PPT Slide
Scheduling in Real Operating Systems
- Solaris
- Similar to SVR4
- Adds 10 more priority levels (160-169 for interrupt handlers).
- Shorter time quanta: from 4 to 20 milliseconds.
- Priority inheritance - a process with a lock will inherit the priority of a process blocked on the lock. Prevents priority inversion -- the starvation of a chain of processes that have different priorities.
- OS/2 version 2.0
- 128 priority levels in 4 classes (time critical, server, regular and idle classes).
- Time quanta: 32 to 248 milliseconds.
- Interactive, freshly-unblocked & waiting priorities increase