Solaris™ Internals: Solaris 10 and OpenSolaris Kernel Architecture, Second Edition

3. Scheduling Classes and the Dispatcher

Contributions by Jonathan Chew, Eric Saxe, and Andrei Dorofeev

One of the core functions of any modern multitasking operating system is the management and scheduling of runnable threads onto available processors. The kernel’s primary goal is to maintain fairness: allowing all threads to get processor cycles while ensuring that critical work, such as interrupt handling, gets done as needed. This is the function of the kernel dispatcher—selecting threads and dispatching them to available system processors. The threads will be in one of several possible scheduling classes, by which the thread’s priority is established relative to all other threads on the system. Multiple scheduling classes provide a powerful ...