Low-energy EDF (earliest deadline first) real-time task scheduling method for mixed main memory embedded system

Abstract

The invention discloses a low-energy EDF (earliest deadline first) real-time task scheduling method for a mixed main memory embedded system. With the adoption of advantages that a PCM (phase-change memory) is non-volatile, low in energy and high in performance and in combination of a dynamic EDF algorithm, real-time constraint of the whole task set is guaranteed, accordingly, power consumption of the whole system is reduced, and the real-time constraint of tasks is not influenced. The method comprises the steps as follows: 1), tasks in the task set T are arranged according to a (Wpi-Wdi)Nwi descending order; 2), all the tasks are initialized; 3), the tasks are placed in the PCM one by one according to a task sequence of the task set T, if the task set still can be scheduled, the task is marked as P-task, Ci is equal to Wpi, and operation is performed until all the tasks in the task set T are checked; 4), the system starts to execute the tasks; 5), free time which is assigned to all the tasks with the dynamic EDF algorithm is calculated; 6), the free time is assigned with the dynamic EDF algorithm according to priority; and 7), the step 6 is repeated until the whole task set T is finished.

Description

technical field [0001] The invention relates to the field of real-time embedded systems (Real-Time Embedded Systems), in particular to a low-energy consumption EDF real-time task scheduling method for mixed main memory embedded systems. Background technique [0002] An embedded system is a computer system for some specific applications. Considering factors such as security and reliability of embedded systems, its applications usually have real-time constraints. In recent years, embedded systems have developed rapidly, and various smart devices have quietly entered people's lives. However, as functions and applications become more complex, battery life becomes the biggest limitation on these devices. Studies have shown that in modern embedded systems, the energy consumption of the main memory accounts for an increasing proportion of the entire system energy consumption. Therefore, reducing the energy consumption of the main memory is an effective method to prolong the avai...

AI Technical Summary

Problems solved by technology

The current research only considers the allocation of tasks but not the scheduling of tasks, and only optimizes the main memory controller without considering the specific real-time scheduling algorithm.

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