PPT Slide
Scheduling in Real Operating Systems
- Windows NT 3.51
- Priority thread scheduler with 32 levels in two classes (real-time & time-sharing threads).
- Priorities can increase due to I/O (disk, keyboard, mouse, etc.) and decrease due to CPU usage.
- Mach
- 128 priority levels
- Hands-off scheduling: a receiver blocked on a message will get scheduled immediately, regardless of the scheduling queues.
- Linux
- Three scheduler algorithms: RR & FIFO (used in real time applications) and OTHER; based on POSIX work.
- See “man sched_setscheduler” for more information.