Editing Priority inversion (section)

==Consequences==
In some cases, priority inversion can occur without causing immediate harm—the delayed execution of the high-priority task goes unnoticed, and eventually, the low-priority task releases the shared resource. However, there are also many situations in which priority inversion can cause serious problems. If the high-priority task is left [[Resource starvation|starved]] of the resources, it might lead to a system malfunction or the triggering of pre-defined corrective measures, such as a [[watchdog timer]] resetting the entire system. The trouble experienced by the [[Mars Pathfinder]] lander in 1997<ref>{{citation |url=https://www.cs.unc.edu/~anderson/teach/comp790/papers/mars_pathfinder_long_version.html |title=What Really Happened on Mars |author=Glenn Reeves |publisher=JPL Pathfinder team |access-date=2019-01-04}}</ref><ref>{{citation |url=https://users.cs.fiu.edu/~cpoellab/teaching/cse40463/slides6.pdf |title=Explanation of priority inversion problem experienced by Mars Pathfinder |access-date=2019-01-04}}</ref> is a classic example of problems caused by priority inversion in [[Real-time computing|realtime]] systems.

Priority inversion can also reduce the [[perceived performance]] of the system. Low-priority tasks usually have a low priority because it is not important for them to finish promptly (for example, they might be a [[batch job]] or another non-interactive activity). Similarly, a high-priority task has a high priority because it is more likely to be subject to strict time constraints—it may be providing data to an interactive user, or acting subject to real-time response guarantees. Because priority inversion results in the execution of a lower-priority task blocking the high-priority task, it can lead to reduced system responsiveness or even the violation of response time guarantees.

A similar problem called [[Earliest deadline first scheduling#Deadline interchange|deadline interchange]] can occur within [[earliest deadline first scheduling]] (EDF).