嵌入式Linux系统内核实时性研究
发布时间:2018-09-09 09:23
【摘要】:在众多的嵌入式操作系统中,嵌入式Linux系统由于其源代码开放、内核易于裁剪、可移植性强等特点,被广泛应用在嵌入式系统的开发中。然而,Linux最初作为分时系统设计,其目标是提高系统的吞吐量和整体性能,在实时性方面很难满足一些嵌入式实时应用系统的要求,因此有必要对Linux系统实时性进行研究。 在对Linux系统内核研究基础上,本文对Linux构造嵌入式实时系统的优势和在实时性方面的缺陷进行了分析,重点研究了提高Linux实时性的方法。进程调度策略是影响嵌入式Linux系统实时性能最重要的因素。本文根据Linux中task_struct数据结构的定义,对非实时任务采用多级反馈轮转调度,实时任务采用FIFO(先来先服务)和RR(时间片轮转)调度。并通过两方面的工作来提高嵌入式Linux内核实时性。一方面,利用双内核结构,将RT-Linux移植到Linux中作为处理实时任务的内核。系统采用虚拟中断机制由实时核心进行中断响应,解决中断屏蔽问题。另一方面,通过添加实时调度器从Linux进程调度机制上改善系统性能。对于静态周期任务,采用RM调度器,周期短的任务优先级高;对于动态任务,采用EDF调度器,,根据任务的最早截止时间,截止时间早的任务优先级高。经过验证,本文方法能有效提高嵌入式Linux内核的实时性。
[Abstract]:Among many embedded operating systems, embedded Linux system is widely used in the development of embedded system because of its open source code, easy to cut the kernel, strong portability and so on. However, Linux was originally designed as a time-sharing system, its goal is to improve the throughput and overall performance of the system, it is difficult to meet the real-time requirements of some embedded real-time application systems, so it is necessary to study the real-time performance of Linux system. On the basis of the research on the kernel of Linux system, this paper analyzes the advantages and disadvantages of Linux in constructing embedded real-time system, and focuses on the methods to improve the real-time performance of Linux. Process scheduling strategy is the most important factor affecting the real-time performance of embedded Linux system. In this paper, according to the definition of task_struct data structure in Linux, multilevel feedback rotation scheduling is adopted for non-real-time tasks, and FIFO (first come, first served) and RR (time slice rotation) scheduling for real-time tasks. And through two aspects of work to improve the real-time embedded Linux kernel. On the one hand, RT-Linux is transplanted to Linux as the kernel to handle real-time tasks by using dual-kernel structure. The system adopts the virtual interrupt mechanism to respond to the interrupt by the real-time core to solve the problem of interrupt shielding. On the other hand, the system performance is improved by adding a real-time scheduler from the Linux process scheduling mechanism. For static periodic tasks, RM scheduler is adopted, and for dynamic tasks, EDF scheduler is used. According to the earliest deadline of tasks, the tasks with early deadline are of high priority. It is proved that this method can effectively improve the real-time performance of embedded Linux kernel.
【学位授予单位】:沈阳工业大学
【学位级别】:硕士
【学位授予年份】:2012
【分类号】:TP316.81;TP368.1
本文编号:2231978
[Abstract]:Among many embedded operating systems, embedded Linux system is widely used in the development of embedded system because of its open source code, easy to cut the kernel, strong portability and so on. However, Linux was originally designed as a time-sharing system, its goal is to improve the throughput and overall performance of the system, it is difficult to meet the real-time requirements of some embedded real-time application systems, so it is necessary to study the real-time performance of Linux system. On the basis of the research on the kernel of Linux system, this paper analyzes the advantages and disadvantages of Linux in constructing embedded real-time system, and focuses on the methods to improve the real-time performance of Linux. Process scheduling strategy is the most important factor affecting the real-time performance of embedded Linux system. In this paper, according to the definition of task_struct data structure in Linux, multilevel feedback rotation scheduling is adopted for non-real-time tasks, and FIFO (first come, first served) and RR (time slice rotation) scheduling for real-time tasks. And through two aspects of work to improve the real-time embedded Linux kernel. On the one hand, RT-Linux is transplanted to Linux as the kernel to handle real-time tasks by using dual-kernel structure. The system adopts the virtual interrupt mechanism to respond to the interrupt by the real-time core to solve the problem of interrupt shielding. On the other hand, the system performance is improved by adding a real-time scheduler from the Linux process scheduling mechanism. For static periodic tasks, RM scheduler is adopted, and for dynamic tasks, EDF scheduler is used. According to the earliest deadline of tasks, the tasks with early deadline are of high priority. It is proved that this method can effectively improve the real-time performance of embedded Linux kernel.
【学位授予单位】:沈阳工业大学
【学位级别】:硕士
【学位授予年份】:2012
【分类号】:TP316.81;TP368.1
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