Optimizing Heterogeneous Task Scheduling through Adaptive Priority in Task-based Runtime Systems

Основные понятия

INSPIRIT, an efficient and lightweight scheduling framework with adaptive priority, is proposed to optimize task scheduling in task-based runtime systems on heterogeneous hardware. INSPIRIT introduces two novel task attributes - inspiring ability and inspiring efficiency - to determine task priorities, eliminating the need for application domain knowledge. INSPIRIT also jointly considers runtime information such as the number of ready tasks in worker queues to guide task scheduling, exposing more performance opportunities in heterogeneous hardware while reducing overhead.

Аннотация

The paper proposes INSPIRIT, an efficient and lightweight scheduling framework designed for task-based runtime systems on heterogeneous hardware resources.

Key highlights:

• INSPIRIT introduces two novel task attributes - inspiring ability and inspiring efficiency - to determine task priorities, eliminating the need for application domain knowledge.
• INSPIRIT jointly considers runtime information such as the number of ready tasks in worker queues to guide task scheduling, exposing more performance opportunities in heterogeneous hardware while reducing overhead.
• Experimental results demonstrate that INSPIRIT achieves superior performance compared to cutting-edge scheduling schemes on both synthesized and real-world task DAGs.

The paper first observes that priority-based scheduling can effectively improve performance, but the generation of optimal priorities is challenging as it heavily depends on both the application and hardware characteristics. To address this, the authors propose the concepts of inspiring ability and inspiring efficiency.

Inspiring ability represents the number of dependencies released upon task completion, while inspiring efficiency represents the number of dependencies a task can release per unit time. INSPIRIT leverages these two attributes to adaptively adjust task priorities during runtime. When there are not enough tasks scheduled, INSPIRIT prioritizes tasks with higher inspiring efficiency to ensure maximum hardware utilization. When there are sufficient tasks, INSPIRIT prioritizes tasks with higher inspiring ability to generate more potential tasks and sustain parallelism.

INSPIRIT also monitors the number of ready tasks (Nready) in worker queues as an indicator to guide task execution. By regulating Nready, INSPIRIT can effectively reduce the overhead of task mapping adjustment across different hardware while concurrently monitoring the runtime state.

The evaluation results demonstrate that INSPIRIT achieves superior performance compared to cutting-edge scheduling schemes on both synthesized and real-world task DAGs, with speedups ranging from 1.03x to 3.22x.

Статистика

The number of tasks executed within a unit time window is less than the upper limit, nbound, which is closely related to the hardware configurations and the type of tasks executed.

Цитаты

"INSPIRIT introduces two novel task attributes inspiring ability and inspiring efficiency for dictating scheduling, eliminating the need for application domain knowledge."
"INSPIRIT jointly considers runtime information such as ready tasks in worker queues to guide task scheduling, exposing more performance opportunities in heterogeneous hardware at runtime while effectively reducing the overhead for adjusting task priorities."

Ключевые выводы из

INSPIRIT

by Yiqing Wang,... в arxiv.org 04-05-2024

https://arxiv.org/pdf/2404.03226.pdf

Дополнительные вопросы

How can INSPIRIT's adaptive priority scheduling be extended to handle dynamic task arrival patterns or task dependencies that change during runtime

To extend INSPIRIT's adaptive priority scheduling to handle dynamic task arrival patterns or changing task dependencies during runtime, we can introduce dynamic adjustment mechanisms based on real-time monitoring and analysis. One approach could involve continuously monitoring the task queue and the dependencies between tasks. When new tasks arrive or dependencies change, the system can dynamically recalculate the inspiring ability and inspiring efficiency metrics for the affected tasks. By incorporating real-time data and feedback loops, INSPIRIT can adapt its scheduling decisions on the fly to accommodate these dynamic changes. Additionally, machine learning algorithms or reinforcement learning techniques can be employed to predict future task patterns and adjust priorities proactively.

What are the potential limitations or drawbacks of the inspiring ability and inspiring efficiency metrics, and how could they be further refined or combined with other task characteristics

While inspiring ability and inspiring efficiency metrics offer valuable insights into task scheduling, they may have limitations in certain scenarios. One potential drawback is that these metrics may not fully capture the complexity of task dependencies or the specific characteristics of different applications. To address this, we could refine these metrics by incorporating additional factors such as task execution time, resource utilization, or critical path analysis. By combining inspiring ability and inspiring efficiency with other task characteristics, we can create a more comprehensive and nuanced prioritization system that takes into account a wider range of factors influencing task scheduling. Furthermore, machine learning algorithms can be utilized to optimize the weighting and calculation of these metrics based on historical data and performance feedback.

Given the heterogeneous nature of modern hardware, how could INSPIRIT's scheduling approach be adapted to consider energy efficiency or power constraints in addition to performance optimization

To adapt INSPIRIT's scheduling approach to consider energy efficiency or power constraints in addition to performance optimization, we can introduce energy-aware scheduling policies and constraints into the task prioritization process. This could involve incorporating energy consumption models for different hardware components, such as CPUs and GPUs, into the task attribute calculations. By assigning priorities based on not only performance metrics but also energy efficiency considerations, INSPIRIT can optimize task scheduling to minimize energy consumption while maintaining high performance levels. Additionally, dynamic power management techniques can be integrated to adjust task priorities based on real-time power measurements and constraints, ensuring that the system operates within specified power limits without sacrificing performance.