Figure 2 shows the architecture of RightSpeed. The main component is RSTask, a kernel module that receives requests to begin and end tasks and schedules the CPU speed accordingly. Its main components are the speed controller, the task type group file manager, the automatic schedule computer, and the idleness detector, each of which we will discuss later. Alongside RSTask is RSIoCnt, a kernel module that interposes on all file system requests to monitor when any synchronous I/O's are ongoing. The next kernel component is RSLog, a low-overhead logger we use for benchmarking and debugging. The last kernel mode component is RSInit, a driver that starts before all other drivers and facilitates communication between them. In user mode we have RSLib, a user-level library that the system loads into the address space of every application. It interacts with the GUI to interpose the user interface event delivery system and thereby implement the automatic task detector. This library also exports functions that applications can use to communicate with RightSpeed.
