PPT Slide
Thrashing & Load Control
- Thrashing: Overhead is higher than throughput per time unit. For paging performance, this means that page fault processing is taking more time than processes are getting over a period of time.
- Classic thrashing behavior seen by old page fault algorithm that allowed in more processes when the user CPU consumption rate decreased. This would lead to more paging, more overhead, less user CPU consumption. A positive feedback loop resulted and the machine spent more time paging than allowing user processes to run.
- This leads to the need for better load control (Figure 12.11).