Design of multithreaded JFFS3 to improve Flash read/write performance

• Main Authors: Steven, 林甫鈞
• Other Authors: Arul
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/37982521922273946266

碩士 === 輔仁大學 === 資訊工程學系 === 98 === Abstract Flash memory has become a popular device and widely used in mobile electronic products because of its advantages of shock resistance, lightweight, low power consumption and faster random access. Flash memory’s Solid State Disks (SSD) are slowly being used instead of Hard Disk Drives (HDD) in lightweight notebook PCs. Since, flash memory uses out-of-place update we must use two different kinds of method to manage the flash memory. One is by using the general disk file system and the other is through the flash translation layer to manage flash memory. Like the flash translation layer the flash-based file system also can directly manage the flash memory. Currently, multi-core computers have become the mainstream and SSD can support inherent parallel access block, but if the software doesn’t support parallel processing, the hardware can’t be efficiently used. In order to address this issue as well as taking advantage of current computers that are built with dual and quad cores, for this research we plan to use all the cores available as well as using multithreaded technology to improve the read/write times of flash memory. For this research, we used the flash-based file system called Journaling Flash File System version3 (JFFS3). We utilized the multi-core computers and added multithreaded scheme in the Journaling Flash File System version3 to improve the flash read/write performance. For the experiment purpose, different kinds of files such as text files, music files and movie files of different sizes were used. The improvement in read/write time shows promising results using various cores. As a result of our simulation, we can find that using two threads the read/write performance shows an improvement of 1.8 times than using single thread on a dual-core processor. On a quad core processor using four threads, the flash read/write performance shows 3.8 times faster than using single thread. Finally, on an Octo core processor, using eight threads, the performance improvement is about 7.5 times than using single thread. Since the hardware comes with multi-core processor, the technology can take advantage of this multiple cores to improve the read/write performance of the flash memory.