Selective Context Switching on Flash Memory

摘要

Flash memory prevails as a mobile storage device because it offers a fast read access time and better shock resistance compared to a hard disk. However, generic operating systems such as Linux do not take advantages of the hardware performance of flash memory because they do not change the architectures which are optimized for hard disks. The existing operation systems switch contexts to handle requests upon every device activation. If Linux switches contexts with every request when using hard disks as storage devices,the context switching time is not burdened compared to its total I/O time. However, in the event that Linux uses flash memory as a storage device, the context switching time becomes greatly burdened due to its fast access time. This paper improves the context switching scheme by reducing the amount of unnecessary context switching. As a result,an overall performance increase of 5% is gained regardless of the workloads.