This paper presents SLATE, a fully-managed, heterogeneous Function-as-a-Service (FaaS) system for deploying serverless functions onto heterogeneous cloud infrastructures. We extend the traditional homogeneous FaaS execution model to support heterogeneous functions, automating and abstracting runtime management of heterogeneous compute resources in order to improve cloud tenant accessibility to specialised, accelerator resources, such as FPGAs and GPUs. In particular, we focus on the mechanisms required for heterogeneous scaling of deployed function instances to guarantee latency objectives while minimising cost. We develop a simulator to validate and evaluate our approach, considering case-study functions in three application domains: machine learning, bio-informatics, and physics. We incorporate empirically derived performance models for each function implementation targeting a hardware platform with combined computational capacity of 24 FPGAs and 12 CPU cores. Compared to homogeneous CPU and homogeneous FPGA functions, simulation results achieve respectively a cost improvement for non-uniform task traffic of up to 8.7 times and 1.7 times, while maintaining specified latency objectives.

This paper describes an unconventional way to apply wireless networking in emerging technologies. It makes the case for using a two-tier hybrid wireless/wired architecture to interconnect hundreds to thousands of cores in chip multiprocessors (CMPs), where current interconnect technologies face severe scaling limitations in excessive latency, long wiring, and complex layout. We propose a recursive wireless interconnect structure called the WCube that features a single transmit antenna and multiple receive antennas at each micro wireless router and offers scalable performance in terms of latency and connectivity. We show the feasibility to build miniature on-chip antennas, and simple transmitters and receivers that operate at 100 − 500 GHz sub-terahertz frequency bands. We also devise new two-tier wormhole based routing algorithms that are deadlock free and ensure a minimum-latency route on a 1000core on-chip interconnect network. Our simulations show that our protocol suite can reduce the observed latency by 20 % to 45%, and consumes power that is comparable to or less than current 2-D wiredmeshdesigns.

In this paper, we explore the use of multi-band radio frequency interconnect (or RF-I) with signal propagation at the speed of light to provide shortcuts in a many core network-on-chip (NoC) mesh topology. We investigate the costs associated with this technology, and examine the latency and bandwidth benefits that it can provide. Assuming a 400mm2die, we demonstrate that in exchange for 0.13% of area overhead on the active layer, RF-I can provide an average 13% (max 18%) boost in application performance, corresponding to an average 22% (max 24%) reduction in packet latency. We observe that RF access points may become traffic bottlenecks when many packets try to use the RF at once, and conclude by proposing strategies that adapt RF-I utilization at runtime to actively combat this congestion.

The ability to integrate diverse components such as processor cores, memories, custom hardware blocks and complex network-on-chip (NoC) communication frameworks onto a single chip has greatly increased the design space available for system-on-chip (SoC) designers. Efficient and accurate performance estimation tools are needed to assist the designer in making design decisions. In this paper, we present MC-Sim, a heterogeneous multi-core simulator framework which is capable of accurately simulating a variety of processor, memory, NoC configurations and application specific coprocessors. We also describe a methodology to automatically generate fast, cycle-true behavioral, C-based simulators for coprocessors using a high-level synthesis tool and integrate them with MC-Sim, thus augmenting it with the capacity to simulate coprocessors. Our C-based simulators provide on an average 45times improvement in simulation speed over that of RTL descriptions. We have used this framework to simulate a number of real-life applications such as the MPEG4 decoder and litho-simulation, and experimented with a number of design choices. Our simulator framework is able to accurately model the performance of these applications (only 7% off the actual implementation) and allows us to explore the design space rapidly and achieve interesting design implementations.

As chip multiprocessors scale to a greater number of processing cores, on-chip interconnection networks will experience dramatic increases in both bandwidth demand and power dissipation. Fortunately, promising gains can be realized via integration of radio frequency interconnect (RF-I) through on-chip transmission lines with traditional interconnects implemented with RC wires. While prior work has considered the latency advantage of RF-I, we demonstrate three further advantages of RF-I: (1) RF-I bandwidth can be flexibly allocated to provide an adaptive NoC, (2) RF-I can enable a dramatic power and area reduction by simplification of NoC topology, and (3) RF-I provides natural and efficient support for multicast. In this paper, we propose a novel interconnect design, exploiting dynamic RF-I bandwidth allocation to realize a reconfigurable network-on-chip architecture. We find that our adaptive RF-I architecture on top of a mesh with 4B links can even outperform the baseline with 16B mesh links by about 1%, and reduces NoC power by approximately 65% including the overhead incurred for supporting RF-I.