FreeRTOS内存管理方案的分析与改进  

Analysis and improvement of memory management scheme in FreeRTOS

作　　者：刘林[1] 朱青[1] 何昭晖 

机构地区：[1]湖南大学电气与信息工程学院,长沙410082 [2]威胜集团有限公司,长沙410205

出　　处：《计算机工程与应用》2016年第13期76-80,共5页Computer Engineering and Applications

基　　金：国家高技术研究发展计划(863)(No.2011AA05A120)

摘　　要：针对FreeRTOS内存管理方案分配时间不确定,切割次数较多,利用率低及合并机制不足等缺点,采用一种"精确切割"和"延时合并"相结合的策略以最大限度减少内存碎片,提高内存利用率。具体实现方法是在FreeRTOS中引入TLSF(Two-level Segregated Fit)算法数据结构,采用二级位图索引对动态内存进行管理,并改进TLSF算法的内存分配和释放过程;最后将改进的算法以及FreeRTOS移植到STM32开发平台上进行实验测试。测试结果表明该方法提高了FreeRTOS的内存分配速度,减少了内存碎片率。The memory management shceme of Free Real Time Operating System（FreeRTOS）has some shortcomings,such as uncertain allocation time, frequent cutting, low utilization rate as well as inadequate consolidation mechanism,this paper adopts a strategy of“precised cutting”and“delayed merging”in order to reduce memory fragment and raiseutilization rate furthest. Thus it introduces TLSF（Two-Level Segregated Fit）algorithm into FreeRTOS, using two levelsof bitmap index to manage its dynamic memory and improving its process of memory allocation as well as release, thenconducts the experimental test on the STM32 platform which ports with FreeRTOS. At last, the results show that thismethod improves the speed of memory allocation and reduces memory fragmentation rate.

关 键 词：FreeRTOS操作系统 内存管理 TLSF算法 STM32开发平台 内存碎片 

分 类 号：TP316.2[自动化与计算机技术—计算机软件与理论]