CSC369H5 Chapter 1-2: Textbook MLFQ-Intro-Scheduling
Document Summary
Software that manages system supports conccurency shared memory management interaction with devices makes sure system operates correctly and e ciently takes physical resource turns it to more general & simpler vitual form of itself interfaces given by os. Used to access controlled resources known as standard library. Manages resources by giving equal sharing, and maintains control. Optimize turnaround time without knowing how long process runs for. Learn from the past, predict the future. Lower priority = using cpu for long periods of time. Rule 1: if priority(a) > priority(b), a runs and b doesn"t. Rule 2: if priority(a) = priority(b), a and b run in rr. Rule 3: when a job enters system, it"s given highest priority. Rule 4: once a job uses up schedule quantum at a given level, priority is reduced, regardless of how many times it has given up the cpu. Rule 5: after some time period, move all jobs to topmost queue.
