions should be expanded to let applications tap into these computational resources and make the best use of them. Therefore, we propose the HYDRA framework, which lets application developers use the combined power of every compute resource in a coherent way. HYDRA is a programming model and a runtime support layer which enables utilization of host processors as well as various programmable peripheral devices' processors. We present the frameworkand its application for a demonstrative use-case, as well as provide a thorough evaluation of its capabilities. Using HYDRA we were able to cut down the development cost of a system that uses multiple heterogenous compute resources significantly.