While Convolutional Neural Networks (CNNs) are going mainstream and deployed in widespread domains including safety-critical systems, the impact of reliability issues in CNN-hosting systems are still under-explored. In this paper, we experimentally evaluate the inherent fault tolerance of CNNs through fault injection experiments. Our experiments demonstrate that quantization increases reliability. We also show the most vulnerable bits in the IEEE 754 format representation. At the layer-level, a study on the network architecture was performed to identify the most vulnerable layers. This exploratory study is useful for comprehensive critical system reliability enhancement since only the vulnerable parts will be protected.
9 September 2023 in ACM Transactions on Embedded Computing Systems
Graph Neural Networks (GNNs) are becoming increasingly popular for vision-based applications due to their intrinsic capacity in modeling structural and contextual relations between various parts of an image frame. On another front, the rising popularity of deep vision-based applications at the edge has been facilitated by the recent advancements in heterogeneous multi-processor Systems on Chips (MPSoCs) that enable inference under real-time, stringent execution requirements. By extension, GNNs employed for vision-based applications must adhere to the same execution requirements. Yet contrary to typical deep neural networks, the irregular flow of graph learning operations poses a challenge to running GNNs on such heterogeneous MPSoC platforms. In this paper, we propose a novel unified design-mapping approach for efficient processing of vision GNN workloads on heterogeneous MPSoC platforms. Particularly, we develop MaGNAS, a mapping-aware Graph Neural Architecture Search framework. MaGNAS proposes a GNN architectural design space coupled with prospective mapping options on a heterogeneous SoC to identify model architectures that maximize on-device resource efficiency. To achieve this, MaGNAS employs a two-tier evolutionary search to identify optimal GNNs and mapping pairings that yield the best performance trade-offs. Through designing a supernet derived from the recent Vision GNN (ViG) architecture, we conducted experiments on four (04) state-of-the-art vision datasets using both ( i ) a real hardware SoC platform (NVIDIA Xavier AGX) and ( ii ) a performance/cost model simulator for DNN accelerators. Our experimental results demonstrate that MaGNAS is able to provide 1.57 × latency speedup and is 3.38 × more energy-efficient for several vision datasets executed on the Xavier MPSoC vs. the GPU-only deployment while sustaining an average 0.11% accuracy reduction from the baseline.
We propose FLASH-RL, a framework utilizing Double Deep Q-Learning (DDQL) to address system and static heterogeneity in Federated Learning (FL). FLASH-RL introduces a new reputation-based utility function to evaluate client contributions based on their current and past performances. Additionally, an adapted DDQL algorithm is proposed to expedite the learning process. Experimental results on MNIST and CIFAR-10 datasets demonstrate that FLASH-RL strikes a balance between model performance and end-to-end latency, reducing latency by up to 24.83% compared to FedAVG and 24.67% compared to FAVOR. It also reduces training rounds by up to 60.44% compared to FedAVG and 76% compared to FAVOR. Similar improvements are observed on the MobiAct Dataset for fall detection, underscoring the real-world applicability of our approach.
15 April 2023 in ACM Transactions on Architecture and Code Optimization
Deep learning (DL) models such as convolutional neural networks (ConvNets) are being deployed to solve various computer vision and natural language processing tasks at the edge. It is a challenge to find the right DL architecture that simultaneously meets the accuracy, power, and performance budgets of such resource-constrained devices. Hardware-aware Neural Architecture Search (HW-NAS) has recently gained steam by automating the design of efficient DL models for a variety of target hardware platforms. However, such algorithms require excessive computational resources. Thousands of GPU days are required to evaluate and explore an architecture search space such as FBNet [ 45 ]. State-of-the-art approaches propose using surrogate models to predict architecture accuracy and hardware performance to speed up HW-NAS. Existing approaches use independent surrogate models to estimate each objective, resulting in non-optimal Pareto fronts. In this article, HW-PR-NAS, 1 a novel Pareto rank-preserving surrogate model for edge computing platforms, is presented. Our model integrates a new loss function that ranks the architectures according to their Pareto rank, regardless of the actual values of the various objectives. We employ a simple yet effective surrogate model architecture that can be generalized to any standard DL model. We then present an optimized evolutionary algorithm that uses and validates our surrogate model. Our approach has been evaluated on seven edge hardware platforms from various classes, including ASIC, FPGA, GPU, and multi-core CPU. The evaluation results show that HW-PR-NAS achieves up to 2.5× speedup compared to state-of-the-art methods while achieving 98% near the actual Pareto front.
Vision Transformers have enabled recent attention-based Deep Learning (DL) architectures to achieve remarkable results in Computer Vision (CV) tasks. However, due to the extensive computational resources required, these architectures are rarely implemented on resource-constrained platforms. Current research investigates hybrid handcrafted convolution-based and attention-based models for CV tasks such as image classification and object detection. In this paper, we propose HyT-NAS, an efficient Hardware-aware Neural Architecture Search (HW-NAS) including hybrid architectures targeting vision tasks on tiny devices. HyT-NAS improves state-of-the-art HW-NAS by enriching the search space and enhancing the search strategy as well as the performance predictors. Our experiments show that HyT-NAS achieves a similar hypervolume with less than 5x training evaluations. Our resulting architecture outperforms MLPerf MobileNetVl by 6.3% accuracy improvement with 3.5x less number of parameters on Visual Wake Words.
1 November 2016 in Microprocessors and Microsystems