Seonglae ChoRunqueue
- Each CPU has a runqueue made up of 140 priority lists
Implementation
- Two runqueues for CPU is active and expired for find active
- expired is queue for waiting re-assignment of time slice
The switch between active and expired queue list can thus only happen when no real-time tasks are in the
TASK_RUNNING stateSCHED_NORMAL
- Processes that have consumed their time slice become expired
- Eventually every active process manages to get the CPU
- For the SCHED_NORMAL class the Linux scheduler figures out whether a process is I/O-bound or CPU-bound.
- The kernel keeps track on how much time a process sleeps vs. how much time a process runs.