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Improving Machine Learning Predictions with Weight Sharing

A new technique enhances efficiency in Machine Learning models for faster predictions.

― 7 min read


Boosting ML EfficiencyBoosting ML Efficiencywith Weight SharingML predictions.Innovative methods for faster, accurate
Table of Contents

Many modern applications use Machine Learning (ML) to improve how they make predictions. For these applications, getting better predictions quickly is important. People are researching how to make ML models work better together with computer Hardware. The goal is to make sure that ML models can quickly give accurate results.

There are various methods used to improve how fast ML models work. These methods include things like reducing the size of the model, changing the way numbers are stored, and creating special designs for hardware that can perform these computations more efficiently. However, most of these techniques look at only one specific way to improve speed and Accuracy. This paper talks about the need for methods that can adapt to changing conditions where a single way doesn't always work best.

The focus is on a new technique that allows for the efficient use of resources when dealing with a stream of questions or tasks. This new approach looks at how often certain tasks use the same resources. By understanding this pattern, the system can work better and respond more quickly.

Background

The demand for ML solutions is growing. They are used in various areas, such as self-driving cars, healthcare, and more. Many of these applications must make predictions within a specific time limit. If they do not meet this time requirement, their effectiveness decreases. Users expect these applications to deliver accurate predictions while also responding quickly.

Different methods have been developed to improve the speed and accuracy of ML models. These include changing the way models are structured, decreasing the number of calculations required, and using specific types of hardware that can handle these tasks more effectively. However, these solutions often optimize for just one condition, meaning they may not work well if circumstances change.

Applications that require quick decisions might face unexpected changes. This could be due to varying demand (like more users suddenly making requests) or shifts in how complicated the tasks are. Under these conditions, using just one static model is often not effective. If the workload changes, the model used may result either in missed opportunities or reduced quality in predictions.

The ideal solution would allow for dynamically selecting the best approach based on the current workload and conditions. This way, the system can consider the changing demands from the applications and make adjustments accordingly.

Weight-Shared Neural Networks

A recent approach called weight-sharing in neural networks has shown promise for applications with different requirements. Weight-sharing allows multiple models to use the same underlying parameters while changing their structure slightly. This enables one large model to serve different tasks without requiring separate models for each one.

With weight-sharing, the network can adapt to different needs. For instance, if one task requires speed and another requires accuracy, the system can adjust which part of the model is used based on the requirements of the current task. This allows for a more efficient use of computing resources, as the same parameters can cater to different queries or tasks simultaneously.

Hardware Support for Weight-Shared Inference

The ability to serve multiple queries with different demands for speed and accuracy requires well-designed hardware. The right hardware can help reduce delays and optimize the use of energy. However, simply adding more processing power is not enough. There is a need for specific designs that can manage the weights shared among various models.

The hardware should facilitate efficient use of memory, ensuring that commonly used weights remain accessible. This is important because moving data in and out of memory can slow down processing. If parts of the model are stuck waiting for data, it can negate any performance gains achieved through other optimizations.

Optimizing the hardware also involves creating specialized caches that can temporarily hold data. These caches should be able to store frequently accessed weights and values while minimizing the time it takes to retrieve them.

Dynamic Query Handling

To efficiently serve a stream of questions or tasks in real-time, a Scheduler is needed. This scheduler must decide which part of the model to activate for each query based on the current situation. It should also decide what data should remain cached for quick access.

The scheduler must consider each query's accuracy and speed requirements. It will choose which model is best suited for the current task. This requires not only knowledge of the queries but also insight into the system's current status, like how much data is already cached and what resources are available.

The selection process parallels how a person might choose an outfit depending on the weather and what activities they expect to engage in. Similarly, the scheduler needs to be adaptive, able to consider the constraints and needs of each incoming query.

Implementation Details

In our approach, the hardware and software components are designed to work together. The hardware includes a specialized architecture that provides the necessary support for Weight Sharing. Components within the system work in conjunction, dynamically adapting based on the current workload.

Scheduler

The scheduler acts as the brain of the system. It processes incoming queries and makes real-time decisions. Each query is accompanied by its required accuracy and speed characteristics. The scheduler uses information from previously processed queries to inform its decisions.

The scheduler operates in two primary phases: it selects the most appropriate model to serve a query and decides which weights to keep in cache. This selection process involves estimating the expected Latency for serving a query based on the cached weights.

Caching is crucial, as it helps to reduce the need for fetching data from slower off-chip memory. The scheduler continually updates its cache based on past queries, ensuring that the most relevant data is ready for quick access.

Specialized Hardware

On the hardware end, components are designed to balance workloads efficiently. The main goal is to minimize latency while maximizing throughput. To achieve this, various processing elements are arranged in a way that allows simultaneous operations, improving efficiency.

A key part of the hardware design is a persistent buffer (PB). This buffer holds weights that are frequently accessed, allowing for improved performance. By reducing the need to access data from off-chip memory repeatedly, the system saves time and energy.

The design of the hardware must consider memory limitations as well. It must efficiently manage the available space while still allowing for quick access and optimal performance.

Experimental Results

The proposed system has been tested against different models to evaluate its performance. The results show that it can significantly reduce latency while improving accuracy. By utilizing both hardware optimizations and smart scheduling, the system can serve requests more quickly and effectively.

Latency and Accuracy Measurements

In testing, the system showed a reduction in average latency of up to 25% while achieving an accuracy increase of nearly 1%. These improvements are significant, particularly for applications that operate under strict time constraints.

When the model is required to handle different types of queries, it can adjust dynamically using the scheduler, leading to better performance and efficiency. The ability to switch between different configurations on the fly allows applications to operate within their specific requirements more effectively.

Energy Consumption

Energy consumption is a crucial factor in determining the overall efficiency of the system. The new design has shown substantial savings in energy use, particularly when it comes to fetching data from off-chip memory. By optimizing how data is cached and accessed, the system can achieve energy savings of nearly 78.7%.

The collaborative efforts of hardware and software not only boost performance but also ensure that energy consumption is kept to a minimum, making it ideal for use in resource-constrained environments.

Conclusion

The integration of weight-shared neural networks with a specialized hardware-software design creates a robust system that can efficiently handle a variety of ML tasks. By allowing for dynamic changes based on current workloads, the system can provide improved accuracy and reduced latency.

As applications of Machine Learning continue to grow, the need for efficient processing becomes increasingly critical. This approach is well-positioned to meet those needs, providing an effective solution for real-time response in demand-sensitive environments.

Future work should focus on further refining the scheduler, improving hardware capabilities, and exploring additional applications where this model can be implemented effectively. Through ongoing research and development, the field of Machine Learning can continue to evolve and adapt, meeting the ever-changing demands of modern applications.

Original Source

Title: Subgraph Stationary Hardware-Software Inference Co-Design

Abstract: A growing number of applications depend on Machine Learning (ML) functionality and benefits from both higher quality ML predictions and better timeliness (latency) at the same time. A growing body of research in computer architecture, ML, and systems software literature focuses on reaching better latency-accuracy tradeoffs for ML models. Efforts include compression, quantization, pruning, early-exit models, mixed DNN precision, as well as ML inference accelerator designs that minimize latency and energy, while preserving delivered accuracy. All of them, however, yield improvements for a single static point in the latency-accuracy tradeoff space. We make a case for applications that operate in dynamically changing deployment scenarios, where no single static point is optimal. We draw on a recently proposed weight-shared SuperNet mechanism to enable serving a stream of queries that uses (activates) different SubNets within this weight-shared construct. This creates an opportunity to exploit the inherent temporal locality with our proposed SubGraph Stationary (SGS) optimization. We take a hardware-software co-design approach with a real implementation of SGS in SushiAccel and the implementation of a software scheduler SushiSched controlling which SubNets to serve and what to cache in real-time. Combined, they are vertically integrated into SUSHI-an inference serving stack. For the stream of queries, SUSHI yields up to 25% improvement in latency, 0.98% increase in served accuracy. SUSHI can achieve up to 78.7% off-chip energy savings.

Authors: Payman Behnam, Jianming Tong, Alind Khare, Yangyu Chen, Yue Pan, Pranav Gadikar, Abhimanyu Rajeshkumar Bambhaniya, Tushar Krishna, Alexey Tumanov

Last Update: 2023-06-21 00:00:00

Language: English

Source URL: https://arxiv.org/abs/2306.17266

Source PDF: https://arxiv.org/pdf/2306.17266

Licence: https://creativecommons.org/licenses/by/4.0/

Changes: This summary was created with assistance from AI and may have inaccuracies. For accurate information, please refer to the original source documents linked here.

Thank you to arxiv for use of its open access interoperability.

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