提高嵌入式文件系统在块设备上实时性的研究

摘要

标准块设备驱动读写最耗时点在处理命令上,导致在其上配置的嵌入式文件系统实时性降低.针对该问题,提出了虚块管理机制,在块设备驱动层之上建立由虚块组成的虚拟块设备,虚块由固定数目的真实扇区组成.文件系统对虚拟块设备进行操作,虚拟块设备对真实块设备进行操作,用户读写同等大小的数据能够有效减少驱动访问次数.分析测试结果得出,嵌入式文件系统使用虚块管理机制之后,能够显著提升整体读写性能,且组成虚块的真实扇区越多,虚拟块设备提升文件系统性能的效果越明显,这些都表明了虚块管理机制能够有效提升文件系统的实时性.%The most time-consuming point of standard block device's driver reading/writing is dealing with command,this character will reduce the real-time when configuring embedded file system in the block device.To solve this problem,this paper proposes the virtual block management mechanism,this mechanism will create the virtual block device upon the block device's driver layer,the virtual block is compose of a fixed number of real sectors.The file system is interacting with the virtual block device,and the virtual block device is interacting with the real block device,when user reading/writing the same size data,the virtual block device can effectively reduce the number of access to the real block device.According to test result,when embedded file system using the virtual block management mechanism,the reading/writing performance is remarkably advanced,as the virtual block is compose with more number of real sectors,the virtual block device can advance the performance of file system more effectively.All these indicate that the virtual block management mechanism can effectively improve the real-time of file system.