Optimizing the Cost of Garbage Collection in F2FS Using Working Set Strategy

Abstract

As an important part of the operating system, the file system has always received wide attention, and different types of file system architectures have been constantly proposed and practiced, this time, we mainly focus on the log structured file system (LFS) type flash friendly file system (F2FS) file system. The existing garbage collection algorithm has offered a interface for future improvement. Hence, we tried to improve existing garbage collection algorithms by implementing the working set strategy in victim select algorithm and analyze the existing deficiencies of the F2FS file system. Under the original strategy, when F2FS selects a segment, it will select the section with the fewest valid blocks. After we change it, we have completed the balance consideration of the change time, the number of valid blocks, and the proportion of changes. It is expected that the Flash device will have the longer life. By using the proposed technique, the cost of garbage collection has reduced by 10%. At the same time, based on the cold and hot data separation characteristics of the F2FS file system, we propose optimization suggestions for the cold and hot data separation strategy.