Arachne Priorities and Starvation

PRIORITY DESIGN QUESTIONS

• Are two priorities sufficient?

• How do we manage starvation?

• What is the performance cost of having arbitrary priority levels?

HOW TO PREVENT STARVATION

•  In a priority system, do we want to starve the low priority threads?

  •  Consider specific actual or expected use cases.

• Idea 1: Ensure that the number of CPU-bound high priority threads is lower than the number of cores.

• Idea 2: Ensure there is at least one core to run only low priority threads, even if that means putting more than one high-priority thread on the same core.