FPGAs have been widely deployed in public clouds, e.g., Amazon Web Services (AWS) and Huawei Cloud. However, simply offloading accelerated kernels from CPU hosts to PCIe-based FPGAs does not guarantee out-of-pocket cost savings in a pay-as-you-go public cloud. Taking Genome Analysis Toolkit (GATK) applications as case studies, although the adoption of FPGAs reduces the overall execution time, it introduces 2.56× extra cost, due to insufficient application-level speedup by Amdahl's law. To optimize the out-of-pocket cost while keeping high speedup and throughput, we propose Mocha framework as a distributed runtime system to fully utilize the accelerator resource by accelerator sharing and CPU-FPGA partial task offloading. Evaluation results on Haplotype Caller (HTC) and Mutect2 in GATK show that on AWS, Mocha saves on the application cost by 2.82x for HTC, 1.06x for Mutect2 and on Huawei Cloud by 1.22x, 1.52x respectively than straightforward CPU-FPGA integration solution with less than 5.1% performance overhead.

Since its establishment in 2009, the Center for Domain-Specific Computing (CDSC) has focused on customizable computing. We believe that future computing systems will be customizable with extensive use of accelerators, as custom-designed accelerators often provide 10-100X performance/energy efficiency over the general-purpose processors. Such an accelerator-rich architecture presents a fundamental departure from the classical von Neumann architecture, which emphasizes efficient sharing of the executions of different instructions on a common pipeline, providing an elegant solution when the computing resource is scarce. In contrast, the accelerator-rich architecture features heterogeneity and customization for energy efficiency; this is better suited for energy-constrained designs where the silicon resource is abundant and spatial computing is favored-which has been the case with the end of Dennard scaling. Currently, customizable computing has garnered great interest; for example, this is evident by Intel's $17 billion acquisition of Altera in 2015 and Amazon's introduction of field-programmable gate-arrays (FPGAs) in its AWS public cloud. In this paper, we present an overview of the research programs and accomplishments of CDSC on customizable computing, from single chip to server node and to datacenters, with extensive use of composable accelerators and FPGAs. We highlight our successes in several application domains, such as medical imaging, machine learning, and computational genomics. In addition to architecture innovations, an equally important research dimension enables automation for customized computing. This includes automated compilation for combining source-code-level transformation for high-level synthesis with efficient parameterized architecture template generations, and efficient runtime support for scheduling and transparent resource management for integration of FPGAs for datacenter-scale acceleration with support to the existing programming interfaces, such as MapReduce, Hadoop, and Spark, for large-scale distributed computation. We will present the latest progress in these areas, and also discuss the challenges and opportunities ahead.

With the slowing down of Moore's law, major cloud service providers---such as Amazon Web Services, Microsoft Azure, and Alibaba Cloud---all started deploying FPGAs in their cloud platforms to improve the performance and energy-efficiency. From the perspective of performance per unit cost in the cloud, it is essential to efficiently utilize all available CPU and FPGA resources within a requested computing instance. However, most prior studies overlook the CPU-FPGA co-optimization or require a considerable amount of manual efforts to achieve it. In this poster, we present a framework called K-Flow, which enables easy FPGA accelerator integration and efficient CPU-FPGA co-scheduling for big data applications. K-Flow abstracts an application as a widely used directed acyclic graph (DAG), and dynamically schedules a number of CPU threads and/or FPGA accelerator processing elements (PEs) to execute the dataflow tasks on each DAG node. Moreover, K-Flow provides user-friendly interfaces to program each DAG node and automates the tedious process of FPGA accelerator integration and CPU-FPGA co-optimization using the genomic read alignment application BWA-MEM as a case study. Experimental results show that K-Flow achieves a throughput that is on average 94.5% of the theoretical upper bound and 1.4x better than a straightforward FPGA integration.

With the end of CPU core scaling due to dark silicon limitations, customized accelerators on FPGAs have gained increased attention in modern datacenters due to their lower power, high performance and energy efficiency. Evidenced by Microsoft's FPGA deployment in its Bing search engine and Intel's 16.7 billion acquisition of Altera, integrating FPGAs into datacenters is considered one of the most promising approaches to sustain future datacenter growth. However, it is quite challenging for existing big data computing systems-like Apache Spark and Hadoop-to access the performance and energy benefits of FPGA accelerators. In this paper we design and implement Blaze to provide programming and runtime support for enabling easy and efficient deployments of FPGA accelerators in datacenters. In particular, Blaze abstracts FPGA accelerators as a service (FaaS) and provides a set of clean programming APIs for big data processing applications to easily utilize those accelerators. Our Blaze runtime implements an FaaS framework to efficiently share FPGA accelerators among multiple heterogeneous threads on a single node, and extends Hadoop YARN with accelerator-centric scheduling to efficiently share them among multiple computing tasks in the cluster. Experimental results using four representative big data applications demonstrate that Blaze greatly reduces the programming efforts to access FPGA accelerators in systems like Apache Spark and YARN, and improves the system throughput by 1.7 × to 3× (and energy efficiency by 1.5× to 2.7×) compared to a conventional CPU-only cluster.

In this paper we present our ongoing study and deployment efforts for enabling FPGAs in datacenters. An important focus is to provide a quantitative evaluation of a wide range of heterogeneous system designs and integration options, from low-power field-programmable SoCs to server-class computer nodes plus high-capacity FPGAs, with real system prototyping and implementation on real-life applications. In the meantime, we develop a cloud-friendly programming interface and a runtime environment for efficient accelerator deployment, scheduling and transparent resource management for integration of FPGAs for large-scale acceleration across different system integration platforms to enable "write once, execute everywhere".

This paper focuses on the development of an infrastructure to enable FPGA-based acceleration in data centers. We present an initial version of an integrated solution that includes automated compilation for accelerator generation, runtime accelerator resource scheduling and management, and acceleration libraries for FPGA-based customized computing for big data applications. The solution can help overcome some of the main challenges with FPGA-based accelerated computing. It has the potential to bring significant performance and energy efficiency improvement for data center applications.

Recently, FPGA-based CNN accelerators have demonstrated superior energy efficiency compared to high-performance devices like GPGPUs. However, due to the constrained on-chip resource and many other factors, single-board FPGA designs may have difficulties in achieving optimal energy efficiency. In this paper we present a deeply pipelined multi-FPGA architecture that expands the design space for optimal performance and energy efficiency. A dynamic programming algorithm is proposed to map the CNN computing layers efficiently to different FPGA boards. To demonstrate the potential of the architecture, we built a prototype system with seven FPGA boards connected with high-speed serial links. The experimental results on AlexNet and VGG-16 show that the prototype can achieve up to 21x and 2x energy efficiency compared to optimized multi-core CPU and GPU implementations, respectively.

Although the expectation maximization (EM)based 3D computed tomography (CT) reconstruction algorithm lowers radiation exposure, its long execution time hinders practical usage. To accelerate this process, we introduce a novel external memory bandwidth reduction strategy by reusing both the sinogram and the voxel intensity. Also, a customized computing engine based on field-programmable gate array (FPGA) is presented to increase the effective memory bandwidth. Experiments on actual patient data show that 85X speedup can be achieved over single-threaded CPU.

In this poster we describe a platform-based approach for rapid construction of FPGA-based simulation of neural microcircuits composed from integrate-and-fire (IAF) neurons. Our approach exploits high-level synthesis to bypass the high design complexity of RTL coding, and enables automatic optimization and design space exploration. We demonstrate the benefits of this approach by simulating a neural microcircuit that performs oscillatory path integration, which evidence suggests may be a critical building block of the navigation system inside a rodent's brain. Experiments show that our FPGA simulation engine can achieve up to 23x speedup and 450x energy reduction compared to commodity CPU. The methodology described in this paper should be broadly applicable for creating FPGA simulations over a wide range neural microcircuit architectures.

In this paper we describe an FPGA-based platform for high-performance and low-power simulation of neural microcircuits composed from integrate-and-fire (IAF) neurons. Based on high-level synthesis, our platform uses design templates to map hierarchies of neuron model to logic fabrics. This approach bypasses high design complexity and enables easy optimization and design space exploration. We demonstrate the benefits of our platform by simulating a variety of neural microcircuits that perform oscillatory path integration, which evidence suggests may be a critical building block of the navigation system inside a rodent's brain. Experiments show that our FPGA simulation engine for oscillatory neural microcircuits can achieve up to 39x speedup compared to software benchmarks on commodity CPU, and 232x energy reduction compared to embedded ARM core.