Priority Inversion (feat. Embeded system)

 Priority inversion is an operating system scenario in which a higher priority task is preempted by a lower priority task.

Problem: Higher priority task is blocked by a lower priority one. 

Solutions: 

1. Priority inheritance protocol: When a task blocks one or more higher-priority tasks it temporarily inherits the highest priority of the blocked tasks. 

- PIP does not prevent deadlock. It also cannot prevent other problems induced by semaphores(recall flawed semaphore implementation.)

2. Priority Ceiling

- PCP, temporary changing the priority. 

 

 

Priority Inversion

Solution: Priority Inheritance

Priority inversion

Solution