Towards a Scalable Software Defined Network-on-Chip for Next Generation Cloud

Abstract

The rapid evolution of Cloud-based services and the growing interest in deep learning (DL)-based applications is putting increasing pressure on hyperscalers and general purpose hardware designers to provide more efficient and scalable systems. Cloud-based infrastructures must consist of more energy efficient components. The evolution must take place from the core of the infrastructure (i.e., data centers (DCs)) to the edges (Edge computing) to adequately support new/future applications. Adaptability/elasticity is one of the features required to increase the performance-to-power ratios. Hardware-based mechanisms have been proposed to support system reconfiguration mostly at the processing elements level, while fewer studies have been carried out regarding scalable, modular interconnected sub-systems. In this paper, we propose a scalable Software Defined Network-on-Chip (SDNoC)-based architecture. Our solution can easily be adapted to support devices ranging from low-power computing nodes placed at the edge of the Cloud to high-performance many-core processors in the Cloud DCs, by leveraging on a modular design approach. The proposed design merges the benefits of hierarchical network-on-chip (NoC) topologies (via fusing the ring and the 2D-mesh topology), with those brought by dynamic reconfiguration (i.e., adaptation). Our proposed interconnect allows for creating different types of virtualised topologies aiming at serving different communication requirements and thus providing better resource partitioning (virtual tiles) for concurrent tasks. To further allow the software layer controlling and monitoring of the NoC subsystem, a few customised instructions supporting a data-driven program execution model (PXM) are added to the processing element’s instruction set architecture (ISA). In general, the data-driven programming and execution models are suitable for supporting the DL applications. We also introduce a mechanism to map a high-level programming language embedding concurrent execution models into the basic functionalities offered by our SDNoC for easing the programming of the proposed system. In the reported experiments, we compared our lightweight reconfigurable architecture to a conventional flattened 2D-mesh interconnection subsystem. Results show that our design provides an increment of the data traffic throughput of 9.5% and a reduction of 2.2× of the average packet latency, compared to the flattened 2D-mesh topology connecting the same number of processing elements (PEs) (up to 1024 cores). Similarly, power and resource (on FPGA devices) consumption is also low, confirming good scalability of the proposed architecture.

SDN-Based Secure Application Admission and Execution for Many-Cores

“…Its main advantage is to unify the management of different device vendors, removing the control from the network device, and bring it to a software Controller. Recent works investigate SDN for MCSoCs using a centralized approach [8,9,20], while others propose distributed SDN management [7,21], including cluster-based organizations [7].…”

“…Some SDN proposals target specific goals, as power management [21] and QoS [8], while other works are generic, focusing on the SDN paradigm support over the MCSoC architecture [9,22]. Ellinidou et al [20] address security, proposing a secure protocol to the Controller to configure SDN routers at runtime, using an architecture based on a Chiplet design, and not MCSoCs.…”

“…A cluster has a set of SPs, managed by one M PE. Figure 1 , which may be a task running in a given PE (centralized SDN [8,9,20]) or several tasks distributed in the system (distributed SDN [7,21]). The Controller is a task with OS privileges.…”

A Systemic and Secure SDN Framework for NoC-Based Many-Cores

“…The router becomes a simple and configurable unity able to redirect NoC packets according to the Controller rules. Due to its global knowledge of NoC's resources, the Controller may adopt policies to mitigate faults, to balance the communication load, to manage the NoC power consumption [7], and to provide QoS for real-time flows [3,4]. Moreover, all such features can be combined into the Controller, resulting in multi-objective management.…”

“…Although several works describe SDN designs for NoCs [7,8,12,13], we identify the lack of SDN frameworks detailing the protocols and methods to achieve secure SDN management. Therefore, the work's main contribution is a systemic and secure SDN framework (SDN-SS) for the design of MCSoCs, with the following original contributions: 1) a step-by-step framework description addressing the phases required to support a secure SDN management for MCSoCs (steps 1 to 5 in Figure 1(a)); 2) a secure SDN router configuration mechanism, step 3, based on a hardware/software co-design; 3) a dynamic subnet change protocol allowing user's tasks to change at runtime its communicating network, without losing packets (step 5).…”