Chuck Pilkington

StepNP: a system-level exploration platform for network processors

The fast-changing communications market requires high-performance yet flexible network-processing platforms. StepNP is an exploratory network processor simulation environment for exploring applications, multiprocessor network-processing architectures, and SoC tools. Supporting model interaction, instrumentation, and analysis, the platform lets R&D teams easily add new processors, coprocessors, and interconnects.

Parallel programming models for a multiprocessor SoC platform applied to networking and multimedia

The MultiFlex system is an application-to-platform mapping tool that integrates heterogeneous parallel components-H/W or S/W- into a homogeneous platform programming environment. This leads to higher quality designs through encapsulation and abstraction. Two high-level parallel programming models are supported by the following MultiFlex platform mapping tools: a distributed system object component (DSOC) object-oriented message passing model and a symmetrical multiprocessing (SMP) model using shared memory. We demonstrate the combined use of the MultiFlex multiprocessor mapping tools, supported by high-speed hardware-assisted messaging, context-switching, and dynamic scheduling using the StepNP demonstrator multiprocessor system-on-chip platform, for two representative applications: 1) an Internet traffic management application running at 2.5 Gb/s and 2) an MPEG4 video encoder (VGA resolution, at 30 frames/s). For these applications, a combination of the DSOC and SMP programming models were used in interoperable fashion. After optimization and mapping, processor utilization rates of 85%-91% were demonstrated for the traffic manager. For the MPEG4 decoder, the average processor utilization was 88%

Parallel programming models for a multi-processor SoC platform applied to high-speed traffic management

We describe the MultiFlex multi-processor SoC programming environment, with the focus on two programming models: a distributed system object component (DSOC) message passing model, and a symmetrical multi-processing (SMP) model using shared memory. The MultiFlex tools map these models onto the StepNP multi-processor SoC platform, while making use of hardware accelerators for message passing and task scheduling. We present the results of mapping an Internet traffic management application, running at 2.5 Gb/s.

Application of a multi-processor SoC platform to high-speed packet forwarding

In this paper, we explore the requirements of emerging complex SoCs and describe StepNP, an experimental flexible, multi-processor SoC platform targeted towards communications and networking applications. We present the results of mapping an internet protocol (IPv4) packet forwarding application, running at 2.5 Gb/s and 10 Gb/s. We demonstrate how the use of high-speed hardware-assisted messaging and dynamic task allocation in the StepNP platform allows us to achieve very high processor utilization rates (up to 97%) in spite of the presence of high network-on-chip and memory access latencies. The inter-processor communication overhead is kept very low, representing only 9% of instructions.

Exploiting TLM and Object Introspection for System-Level Simulation

The introduction of transaction level modeling (TLM) allows a system designer to model a complete application, composed of hardware and software parts, at several levels of abstraction. The simulation speed of TLM is orders of magnitude faster than traditional RTL simulation; nevertheless, it can become a limiting factor when considering a multi-processor system-on-chip (MP-SoC), as the analysis of these systems can be very complex. The main goal of this paper is to introduce a novel way of exploiting TLM features to increase simulation efficiency of complex systems by switching TLM models at runtime. Results show that simulation performance can be increased significantly without sacrificing the accuracy of critical application kernels

He-P2012: architectural heterogeneity exploration on a scalable many-core platform

Architectural heterogeneity is a promising solution to overcome the utilization wall and provide Moores Law-like performance scaling in future SoCs. However, heterogeneous architectures increase the size and complexity of the design space along several axes: granularity of the heterogeneous processors, coupling with the software cores, communication interfaces, etc. As a consequence, significant enhancements are required to tools and methodologies to explore the huge design space effectively. In this work, we provide three main contributions: first, we describe an extension to the STMicroelectronics P2012 platform to support tightly-coupled shared memory HW processing elements (HWPE), along with our changes to the P2012 simulation flow to integrate this extension. Second, we propose a novel methodology for the semi-automatic definition and instantiation of HWPEs from a C program based on a interface description language. Third, we explore several architectural variants on a set of benchmarks originally developed for the homogeneous version of P2012, achieving up to 123x speedup for the accelerated code region (~98% of the Amdahl limit for the whole application), thereby demonstrating the efficiency of tightly memory-coupled hardware acceleration.

He-P2012: Architectural heterogeneity exploration on a scalable many-core platform

Architectural heterogeneity is a promising solution to overcome the utilization wall and provide Moores Law-like performance scaling in future SoCs. However, heterogeneous architectures increase the size and complexity of the design space along several axes: granularity of the heterogeneous processors, coupling with the software cores, communication interfaces, etc. As a consequence, significant enhancements are required to tools and methodologies to explore the huge design space effectively. In this work, we provide three main contributions: first, we describe an extension to the STMicroelectronics P2012 platform to support tightly-coupled shared memory HW processing elements (HWPE), along with our changes to the P2012 simulation flow to integrate this extension. Second, we propose a novel methodology for the semi-automatic definition and instantiation of HWPEs from a C program based on a interface description language. Third, we explore several architectural variants on a set of benchmarks originally developed for the homogeneous version of P2012, achieving up to 123x speedup for the accelerated code region (~98% of the Amdahl limit for the whole application), thereby demonstrating the efficiency of tightly memory-coupled hardware acceleration.

Network processing challenges and an experimental NPU platform [network processor unit]

The fast-changing communications market requires high-performance yet flexible network-processing platforms. StepNP/spl trade/ is an exploratory network processor simulation environment for exploring router applications, multiprocessor network-processing architectures, and SoC tools. Supporting model interaction, instrumentation, and analysis, the platform lets R&D teams easily add new processors, coprocessors, and interconnects.

He-P2012: Performance and Energy Exploration of Architecturally Heterogeneous Many-Cores

The end of Dennardian scaling in advanced technologies brought about new architectural templates to overcome the so-called utilization wall and provide Moore’s Law-like performance and energy scaling in embedded SoCs. One of the most promising templates, architectural heterogeneity, is hindered by high cost due to the design space explosion and the lack of effective exploration tools. Our work provides three contributions towards a scalable and effective methodology for design space exploration in embedded MC-SoCs. First, we present the He-P2012 architecture, augmenting the state-of-art STMicroelectronics P2012 platform with heterogeneous shared-L1 coprocessors called HW processing elements (HWPE). Second, we propose a novel methodology for the semi-automatic definition and instantiation of shared-memory HWPEs from a C source, supporting both simple and structured data types. Third, we demonstrate that the integration of HWPEs can provide significant performance and energy efficiency benefits on a set of benchmarks originally developed for the homogeneous P2012, achieving up to 123x speedup on the accelerated code region (∼98 % of Amdahl’s law limit) while saving 2/3 of the energy.

A dynamic stream link for efficient data flow control in NoC based heterogeneous MPSoC

As Systems-on-Chip size increase, the communication costs become critical and Networks-on-Chip (NoC) bring innovative solutions. Efficient stream-based protocols over NoC have been widely studied to address dataflow communications. They are usually controlled by a set of static parameters. However, new applications, such as high-resolution video decoders, present more data-dependent behaviors forcing communication protocols to support higher dynamicity. For this purpose, we present in this paper dynamic stream links for stream-based end-to-end NoC communications by introducing two link protocols, both independent of the transfer size, allowing to improve the hardware/software control flexibility. The proposed protocols have been modeled in a MPSoC virtual platform and the hardware cost evaluated. Based on simulations, we provide guidelines to exploit these protocols according to application needs.